Agronomy

Article

15 pages, 1435 KiB

Open AccessEditor’s ChoiceArticle

Early Season Growth Responses of Resistant and Susceptible Cotton Genotypes to Reniform Nematode and Soil Potassium Application

by Bhupinder Singh, Daryl R. Chastain, Salliana R. Stetina, Emile S. Gardiner and John L. Snider

Agronomy 2022, 12(11), 2895; https://doi.org/10.3390/agronomy12112895 - 19 Nov 2022

Cited by 1 | Viewed by 2974

Abstract

A greenhouse study was conducted to investigate the roles that host plant resistance and soil potassium (K) levels play in affecting Rotylenchulus reniformis Linford and Oliveira (Tylenchida: Hoplolaimidae) (RN) populations and early season cotton (Gossypium hirsutum L.) growth. Two upland, RN-resistant cotton [...] Read more.

A greenhouse study was conducted to investigate the roles that host plant resistance and soil potassium (K) levels play in affecting Rotylenchulus reniformis Linford and Oliveira (Tylenchida: Hoplolaimidae) (RN) populations and early season cotton (Gossypium hirsutum L.) growth. Two upland, RN-resistant cotton lines (G. barbadense introgressions: 08SS110-NE06.OP and 08SS100), a genetic standard (Deltapine 16) and a commercially available susceptible cultivar (PHY 490 W3FE) were evaluated at four different levels of K [100% of recommended rate, 150% of recommended, 50% of recommended, and a base level] from seeding until harvesting, 60 days after sowing (DAS). Quadratic functions (r² = 0.82 to 0.95) best described the early season growth response of cotton genotypes to soil K. The base K level was associated with the lowest values for most morphological variables, including plant height (PH), mainstem nodes (MSN), leaf area, and dry weight at 30 DAS and 60 DAS. However, soil K did not affect RN population counts (RC). Additionally, soil K did not influence the rate of change in growth variables among genotypes. The resistant genotype 08SS110-NE06.OP showed greater growth in terms of time to first true leaf, PH, MSN, and above-ground dry weights compared to the commercially available susceptible genotype. No interaction between K and RN or genotype and RN was found in early season cotton growth. However, RC in pots of resistant genotypes was less than in pots of susceptible genotypes. Our research on the early season growth response to soil K by novel, RN-resistant genotypes and susceptible genotypes contributes to the development of improved RN resistance and fertilization management in cotton. Full article

(This article belongs to the Special Issue Effects of Nematodes on Crops)

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19 pages, 2226 KiB

Open AccessEditor’s ChoiceArticle

Influence of Planting Date on Winter Rye Performance in Kentucky

by Elżbieta Szuleta, Timothy Phillips, Carrie A. Knott, Chad D. Lee and David A. Van Sanford

Agronomy 2022, 12(11), 2887; https://doi.org/10.3390/agronomy12112887 - 18 Nov 2022

Cited by 12 | Viewed by 2580

Abstract

Winter rye (Secale cereale L.) is a grain crop well known for its outstanding tolerance to unfavorable weather and soil conditions. Because of rye’s wide range of possible uses (e.g., cover crop, feed for livestock, bread, cookies, distilled and brewed beverages), its [...] Read more.

Winter rye (Secale cereale L.) is a grain crop well known for its outstanding tolerance to unfavorable weather and soil conditions. Because of rye’s wide range of possible uses (e.g., cover crop, feed for livestock, bread, cookies, distilled and brewed beverages), its pro-health properties and unique flavor, interest in this crop is increasing in the United States. In 2018/2019 and 2019/2020 we tested 24 winter rye varieties that were available in the US at 3 planting dates: early, intermediate, and late. The aims of this study were to (1) identify conventional and hybrid varieties suitable for the US mid-south environment; (2) establish an optimal planting date of winter rye and (3) quantify genotype x planting date interaction. At both locations and in both growing seasons the best yielding, and most resistant to disease and lodging entries were European hybrids (KWS Serafino, KWS Daniello, KWS Bono and KWS Brasetto), and the best yielding conventional varieties were AC Hazlet and ND Dylan. There were statistically significant (p < 0.01 in 2019 and p < 0.0001 in 2020) differences in yield between planting dates both seasons. The response to planting date differed between varieties. In the 2018/2019 growing season we observed that, on average, rye performed better when planted early, but in 2019/2020, a severe May freeze caused extensive damage in early planted rye, and the best planting date was the late one. Overall, the majority of varieties analyzed individually performed the best at intermediate and late planting dates. Full article

(This article belongs to the Section Crop Breeding and Genetics)

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16 pages, 3298 KiB

Open AccessEditor’s ChoiceArticle

Wheat Yield Estimation Using Remote Sensing Indices Derived from Sentinel-2 Time Series and Google Earth Engine in a Highly Fragmented and Heterogeneous Agricultural Region

by Hajar Saad El Imanni, Abderrazak El Harti and Lahcen El Iysaouy

Agronomy 2022, 12(11), 2853; https://doi.org/10.3390/agronomy12112853 - 15 Nov 2022

Cited by 19 | Viewed by 5008

Abstract

In Morocco, monitoring and estimation of wheat yield at the regional and national scales are critical issues for national food security. The recent Sentinel-2 imagery offers potential for managing grain production systems on a field and regional level. The present study was planned [...] Read more.

In Morocco, monitoring and estimation of wheat yield at the regional and national scales are critical issues for national food security. The recent Sentinel-2 imagery offers potential for managing grain production systems on a field and regional level. The present study was planned based on a time series of six remote sensing indices and Multiple Linear Regression (MLR) methods for real-time estimation of wheat yield using the Google Earth Engine (GEE) platform in a highly heterogeneous and fragmented agricultural region, such as the Tadla Irrigated Perimeter (TIP). First, the spatial distribution of wheat in the TIP region was mapped by performing Random Forest (RF) classification of Sentinel 2 images. Following that, using MLR models, the wheat yield of nine sampled fields was estimated for the different phenological stages of wheat. The yield measured in-situ was the independent variable of the regressions. The dependent variables included the remote sensing indices derived from Sentinel-2. The remote sensing index and the phenological period of the greatest model were investigated to estimate and map the wheat yield in the entire study area. The RF generated the wheat mapping of the study area with an overall accuracy (OA) of 93.82%. Furthermore, the coefficient of determination (R²) of the tested MLR was from 0.53 to 0.89, while the Root Mean Square Error (RMSE) varied from 4.29 to 7.78 q ha⁻¹. The best model was the one that uses the Green Normalized Difference Vegetation Index (GNDVI) in the tillering and maturity stages. Full article

(This article belongs to the Special Issue Current Research on Hyperspectral and Multispectral Imaging and Their Applications in Precision Agriculture)

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19 pages, 1323 KiB

Open AccessEditor’s ChoiceArticle

Identification of Genomic Loci Controlling Grain Macro and Micronutrient Variation in a Wild Barley (Hordeum vulgare spp. spontaneum) Diversity Panel

by Jillian A. Abendroth, Ahmad H. Sallam, Brian J. Steffenson, Marcus A. Vinje, Ramamurthy Mahalingam and Jason G. Walling

Agronomy 2022, 12(11), 2839; https://doi.org/10.3390/agronomy12112839 - 14 Nov 2022

Cited by 4 | Viewed by 2811

Abstract

Nutrient deficiencies in humans are problematic on a global scale but are more prevalent in regions where high-quality and nutrient-dense foods are scarce. Developing nutrient-rich crops that thrive in these regions of the world would help alleviate the disparity. We leveraged the wild [...] Read more.

Nutrient deficiencies in humans are problematic on a global scale but are more prevalent in regions where high-quality and nutrient-dense foods are scarce. Developing nutrient-rich crops that thrive in these regions of the world would help alleviate the disparity. We leveraged the wild barley (Hordeum vulgare spp. spontaneum) Diversity Collection (WBDC) (N = 232) to characterize the variation in seed macronutrient (P, K, Ca, and Mg) and micronutrient (B, Cu, Fe, Mn, and Zn) contents found in this subspecies and to reveal chromosomal regions associated with these traits. Most micro- and macronutrients displayed variation in the WBDC and, except for boron and phosphorous, had a modest level of heritability (>0.5). Variation due to environment was significant (p < 0.001) for each element, except iron, and genotype was significant for all the tested nutrients, except boron. Thirty-seven marker–trait associations (MTAs) were detected for three (K, Ca, and Mg) of the four macro- and four (Cu, Fe, Mn, and Zn) of the five micronutrients. Several compelling candidate genes harbored within MTAs were also identified, including ABC transporters, NAC transcription factors, and bZIP transcription factors. Full article

(This article belongs to the Topic Plants Nutrients)

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15 pages, 1963 KiB

Open AccessEditor’s ChoiceArticle

Rice Leaf Chlorophyll Content Estimation Using UAV-Based Spectral Images in Different Regions

by Songtao Ban, Weizhen Liu, Minglu Tian, Qi Wang, Tao Yuan, Qingrui Chang and Linyi Li

Agronomy 2022, 12(11), 2832; https://doi.org/10.3390/agronomy12112832 - 12 Nov 2022

Cited by 29 | Viewed by 4090

Abstract

Estimation of crop biophysical and biochemical characteristics is the key element for crop growth monitoring with remote sensing. With the application of unmanned aerial vehicles (UAV) as a remote sensing platform worldwide, it has become important to develop general estimation models, which can [...] Read more.

Estimation of crop biophysical and biochemical characteristics is the key element for crop growth monitoring with remote sensing. With the application of unmanned aerial vehicles (UAV) as a remote sensing platform worldwide, it has become important to develop general estimation models, which can interpret remote sensing data of crops by different sensors and in different agroclimatic regions into comprehensible agronomy parameters. Leaf chlorophyll content (LCC), which can be measured as a soil plant analysis development (SPAD) value using a SPAD-502 Chlorophyll Meter, is one of the important parameters that are closely related to plant production. This study compared the estimation of rice (Oryza sativa L.) LCC in two different regions (Ningxia and Shanghai) using UAV-based spectral images. For Ningxia, images of rice plots with different nitrogen and biochar application rates were acquired by a 125-band hyperspectral camera from 2016 to 2017, and a total of 180 samples of rice LCC were recorded. For Shanghai, images of rice plots with different nitrogen application rates, straw returning, and crop rotation systems were acquired by a 5-band multispectral camera from 2017 to 2018, and a total of 228 samples of rice LCC were recorded. The spectral features of LCC in each study area were analyzed and the results showed that the rice LCC in both regions had significant correlations with the reflectance at the green, red, and red-edge bands and 8 vegetation indices such as the normalized difference vegetation index (NDVI). The estimation models of LCC were built using the partial least squares regression (PLSR), support vector regression (SVR), and artificial neural network (ANN) methods. The PLSR models tended to be more stable and accurate than the SVR and ANN models when applied in different regions with R² values higher than 0.7 through different validations. The results demonstrated that the rice canopy LCC in different regions, cultivars, and different types of sensor-based data shared similar spectral features and could be estimated by general models. The general models can be implied to a wider geographic extent to accurately quantify rice LCC, which is helpful for growth assessment and production forecasts. Full article

(This article belongs to the Special Issue Intelligent Monitoring, Modeling, Optimization and Control in Smart Agriculture)

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13 pages, 2070 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Diversity and Resistance to Thiophanate-Methyl of Colletotrichum spp. in Strawberry Nursery and the Development of Rapid Detection Using LAMP Method

by Jianyan Wu, Shuodan Hu, Boyang Ye, Xiaoran Hu, Wenfei Xiao, Hong Yu and Chuanqing Zhang

Agronomy 2022, 12(11), 2815; https://doi.org/10.3390/agronomy12112815 - 11 Nov 2022

Cited by 12 | Viewed by 2928

Abstract

Anthracnose is a devastating fungal disease in strawberry nurseries. Multiple Colletotrichum species are responsible for strawberry anthracnose. In this study, 105 Colletotrichum isolates were obtained from strawberry seedlings with anthracnose symptoms in fifteen nurseries located in Zhejiang province, China, and were classified based [...] Read more.

Anthracnose is a devastating fungal disease in strawberry nurseries. Multiple Colletotrichum species are responsible for strawberry anthracnose. In this study, 105 Colletotrichum isolates were obtained from strawberry seedlings with anthracnose symptoms in fifteen nurseries located in Zhejiang province, China, and were classified based on multilocus sequence and morphological characteristic analyses. Analysis of ITS, ACT, CAL, CHS-1, and GAPDH revealed that four species within C. gloeosporioides species complex, including C. siamense (56 isolates, 53.3%), C. fructicola (37 isolates, 35.2%), C. gloeosporioides (7 isolates, 6.7%), and C. aenigma (5 isolates, 4.8%), were detected in diseased seedlings. Thiophanate-methyl is one of the benzimidazole fungicides, and has long been used to control strawberry anthracnose in China. Here, thiophanate-methyl resistance of Colletotrichum isolates was determined by the minimum inhibitory concentration (MIC) method. Our results indicated that the resistance frequency was up to 96.2%, containing 94.3% of highly resistant isolates. Only four sensitive isolates (two C. fructicola, one C. gloeosporioides, and one C. siamense isolates) and two moderately resistant isolates (one C. aenigma isolate and one C. siamense isolate) were detected. Our data indicated that the high resistance was mainly caused by the E198A mutation in the β-tubulin protein. In addition, F200Y (TTC→TAC) in the β-tubulin protein were detected in two moderately resistant isolates. Based on the point mutation at codon 198 (GAG→GCG) in the β-tubulin gene of Colletotrichum isolates, we developed a loop-mediated isothermal amplification (LAMP) assay to rapidly detect the E198A mutants. Collectively, our study indicated that four species within the C. gloeosporioides species complex were associated with anthracnose symptoms in strawberry nurseries in Zhejiang province, and serious resistance was widespread in each Colletotrichum species. Full article

(This article belongs to the Special Issue Plant Anthracnose: Etiology and Current Management Options)

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17 pages, 2549 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Optimal Nutrient Solution and Dose for the Yield of Nuclear Seed Potatoes under Aeroponics

by Jaime B. Silva Filho, Paulo Cezar Rezende Fontes, Jorge F. S. Ferreira, Paulo R. Cecon and Elizabeth Crutchfield

Agronomy 2022, 12(11), 2820; https://doi.org/10.3390/agronomy12112820 - 11 Nov 2022

Cited by 6 | Viewed by 3588

Abstract

The aeroponic production of certified seed potatoes is a booming alternative for arid and semi-arid areas where fresh water is scarce and soil-borne diseases and nematodes preclude field production. Although widely used in aeroponics, nutrient-solution salinity effects have not been evaluated in potatoes. [...] Read more.

