Editor's Choice Articles

Editor’s Choice articles are based on recommendations by the scientific editors of MDPI journals from around the world. Editors select a small number of articles recently published in the journal that they believe will be particularly interesting to authors, or important in this field. The aim is to provide a snapshot of some of the most exciting work published in the various research areas of the journal.

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Article
Combining Ability of Drought-Tolerant Bread Wheat Genotypes for Agronomic and Physiological Traits
Agronomy 2022, 12(4), 862; https://doi.org/10.3390/agronomy12040862 - 31 Mar 2022
Abstract
A combining-ability analysis is key to select desirable parents and progenies with enhanced response to selection under water-limited environments. The objective of this study was to determine combining ability for agronomic and physiological traits among distantly related drought-tolerant bread wheat (Triticum aestivum [...] Read more.
A combining-ability analysis is key to select desirable parents and progenies with enhanced response to selection under water-limited environments. The objective of this study was to determine combining ability for agronomic and physiological traits among distantly related drought-tolerant bread wheat (Triticum aestivum L.) genotypes under well-watered (WW) and terminal-drought (TD) conditions to determine their genetic merit for breeding. Ten heat- and drought-tolerant wheat genotypes were crossed in a half-diallel mating design to generate 45 F1s, which were evaluated under WW and TD moisture regimes in rainout shelter (RS) and greenhouse (GH) environments. The following agronomic traits were assessed: days to 50% maturity (DTM), plant height (PH), spike length (SL), number of productive tillers (TN), spikelets number per spike (SPS), number of grains per spike (GPS), grain yield (GY) and thousand-kernel weight (TKW); and physiological traits (stomatal conductance (SC) and chlorophyll content index (CCI)). Variances attributable to general combining ability (GCA) and specific combining ability (SCA) were significant (p < 0.05) for GY, DTM, PH, SL, SPS, GPS, TKW and CCI. The parental genotypes LM72, LM81 and LM95 with positive and significant GCA effects on GY were selected to make crosses to develop high-yielding wheat genotypes for water-limited environments. Crosses LM71 × LM02, LM71 × LM81, LM82 × LM02, LM82 × LM81, LM22 × LM100, LM22 × LM81 and LM95 × LM22 were selected with positive and significant SCA effects for GY. The selected parents and crosses are valuable genetic resources for breeding and genetic advancement. Full article
(This article belongs to the Topic Advanced Breeding Technology for Plants)
Article
Nitrogen Fertilizer Modulates Plant Growth, Chlorophyll Pigments and Enzymatic Activities under Different Irrigation Regimes
Agronomy 2022, 12(4), 845; https://doi.org/10.3390/agronomy12040845 - 30 Mar 2022
Cited by 2
Abstract
Nitrogen fertilization and irrigation patterns have been extensively studied for common maize (Zea mays L.), but there is limited published work for Zhengda 619, especially in subtropical areas. Nitrogen (N) fertilizer and irrigation play an important role in crop growth and yield [...] Read more.
Nitrogen fertilization and irrigation patterns have been extensively studied for common maize (Zea mays L.), but there is limited published work for Zhengda 619, especially in subtropical areas. Nitrogen (N) fertilizer and irrigation play an important role in crop growth and yield improvements. The study aimed to investigate the yield, growth, chlorophyll content, reactive oxygen species (ROS) and enzyme activities of hybrid maize (Zhengda 619) under greenhouse conditions. Individual plants grown in plastic pots were subjected to two irrigation types—low irrigation (LW; 60% field capacity) and high irrigation water (HW; 80% field capacity)—and five N rates. Our results demonstrate that the LW irrigation increased dry matter, kernel yield, leaf chlorophyll, total root length, root diameter, root volume, and root surface area, as well as soil enzymes and plant antioxidant enzymes, while it lowered malondialdehyde (MDA), proline, and ROS. Moreover, most of the above parameters increased with increasing N application rates up to N3 under LW irrigation due to the increased N availability to the plant and soil enzymes. It is concluded that increasing N rates could improve soil enzyme activities as well as plant antioxidant enzymes and decrease ROS, ultimately resulting in a higher kernel yield under LW irrigation. Full article
(This article belongs to the Special Issue Molecular Genetic Improvement of Crop Drought Tolerance)
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Article
Arable Weeds at the Edges of Kettle Holes as Overwintering Habitat for Phytopathogenic Fungi
Agronomy 2022, 12(4), 823; https://doi.org/10.3390/agronomy12040823 - 28 Mar 2022
Abstract
Weeds in agricultural landscapes can serve as alternate hosts for phytopathogenic fungi and promote the spatial and long-term distribution of these fungi. Especially, semi-natural habitats such as kettle holes are considered as a source of fungal pathogens because they are a permanent habitat [...] Read more.
Weeds in agricultural landscapes can serve as alternate hosts for phytopathogenic fungi and promote the spatial and long-term distribution of these fungi. Especially, semi-natural habitats such as kettle holes are considered as a source of fungal pathogens because they are a permanent habitat for various weed species in arable lands. In our study, we investigated the suitability of nine different weed species and families at the edges of 18 kettle holes in two consecutive autumn/winter seasons as alternate hosts for Fusarium and Alternaria. We detected a fungal infestation with both genera on every weed species investigated with significantly higher abundances of these fungi in the second, notably wetter season. Eight weed species were described as non-host plants for Fusarium and Alternaria in agricultural landscapes in Brandenburg, Germany for the first time. In both autumn/winter periods, weeds harbored more Alternaria than Fusarium. The study revealed a high Fusarium species diversity in weeds and a community structure of up to 12 Fusarium species at the edges of kettle holes. Grasses showed the highest diversity and often the highest fungal abundances compared to herbaceous plants. Therefore, these habitats in arable lands can act as ecosystem disservice and promote the spread of fungal diseases in the surrounding crop fields. Full article
(This article belongs to the Section Weed Science and Weed Management)
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Article
Oligosaccharins Alleviate Heat Stress in Greenhouse-Grown Tomatoes during the Spring-Summer Season in a Semi-Arid Climate
Agronomy 2022, 12(4), 802; https://doi.org/10.3390/agronomy12040802 - 26 Mar 2022
Abstract
The use of plant biostimulants is a promising tool to stimulate crop growth and yield, as well as to promote plant defense mechanisms under abiotic stresses. The aim of the present work was to investigate the effect of oligosaccharides and their mode of [...] Read more.
The use of plant biostimulants is a promising tool to stimulate crop growth and yield, as well as to promote plant defense mechanisms under abiotic stresses. The aim of the present work was to investigate the effect of oligosaccharides and their mode of application (to roots, leaves, or both) on the yield and fruit composition of tomatoes grown under greenhouse conditions. Two set-point temperatures for ventilation were established, resulting in two high-temperature levels, one higher than the other. Oligosaccharins stimulated photosynthesis and improved fruit production at both temperatures, but increased yields were more evident under lower temperature-stress. Treatments that included the application of oligosaccharins to the roots decreased the concentrations of sugars, lutein, lycopene, and most phenolic compounds in the fruit. However, when oligosaccharins were applied via the leaves, the concentration of most of the metabolites of nutritional interest in the fruit did not change. The different effects of oligosaccharins on the concentration of the different compounds may be due to a dilution effect due to increased fruit yield, and/or to the possible role of the biostimulants in reducing the stress situation in tomato plants. The results show that the application of biostimulants such as oligosaccharins can improve tomato yield under stress conditions, with the advantage that they are natural products with no negative effect on the environment. Full article
(This article belongs to the Special Issue The Role of Plant Biostimulants in Stressful Agriculture)
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Article
Simulation and Experiment of the Spiral Digging End-Effector for Hole Digging in Plug Tray Seedling Substrate
Agronomy 2022, 12(4), 779; https://doi.org/10.3390/agronomy12040779 - 24 Mar 2022
Abstract
Usually the planters used in agricultural machinery face two problems: The planters have to spread the soil twice using the tray seed planter, and it is difficult for them to dig the holes before planting. This study has designed a spiral digging end-effector [...] Read more.