The aeroponic production of certified seed potatoes is a booming alternative for arid and semi-arid areas where fresh water is scarce and soil-borne diseases and nematodes preclude field production. Although widely used in aeroponics, nutrient-solution salinity effects have not been evaluated in potatoes. This study aimed to (1) establish the best of two nutrient solutions (Otazú vs. modified Furlani) at 20, 50, 100, and 150% of the crop-recommended dose for seed-potato production, (2) evaluate growth indexes to diagnose plant-N status, and (3) establish a prognosis for the yield of nuclear seed potatoes under aeroponics. At 21 days after transplanting, there was a significant correlation between the nitrate-N petiole-sap test and some of the parameters measured. The 4th leaf indexes correlated with yield parameters indicating that they can be used to prognosticate the final minituber yield. The best parameters to diagnose the N status in potato plants were: 4th leaf area, length, and dry weight (Otazú’s), SPAD, and 4th leaf area (modified Furlani’s). Although both nutrient solutions had similar nitrogen concentrations, Otazú’s nutrient solution at 100% of the recommended nitrogen dose had lower salinity than the modified Furlani’s solution and was the best to produce nuclear seed potatoes. Full article

(This article belongs to the Topic Plants Nutrients)

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20 pages, 2483 KiB

Open AccessEditor’s ChoiceArticle

Wheat Nutrient Management Strategies to Increase Productivity, Profitability and Quality on Sandy Loam Soils

by Lali Jat, Rama Krishna Naresh, Rajan Bhatt, Mandapelli Sharath Chandra, Sanskriti Singh, S. K. Gupta, Abed Alataway, Ahmed Z. Dewidar and Mohamed A. Mattar

Agronomy 2022, 12(11), 2807; https://doi.org/10.3390/agronomy12112807 - 10 Nov 2022

Cited by 10 | Viewed by 3536

Abstract

By 2050, the population of the world is anticipated to increase from 7.7 billion to 9.7 billion people, and, and wheat is expected to continue to play a vital role in ensuring food security globally. It is the main diet for 40% of [...] Read more.

By 2050, the population of the world is anticipated to increase from 7.7 billion to 9.7 billion people, and, and wheat is expected to continue to play a vital role in ensuring food security globally. It is the main diet for 40% of the world’s population and supplies food for more than 4.5 billion people in 94 countries contains 21% of the joules and 20% of the protein. The present investigations were carried out during rabi 2017–2018 and 2018–2019 to determine how optimal nutrient management (INM) practices enhance fertilizer usage efficiency, productivity, soil health, and viability in wheat (Variety DBW 71) through innovative nutritional sources and their modes of application methods. The treatments comprised of, viz., control, basal applications of recommended NPK (80:60:40)/NPK granules (200 kg/ha) + FYM (5 t ha⁻¹) + bio-stimulant granules (62.5 kg/ha), +NPK bio-fertilizer (seed treatment), along with a top dressing of urea (20 kg/ha)/bio-stimulant (625 mL ha⁻¹)/NPK Powder (1%) sprays (40/55/70 DAS), which had triplicated randomized block design (RBD) at the crop research farm of SVPUA&T, Meerut (U.P.). The results revealed that wheat grown with incorporation of FYM and bio-stimulant –L attained significantly better growth and higher dry matter accumulation across the stages. The crop contained 1.63% N, 0.31% P, 0.69% K in grain, and 0.57% N, 0.11% P and 1.34% K in straw. Such crops exhibited agronomic, physiological, and apparent recovery efficiency of NPK of the order of 3.2 kg kg⁻¹ of nutrient applied, 14.0 kg kg⁻¹ of nutrient uptake, and 0.23% against recommended NPK. Applications of FYM, NPK bio-fertilizer+ urea, and bio-stimulant + NPK sprays worked synergistically and increased grain yields by 29.8, 35.2, 50.3 and 41.1% over their respective controls. The results also indicated that soil organic carbon (0.47%), available NPK (227.0, 27.7, 172.1 kg/ha), dehydrogenase activity, and microbial population (bacteria, fungal and actinomycetes) in soil was also highest with the treatment. Finally, the wheat crop required an investment of Rs ha⁻¹ 131,453 and fetched a net reoccurrence of Rs. 96,154, with benefits of Rs. 3.72 over cost, respectively. Therefore, the study reveals that integrated nutrient management, viz., FYM 5 t ha⁻¹ +NPK (12–32–16) -G @ 200 kg/ha + NPK bio-fertilizer (seed treatment) + urea @ 20 kg/ha, foliar application NPK (18−18−18) -P@ 1% and bio-stimulant –L 0.62 L ha⁻¹ improved the better growth, productivity, soil health and profitability of wheat crops. Finally, to boost production, the region must emphasize the wheat crop’s part in integrated nutrition management with foliar application of bio-stimulants. Furthermore, these investigations must be reinvestigated at different sites with different agro-climatic conditions and texturally divergent soils. Full article

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18 pages, 1968 KiB

Open AccessEditor’s ChoiceArticle

Long-Term Effects of Compost Amendments and Brassica Green Manures in Potato Cropping Systems on Soil and Crop Health and Productivity

by Robert P. Larkin

Agronomy 2022, 12(11), 2804; https://doi.org/10.3390/agronomy12112804 - 10 Nov 2022

Cited by 8 | Viewed by 3659

Abstract

Beneficial soil and crop management practices, such as longer rotations, cover crops and green manures, organic amendments, and reduced tillage, may improve soil and crop health and productivity when incorporated into cropping systems. Long-term trials are needed to assess the full impacts and [...] Read more.

Beneficial soil and crop management practices, such as longer rotations, cover crops and green manures, organic amendments, and reduced tillage, may improve soil and crop health and productivity when incorporated into cropping systems. Long-term trials are needed to assess the full impacts and effects of these systems. In field trials originally established in 2004, three different 3-yr potato cropping systems focused on management goals of soil conservation (SC), soil improvement (SI), and disease suppression (DS) were evaluated and compared to a standard 2-yr rotation (SQ) and a nonrotation control (PP). After 12–15 years and results compiled over a four-year period (2015–2018), the SI system (with history of compost amendments) increased total and marketable tuber yields relative to all other systems, with yields averaging 26 to 36% higher than the standard SQ system and 36 to 59% greater than PP. SI also improved soil properties such as organic matter and soil water content, nutritional characteristics, and microbial activity compared to the other systems. The SI system continued to provide these improvements several years after compost amendments ended, indicating the long-term benefits. The DS system, which included a disease-suppressive green manure rotation crop and fall cover crops, also improved yield (by 16–20%), had higher organic matter content (by 12%), and increased microbial activity (by 22%) relative to SQ, as well as reducing the soilborne tuber diseases black scurf and common scab by 10–30%. The nonrotation PP system resulted in the notable degradation of soil properties and yield over time. These results demonstrate that soil health management practices can be effectively incorporated into viable potato cropping systems to improve soil properties and crop health, and may enhance long-term sustainability. Full article

(This article belongs to the Special Issue Multiple Cropping Systems for Improving Crop Yield and Soil Quality)

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20 pages, 7849 KiB

Open AccessEditor’s ChoiceArticle

Efficient Identification of Apple Leaf Diseases in the Wild Using Convolutional Neural Networks

by Qing Yang, Shukai Duan and Lidan Wang

Agronomy 2022, 12(11), 2784; https://doi.org/10.3390/agronomy12112784 - 9 Nov 2022

Cited by 52 | Viewed by 4720

Abstract

Efficient identification of apple leaf diseases (ALDs) can reduce the use of pesticides and increase the quality of apple fruit, which is of significance to smart agriculture. However, existing research into identifying ALDs lacks models/methods that satisfy efficient identification in the wild environment, [...] Read more.

Efficient identification of apple leaf diseases (ALDs) can reduce the use of pesticides and increase the quality of apple fruit, which is of significance to smart agriculture. However, existing research into identifying ALDs lacks models/methods that satisfy efficient identification in the wild environment, hindering the application of smart agriculture in the apple industry. Therefore, this paper explores an ACCURATE, LIGHTWEIGHT, and ROBUST convolutional neural network (CNN) called EfficientNet-MG, improving the conventional EfficientNet network by the multistage feature fusion (MSFF) method and gaussian error linear unit (GELU) activation function. The shallow and deep convolutional layers usually contain detailed and semantic information, respectively, but conventional EfficientNets do not fully utilize the different stage convolutional layers. Thus, MSFF was adopted to improve the semantic representation capacity of the last layer of features, and GELU was used to adapt to complicated tasks. Further, a comprehensive ALD dataset called AppleLeaf9 was constructed for the wild environment. The experimental results show that EfficientNet-MG achieves a higher accuracy (99.11%) and fewer parameters (8.42 M) than the five classical CNN models, thus proving that EfficientNet-MG achieves more competitive results on ALD identification. Full article

(This article belongs to the Special Issue Computer Vision for Intelligent Crop Identification and Crop Protection)

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17 pages, 1934 KiB

Open AccessEditor’s ChoiceArticle

Long-Term Conservation Tillage and Precision Nutrient Management in Maize–Wheat Cropping System: Effect on Soil Properties, Crop Production, and Economics

by Biswajit Pramanick, Mritunjay Kumar, Banavath Mahesh Naik, Mukesh Kumar, Santosh Kumar Singh, Sagar Maitra, B. S. S. S. Naik, Vishnu D. Rajput and Tatiana Minkina

Agronomy 2022, 12(11), 2766; https://doi.org/10.3390/agronomy12112766 - 6 Nov 2022

Cited by 33 | Viewed by 4521

Abstract

Intensive tillage coupled with imbalanced nutrient management in maize–wheat systems in low-carbon calcareous soils often results in poor productivity vis-à-vis degradation in soil health. Conservation tillage viz. permanent bed planting (PB) and zero tillage (ZT)/direct seeding with residue retention coupled with precision nutrient [...] Read more.

Intensive tillage coupled with imbalanced nutrient management in maize–wheat systems in low-carbon calcareous soils often results in poor productivity vis-à-vis degradation in soil health. Conservation tillage viz. permanent bed planting (PB) and zero tillage (ZT)/direct seeding with residue retention coupled with precision nutrient management might improve soil properties and yield of crops. Concerning this, a long-term experiment was conducted from 2014–2015 to 2020–2021 with a maize–wheat cropping system at TCA, Dholi farm of RPCAU, Pusa. Treatments consisted of three main plots of different tillage practices, viz. PB, ZT, and conventional tillage (CT) and three sub-plots of nutrient management options, viz. farmers’ fertilization practice (FFP), site-specific nutrient management with Nutrient Expert^® (NE) software, and GreenSeeker (GS) based nitrogen-management. From this study, it was observed that both the PB and ZT resulted in about 31–33% and 43–45% improvement in SOC and water-soluble aggregates (WSA), respectively, comparing them under CT. These two conservation tillage practices also improved the other soil bio-chemical properties. Better soil properties under PB and ZT helped in the improvement of system yield by about 13–18% comparing yield under CT. Moreover, both these tillage practices showed an additional net return of USD 330–USD 400 over CT. PB was found a bit better over ZT concerning soil properties, yield, and economics. Comparing nutrient management options, precision nutrition using NE and GS showed significant improvement in the soil bio-chemical parameters, yield, and economics of the cropping system over FFP. SSNM using NE showed slightly better results than GS. Thus, from this long-term study, it can be concluded that the permanent bed system with residue retention and precision nutrition using Nutrient Expert^® software are the best options concerning tillage and nutrient management, respectively, for improvement of the soil properties of problematic calcareous soils, thereby, enhancing the yield and economics of the maize–wheat cropping system. Full article

(This article belongs to the Special Issue Effects of Tillage, Cover Crop and Crop Rotation on Soil)

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18 pages, 1748 KiB

Open AccessEditor’s ChoiceArticle

Control of Stored Agro-Commodity Pests Sitophilus granarius and Callosobruchus chinensis by Nitrogen Hypoxic Atmospheres: Laboratory and Field Validations

by Radek Aulicky, Jawad Ali Shah, Vlastimil Kolar, Zhihong Li and Vaclav Stejskal

Agronomy 2022, 12(11), 2748; https://doi.org/10.3390/agronomy12112748 - 5 Nov 2022

Cited by 9 | Viewed by 2786

Abstract

Given the complexity of the practical usage of controlled atmospheres for the protection of agro-commodities, several researchers have pointed out that there is not enough robust scientific documentation regarding the usage of inert gases for their widespread practical application. Therefore, this work evaluated [...] Read more.

Given the complexity of the practical usage of controlled atmospheres for the protection of agro-commodities, several researchers have pointed out that there is not enough robust scientific documentation regarding the usage of inert gases for their widespread practical application. Therefore, this work evaluated various regimes of hypoxic and anoxic nitrogen atmospheres for the control of two key stored-product pests, in laboratory and under field conditions in silos. Sitophilus granarius and Callosobruchus chinensis were selected as the tested species since they are important pests of grain/rice or legumes in Europe and Asia. Under laboratory conditions, we tested nitrogen (N₂) concentrations (from 95 to 100%) and exposure times (1–20 days) on the developmental stages of both pest species. In most developmental stages of S. granarius and C. chinensis, the shortest effective exposure was found for nitrogen concentration of 99%. Based on our laboratory tests, validation studies were subsequently carried out in semi-hermetic steel silos (25t) using continuous nitrogen saturation by on-site built swing pressure generators. It was found that a full control of all stages of S. granarius and C. chinensis was achieved in 11 days of nitrogen exposure, using concentrations ranging above 99% and below 100%. Our work shows that hypoxic nitrogen treatment can be effectively achieved in small steel silos under proper technological and environmental conditions. Full article

(This article belongs to the Special Issue Post-harvest Pest and Disease Management)

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13 pages, 1528 KiB

Open AccessEditor’s ChoiceArticle

Impact of 2,4-D and Glyphosate on Soil Enzyme Activities in a Resistant Maize Cropping System

by Heather L. Tyler

Agronomy 2022, 12(11), 2747; https://doi.org/10.3390/agronomy12112747 - 5 Nov 2022

Cited by 10 | Viewed by 3386

Abstract

Crop varieties resistant to multiple herbicides have been developed to provide better control of weed populations in row-crop fields where glyphosate resistance has become common. These new varieties include lines of maize (Zea mays) resistant to both glyphosate and 2,4-dichlorophenoxyacetic acid [...] Read more.