Usually the planters used in agricultural machinery face two problems: The planters have to spread the soil twice using the tray seed planter, and it is difficult for them to dig the holes before planting. This study has designed a spiral digging end-effector to dig holes in parallel effectively and quickly so that the seeds can be planted in the holes easily. A spiral digging end-effector was designed with five spiral bits, a synchronous belt, a cylinder, a gear motor, and a connecting plate based on the tray size and the pumpkin seed characteristics. Before the optimization of the end-effector’s parameters, the substrate discrete element model parameters were calibrated using the method of “material funneling” applied for the EDEM discrete element model simulation. The contact parameters and model parameters (substrate–substrate static friction coefficient, substrate–substrate rolling friction coefficient, and surface energy) that have significant impacts on the substrate AOR (angle of repose) were selected by applying the Plackett–Burman Design and the path of steepest ascent method, and their respective optimal value range were determined. The optimal parameter values were obtained through the Central Composite Design response surface analysis test, and the parameters of the spiral digging end-effector were optimized combining the substrate particle simulation. The verification test results indicate that the substrate discrete element model parameters were accurate and reliable if the substrate static friction coefficient was 0.427; the substrate rolling friction coefficient was 0.039, and the surface energy was 0.228. When the cone angle is 30°, the spiral angle is 80°, and the rotational speed is 240 r/min, the section width at the hole depth of 13 mm is 23.1 mm, and the particle overflow proportion is about 2.05%. Compared with the protrusions penetrating end-effector, soil porosity is increased, and soil aeration is improved. Therefore, the spiral digging end-effector can effectively and quickly dig holes in the seedling substrate and can sow pumpkin seeds, which provides a research basis for the design and improvement of automatic pumpkin seed sowing equipment. Full article
(This article belongs to the Section Agricultural Biosystem and Biological Engineering)
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Article
Investigation of the Secondary Succession of Abandoned Areas from Different Cultivation in the Pannonian Biogeographic Region
Agronomy 2022, 12(4), 773; https://doi.org/10.3390/agronomy12040773 - 23 Mar 2022
Abstract
Areas abandoned for various reasons are widespread on Earth, with a significant proportion in some regions of Europe. Our knowledge of vegetation dynamics in abandoned lands is incomplete, in part because research comparing types abandoned from different cultivars is limited. This paper compared [...] Read more.
Areas abandoned for various reasons are widespread on Earth, with a significant proportion in some regions of Europe. Our knowledge of vegetation dynamics in abandoned lands is incomplete, in part because research comparing types abandoned from different cultivars is limited. This paper compared the textural and structural changes of previously extensively treated vineyards, arables, and grasslands over a 30-year timescale in secondary succession studies. Based on the botanical surveys, it can be said that the total species number and diversity of abandoned vineyards and arable lands did not increase linearly in the four age groups studied. The way of secondary succession of former vineyards and arable lands showed many similarities. In these types, rapid regeneration of natural vegetation can be observed, the rate of which can only be reduced by the abundance of a few strong competitor species. However, the abandonment of extensively grazed and mowed grasslands has reduced species numbers and diversity, which may reduce the resilience of such grasslands to environmental factors. In abandoned lands, the mosaic landscape and previous extensive small-plot farming appear to have a positive effect on the rate of secondary succession and regeneration, as the species-rich vegetation patches provide a suitable propagule source for regeneration. Full article
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Article
Response of the Five Highbush Blueberry Cultivars to In Vitro Induced Drought Stress by Polyethylene Glycol
Agronomy 2022, 12(3), 732; https://doi.org/10.3390/agronomy12030732 - 17 Mar 2022
Cited by 2
Abstract
Stress caused by drought is an important factor that affects the growth and development of highbush blueberry plants. In vitro screening for drought stress tolerance is of major importance in identifying cultivars that have optimal stress tolerance and productivity. The aim of this [...] Read more.
Stress caused by drought is an important factor that affects the growth and development of highbush blueberry plants. In vitro screening for drought stress tolerance is of major importance in identifying cultivars that have optimal stress tolerance and productivity. The aim of this study was to evaluate the responses of five in vitro-grown highbush blueberry cultivars (Bluecrop, Brigitta Blue, Duke, Goldtraube and Hortblue Petite) under drought stress. Five concentrations of polyethylene glycol (PEG 6000), 0 g/L, 10 g/L, 20 g/L, 30 g/L, 40 g/L, 50 g/L, were applied to induce drought stress in the culture media. Significant differences were found in shoot length and number, proliferation rate, fresh weight, dry weight, water content, chlorophyll, and carotenoid content. Drought stress had a negative impact on shoots length, chlorophyll, and carotenoid content for all highbush blueberry varieties. The conclusion of the study highlights that Goldtraube had the highest drought tolerance efficiency, followed by Bluecrop, Hortblue Petite, Duke, and Brigitta Blue. Full article
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Article
Nutrient Contents and Productivity of Triticum aestivum Plants Grown in Clay Loam Soil Depending on Humic Substances and Varieties and Their Interactions
Agronomy 2022, 12(3), 705; https://doi.org/10.3390/agronomy12030705 - 14 Mar 2022
Abstract
Due to an extreme increase in population growth, Egypt suffers from a widening gap in the quantity of imported wheat compared with production and local consumption. Two field trials were conducted during the 2018/2019 and 2019/2020 seasons with three levels of humic substances [...] Read more.