Crop varieties resistant to multiple herbicides have been developed to provide better control of weed populations in row-crop fields where glyphosate resistance has become common. These new varieties include lines of maize (Zea mays) resistant to both glyphosate and 2,4-dichlorophenoxyacetic acid (2,4-D). As these herbicides have the potential to impact microbial communities in soil, there is concern that their co-application may have a greater effect on activities linked to soil nutrient cycling than if they were applied individually. To investigate this possibility, a field study was conducted on 2,4-D+glyphosate-resistant maize to determine the impact of 2,4-D alone and 2,4-D+glyphosate on extracellular enzyme activity in both bulk and rhizosphere soil. Maize was treated at the V2 and V8 developmental stages. Changes in soil activities were small in magnitude and inconsistent between timepoints. 2,4-D+glyphosate-treated plots had higher beta-glucosidase, cellobiohydrolase, and phosphatase activities, but only after the V2 application in bulk soil in the first year of the study, while no significant effects were observed in the rhizosphere. Enzyme activities were more impacted by soil organic matter than herbicide treatments. These results suggest that, when applied at label rates, 2,4-D+glyphosate application will not adversely affect soil microbial enzyme activities. Full article

(This article belongs to the Special Issue Impact of Agrochemicals on Soil)

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12 pages, 635 KiB

Open AccessEditor’s ChoiceArticle

Weed Management by In Situ Cover Crops and Anaerobic Soil Disinfestation in Plasticulture

by Gursewak Singh, Brian Ward, Amnon Levi and Matthew Cutulle

Agronomy 2022, 12(11), 2754; https://doi.org/10.3390/agronomy12112754 - 5 Nov 2022

Cited by 4 | Viewed by 2482

Abstract

Weeds negatively affect organic vegetable crop growth and profitability. Weed management is the greatest challenge for vegetable organic growers since control options are limited for organic vegetable production. Anaerobic soil disinfestation (ASD) is a novel non-chemical pest management technique that creates anoxic conditions [...] Read more.

Weeds negatively affect organic vegetable crop growth and profitability. Weed management is the greatest challenge for vegetable organic growers since control options are limited for organic vegetable production. Anaerobic soil disinfestation (ASD) is a novel non-chemical pest management technique that creates anoxic conditions in the topsoil layer for a limited time. ASD is primarily based on the addition of labile carbon sources to topsoil to promote anaerobic conditions driven by microorganisms in moist soil mulched with polyethylene film (polyfim). Field studies were conducted in the summer–fall of 2020 and 2021 to determine the efficacy of warm season cover crops used as carbon sources for ASD and their role in weed management. The study used a factorial experimental design with four cover crop residue treatments (sorghum-sudangrass, sunn hemp, both, or none) in two soil aeration conditions (aerated or non-aerated). Cover crops were grown for 75 days, incorporated into the soil, and sealed with totally impermeable film (TIF) clear mulch, followed by a 4-week ASD process. All incorporated cover crop treatments in non-aerated conditions generated moderate to higher anaerobic conditions (0–150 mV) and provided significantly higher (p < 0.05) weed control than all the other treatments tested or controls. Tomato plants transplanted in non-aerated, cover crops incorporated plots were more vigorous and produced higher yields than aerated plots. No phytotoxicity was observed on tomato plants following ASD treatment in any of the treatments tested. This study demonstrated that warm season cover crops could potentially serve as a carbon source for ASD in organic tomato production. Full article

(This article belongs to the Special Issue Sustainable Weed Management: Biological Principles and Improvement of Conventional Methods)

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16 pages, 6787 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

An AI Based Approach for Medicinal Plant Identification Using Deep CNN Based on Global Average Pooling

by Rahim Azadnia, Mohammed Maitham Al-Amidi, Hamed Mohammadi, Mehmet Akif Cifci, Avat Daryab and Eugenio Cavallo

Agronomy 2022, 12(11), 2723; https://doi.org/10.3390/agronomy12112723 - 2 Nov 2022

Cited by 69 | Viewed by 23337

Abstract

Medicinal plants have always been studied and considered due to their high importance for preserving human health. However, identifying medicinal plants is very time-consuming, tedious and requires an experienced specialist. Hence, a vision-based system can support researchers and ordinary people in recognising herb [...] Read more.

Medicinal plants have always been studied and considered due to their high importance for preserving human health. However, identifying medicinal plants is very time-consuming, tedious and requires an experienced specialist. Hence, a vision-based system can support researchers and ordinary people in recognising herb plants quickly and accurately. Thus, this study proposes an intelligent vision-based system to identify herb plants by developing an automatic Convolutional Neural Network (CNN). The proposed Deep Learning (DL) model consists of a CNN block for feature extraction and a classifier block for classifying the extracted features. The classifier block includes a Global Average Pooling (GAP) layer, a dense layer, a dropout layer, and a softmax layer. The solution has been tested on 3 levels of definitions (64 × 64, 128 × 128 and 256 × 256 pixel) of images for leaf recognition of five different medicinal plants. As a result, the vision-based system achieved more than 99.3% accuracy for all the image definitions. Hence, the proposed method effectively identifies medicinal plants in real-time and is capable of replacing traditional methods. Full article

(This article belongs to the Special Issue Imaging Technology for Detecting Crops and Agricultural Products)

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18 pages, 3291 KiB

Open AccessEditor’s ChoiceArticle

The Effects of Winter Cover Crops on Maize Yield and Crop Performance in Semiarid Conditions—Artificial Neural Network Approach

by Bojan Vojnov, Goran Jaćimović, Srđan Šeremešić, Lato Pezo, Biljana Lončar, Đorđe Krstić, Svetlana Vujić and Branko Ćupina

Agronomy 2022, 12(11), 2670; https://doi.org/10.3390/agronomy12112670 - 28 Oct 2022

Cited by 19 | Viewed by 3362

Abstract

Maize is the most widespread and, along with wheat, the most important staple crop in the Republic of Serbia, which is of great significance for ensuring national food security. With the increasing demand for food and forage, intensive agricultural practices have been adopted [...] Read more.

Maize is the most widespread and, along with wheat, the most important staple crop in the Republic of Serbia, which is of great significance for ensuring national food security. With the increasing demand for food and forage, intensive agricultural practices have been adopted in the maize production systems. In this direction, considerable research efforts have been made to examine the effects of different types of cover crops as a green manure on maize productivity; however, no consistent conclusions have been reached so far. Therefore, the objective of the present study is to examine the possibility of predicting the effects of winter cover crops (CC) integrated with different management practices on the morphological traits, yield, and yield components of maize. The experiment was carried out on chernozem soil from 2016 to 2020 as a randomized complete block design arranged as a split-split-plot with three replicates. The pea as a sole crop (P) and the mixture of pea and triticale (PT) are sown as winter CC with the following subplots: (i) CC used as green manure, and (ii) CC used as forage and removed before maize sowing. The artificial neural network is used for exploring nonlinear functions of the tested parameters and 13 categorical input variables for modeling according to the following factors: CC, way of using CC, N fertilization, and year. The computed maximums of plant height, number of leaves, number of internodes, plant density, number of ears, grain yield, 1000-grain weight, hectolitre weight, dry matter harvest residue, harvest index, leaves percentage, stems percentage, and ears percentage are as follows: 232.3 cm; 9.7; 10.2; 54,340 plants ha⁻¹; 0.9; 9.8 t ha⁻¹; 272.4 g; 67.0 kg HL⁻¹; 9.2 t ha⁻¹; 0.52; 18.9%; 36.0%, and 45.1%, respectively. The optimal result is obtained with peas used as green manure, with 50 kg N ha⁻¹ and in the climatic conditions of 2018. Consequently, maize production under subsequent sowing periods can be successfully optimized by adapting selected management options for higher yield accomplishment. Full article

(This article belongs to the Special Issue Conservation Agriculture as a Key Challenge for Sustainable Agroecosystems in Climate Change Mitigation and Adaptation - Series II)

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13 pages, 4399 KiB

Open AccessEditor’s ChoiceArticle

Evaluation of Diode Laser Treatments to Manage Weeds in Row Crops

by Canicius Mwitta, Glen C. Rains and Eric Prostko

Agronomy 2022, 12(11), 2681; https://doi.org/10.3390/agronomy12112681 - 28 Oct 2022

Cited by 12 | Viewed by 4891

Abstract

Herbicides have been the primary weed management practice in agriculture for decades. However, due to their effects on the environment in addition to weeds becoming resistant, alternative approaches to weed control are critical. One approach is using lasers, particularly diode lasers because of [...] Read more.

Herbicides have been the primary weed management practice in agriculture for decades. However, due to their effects on the environment in addition to weeds becoming resistant, alternative approaches to weed control are critical. One approach is using lasers, particularly diode lasers because of their portability, low power demand, and cost effectiveness. In this research, weeds’ response to diode laser treatments was investigated. Three experiments were conducted. The first experiment involved treating two species of weeds with four different laser powers to determine the time it takes to sever the weed stem. The second experiment involved monitoring the status of two species of weeds for a week after treating them with two lasers at constant application times of 1 s, 2 s, and 3 s. The third experiment was a repeat of the second with higher laser powers and shorter treatment times. The results showed diode lasers have a potential to be an effective weed controlling tool. Weed stem diameter, laser power, treatment duration, and distance between laser and weed were all statistically significant in weed mortality, with weed species having no significance. Furthermore, it was found that weed management is possible by exposing the stem of the two weed species between 0.8 and 2.65 mm diameter to a laser beam dosage without necessarily severing it, with 80% effectiveness at 0.5 s treatment time, and 100% effectiveness using a 6.1 W laser for 1.5 s. Full article

(This article belongs to the Special Issue The Future of Weed Science—Novel Approaches to Weed Management)

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16 pages, 2520 KiB

Open AccessEditor’s ChoiceArticle

Characterization of the Volatile Profiles of Six Industrial Hemp (Cannabis sativa L.) Cultivars

by Fern Kumeroa, Shanika Komahan, Svetla Sofkova-Bobcheva and Andrea Clavijo McCormick

Agronomy 2022, 12(11), 2651; https://doi.org/10.3390/agronomy12112651 - 27 Oct 2022

Cited by 11 | Viewed by 5277

Abstract

Volatile organic compounds (VOCs) play an important role in plant ecology and can be useful in pest management. This work characterises, for the first time, the VOC emissions of six industrial hemp (Cannabis sativa L.) cultivars grown in New Zealand: CFX-2, CRS-1, [...] Read more.

Volatile organic compounds (VOCs) play an important role in plant ecology and can be useful in pest management. This work characterises, for the first time, the VOC emissions of six industrial hemp (Cannabis sativa L.) cultivars grown in New Zealand: CFX-2, CRS-1, Ferimon 12, Katani, Futura 75, and Finola. Volatiles emitted from flowers and foliage of eight-week-old plants were collected using a dynamic headspace sampling method and analysed using gas chromatography coupled to mass spectrometry. We assessed the effect of cultivar, sex (monoecious, male, and female), and site (i.e., two sites differing in soil types, maintained under irrigation and rain-fed conditions) on VOC emissions. Thirty-five volatile compounds were tentatively identified from the headspace samples of hemp plants, but none of the cultivars emitted all 35 compounds. β-Myrcene was the most abundant compound in most cultivars. Overall, there was a significant effect of sex, and the interaction of sex and cultivar on the volatile profiles, but no effect of site. Female plants typically emitted more volatiles than their male counterparts and monoecious cultivars. The main compounds driving the difference between cultivars and sexes were (Z)- and (E)-β-ocimene. We hypothesize that differences in emission emerged as a defence strategy to protect costly female flowers from herbivores (since C. sativa is wind pollinated), but this hypothesis needs further testing. We recommend additional studies exploring how biotic and abiotic factors influence hemp VOC emissions, changes in VOCs throughout the crop cycle, the role of VOCs in plant-insect interactions and their use in pest management. Full article

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18 pages, 1709 KiB

Open AccessEditor’s ChoiceArticle

The Impact of Polymer on the Productivity and Photosynthesis of Soybean under Different Water Levels

by Lucas Felisberto Pereira, Walter Quadros Ribeiro Júnior, Maria Lucrecia Gerosa Ramos, Guilherme Filgueiras Soares, Cristiane Andréa de Lima Guimarães, Sebastião Pedro da Silva Neto, Onno Muller, Christina Cleo Vinson, André Ferreira Pereira and Thomas Christopher Rhys Williams

Agronomy 2022, 12(11), 2657; https://doi.org/10.3390/agronomy12112657 - 27 Oct 2022

Viewed by 2014

Abstract

In order to practice sustainable and resource-efficient agriculture, the use of new technologies such as water-retaining polymers is essential. The objective of this study was to evaluate the effect of a polymer incorporated into the soil on gas exchange and yield under different [...] Read more.

In order to practice sustainable and resource-efficient agriculture, the use of new technologies such as water-retaining polymers is essential. The objective of this study was to evaluate the effect of a polymer incorporated into the soil on gas exchange and yield under different water regimes (WR) in three soybean cultivars. The experiment was conducted at Embrapa Cerrados under field conditions in 2016 and 2017, using three different cultivars (BRS 5980IPRO, NA 5909RG and BRS 7280RR). Soybean cultivars were submitted to four water regimes (representing 30%, 50%, 83% and 100% of evapotranspiration replacement, namely WR1, WR2, WR3 and WR4). No beneficial results were observed in 2016 with Polymer. Most of the reductions in photosynthesis and transpiration by adding the polymer can be attributed to stomatal control, but such reductions did not influence productivity. In 2017, the yield was higher using Polymer in WR4 and WR3 by 40 to 20%, depending on the cultivar. Under severe stress (WR2 and WR1), reduced gas exchange was obtained with Polymer, but the yield was not reduced. These results indicate that Polymer contributed to the prolongation of photosynthetic activity during the reproductive phase of soybean and may represent a potential strategy for increasing yield under moderate drought stress. Full article

(This article belongs to the Special Issue Management Alternatives in Legumes Cropping)

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17 pages, 4207 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Dynamics of Crop Evapotranspiration of Four Major Crops on a Large Commercial Farm: Case of the Navajo Agricultural Products Industry, New Mexico, USA

by Koffi Djaman, Komlan Koudahe and Ali T. Mohammed

Agronomy 2022, 12(11), 2629; https://doi.org/10.3390/agronomy12112629 - 26 Oct 2022

Cited by 5 | Viewed by 2804

Abstract

Crop evapotranspiration (ETa) is the main source of water loss in farms and watersheds, and with its effects felt at a regional scale, it calls for irrigation professionals and water resource managers to accurately assess water requirements to meet crop water use. On [...] Read more.