Due to an extreme increase in population growth, Egypt suffers from a widening gap in the quantity of imported wheat compared with production and local consumption. Two field trials were conducted during the 2018/2019 and 2019/2020 seasons with three levels of humic substances (HSs) as a foliar spray (1.0, 2.0 and 4.0 g L−1; HS1, HS2 and HS3) and three levels (5.04, 7.56 and 10.08 kg ha−1; HS4, HS5 and HS6) as a soil application. These were applied three times (30, 45 and 60 days after sowing) in comparison with the control (HS0) to evaluate the performance of three wheat varieties (Seds1 (V1), Misr2 (V2) and Giza168 (V3)) grown in clay loam soil. The experiment was set up according to the split-plot structure in a randomized complete block design; however, the varieties were set as the main plot and treatments were a sub-main plot. Generally, the data indicated that the soil application treatments recorded maximum values for most growth and yield attributes, except for spike length and grain weight per spike, SPAD reading and total grain yield in the first season, and leaf area and biological yield in the second season. HS1, HS2, HS5, and HS6 were the superior treatments for most of the nutrient contents studied. Regarding the influence of variety, the results showed that V3 recorded maximum values for LA, SpL, TGW, TGY and leaf Zn and Cu contents in both seasons; PH, GWS and leaf N content in the first season; and SPAD reading, BY and leaf K, Fe and Mn contents in the second season. V1 was the superior variety for GWS, BY, leaf K and Mn contents in the 2018/2019 season and PH, GNS in the second season, followed by V2, which had the greatest values for leaf P contents in both seasons, and SPAD reading, GNS and leaf Fe content in the 2018/2019 season and GWS and leaf N content in the second season. Full article
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Article
Yielding and Bioaccumulation of Zinc by Cocksfoot under Conditions of Different Doses of This Metal and Organic Fertilization
Agronomy 2022, 12(3), 686; https://doi.org/10.3390/agronomy12030686 - 11 Mar 2022
Abstract
Zinc is essential for the growth and development of plants, but in excessive amounts in the soil it can be toxic for them. Its mobility depends in part on the organic matter content of the soil. The aim of the study was to [...] Read more.
Zinc is essential for the growth and development of plants, but in excessive amounts in the soil it can be toxic for them. Its mobility depends in part on the organic matter content of the soil. The aim of the study was to investigate the effect of application of increasing amounts of zinc (200, 400 and 600 mg Zn·kg−1 of soil) together with various forms of organic fertilizer (cattle manure, chicken manure and spent mushroom substrate) on the yield of cocksfoot and the content and uptake of this metal, and to determine its bioaccumulation factor and tolerance indices. A minor effect of zinc on cocksfoot, expressed as a decrease in yield, was observed following the application of 400 mg Zn·kg−1 of soil. Increasing application to 600 mg Zn·kg−1 caused a significant decrease in yield. Application of 400 and 600 mg Zn·kg−1 of soil significantly reduced the value of the Zn/Org tolerance index. Increasing levels of zinc application increased its content and uptake by cocksfoot and reduced the bioaccumulation factor in the plants. All of the organic materials applied increased the yield of cocksfoot and its uptake of zinc. Spent mushroom substrate increased the Zn/Org tolerance index, while cattle manure and chicken manure increased the Org/Zn tolerance index, which confirms their protective action against high zinc content in the soil. Full article
(This article belongs to the Special Issue Heavy Metal Pollution and Its Effects on Agriculture—2nd Edition)
Article
Strong Fitness Costs of Fall Armyworm Resistance to Dual-Gene Bt Maize Are Magnified on Less-Suitable Host-Crop Cultivars
Agronomy 2022, 12(3), 682; https://doi.org/10.3390/agronomy12030682 - 11 Mar 2022
Abstract
We examined the fitness costs of resistance to transgenic Cry1A.105+Cry2Ab2 Bacillus thuringiensis (Bt) maize in the fall armyworm, Spodoptera frugiperda, a globally invasive pest species. Using Bt-resistant and -susceptible populations of similar genetic backgrounds, we compared insect life-history traits and population growth [...] Read more.