Crop evapotranspiration (ETa) is the main source of water loss in farms and watersheds, and with its effects felt at a regional scale, it calls for irrigation professionals and water resource managers to accurately assess water requirements to meet crop water use. On a multi-crop commercial farm, different factors affect cropland allocation, among which crop evapotranspiration is one of the most important factors regarding the seasonally or annually available water resources for irrigation in combination with the in-season effective precipitation. The objective of the present study was to estimate crop evapotranspiration for four major crops grown on the Navajo Agricultural Products Industry (NAPI) farm for the 2016–2010 period to help crop management in crop plant allocation based on the different objectives of the NAPI. The monthly and seasonal satellite-based ETa of maize, potatoes, dry beans, and alfalfa were retrieved and compared using the analysis of variance and the least significant difference (LSD) at 5% of significance. Our results showed the highly significant effects of year, months, and crops. The year 2020 obtained the highest crop ETa, and July had the most evapotranspiration demand, followed by August, June, September, and May, and the pool of April, March, February, January, December, and November registered the lowest crop ETa. Maize monthly ETa varied from 17.5 to 201.7 mm with an average seasonal ETa of 703.8 mm. The monthly ETa of potatoes varied from 9.8 to 207.5 mm, and their seasonal ETa averaged 600.9 mm. The dry bean monthly ETa varied from 10.4 to 178.4 mm, and the seasonal ETa averaged 506.2 mm. The alfalfa annual ETa was the highest at 1015.4 mm, as it is a perennial crop. The alfalfa monthly ETa varied from 8.2 to 202.1 mm. The highest monthly crop ETa was obtained in July for all four crops. The results of this study are very critical for cropland allocation and irrigation management under limited available water across a large commercial farm with multiple crops and objectives. Full article

(This article belongs to the Special Issue Precision Water Management)

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18 pages, 3501 KiB

Open AccessEditor’s ChoiceArticle

Weed Pressure, Nutrient Content, and Seed Yield in Field Grown Sulfonylurea-Resistant Camelina sativa and Brassica napus

by James V. Anderson, Brant B. Bigger, Kirk Howatt, Joseph Mettler and Marisol T. Berti

Agronomy 2022, 12(11), 2622; https://doi.org/10.3390/agronomy12112622 - 25 Oct 2022

Cited by 6 | Viewed by 2617

Abstract

Camelina [(Camelina sativa (L.) Crantz], an oilseed species of Brassicaceae, does not have approved herbicides for weed control, which limits its expansion as a commercial crop. To evaluate agronomic traits and ecosystem services of non-transgenic cultivars of sulfonylurea-resistant camelina and canola ( [...] Read more.

Camelina [(Camelina sativa (L.) Crantz], an oilseed species of Brassicaceae, does not have approved herbicides for weed control, which limits its expansion as a commercial crop. To evaluate agronomic traits and ecosystem services of non-transgenic cultivars of sulfonylurea-resistant camelina and canola (Brassica napus L.), a field study was conducted near Fargo, North Dakota. Two replicated locations (NDSU and NW22) were set up in a randomized complete block design including four blocks of camelina, canola, and fallow per location. Camelina and canola were seeded (18 May) at 4.9 and 2.9 kg ha⁻¹, respectively, using 19-cm row spacing. Data was collected mid- and late-season (29 June and 22 July 2020 respectively) for crop and weed stem count (no. m⁻²), biomass dry matter (kg m⁻²), and nutrient (N, P, K, S) content (kg ha⁻¹), as-well-as final season (7 August) seed yield (kg ha⁻¹) for camelina and canola treated with and without sulfonylurea. Using Prefer 90 (NIS) at 0.25% v/v, camelina was treated with thifensulfuron at 6.3 g a.i. ha⁻¹, and canola was treated with thifensulfuron at 10.5 g a.i. ha⁻¹ and tribenuron at 5.3 g a.i. ha⁻¹. Sulfonylurea-resistant camelina and canola reduced late-season dry weight biomass of weeds by >75% and ≥60%, respectively, compared with fallow plots. Application of sulfonylurea herbicides to camelina or canola prior to mid-season analyses was not a significant factor (p ≤ 0.05) for reducing weed pressure and generally had little impact on altering crop biomass, seed yield, and nutrient retention. However, in some cases, herbicide treatment had an additive effect of reducing weed pressure over that of camelina or canola alone. Depending on the rotational cropping system, sulfonylurea-resistant camelina and canola should provide additional options for integrated weed management approaches and reducing nutrient leaching in the upper Midwest and northern Great Plains of the USA. Full article

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13 pages, 5761 KiB

Open AccessEditor’s ChoiceArticle

Factors Driving Autumn Quercus Flowering in a Thermo-Mediterranean Area

by Herminia García-Mozo, Rocío López-Orozco, Jose Oteros and Carmen Galán

Agronomy 2022, 12(11), 2596; https://doi.org/10.3390/agronomy12112596 - 22 Oct 2022

Cited by 10 | Viewed by 1805

Abstract

The flowering period of plants is a critical time since it determines their reproductive success. Flowering is controlled by different factors including genetic regulation and environmental conditions. In the Mediterranean area, favourable conditions usually occur in spring, when most plant species flower including [...] Read more.

The flowering period of plants is a critical time since it determines their reproductive success. Flowering is controlled by different factors including genetic regulation and environmental conditions. In the Mediterranean area, favourable conditions usually occur in spring, when most plant species flower including those of the Mediterranean Quercus genus. This paper reveals and analyses an unusual and lesser-known phenomenon occurring in the two main Mediterranean agroforestry ecosystems of South Europe, the Mediterranean forest and “dehesa”, that is, a second flowering occurring in autumn for the species Quercus ilex subsp. ballota (holm oak). The continuous pollen monitoring of the atmosphere in the city of Cordoba (southern Spain) for 25 years, together with field phenological observations in the area, has indicated that, apart from the main pollination period in spring, secondary flowerings also occasionally occur in this area, specifically in autumn. The present work examines these uncommon pollination events detected in the autumns of certain years with the aim of determining the main environmental factors that influence and control them. During the 25-year study period, there were 7 years in which a secondary Quercus flowering was detected in the area from the second half of October until the end of November. The univariate statistical analysis of the influence of environmental variables determined that the meteorological conditions in September were the most influential. Low mean temperatures, together with record rainfall in that month, led to autumn flowering events. The phenological characteristics of the spring pollen season were also influential. In the years with a shorter spring, the Quercus pollen season tended to present autumn flowerings. A multivariate adaptive regression splines (MARS) model was built to explain the effects of the different variables on the occurrence of autumn pollination. The results indicated that the combined effect of three predicting variables, September rainfall, the length of the spring pollen season, and the end of the spring pollen season, explained 92% of the variance. The validation showed a strong relationship between the expected and the observed autumn pollen concentrations. Therefore, the present analysis of a long-term pollen database revealed that the main causes of this unusual second flowering in autumn were strongly related to climate change, i.e., strong dry summers and warm autumns. In addition, the results showed that the phenomenon was more frequent in the years with low pollination during spring due to different meteorological events potentiated by climate change, such as dryness or heavy rain episodes, as a way of ensuring acorn crops. The results explain how this unusual and lesser-known phenomenon in agroforestry dynamics is related to the adaptation to climate change and the main factors that are driving it, as well as the potential consequences for these important and endangered Mediterranean ecosystems. Full article

(This article belongs to the Special Issue Adaptations to Climate Change in Agricultural Systems)

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21 pages, 1278 KiB

Open AccessEditor’s ChoiceArticle

Effect of Different Cover Crops, Mass-Trapping Systems and Environmental Factors on Invertebrate Activity in Table Olive Orchards—Results from Field Experiments in Crete, Greece

by Nikolaos Volakakis, Emmanouil Kabourakis, Leonidas Rempelos, Apostolos Kiritsakis and Carlo Leifert

Agronomy 2022, 12(10), 2576; https://doi.org/10.3390/agronomy12102576 - 20 Oct 2022

Cited by 5 | Viewed by 2418

Abstract

Background: Although the negative effects of insecticides and herbicides on beneficial and non-target invertebrates are well documented, there is limited information on potential negative impacts of pest and weed management practices used in organic farming on invertebrate activity. Methods: Using established field experiments [...] Read more.

Background: Although the negative effects of insecticides and herbicides on beneficial and non-target invertebrates are well documented, there is limited information on potential negative impacts of pest and weed management practices used in organic farming on invertebrate activity. Methods: Using established field experiments designed to compare different ground cover crops (used to suppress weeds and increase nitrogen availability and soil health) and mass-trapping systems (used for olive fly control) in organic olive production systems, we monitored the impact of these practices on invertebrate activity. Results: When different ground cover crops were compared, ground cover crops established from a vetch/pea/barley seed mixtures resulted in significantly higher parasitic wasps activity than ground cover vegetation in control plots (plots in which Medicago seed were sown and failed to establish) that were dominated by the weed Oxalis pes-caprae. When two bottle based mass-trapping systems were compared, the traps caught similar numbers of olive flies and some non-target invertebrates (mainly other Diptera, Neuroptera and Lepidotera and Formicidae), although no parasitic wasps or pollinators (bees; bumble bees) were caught in traps. Analyses of invertebrate profiles found in McPhail monitoring traps showed that invertebrate activity profiles were similar in plots with and without mass-trapping devices. In addition, as expected, redundancy analyses showed that climatic parameters (temperature, rainfall, humidity, wind direction) are significant explanatory variables/drivers for invertebrate activity in olive orchards. Conclusions: The results presented indicate that mixed legume/cereal ground cover crops may increase the activity of parasitic wasps and may act as a reservoir for natural enemies of agricultural pest and that olive fly mass-trapping systems may lure and kill some non-target invertebrates, but do not affect the activity of two main groups of beneficial invertebrates namely pollinators and parasitic wasps. Full article

(This article belongs to the Special Issue Integrated Soil, Crop and Human Nutrition and Health Management in Organic Agriculture)

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20 pages, 1934 KiB

Open AccessEditor’s ChoiceArticle

Shade and Altitude Implications on the Physical and Chemical Attributes of Green Coffee Beans from Gorongosa Mountain, Mozambique

by Crimildo T. Cassamo, Adilson V. J. Mangueze, António E. Leitão, Isabel P. Pais, Rita Moreira, Claudine Campa, Rogério Chiulele, Fabrício O. Reis, Isabel Marques, Paula Scotti-Campos, Fernando C. Lidon, Fábio L. Partelli, Ana I. Ribeiro-Barros and José C. Ramalho

Agronomy 2022, 12(10), 2540; https://doi.org/10.3390/agronomy12102540 - 18 Oct 2022

Cited by 30 | Viewed by 5559

Abstract

Coffea arabica L. is as a tropical crop that can be grown under monocrop or agroforestry (AFS) systems, usually at altitudes greater than 600 m, with suitable environmental conditions to bean quality. This study aimed to assess the effect of altitude (650, 825, [...] Read more.

Coffea arabica L. is as a tropical crop that can be grown under monocrop or agroforestry (AFS) systems, usually at altitudes greater than 600 m, with suitable environmental conditions to bean quality. This study aimed to assess the effect of altitude (650, 825, and 935 m) and light conditions (deep shade—DS, and moderate shade—MS provided by native trees, and full Sun—FS) on the physical and chemical attributes of green coffee beans produced in the Gorongosa Mountain. Regardless of altitude, light conditions (mainly MS and FS) scarcely affected most of the studied physical and chemical attributes. Among the few exceptions in physical attributes, bean mass tended to lower values under FS in all three altitudes, whereas bean density increased under FS at 650 m. As regards the chemical compound contents, sporadic changes were found. The rises in trigonelline (MS and FS at 935 m), soluble sugars (FS at 935 m), and the decline in p-coumaric acid (MS and FS at 825 m), may indicate an improved sensory profile, but the rise in FQAs (FS at 825 m) could have a negative impact. These results highlight a relevant uncertainty of the quality changes of the obtained bean. Altitude (from 650 to 935 m) extended the fruit maturation period by four weeks, and altered a larger number of bean attributes. Among physical traits, the average sieve (consistent tendency), bean commercial homogeneity, mass, and density increased at 935 m, whereas the bean became less yellowish and brighter at 825 and 935 m (b*, C* colour attributes), pointing to good bean trade quality, usually as compared with beans from 650 m. Furthermore, at 935 m trigonelline and 5-CQA (MS and FS) increased, whereas FQAs and diCQAs isomers declined (in all light conditions). Altogether, these changes likely contributed to improve the sensory cup quality. Caffeine and p-coumaric acid showed mostly inconsistent variations. Overall, light conditions (FS, MS, or DS) did not greatly and consistently altered bean physical and chemical attributes, whereas altitude (likely associated with lower temperature, greater water availability (rainfall/fog), and extended maturation period) was a major driver for bean changes and improved quality. Full article

(This article belongs to the Special Issue Coffee—from Plant to Cup)

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13 pages, 2599 KiB

Open AccessEditor’s ChoiceArticle

Effects of Long-Term Straw Return and Environmental Factors on the Spatiotemporal Variability of Soil Organic Matter in the Black Soil Region: A Case Study

by Yang Yan, Wenjun Ji, Baoguo Li, Guiman Wang, Bifeng Hu, Chao Zhang and Abdul Mounem Mouazen

Agronomy 2022, 12(10), 2532; https://doi.org/10.3390/agronomy12102532 - 17 Oct 2022

Cited by 16 | Viewed by 3477

Abstract

Exploring the effects of straw return and environmental factors on the spatiotemporal variation of soil organic matter (SOM) in black soil regions is essential for soil carbon sequestration research. However, studies seldom quantified the effects of long-term straw return on a long-term SOM [...] Read more.

Exploring the effects of straw return and environmental factors on the spatiotemporal variation of soil organic matter (SOM) in black soil regions is essential for soil carbon sequestration research. However, studies seldom quantified the effects of long-term straw return on a long-term SOM variation at a regional scale in typical black soil areas. The case was conducted in one of the three major black soil regions in the Northern Hemisphere, where the straw return policy has been implemented for a long time. The study obtained the SOM spatial distribution in 2007, 2009, 2012, 2015, and 2018 with approximately 9000 samples and analyzed the effects of soil types, texture, elevation, and human management on the spatiotemporal variation. The results indicated that from the 1980s to 2007, before the straw return policy implementation, the mean SOM content decreased from 24.38 g kg⁻¹ to 18.94 g kg⁻¹. In contrast, the mean SOM content gradually increased from 2007 to 2018 after implementing straw return practices. In addition, the area of SOM within 20–30 g kg⁻¹ increased gradually, with 32.2%, 40.5%, 50.2%, 49.4%, and 60.5% in 2007, 2009, 2012, 2015, and 2018, respectively. Surprisingly, the SOM within 30–40 g kg⁻¹ emerged in 2018. The results indicated that returning straw to the field might promote SOM accumulation. However, the SOM contents in Phaezems (19.25–21.82 g kg⁻¹) were lower than that in natural Phaezems (40–60 g kg⁻¹), indicating severe degradation. The clay content positively correlated to SOM and was a major explanatory variable for the response of SOM to straw return. Straw return practices are promising measures in the black soil region and are worth exploring more effective approaches to allow straw return to play a better role. Full article

(This article belongs to the Special Issue Soil Sustainability in the Anthropocene)

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16 pages, 2795 KiB

Open AccessEditor’s ChoiceArticle

A Systematic Study of Estimating Potato N Concentrations Using UAV-Based Hyper- and Multi-Spectral Imagery

by Jing Zhou, Biwen Wang, Jiahao Fan, Yuchi Ma, Yi Wang and Zhou Zhang

Agronomy 2022, 12(10), 2533; https://doi.org/10.3390/agronomy12102533 - 17 Oct 2022

Cited by 17 | Viewed by 3190

Abstract

Potato growth depends largely on nitrogen (N) availability in the soil. However, the shallow-root crop coupled with its common cultivation in coarse-textured soils leads to its poor N use efficiency. Fast and accurate estimations of potato tissue N concentrations are urgently needed to [...] Read more.

Potato growth depends largely on nitrogen (N) availability in the soil. However, the shallow-root crop coupled with its common cultivation in coarse-textured soils leads to its poor N use efficiency. Fast and accurate estimations of potato tissue N concentrations are urgently needed to assist the decision making in precision fertilization management. Remote sensing has been utilized to evaluate the potato N status by correlating spectral information with lab tests on leaf N concentrations. In this study, a systematic comparison was conducted to quantitatively evaluate the performance of hyperspectral and multispectral images in estimating the potato N status, providing a reference for the trade-off between sensor costs and performance. In the experiment, two potato varieties were planted under four fertilization rates with replicates. UAV images were acquired multiple times during the season with a narrow-band hyperspectral imager. Multispectral reflectance was simulated by merging the relevant narrow bands into broad bands to mimic commonly used multispectral cameras. The whole leaf total N concentration and petiole nitrate-N concentration were obtained from 160 potato leaf samples. A partial least square regression model was developed to estimate the two N status indicators using different groups of image features. The best estimation accuracies were given by reflectance of the full spectra with 2.2 nm narrow, with the coefficient of determination (R²) being 0.78 and root mean square error (RMSE) being 0.41 for the whole leaf total N concentration; while, for the petiole nitrate-N concentration, the 10 nm bands had the best performance (R² = 0.87 and RMSE = 0.13). Generally, the model performance decreased with an increase of the spectral bandwidth. The hyperspectral full spectra largely outperformed all three multispectral cameras, but there was no significant difference among the three brands of multispectral cameras. The results also showed that spectral bands in the visible regions (400–700 nm) were the most highly correlated with potato N concentrations. Full article

(This article belongs to the Special Issue Computer Vision for Intelligent Crop Identification and Crop Protection)

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19 pages, 2400 KiB

Open AccessEditor’s ChoiceArticle

Impacts of Drought Stress on Water Use Efficiency and Grain Productivity of Rice and Utilization of Genotypic Variability to Combat Climate Change

by Tajamul Hussain, Nurda Hussain, Muhammad Tahir, Aamir Raina, Sobia Ikram, Saliha Maqbool, Muhammad Fraz Ali and Saowapa Duangpan

Agronomy 2022, 12(10), 2518; https://doi.org/10.3390/agronomy12102518 - 15 Oct 2022

Cited by 34 | Viewed by 5933

Abstract

Rice is an important cereal and drought stress is a critical abiotic stress that negatively influences the performance and productivity of rice crop, particularly under a changing climate scenario. The objectives of this study were to evaluate the impacts of drought stress on [...] Read more.

Rice is an important cereal and drought stress is a critical abiotic stress that negatively influences the performance and productivity of rice crop, particularly under a changing climate scenario. The objectives of this study were to evaluate the impacts of drought stress on grain productivity and water use efficiency of rice cultivars and to assess the genotypic variability among the tested cultivars. Two irrigation treatments including a control and drought stress were applied to the experiments during 2018–2019 and 2019–2020. The statistical evaluation included a comparison of means, genotypic and phenotypic coefficients of variation, path analysis, correlation assessment, hierarchical clustering of tested cultivars and principal component analysis. The results indicated that drought stress negatively affected the grain productivity of the rice cultivars. The grain productivity of the cultivars decreased, ranging between 21–45% and 21–52% in the first and second season, respectively. Similarly, water use efficiency was significantly decreased ranging between 7–53% and 21–55% during the first and the second season, respectively. The broad-sense heritability for grain productivity was differed under control and drought stress treatment, indicating that the chances of the transfer of grain-productivity-related traits could be affected during selection for stress tolerance. The correlation assessment indicated that the intensity of association among the evaluated parameters was higher under the control treatment. A maximum direct effect was observed by water consumption (1.76) under control whereas, by water use efficiency (1.09) under drought stress treatment on grain productivity in path analysis. Considering the water use efficiency as a desired trait for selection in path analysis, a maximum direct effect was observed by grain productivity under the control (0.68) and under drought treatment (0.88). Hom Pathum and Pathum Thani−1 were identified as highly tolerant cultivars in the hierarchical clustering and principal component analysis. It was concluded that the results obtained for the assessment of drought stress on grain productivity, water use efficiency and genotypic variability among these cultivars could be utilized in selection program for stress tolerance and the stress tolerant cultivars could be used for sustaining grain productivity to reduce the impacts of climate change. Full article

(This article belongs to the Special Issue Strategizing Agricultural Management for Climate Change Adaptation and Mitigation-Series II)

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23 pages, 6089 KiB

Open AccessEditor’s ChoiceArticle

Precision Variable-Rate Spraying Robot by Using Single 3D LIDAR in Orchards

by Limin Liu, Yajia Liu, Xiongkui He and Weihong Liu

Agronomy 2022, 12(10), 2509; https://doi.org/10.3390/agronomy12102509 - 14 Oct 2022

Cited by 40 | Viewed by 4432

Abstract

Automatic navigation (AN) is an essential component to ensure the safety of pesticide application in orchards, whereas precision variable-rate spraying (PVS) serves as an indispensable technology for reducing the application of pesticides and protecting the environment. At present, AN and PVS are not [...] Read more.

Automatic navigation (AN) is an essential component to ensure the safety of pesticide application in orchards, whereas precision variable-rate spraying (PVS) serves as an indispensable technology for reducing the application of pesticides and protecting the environment. At present, AN and PVS are not closely combined. In this case, a single three-dimension (3D) light detection and ranging (LIDAR) sensor is hereby adopted to sense the information of fruit trees around the robot and determine the region of interest (ROI). Moreover, two-dimensional (2D) processing is conducted over the point clouds within the ROI to obtain the center-of-mass coordinates of fruit trees, and determine the vertical distance of the robot to the center line of the fruit tree row (FTR) based on the FTR on both sides using the Random Sample Consensus (RANSAC) algorithm. Then, the robot is controlled to drive along the center line of the FTR. At the same time, the speed and position of the robot are determined by the encoder and inertial measurement unit (IMU), and the IMU corrects the information collected from the zoned canopy of the fruit trees. The results present a lateral deviation (LD) of less than 22 cm and a course deviation (CD) of less than 4.02° during AN. Compared with the traditional spraying (TS), the PVS applies 32.46%, 44.34% and 58.14% less pesticide application, air drift and ground loss, respectively. With the spraying effect guaranteed, the single 3D LIDAR, the encoder and IMU realize the AN and PVS of the robot, reduce the volume of pesticide application, ground loss and air drift, and effectively control the pollution caused by pesticides to the environment. Full article

(This article belongs to the Section Agricultural Biosystem and Biological Engineering)

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23 pages, 5345 KiB

Open AccessEditor’s ChoiceArticle

Soil Chemical Properties Depending on Fertilization and Management in China: A Meta-Analysis

by Shengnan Jia, Ding Yuan, Wenwen Li, Wei He, Sajjad Raza, Yakov Kuzyakov, Kazem Zamanian and Xiaoning Zhao

Agronomy 2022, 12(10), 2501; https://doi.org/10.3390/agronomy12102501 - 13 Oct 2022

Cited by 29 | Viewed by 5586

Abstract

The long-term overuse of fertilizers negatively affects soil chemical properties and health, causing unsustainable agricultural development. Although many studies have focused on the effects of long-term fertilization on soil properties, few comparative and comprehensive studies have been conducted on fertilization management over the [...] Read more.

The long-term overuse of fertilizers negatively affects soil chemical properties and health, causing unsustainable agricultural development. Although many studies have focused on the effects of long-term fertilization on soil properties, few comparative and comprehensive studies have been conducted on fertilization management over the past 35 years in China. This meta-analysis (2058 data) evaluated the effects of the fertilizer, climate, crop types, cultivation duration and soil texture on the soil chemical properties of Chinese croplands. NPKM (NPK fertilizers + manure) led to the highest increase in pH (−0.1), soil organic carbon (SOC) (+67%), total nitrogen (TN) (+63%), alkali-hydrolysable nitrogen (AN) (+70%), total phosphorus (TP) (+149%) and available potassium (AK) (+281%) compared to the unfertilized control, while the sole nitrogen fertilizer (N) led to the lowest increase. The SOC (+115%) and TN (+84%) showed the highest increase under the influence of NPKM in an arid region. The increase in the chemical properties was higher in unflooded crops, with the maximum increase in the wheat–maize rotation, compared to rice, under NPKM. The SOC and TN increased faster under the influence of organic fertilizers (manure or straw) compared to mineral fertilization. Fertilizers produced faster effects on the change in the SOC and TN in sandy loam compared to the control. Fertilizers showed the highest and lowest effects on change in pH, organic C to total N ratio (C/N), TP and TK in clay loam with the cultivation duration. NPKM greatly increased the C/N compared to NPK in an arid region by 1.74 times and in wheat by 1.86 times. Reaching the same SOC increase, the lowest TN increase was observed in wheat, and the lowest increase in TP and AK was observed in rice, compared to the other crops. These results suggest that organic fertilizers (manure or straw) play important roles in improving soil fertility and in acidification. NPKM greatly increased the potential for soil C sequestration in wheat and in the arid region. The small increases in TP and TK can increase the SOC in rice and in the humid region. Therefore, considering the crop types and climatic conditions, reduced fertilization and the combination of mineral fertilizers with manure may be the best ways to avoid agricultural soil deterioration and increase soil carbon sequestration. Full article

(This article belongs to the Special Issue Soil Carbon Pools, Turnover, and Distribution Patterns in Agroecosystems)

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21 pages, 23526 KiB

Open AccessEditor’s ChoiceArticle

Automatic Estimation of Apple Orchard Blooming Levels Using the Improved YOLOv5

by Zhaoying Chen, Rui Su, Yuliang Wang, Guofang Chen, Zhiqiao Wang, Peijun Yin and Jinxing Wang

Agronomy 2022, 12(10), 2483; https://doi.org/10.3390/agronomy12102483 - 12 Oct 2022

Cited by 27 | Viewed by 3845

Abstract

The estimation of orchard blooming levels and the determination of peak blooming dates are very important because they determine the timing of orchard flower thinning and are essential for apple yield and quality. In this paper, we propose an orchard blooming level estimation [...] Read more.

The estimation of orchard blooming levels and the determination of peak blooming dates are very important because they determine the timing of orchard flower thinning and are essential for apple yield and quality. In this paper, we propose an orchard blooming level estimation method for global-level and block-level blooming level estimation of orchards. The method consists of a deep learning-based apple flower detector, a blooming level estimator, and a peak blooming day finding estimator. The YOLOv5s model is used as the apple flower detector, which is improved by adding a coordinate attention layer and a small object detection layer and by replacing the model neck with a bidirectional feature pyramid network (BiFPN) structure to improve the performance of the apple flower detector at different growth stages. The robustness of the apple flower detector under different light conditions and the generalization across years was tested using apple flower data collected in 2021–2022. The trained apple flower detector achieved a mean average precision of 77.5%. The blooming level estimator estimated the orchard blooming level based on the proportion of flowers detected at different growth stages. Statistical results show that the blooming level estimator follows the trend of orchard blooming levels. The peak blooming day finding estimator successfully positioned the peak blooming time and provided information for the flower thinning timing decision. The method described in this paper is able to provide orchardists with accurate information on apple flower growth status and is highly automated. Full article

(This article belongs to the Special Issue Application of Deep Learning in Precise Analysis of Agricultural Crops)

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17 pages, 1457 KiB

Open AccessEditor’s ChoiceArticle

Nitrogen Fertilization and Glyphosate as a Growth Regulator: Effects on the Nutritional Efficiency and Nutrient Balance in Emerald Grass

by Raíssa Pereira Dinalli, Salatiér Buzetti, Rodolfo de Niro Gazola, Regina Maria Monteiro de Castilho, Arshad Jalal, Fernando Shintate Galindo and Marcelo Carvalho Minhoto Teixeira Filho

Agronomy 2022, 12(10), 2473; https://doi.org/10.3390/agronomy12102473 - 11 Oct 2022

Cited by 2 | Viewed by 2197

Abstract

Nitrogen (N) is one of the promising nutrients for lawn growth and is required for the lawn’s proper growth and development, but it also increases mowing frequency. Glyphosate herbicide application in sub-doses, as a growth regulator, can reduce the maintenance costs without any [...] Read more.