We examined the fitness costs of resistance to transgenic Cry1A.105+Cry2Ab2 Bacillus thuringiensis (Bt) maize in the fall armyworm, Spodoptera frugiperda, a globally invasive pest species. Using Bt-resistant and -susceptible populations of similar genetic backgrounds, we compared insect life-history traits and population growth rates on the foliage of Bt or non-Bt cultivars of maize, soybean, and cotton. We found that (i) the resistance alleles led to a major reduction in insect fitness on seven of the eight cultivars of three host crops studied; (ii) developmental time was the life-history trait that accounted for most of the fitness variation of the armyworm, and (iii) the magnitude of fitness reduction of the resistant individuals was stronger on cotton foliage, on which the insects did not pass the resistance alleles to subsequent generations. These results show that fall armyworm resistance to Cry1A.105+Cry2Ab2-expressing Bt maize comes with strong fitness costs, which were magnified on less-suitable host plants for the insects. Thus, natural selection may help maintain or even restore the insect susceptibility to the pesticidal proteins and perhaps is a significant factor helping manage fall armyworm resistance to Cry1A.105+Cry2Ab2 Bt maize. These findings indicate that fitness costs of insect resistance to multi-toxin Bt crops can be strong, and host plants or conditions that magnify the fitness differential of susceptible insects could be specifically deployed with refuge to improve resistance management to Bt crops. Full article
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Article
Changes of Soil Water and Heat Transport and Yield of Tomato (Solanum lycopersicum) in Greenhouses with Micro-Sprinkler Irrigation under Plastic Film
Agronomy 2022, 12(3), 664; https://doi.org/10.3390/agronomy12030664 - 09 Mar 2022
Abstract
This study aimed to expound the changes in soil water flow, heat transport, and tomato production under micro-sprinkler irrigation and plastic film (MSPF) conditions. The effects of different irrigation amounts (I1:0.7 Epan; I2:1.0 Epan; and I3:1.2 Epan (Epan is the cumulative evaporation from [...] Read more.
This study aimed to expound the changes in soil water flow, heat transport, and tomato production under micro-sprinkler irrigation and plastic film (MSPF) conditions. The effects of different irrigation amounts (I1:0.7 Epan; I2:1.0 Epan; and I3:1.2 Epan (Epan is the cumulative evaporation from a 20 cm diameter standard pan, mm)) on soil water, soil temperature, and tomato yield were studied. A completely randomized trial design was used; meanwhile, the drip irrigation under plastic film (CK1) and micro-sprinkler irrigation without mulch film (CK2) were used as controls. The results showed that the shape of soil moisture was banded under MSPF; the soil wetting range was larger than that of CK1 and CK2 in the profile of MSPF. The change range of 5 cm soil temperature of MSPF 1–5 days after irrigation was 4.05 °C. The change range of 5 cm soil temperature of MSPF was lower than that of CK1 from 1 to 5 days after irrigation. During the growth period of spring and autumn tomato, the average soil moisture content of 0–40 cm with CK1 was 1.97% and 3.83% (spring and autumn, respectively) higher than that of MSPF, and the average soil temperature of 5–25 cm was 2.36% and 1.66% (spring and autumn, respectively) lower than that of MSPF. Compared with CK2, the average soil moisture content of 0–40 cm under MSPF increased by 8.30% and 3.83% (spring and autumn, respectively), and the average soil temperature of 5–25 cm under MSPF increased by 5.85% and 1.68% (spring and autumn, respectively). The spring and autumn tomato yield of MSPF was significantly higher than that of CK1 by 19.39% and 4.54%, respectively. The spring and autumn tomato yield of MSPF were higher than that of CK2 by about 20.46% and 49.22%, respectively. With an increase in the irrigation amount of MSPF, the soil moisture and yield of spring and autumn tomato increase; the soil temperature and water use efficiency of spring and autumn tomato decrease. Considered comprehensively, the MSPF can be used as one of the methods of greenhouse tomato micro-irrigation, and 1.0 Epan is recommended for irrigation parameters in northwest China facility agriculture. Full article
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Article
Study of Raspberry Genotypes by Biologically Valuable Traits under Conditions of Central Russia
Agronomy 2022, 12(3), 630; https://doi.org/10.3390/agronomy12030630 - 04 Mar 2022
Abstract
In Central Russia, the area of possible effective use of raspberry varieties and their productivity and production values are determined by the plant tolerance to a complex of adverse environmental factors. In this regard, the introduction of new varieties and hybrids should be [...] Read more.