Nitrogen (N) is one of the promising nutrients for lawn growth and is required for the lawn’s proper growth and development, but it also increases mowing frequency. Glyphosate herbicide application in sub-doses, as a growth regulator, can reduce the maintenance costs without any adverse reduction in the density and nutritional status of grasses. The objective of this study was to evaluate the influences of nitrogen and glyphosate doses on the growth, aesthetic quality and nutritional status of emerald grass (Zoysia japonica Steud.). The experiment was conducted at the Research and Extension Education Farm of São Paulo State University (UNESP), Ilha Solteira, SP, Brazil, in an Ultisol. The experiment was designed as a randomized block with 12 treatments arranged in a 3 × 4 factorial scheme with 4 replications, comprised of a control (without N), 15 and 30 g N m⁻² of urea, applied in five splits annually, and glyphosate doses (0, 200, 400 and 600 g ha⁻¹ of the active ingredient, a.i.). The split N fertilization at the rate of 15 g m⁻² and glyphosate at the dose of 400 g ha⁻¹ maintained nutritional status of emerald grass. Nitrogen at the rate 15 g N m⁻² (in five splits per year) was observed to produce lower growth traits, an adequate aesthetic quality and longer stability of the nutrients in emerald grasses through lower exportation, with removal of “clipping” after mowing. In addition, glyphosate, at the dose of 400 g a.i. ha⁻¹, was efficient in reducing the leaf area, plant height, shoot dry matter and total dry matter by 18.3, 14.7, 6.8 and 8.1%, respectively, as compared to the control. However, this dose did not impair the coloration and resulted in a lower exportation of nutrients by reducing the need to replenish by fertilization. Therefore, fertilization with 15 g N m⁻², associated with application of 400 g a.i. ha⁻¹ of glyphosate, is recommended for emerald grass in the tropical savannah of Brazil. Full article

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17 pages, 2153 KiB

Open AccessEditor’s ChoiceArticle

Micronutrients Foliar and Drench Application Mitigate Mango Sudden Decline Disorder and Impact Fruit Yield

by Ummadud din Umar, Niaz Ahmed, Muhammad Zeshan Zafar, Ateequr Rehman, Syed Atif Hasan Naqvi, Muhammad Asif Zulfiqar, Muhammad Tariq Malik, Baber Ali, Muhammad Hamzah Saleem and Romina Alina Marc

Agronomy 2022, 12(10), 2449; https://doi.org/10.3390/agronomy12102449 - 10 Oct 2022

Cited by 31 | Viewed by 4893

Abstract

Mango sudden death (MSD) or quick decline (QD) is the most destructive disease found in mango orchards of Pakistan and is characterized by collapse of the vascular system by Ceratocystis fimbriata and Lasiodiplodia theobromae. Cultural practices, chemicals, and biological control are the [...] Read more.

Mango sudden death (MSD) or quick decline (QD) is the most destructive disease found in mango orchards of Pakistan and is characterized by collapse of the vascular system by Ceratocystis fimbriata and Lasiodiplodia theobromae. Cultural practices, chemicals, and biological control are the most valuable tools for the management of MSD, but the role of micronutrient deficiencies has remained an area that is heavily ignored by the farming community. To study the impact of micronutrients, four mango orchards were selected at different locations where different combinations of micronutrients, i.e., Zinc (Zn), Boran (B), and Copper (Cu) in the form of Zinc sulphate (ZnSO₄), Borax/Boric acid (H₃BO₃), and Copper Sulphate (CuSO₄), were applied both foliar and in drench along with the recommended doses of Nitrogen: Phosphorous: Potassium (NPK), and Farmyard manure (FYM), respectively. The quantities of micronutrients were determined from the soil and leaves before and after application of the treatments. The impact of micronutrients was measured in terms of reduction in disease severity and increase in fruit yield. The results revealed that the application of all three micronutrients both in soil drench and in foliar form significantly decreased the disease severity at three locations and increased the yield in all four mango orchards. Application of ZnSO₄ (0.8%), +H₃BO₃ (0.8%), +CuSO₄ (0.5%) and as soil drench ZnSO₄ (400 g) + Borax (200 g) + CuSO₄ 200 g plant⁻¹ proved to be the best treatments, with an average of 12.88 and 14.03% reduction in disease severity and with an average yield of 128 and 119 kg, respectively. The application of micronutrients would be a promising solution in an integrated disease management program used to tackle MSD. Full article

(This article belongs to the Special Issue Perspectives and Challenges for Sustainable Management of Fruit and Foliar Diseases)

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19 pages, 2204 KiB

Open AccessEditor’s ChoiceArticle

Insight into the Root Transcriptome of a Boron-Tolerant Triticum zhukovskyi Genotype Grown under Boron Toxicity

by Anamika Pandey, Mohd. Kamran Khan, Mehmet Hamurcu, Marian Brestic, Ali Topal and Sait Gezgin

Agronomy 2022, 12(10), 2421; https://doi.org/10.3390/agronomy12102421 - 6 Oct 2022

Cited by 36 | Viewed by 2603

Abstract

Boron (B) toxicity is an important abiotic stress that drastically damages agricultural production worldwide, mostly in arid regions. Several studies have reported large losses in wheat due to high B in arable land. The identification of different B-toxicity-tolerant wheat germplasm and using them [...] Read more.

Boron (B) toxicity is an important abiotic stress that drastically damages agricultural production worldwide, mostly in arid regions. Several studies have reported large losses in wheat due to high B in arable land. The identification of different B-toxicity-tolerant wheat germplasm and using them in breeding programs to develop tolerant cultivars is a potential solution to B toxicity. However, tolerance to B toxicity in such germplasm largely relies on the molecular changes in plants under B toxicity at the transcriptome level. Thus, the aim of this study is to determine the transcriptomic response of the roots of a B-toxicity-tolerant Triticum zhukovskyi genotype, PI296968, grown in a highly toxic B environment (10 mM B) in comparison with a control (3.1 μM B) treatment. T. zhukovskyi is a hexaploid wheat species forming a separate lineage from the main wheat lineage and can be a good source of genes for various stresses. However, it has been hardly explored for tolerance to any abiotic stress condition. This study is the first in the literature reporting the B toxicity tolerance of a T. zhukovskyi genotype along with the molecular changes occurring in it under B toxicity as compared to the control treatment. In the present study, 5992 genes were found to be significantly differentially expressed, with 1679 and 4313 up- and down-regulated genes, respectively. A number of transcription factors and pathways were identified to be significantly involved in the B toxicity response of the T. zhukovskyi genotype. A total of 12582 novel transcripts were determined in the study, with 9238 and 3344 coding and noncoding transcripts, respectively. The results not only suggest several candidate genes that can be further studied to improve wheat tolerance to B toxicity in upcoming breeding programs, but also enhance the understanding of the regulatory and molecular processes behind the wheat response to B toxicity. Further experiments are suggested to functionally characterize the identified high-B-responsive genes to confirm their role in providing B toxicity tolerance to the plants. Full article

(This article belongs to the Special Issue Omics Methods for Probing the Abiotic Stress Responses in Plants)

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19 pages, 4118 KiB

Open AccessEditor’s ChoiceArticle

Deep Learning-Based Leaf Disease Detection in Crops Using Images for Agricultural Applications

by Andrew J., Jennifer Eunice, Daniela Elena Popescu, M. Kalpana Chowdary and Jude Hemanth

Agronomy 2022, 12(10), 2395; https://doi.org/10.3390/agronomy12102395 - 3 Oct 2022

Cited by 214 | Viewed by 51440

Abstract

The agricultural sector plays a key role in supplying quality food and makes the greatest contribution to growing economies and populations. Plant disease may cause significant losses in food production and eradicate diversity in species. Early diagnosis of plant diseases using accurate or [...] Read more.

The agricultural sector plays a key role in supplying quality food and makes the greatest contribution to growing economies and populations. Plant disease may cause significant losses in food production and eradicate diversity in species. Early diagnosis of plant diseases using accurate or automatic detection techniques can enhance the quality of food production and minimize economic losses. In recent years, deep learning has brought tremendous improvements in the recognition accuracy of image classification and object detection systems. Hence, in this paper, we utilized convolutional neural network (CNN)-based pre-trained models for efficient plant disease identification. We focused on fine tuning the hyperparameters of popular pre-trained models, such as DenseNet-121, ResNet-50, VGG-16, and Inception V4. The experiments were carried out using the popular PlantVillage dataset, which has 54,305 image samples of different plant disease species in 38 classes. The performance of the model was evaluated through classification accuracy, sensitivity, specificity, and F1 score. A comparative analysis was also performed with similar state-of-the-art studies. The experiments proved that DenseNet-121 achieved 99.81% higher classification accuracy, which was superior to state-of-the-art models. Full article

(This article belongs to the Special Issue Imaging Technology for Detecting Crops and Agricultural Products)

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14 pages, 2072 KiB

Open AccessEditor’s ChoiceArticle

Assessing the Population Structure of Colorado Potato Beetle Populations in Croatia Using Genetic and Geometric Morphometric Tools

by Martina Kadoić Balaško, Renata Bažok, Katarina M. Mikac, Hugo A. Benítez, Margarita Correa and Darija Lemic

Agronomy 2022, 12(10), 2361; https://doi.org/10.3390/agronomy12102361 - 30 Sep 2022

Cited by 2 | Viewed by 2555

Abstract

The Colorado potato beetle (CPB, Leptinotarsa decemlineata Say) is one of the most successful invasive species worldwide. It has been present in Croatia since 1947, where it has caused significant damage to potato plants and developed resistance to several insecticides. Our study is [...] Read more.

The Colorado potato beetle (CPB, Leptinotarsa decemlineata Say) is one of the most successful invasive species worldwide. It has been present in Croatia since 1947, where it has caused significant damage to potato plants and developed resistance to several insecticides. Our study is the first attempt to investigate the population structure of CPBs in Croatia. SNP and GM techniques provided us with data about the population structure of the CPB population. A Bayesian model-based clustering algorithm implemented in STRUCTURE, principal component analysis (PCA), and discriminant analysis of principal components (DAPC) were used to analyze the genetic structure of CPBs. For the morphometric analysis, the hindwing shape of the same CPB individuals was examined using wing venation patterns. We detected the low genetic and phenotypic variabilities of CPB populations and the presence of a single panmictic population in the study area, well adapted to different environmental conditions, indicating high phenotypic plasticity. Due to such exceptional adaptation of the CPB population, it is necessary to implement an area-wide approach in future pest control management. Full article

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22 pages, 5646 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Designing Integrated Systems for the Low Rainfall Zone Based on Grazed Forage Shrubs with a Managed Interrow

by Andrew P. Smith, Eric Zurcher, Rick S. Llewellyn and Hayley C. Norman

Agronomy 2022, 12(10), 2348; https://doi.org/10.3390/agronomy12102348 - 29 Sep 2022

Cited by 1 | Viewed by 2039

Abstract

Managed plantations of saltbush have the potential to increase the productivity and climate resilience of the farming systems of the low rainfall areas of the world, where livestock are important. The objective was to dynamically simulate the behaviour of grazing saltbush plantations with [...] Read more.

Managed plantations of saltbush have the potential to increase the productivity and climate resilience of the farming systems of the low rainfall areas of the world, where livestock are important. The objective was to dynamically simulate the behaviour of grazing saltbush plantations with a new modelling capacity in the APSIM framework to enable the dynamic grazing of forage systems. Scenarios simulated included: the choice of plant species growing in the interrow area between shrub-rows, density of saltbush spatial arrangement, locations with different climates and soils, and grazing strategy by sheep. Comparisons of scenarios across systems were insightful during rainfall years when the shrub systems are of high value (i.e., driest/lowest 20% rainfall years in the simulation period). Overall, the efficient grazing of shrubs by dry sheep with little supplementary feeding, required the availability of a large amount of low quality interrow. Shrub plantations with an interrow of standing oats required least supplementation. Summer grazing was the optimal time for grazing shrub plantations in low rainfall years. Plantations with more shrubs relative to interrow increased the need for supplementary feeding but reduced the variation between years. This is one of the first uses of systems modelling to explore forage shrub system designs that maximise the grazing value of shrub plus interrow. Full article

(This article belongs to the Section Innovative Cropping Systems)

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20 pages, 3144 KiB

Open AccessEditor’s ChoiceArticle

New Antifungal Compound, 6-Pentyl-α-Pyrone, against the Maize Late Wilt Pathogen, Magnaporthiopsis maydis

by Ofir Degani and Asaf Gordani

Agronomy 2022, 12(10), 2339; https://doi.org/10.3390/agronomy12102339 - 28 Sep 2022

Cited by 25 | Viewed by 3789

Abstract

6-pentyl-α-pyrone (6-PP) is a powerful Magnaporthiopsis maydis antifungal compound, recently discovered when the potent growth medium of Trichoderma asperellum was analyzed. Despite its high potential in plate assay, it was not inspected for plant treatment prevention. Late wilt disease, caused by the fungus [...] Read more.

6-pentyl-α-pyrone (6-PP) is a powerful Magnaporthiopsis maydis antifungal compound, recently discovered when the potent growth medium of Trichoderma asperellum was analyzed. Despite its high potential in plate assay, it was not inspected for plant treatment prevention. Late wilt disease, caused by the fungus M. maydis, threatens commercial maize production in high-risk areas. Thus, the search for control options against the pathogen is one of the top priorities in Israel, Egypt, and other countries. Disease-resistant maize genotypes can reduce the damages. Yet, aggressive variants of the fungus can overcome host resistance. The current study aimed at inspecting T. asperellum and its secreted metabolite, pure 6-PP, against the pathogen in plants over a full growth period. First, adding T. asperellum directly to seeds with sowing provides significant protection to sprouts (up to 42 days) in a growth room, with more than two-fold growth promotion and reduced pathogen root infection (detected by real-time PCR). The same procedure applied in a commercial field was less beneficial in rescuing the plants’ growth and yield. Still, it reduced the cobs’ symptoms by 11% and resulted in nine-fold lower levels of the pathogen’s DNA in the stem tissue. Second, the T. asperellum purified 6-PP compound (30 µg/seed) was used in seed coating and tested against the T. asperellum secretory metabolites’ crude (diluted to 50%). At the season’s end, these treatments improved plant biomass by 90–120% and cob weight by 60%. Moreover, the treatments significantly (p < 0.05) reduced the symptoms (up to 20%) and pathogen infection (94–98%). The current study’s results reveal the potential of 6-PP as a new fungicide against M. maydis. Such a treatment may protect maize plants from other soil diseases. Full article

(This article belongs to the Special Issue Research Progress on Pathogenicity of Fungus in Crop)

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12 pages, 887 KiB

Open AccessEditor’s ChoiceArticle

Agronomic Efficiency of Phosphorus Fertilisers Recovered from Milk Processing Waste

by Shane McIntosh, Terry Rose, Andrew Rose, Lee Kearney and Dirk Erler

Agronomy 2022, 12(10), 2341; https://doi.org/10.3390/agronomy12102341 - 28 Sep 2022

Cited by 2 | Viewed by 1922

Abstract

The recovery of phosphorus (P) from milk processing flotation sludges (MFS) using pyrolysis can contribute to a sustainable reuse of P by converting waste to fertiliser. The objectives of this study were to quantify the recovery and transformation of P following MFS pyrolysis [...] Read more.