In Central Russia, the area of possible effective use of raspberry varieties and their productivity and production values are determined by the plant tolerance to a complex of adverse environmental factors. In this regard, the introduction of new varieties and hybrids should be accompanied by analyzing not only their productivity, but also their winter hardiness and drought resistance. In this paper, we analyzed the winter hardiness of raspberry varieties and indicators of their water regime in the field. By modeling the damaging factors of the winter period, we revealed the stability potential of raspberry varieties for the main components of winter hardiness. The drought resistance of raspberry varieties and forms were assessed in laboratory conditions. According to the results of the complex studies, we identified the frost-resistant accessions: 9-17, 9-35, and 9-70 (freezing ranged from 1.1 to 2.0 points) as well as the medium-hardy varieties Glen Ample, Glen Magna, and Laszka (freezing score ranged from 2.1 to 3.0 points). The indicators of the water regime in the field showed that during the growing season, the studied raspberry varieties were characterized by optimal hydration and water deficiency of the leaf apparatus. This positively affected the yield formation. When modeling drought, raspberry genotypes showed a medium level of drought resistance. At the same time, the Glen Ample, Glen Magna, Glen Lyon, and Laszka varieties as well as the accession 9-70 showed high yields (above 15 t/ha). As a result, promising raspberry genotypes Glen Ample, Glen Magna, Laszka, and 9-70 were selected for further breeding and production cultivation in Central Russia. Full article
(This article belongs to the Special Issue Innovative Technologies in Crop Production and Animal Husbandry)
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Article
Flower Visitation Time and Number of Visitor Species Are Reduced by the Use of Agrochemicals in Coffee Home Gardens
Agronomy 2022, 12(2), 509; https://doi.org/10.3390/agronomy12020509 - 17 Feb 2022
Cited by 2
Abstract
Pollination services, from both wild and managed populations of insect pollinators, have degraded as a result of agricultural intensification. Whilst 75% of economically important crops depend on insect pollinators for cultivation, 40% of insect pollinator species are threatened with extinction. Pollination services must [...] Read more.
Pollination services, from both wild and managed populations of insect pollinators, have degraded as a result of agricultural intensification. Whilst 75% of economically important crops depend on insect pollinators for cultivation, 40% of insect pollinator species are threatened with extinction. Pollination services must be preserved if there is to be enough food for a global population whose demand is expected to double, if not triple, by 2050. Pollinator diversity and pollinator efficiency have been found to increase as a result of wildlife-friendly farming practices (i.e., natural chemicals and fertilizers and agroforestry). We evaluated the presence of insect pollinators in 42 coffee home gardens in West Java, Indonesia. Via generalized linear mixed models, we found that number of visitor species (β = 0.418 ± SE 0.194, p = 0.031) and visitation time (β = 0.845 ± SE 0.308, p = 0.006) decreased as farms were more intensely managed, (i.e., used chemical pesticides), compared to fields using organic practices. As knowledge of pollination services is widespread amongst smallholder farmers in Indonesia and beyond due to the long-held tradition of beekeeping, these results will add to their existing knowledge and empower farmers to enhance resources for pollinator species through agroforestry and natural pest management. Although we found significant differences in pollination services provided in intensely managed and wildlife-friendly farms, chemical use can affect farms far beyond a particular area of production. Therefore, pollinator conservation must be applied at a landscape level and involve all stakeholders, including farmers, when making effective policies. Full article
(This article belongs to the Special Issue Ecological Research on Crop Pollinators)
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Article
Influence of Commercial Seaweed Extract and Microbial Biostimulant on Growth, Yield, Phytochemical Content, and Nutritional Quality of Five Abelmoschus esculentus Genotypes
Agronomy 2022, 12(2), 428; https://doi.org/10.3390/agronomy12020428 - 09 Feb 2022
Abstract
Biostimulant application during the cultivation of underutilized crops is an environmental-friendly approach for their production and utilization to promote food security and human health. This study investigated the effect of two commercial biostimulants (a seaweed-based extract, Kelpak® (1:100, 1:40, and 1:20, dilutions), [...] Read more.