The recovery of phosphorus (P) from milk processing flotation sludges (MFS) using pyrolysis can contribute to a sustainable reuse of P by converting waste to fertiliser. The objectives of this study were to quantify the recovery and transformation of P following MFS pyrolysis and compare the efficacy of raw and pyrolysed MFS as organic P fertilisers. Phosphorus retention in biochars was high (98 ± 0.73% yield), leading to the enrichment of P relative to the raw MFS by a factor of 4.3–4.5. Pyrolysis of the MFS at 450 °C led to a 3-fold increase in the proportion of P in the HCl-extractable fraction (65 ± 0.32%), a 2-fold reduction in NaOH-P (30 ± 2.1%), and negligible amounts of P in the H₂O-P and NaHCO₃-P fractions. The bioavailability of P in raw MFS and 450 °C biochar was compared to a soluble P fertiliser in P-limiting plant bioassays. In the short-term (70 day) trial where ryegrass was grown on three soil types (Arenosol, Vertisol or Ferralsol), biochar MFS showed higher efficacy as a P fertiliser than raw MFS in the acidic Ferralsol, whereas the opposite response was observed in the near-neutral Arenosol. In the Vertisol, neither the raw MFS nor biochar produced more cumulative biomass or P uptake than any of the nil P controls. Over a longer 200-day period, raw MFS and biochar applied to the Arenosol were about 20% as efficient at providing P to ryegrass plants as the water-soluble K₂PO₄, suggesting that higher application rates of MFS or biochar would be required to match synthetic fertilisers in the short term. Full article

(This article belongs to the Special Issue Agricultural Valorization of Agro-Industrial By-Products: From Waste to Value)

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16 pages, 58236 KiB

Open AccessEditor’s ChoiceArticle

Fabrication of Copper Oxide Nanoparticles Using Passiflora edulis Extract for the Estimation of Antioxidant Potential and Photocatalytic Methylene Blue Dye Degradation

by Amina Yasin, Urooj Fatima, Sammia Shahid, Sana Mansoor, Hina Inam, Mohsin Javed, Shahid Iqbal, Hamad Alrbyawi, Hamoud H. Somaily, Rami Adel Pashameah, Eman Alzahrani and Abd-ElAziem Farouk

Agronomy 2022, 12(10), 2315; https://doi.org/10.3390/agronomy12102315 - 27 Sep 2022

Cited by 31 | Viewed by 6640

Abstract

In the present work, copper oxide nanoparticles have been fabricated by using a biological method. Copper oxide nanoparticles (CuO NPs) have received more attention than other metal oxides due to their distinctive properties and applications. Plant-mediated synthesis of nanoparticles has gained the attention [...] Read more.

In the present work, copper oxide nanoparticles have been fabricated by using a biological method. Copper oxide nanoparticles (CuO NPs) have received more attention than other metal oxides due to their distinctive properties and applications. Plant-mediated synthesis of nanoparticles has gained the attention of researchers because of its simple and ecologically sustainable approach. The biosynthesis of CuO NPs included the use of Passiflora edulis leaf extract that acts as a stabilizing and reducing agent. A non-toxic, cost-effective, and ecologically acceptable method was the use of plant leaf extract in the biogenesis of nanoscale materials. UV-vis, SEM, FTIR, and XRD techniques were used to examine the biologically produced copper oxide nanoparticles. The findings of the SEM examination, which gives morphological information, demonstrate that the synthesized NPs have a spherical shape and have an average particle size of between 60 and 65 nm. CuO has been further investigated in the current study as a photo-catalyst in the methylene blue (MB) dye degradation and as an antioxidant in free radical scavenging activities. The decolorization efficiency was approximately 93% after 160 min. Furthermore, CuO nanoparticles were tested for antioxidant performance by scavenging 2, 2-diphenyl-1-picrylhydrazyl hydrate free radicals (DPPH) and evaluated by UV-Vis spectroscopy. The result showed that biologically synthesized CuO NPs can be used as an effective antioxidant. The half maximal inhibitory concentration IC50 of copper oxide nanoparticles was found to be in the range of 0.13–0.20. Full article

(This article belongs to the Special Issue Phytochemicals of Edible Plants—Volume II)

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13 pages, 2547 KiB

Open AccessEditor’s ChoiceCommunication

Nitrous Oxide Emission and Grain Yield in Chinese Winter Wheat–Summer Maize Rotation: A Meta-Analysis

by Chengcheng Yao, Xiongwei Wu, He Bai and Jiangxin Gu

Agronomy 2022, 12(10), 2305; https://doi.org/10.3390/agronomy12102305 - 26 Sep 2022

Cited by 6 | Viewed by 3664

Abstract

A systematic understanding of nitrous oxide (N₂O) emission and grain yield in winter wheat–summer maize rotation, one of the most important cereal cropping systems in China, is still lacking. The primary aim of this study was to quantify the N₂ [...] Read more.

A systematic understanding of nitrous oxide (N₂O) emission and grain yield in winter wheat–summer maize rotation, one of the most important cereal cropping systems in China, is still lacking. The primary aim of this study was to quantify the N₂O emissions and grain yield, as well as responses to mitigation strategies, in this intensively managed agroecosystem. We conducted a pairwise meta-analysis by compiling a comprehensive dataset of annual N₂O emissions (n = 530) and grain yields (n = 352) from peer−reviewed publications. The N₂O emissions increased with nitrogen (N) fertilizer input rates following a linear model (r² = 0.295, p < 0.001), giving a specific emission coefficient and background emission of 0.71% and 0.5 kg N ha⁻¹ yr⁻¹, respectively. The grain yields responded to the N input rates following a linear-plateau model (r² = 0.478, p < 0.001), giving an optimal N input rate and maximum grain yield of 405 kg N ha⁻¹ yr⁻¹ and 15.5 t ha⁻¹ yr⁻¹, respectively. The meta-analyses revealed that reducing N fertilizers (approximately 50% of the full N input), water-saving irrigation, reduced or no tillage, and applying enhanced efficiency fertilizers significantly decreased N₂O emissions (range: −45% to −9%) and increased or did not impact grain yields (range: −1% to 3%). We recommend that reducing agricultural inputs (i.e., N fertilizers, irrigation, and tillage) is a feasible N₂O mitigation strategy in the intensively managed winter wheat–summer maize rotation that can be employed without additional environmental risks. Full article

(This article belongs to the Special Issue Effects of Tillage, Cover Crop and Crop Rotation on Soil)

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15 pages, 2177 KiB

Open AccessEditor’s ChoiceArticle

The Effect of Rotational Cropping of Industrial Hemp (Cannabis sativa L.) on Rhizosphere Soil Microbial Communities

by Lili Tang, Chao Fan, Hongmei Yuan, Guangwen Wu, Jing Sun and Shuquan Zhang

Agronomy 2022, 12(10), 2293; https://doi.org/10.3390/agronomy12102293 - 24 Sep 2022

Cited by 6 | Viewed by 5051

Abstract

Crop rotation affects soil properties and soil microbial diversity and structure. Currently, it is not well understood how soil microbial diversity changes following different crop rotation systems of industrial hemp, an ancient and economically important crop. Therefore, these changes were analyzed in this [...] Read more.

Crop rotation affects soil properties and soil microbial diversity and structure. Currently, it is not well understood how soil microbial diversity changes following different crop rotation systems of industrial hemp, an ancient and economically important crop. Therefore, these changes were analyzed in this study. Our results showed that different rotation systems significantly affected the wilt disease incidence, plant height, yield, soil physicochemical properties and soil microbial communities in the greenhouse. The rotation systems used in this study significantly reduced the plant mortality and increased the yield compared with a monoculture system. The levels of alkaline hydrolysis and available phosphorus in the soil decreased significantly compared with a monoculture cropping system. Using MiSeq high-throughput sequencing, we showed that the soil diversity and number of bacteria and fungi were significantly higher for rotation systems and controls compared to the monoculture system. The relative abundance of pathogens increased with a monoculture system. Redundancy analysis suggests that soil properties may also affect the soil microbial composition. Taken together, different rotation systems used in this study significantly decreased the disease incidence, increased plant yields and increased soil microbial diversity compared with monoculture for industrial hemp. We believe that applying these rotation systems is an efficient and eco-friendly approach to control soil borne pathogenic diseases and increase floral yields. Full article

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20 pages, 1912 KiB

Open AccessEditor’s ChoiceArticle

Salinity Effect on Plant Growth Parameters and Fruit Bioactive Compounds of Two Strawberry Cultivars, Coupled with Environmental Conditions Monitoring

by Nikoleta-Kleio Denaxa, Aggeliki Nomikou, Nikolaos Malamos, Eleni Liveri, Petros Anargyrou Roussos and Vasileios Papasotiropoulos

Agronomy 2022, 12(10), 2279; https://doi.org/10.3390/agronomy12102279 - 23 Sep 2022

Cited by 35 | Viewed by 4833

Abstract

Salinity stress is one of the most vital abiotic stresses, impairing the productivity of crops in both irrigated and dry areas. A pot experiment was carried out in a greenhouse environment, aiming to examine the relevant tolerances and evaluate the effect of salinity [...] Read more.

Salinity stress is one of the most vital abiotic stresses, impairing the productivity of crops in both irrigated and dry areas. A pot experiment was carried out in a greenhouse environment, aiming to examine the relevant tolerances and evaluate the effect of salinity stress on plant growth, fruit physiological, and quality traits of two strawberry cultivars, Camarosa and Rociera. The plants were irrigated with water with electrical conductivity (EC) of 0.4 dS m⁻¹ (control), or with a salt solution with either ECs 2 dS m⁻¹ (moderate salt stress) or 4 dS m⁻¹ (elevated salt stress). Furthermore, several meteorological parameters, as well as soil moisture, were monitored inside the greenhouse. The results showed that salinity induced osmotic stress, water deprivation, and toxic effects, affecting the growth parameters and yield of both cultivars. The elevated salt stress imposed a negative impact on Rociera’s fruits carbohydrates, organic acids, and anthocyanins, while the antioxidant capacity increased. However, Rociera exhibited high total yield/plant and total yield even under elevated salt stress compared to Camarosa. Camarosa plants grown under high salt levels presented low salinity tolerance index, plant water content, and growth parameters. The fruits exhibited low fresh weight but high sweetness index and antioxidant power. An accumulation of soluble sugars under saline conditions, especially sucrose, was also detected in cv. Camarosa fruits when compared to Rociera. Therefore, the two cvs. exhibited a different pattern of response to salinity stress concerning their physiological, biochemical and nutritional characteristics; however, either could be an interesting alternative for cultivation in areas where a slight salinization of the water or soil imposes a limitation on the rather salt-sensitive crops. Agronomic and biochemical evaluation of salinity stress coupled with monitoring of greenhouse microclimatic conditions will lead to a better understanding of the effects on plant growth and quality characteristics, enhancing the productivity of strawberry cultivars, especially under salt-affected environments. Full article

(This article belongs to the Special Issue Toward a "Green Revolution" for Crop Breeding)

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13 pages, 2224 KiB

Open AccessEditor’s ChoiceArticle

Genotype Selection, and Seed Uniformity and Multiplication to Ensure Common Bean (Phaseolus vulgaris L.) var. Liborino

by Diana Peláez, Paula A. Aguilar, Mariana Mercado, Felipe López-Hernández, Manuel Guzmán, Esteban Burbano-Erazo, Kate Denning-James, Clara I. Medina, Matthew W. Blair, José J. De Vega and Andrés J. Cortés

Agronomy 2022, 12(10), 2285; https://doi.org/10.3390/agronomy12102285 - 23 Sep 2022

Cited by 15 | Viewed by 3312

Abstract

Seed uniformity and stability testing, and multiplication, are key steps in the seed supply chain of the common bean (Phaseolus vulgaris L.) and other crops. Optimizing agronomical practices in these phases can ultimately ensure seed quality and availability, and germplasm prospective utilization. [...] Read more.

Seed uniformity and stability testing, and multiplication, are key steps in the seed supply chain of the common bean (Phaseolus vulgaris L.) and other crops. Optimizing agronomical practices in these phases can ultimately ensure seed quality and availability, and germplasm prospective utilization. However, farmers have rarely standardized seed testing and propagation protocols in local common bean landraces conserved in situ. An example of this is the Liborino variety (var.), a promising yellow Andean common bean known for its presumably high digestibility and adaptation to the local conditions of the Cauca river canyon (northwest Andes of Colombia), but likely experiencing genetic erosion after decades of suboptimal propagation. Therefore, this work intended to evaluate and select locally adapted genotypes of common bean var. Liborino for commercial use, to be later multiplied, evaluated by participatory breeding, and eventually shared with farmers. Specifically, we evaluated 44 accessions of var. Liborino common bean in six adaption and yield field trials in the Cauca river canyon at 1100 and 1400 m a.s.l, and in AGROSAVIA’s “La Selva” research station at 2100 m a.s.l. In parallel, we carried out standardized seed multiplication of a Liborino genotype using best practices to guarantee uniformity and stability. From the 44 accessions, nine were well adapted to the tested local conditions. Four of these accessions exhibited a bush type growth habit, while the remaining five were climbers. The trials revealed maximum average extrapolated yields of up to 1169.4 ± 228.4 kg ha⁻¹ for the bush types (G8152) and up to 1720.0 ± 588.4 kg ha⁻¹ for the climbers (G51018), both at 2100 m a.s.l. Three climbing accessions matched farmers’ expectations for seed coat color and shape, according to a participatory selection exercise. Uniform and stable seed of the selected genotype was delivered in 2022 to 39 farmers, ~6.5 kg of seeds per farmer. Our results will allow implementing bean genetic improvement pipelines, promoting var. Liborino commercialization, and boosting the economic and sustainable development of the rural communities in the Cauca river canyon. Seed uniformity testing and multiplication pipelines must be extended to other bean landraces conserved in situ. Full article

(This article belongs to the Special Issue Legumes Cultivars and Their Genetic Improvements)

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13 pages, 3744 KiB

Open AccessEditor’s ChoiceArticle

UAV Multispectral Data: A Reliable Approach for Managing Phosphate-Solubilizing Bacteria in Common Bean

by Antonia Erica Santos de Souza, Marcelo Rodrigues Barbosa Júnior, Bruno Rafael de Almeida Moreira, Rouverson Pereira da Silva and Leandro Borges Lemos

Agronomy 2022, 12(10), 2284; https://doi.org/10.3390/agronomy12102284 - 23 Sep 2022

Cited by 3 | Viewed by 2561

Abstract

Remote sensing can offer stakeholders opportunities to make precise and accurate decisions on agricultural activities. For instance, farmers can exploit aircraft systems to acquire survey-level, high-resolution imagery data for crop and soil management. Therefore, the objective of this study was to analyze whether [...] Read more.

Remote sensing can offer stakeholders opportunities to make precise and accurate decisions on agricultural activities. For instance, farmers can exploit aircraft systems to acquire survey-level, high-resolution imagery data for crop and soil management. Therefore, the objective of this study was to analyze whether an unmanned aerial vehicle (UAV) allows for the assessment and monitoring of biofertilization of the common bean upon vegetation indices (VIs). The biological treatment of the legume crop included its inoculation with phosphate-solubilizing bacteria (PSB), namely Bacillus subtilis and B. megaterium. Indicators of photosynthetic performance, such as chlorophylls (a and b) and carotenoids, were measured from actively growing leaves to determine effectiveness. In addition, images were acquired in the field, both spatially and temporally, to establish functional relationships between biometric and computational features. Microorganisms manifested as growth-promoting agents to the crop as they significantly increased its quantities of light-harvesting pigments. VIs allowed for predicting their impact on photosynthetic performance, making them on-site markers of PSB. Therefore, this research can provide insights into the remote, non-destructive mapping of spectral changes in the common bean upon the application of PSB. Imagery data from UAV would enable producers to generate information on the crop to intervene in the field at the right time and place for improved utilization of biofertilizers. Full article

(This article belongs to the Special Issue Research Advances in Digital Technologies to Improve Agricultural Productivity)

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14 pages, 858 KiB

Open AccessEditor’s ChoiceArticle

Evaluation of One-Time Applications of Foliar Applied Auxin Co-Applied with Surfactant for Use in Commercial Cutting Propagation

by Anthony T. Bowden, Patricia R. Knight, Jenny B. Ryals, Christine E. H. Coker, Scott A. Langlois, Shaun R. Broderick, Eugene K. Blythe, Hamidou F. Sakhanokho and Ebrahiem M. Babiker

Agronomy 2022, 12(10), 2243; https://doi.org/10.3390/agronomy12102243 - 20 Sep 2022

Cited by 4 | Viewed by 3210

Abstract

Use of foliar auxin applications are increasing in the nursery and greenhouse industry. However, previous research has shown that insufficient auxin is absorbed or translocated to the site of action when foliar auxin applications are used. It is theorized that adding surfactants to [...] Read more.

Use of foliar auxin applications are increasing in the nursery and greenhouse industry. However, previous research has shown that insufficient auxin is absorbed or translocated to the site of action when foliar auxin applications are used. It is theorized that adding surfactants to foliar applications of auxin may help with the absorption and translocation of auxin to the site of action. Research was conducted to determine whether adding surfactants to one-time foliar applications of indole-3-butyric acid (IBA) would be as effective as the current industry standard, the basal quick-dip. Terminal, semi-hardwood cuttings of Red Cascade™ miniature climbing rose (Rosa ‘MOORcap’), common camellia (Camellia japonica) and ‘Southern Charm’ magnolia (Magnolia grandiflora ‘Southern Charm’) were sprayed to the drip point using Hortus IBA Water Soluble Salts™ at concentrations of 0 ppm, 50 ppm, 75 ppm, or 100 ppm for rose cuttings or 0 ppm, 500 ppm, 1000 ppm, or 1500 ppm IBA for camellia or magnolia. To serve as an industry control, the basal end of cuttings was immersed for 3-s in a solution of either 250 ppm, 4000 ppm or 2500 ppm for rose, camellia, or magnolia, respectively. A foliar application of 1500 ppm after sticking was as effective as the basal quick-dip for cuttings of ‘Southern Charm’, while other spray treatments were less effective. A basal quick-dip was more effective than a foliar spray for rooting cuttings of camellia. Auxin rate had no impact on rooting of Red Cascade^™ miniature rose. The goal of commercial plant propagation is to produce high-quality rooted cuttings as quickly as possible. Plant propagation places a large demand on labor within the nursery industry, with one recent report being that labor accounts for >50% of a nursery’s budget. Our results from this trial affirm the results reported by similar trials into foliar applications of auxin suggests that the benefits of foliar applications are species dependent Further work is warranted on examining other auxin and surfactant formulations. Full article

(This article belongs to the Collection Propagation and Conservation of Horticultural Plants: In Vitro and In Vivo)

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16 pages, 3340 KiB

Open AccessEditor’s ChoiceArticle

Monitoring Growth Status of Winter Oilseed Rape by NDVI and NDYI Derived from UAV-Based Red–Green–Blue Imagery

by Nazanin Zamani-Noor and Dominik Feistkorn

Agronomy 2022, 12(9), 2212; https://doi.org/10.3390/agronomy12092212 - 16 Sep 2022

Cited by 15 | Viewed by 3592

Abstract

The current study aimed to evaluate the potential of the normalized difference vegetation index (NDVI), and the normalized difference yellowness index (NDYI) derived from red–green–blue (RGB) imaging to monitor the growth status of winter oilseed rape from seeding to the ripening stage. Subsequently, [...] Read more.

The current study aimed to evaluate the potential of the normalized difference vegetation index (NDVI), and the normalized difference yellowness index (NDYI) derived from red–green–blue (RGB) imaging to monitor the growth status of winter oilseed rape from seeding to the ripening stage. Subsequently, collected values were used to evaluate their correlations with the yield of oilseed rape. Field trials with three seed densities and three nitrogen rates were conducted for two years in Salzdahlum, Germany. The images were rapidly taken by an unmanned aerial vehicle carrying a Micasense Altum multi-spectral camera at 25 m altitudes. The NDVI and NDYI values for each plot were calculated from the reflectance at RGB and near-infrared (NIR) bands’ wavelengths pictured in a reconstructed and segmented ortho-mosaic. The findings support the potential of phenotyping data derived from NDVI and NDYI time series for precise oilseed rape phenological monitoring with all growth stages, such as the seedling stage and crop growth before winter, the formation of side shoots and stem elongation after winter, the flowering stage, maturity, ripening, and senescence stages according to the crop calendar. However, in comparing the correlation results between NDVI and NDYI with the final yield, the NDVI values turn out to be more reliable than the NDYI for the real-time remote sensing monitoring of winter oilseed rape growth in the whole season in the study area. In contrast, the correlation between NDYI and the yield revealed that the NDYI value is more suitable for monitoring oilseed rape genotypes during flowering stages. Full article

(This article belongs to the Section Precision and Digital Agriculture)

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15 pages, 998 KiB

Open AccessEditor’s ChoiceArticle

The Effects of Agricultural Socialized Services on Sustainable Agricultural Practice Adoption among Smallholder Farmers in China

by Meili Huan, Yajuan Li, Liang Chi and Shaoguo Zhan

Agronomy 2022, 12(9), 2198; https://doi.org/10.3390/agronomy12092198 - 15 Sep 2022

Cited by 30 | Viewed by 4120

Abstract

In recent years, a growing body of literature has explored the determinants and impacts of sustainable agricultural technologies. However, little is known about the relationship between agricultural socialized services that have reshaped the smallholder agricultural system and promoted scale operation in rural China [...] Read more.

In recent years, a growing body of literature has explored the determinants and impacts of sustainable agricultural technologies. However, little is known about the relationship between agricultural socialized services that have reshaped the smallholder agricultural system and promoted scale operation in rural China and environmentally friendly agricultural innovation adoption of the farm. Our study examines the effects of agricultural socialized services on the adoption of sustainable agricultural practices (SAPs). In this study, we capture the number of SAPs adopted, unlike most existing studies that analyze the dichotomous decision of agricultural technology adoption. We apply an endogenous-treatment Poisson regression model to analyze using a national representative farm-level survey data set with 1357 farm households from 132 villages in China. The results show that socialized service use has a significantly positive effect on the number of SAPs adopted. Our results suggest that agricultural socialized services can promote the adoption of sustainable agricultural technologies among smallholders, and thus help transform conventional agriculture into sustainable agriculture. Full article

(This article belongs to the Special Issue Economy and Sociology in Sustainable Agriculture)

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12 pages, 26420 KiB

Open AccessEditor’s ChoiceArticle

Effects of Bacillus amyloliquefaciens QST713 on Photosynthesis and Antioxidant Characteristics of Alfalfa (Medicago sativa L.) under Drought Stress

by Lingjuan Han, Miaoling Zhang, Lixia Du, Li Zhang and Bin Li

Agronomy 2022, 12(9), 2177; https://doi.org/10.3390/agronomy12092177 - 14 Sep 2022

Cited by 29 | Viewed by 3217

Abstract

Drought stress is a prevalent abiotic stress that adversely affects multiple physiological processes in plants, especially their photosynthetic capacity. Application of plant growth–promoting rhizobacteria (PGPR) has been considered as an eco-friendly strategy to ameliorate the deleterious effects of drought stress on plants. The [...] Read more.

Drought stress is a prevalent abiotic stress that adversely affects multiple physiological processes in plants, especially their photosynthetic capacity. Application of plant growth–promoting rhizobacteria (PGPR) has been considered as an eco-friendly strategy to ameliorate the deleterious effects of drought stress on plants. The present study was carried out to investigate the effects of Bacillus amyloliquefaciens QST713 on plant growth, leaf relative water content (RWC), photosynthesis processes, photosynthetic pigment content and antioxidant enzyme activities in two alfalfa varieties, Galalxie Max (drought-tolerant) and Saidi 7 (drought-sensitive) under drought conditions. The results showed that drought stress significantly declined plant biomass production, RWC, photosynthetic pigment content (Chl a, Chl b and carotenoids) and photosynthetic gas exchange parameters (transpiration rate (Tr), stomatal conductance (Gs) and intercellular CO₂ concentration (Ci)), whereas it enhanced the enzymatic activity of peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) in both cultivars. In contrast, the inoculation of the bacillus strain QST713 was more effective on plant growth, showing higher plant biomass production compared to the non-inoculated plants under drought stress. Moreover, the application of QST713 significantly promoted the content of RWC, the accumulation of chlorophyll content and the activities of antioxidant enzymes as well as enhanced the photosynthetic capacity of alfalfa seedlings under drought stress. These results suggest that QST713 could be considered as a promising bio-inoculant for plants exposed to environmental stresses. Full article

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26 pages, 4469 KiB

Open AccessEditor’s ChoiceArticle

Effect of a Biostimulant Based on Polyphenols and Glycine Betaine on Tomato Plants’ Responses to Salt Stress

by Javier Zuzunaga-Rosas, Sara González-Orenga, Ana Maria Tofei, Monica Boscaiu, Héctor Moreno-Ramón, Sara Ibáñez-Asensio and Oscar Vicente

Agronomy 2022, 12(9), 2142; https://doi.org/10.3390/agronomy12092142 - 9 Sep 2022

Cited by 25 | Viewed by 4833

Abstract

Climate change accentuates abiotic stress conditions putting at risk several commercial cultivars particularly vulnerable to salinity in the early stages of development, which makes adopting new technologies in tune with the environment necessary to mitigate its impact. In this study, we tested the [...] Read more.

Climate change accentuates abiotic stress conditions putting at risk several commercial cultivars particularly vulnerable to salinity in the early stages of development, which makes adopting new technologies in tune with the environment necessary to mitigate its impact. In this study, we tested the possible effects of a commercial biostimulant (BALOX^®) on enhancing salt stress tolerance in salt-treated tomato plants, analysing plant growth and several stress biochemical markers: photosynthetic pigments, ion contents in roots and leaves, leaf concentrations of different osmolytes, oxidative stress markers, non-enzymatic antioxidants, and the specific activities of major antioxidant enzymes. The experimental design consisted of three soil salinity levels (non-saline, saline, and very saline), two biostimulant doses (0.4 mL and 0.8 mL of the BALOX^® stock per litre of irrigation water), and the non-treated control (without biostimulant), evaluated at 30 and 60 days of treatment. The biostimulant favoured plant growth, especially at the root level and in saline soils. In addition, it helped reduce Na⁺ and Cl⁻ uptake by the roots and seemed to stimulate, to some extent, K⁺ and Ca²⁺ transport to the aerial part of the plant. The BALOX^® application significantly reduced the level of stress affecting the plants in saline soils, as shown by the decrease in the contents of proline and oxidative stress biomarkers and the activity of salt-induced antioxidant enzymes. Some of the biostimulant effects were also observed under low salinity conditions; therefore, in addition to enhancing salt stress responses, BALOX^® appears to stimulate the growth of tomato plants through a general improvement of photosynthesis and primary metabolism. Full article

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18 pages, 3054 KiB

Open AccessEditor’s ChoiceArticle

Understanding the Role of Physiological and Agronomical Traits during Drought Recovery as a Determinant of Differential Drought Stress Tolerance in Barley

by Md. Hasanuzzaman, Lana Shabala, Timothy J. Brodribb, Meixue Zhou and Sergey Shabala

Agronomy 2022, 12(9), 2136; https://doi.org/10.3390/agronomy12092136 - 8 Sep 2022

Cited by 9 | Viewed by 2910

Abstract

The fast and efficient recovery could be an important trait defining the efficacy of plant drought adaptation. In this work, we aimed to develop a set of simple and appropriate physiological proxies that could be used as reliable indicators to predict plant drought [...] Read more.

The fast and efficient recovery could be an important trait defining the efficacy of plant drought adaptation. In this work, we aimed to develop a set of simple and appropriate physiological proxies that could be used as reliable indicators to predict plant drought responses and validate the role of specific physiological traits such as root length, stomata density, and residual transpiration, in the drought tolerance and recovery in barley. Eighty barley (Hordeum vulgare L.) genotypes were subjected to progressive droughting until the soil moisture level reached 10%, followed by rewatering. Plants were visually scored at the end of drought period and two weeks after rewatering. SPAD values and chlorophyll fluorescence F_v/F_m ratio were also measured, alongside with stomatal density (SD) and residual transpiration (RT). The same genotypes were germinated in paper rolls treated with 15% (w/v) of polyethylene glycol (PEG) 8000 by quantification of changes in the root growth patterns. Responses to drought stress varied among the genotypes, and drought tolerance and recovery scores were significantly correlated with each other. Changes in SPAD value, F_v/F_m ratio and root length were significantly correlated with the drought tolerance and recovery indices. Both indices correlated strongly with the SD and RT of irrigated plants, although in an unexpected direction. We have also correlated the extent of plants’ drought tolerance to their ability to grow in saline soils (a condition often termed a “physiological drought”) and found a positive association between these two traits. The fact that drought tolerant genotype also possessed higher salinity tolerance implies some common mechanisms conferring both traits. Plants having less SD and more RT under irrigated conditions showed higher drought tolerance. It is concluded that lower SD and higher RT under optimal conditions may be used as proxies for drought tolerance in barley. Full article

(This article belongs to the Collection Crop Breeding for Stress Tolerance)

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