Biostimulant application during the cultivation of underutilized crops is an environmental-friendly approach for their production and utilization to promote food security and human health. This study investigated the effect of two commercial biostimulants (a seaweed-based extract, Kelpak® (1:100, 1:40, and 1:20, dilutions), and plant growth promoting rhizobacteria, PGPR (1:5, 1:10, and 1:15, dilutions)) on the growth, yield, phytochemical content, and nutritional quality of five selected Abelmoschus esculentus genotypes. Biostimulant application significantly influenced vegetative growth and yield in a dose-dependent manner. Plant height, chlorophyll content, stem diameter, number of pods, and total pod fresh and dry weights increased with a decrease in dilution of the biostimulants. The application of PGPR (1:5) significantly promoted both the vegetative growth (plant height, chlorophyll content, and stem diameter) and yield (number of pods, total fresh weight, and total dry weight) when compared to the control (untreated plants) and other biostimulant dilutions. Genotype and biostimulant application had an interactive effect on all the phytochemical (total phenolics, flavonoids, and condensed tannins) and nutritional (β-carotene, vitamin C, calcium, iron, potassium, magnesium, sodium, and zinc) qualities evaluated. This study demonstrated the differential effect of biostimulant application on A. esculentus genotypes. These biostimulants can be used to enhance growth, yield, biochemical, and nutritional contents of underutilised crops such as A. esculentus, depending on the crop genotype, in order to improve crop productivity and combat food insecurity especially in food insecure communities. Full article
(This article belongs to the Special Issue A New Decade of Horticultural and Medicinal Plants Cultivation)
Article
Sustainable Growing Media Blends with Woody Green Composts: Optimizing the N Release with Organic Fertilizers and Interaction with Microbial Biomass
Agronomy 2022, 12(2), 422; https://doi.org/10.3390/agronomy12020422 - 08 Feb 2022
Abstract
The aim of the current study was to create a high quality growing medium blend that replaces 70 vol% peat with 40 vol% woody green compost and 30 vol% bark compost and organic fertilizers (i.e., blood meal and chitin), all locally sourced. A [...] Read more.
The aim of the current study was to create a high quality growing medium blend that replaces 70 vol% peat with 40 vol% woody green compost and 30 vol% bark compost and organic fertilizers (i.e., blood meal and chitin), all locally sourced. A range of “woody composts”, i.e., green composts based on feedstock selection with mainly woody material from tree prunings, were produced for this purpose at green compost facilities. First, the woody composts were characterized chemically and biologically, including their microbial biomass and net N release. In comparison with regular green composts or vegetable, fruit and garden (VFG) waste composts, woody composts are more suitable for use in growing media due to their lower pH, EC and inorganic C content; however, the woody compost had a low N mineralization rate. Three types of composts supported a higher microbial biomass than wood fiber or bark compost. The additional mineral N release after 100 days for compost mixed with blood meal was tested for different VFG and green composts. A significantly higher additional net N release was measured for composts with higher initial mineral N concentrations (317 mg Nmin/L) as well as VFG composts (417 mg Nmin/L) than for green composts with a lower initial mineral N concentration (148 mg Nmin/L). In a last step, woody compost, bark compost, wood fiber, coir and peat were mixed in different ratios, resulting in six blends ranging from 100% peat-free to 100% peat. Two batches of woody compost were compared, and the blends were mixed with blood meal or chitin. A strong effect of both the organic fertilizer and the blend composition on the mineral N release was observed, with a clear link between the microbial biomass and the net N release. There was a significant negative correlation between the net change in microbial biomass and the net N release (R = −0.85), which implies that a larger increase in microbial biomass during incubation with the organic fertilizer resulted in less N mineralization. The blends containing woody compost scored better for nitrification activity, as the NH4-N concentrations were lower in these than for the blends without woody compost. For the peat blends, no effect on the microbial biomass was observed after addition of organic fertilizers; mineral N did increase, however. Woody composts have the potential to be used in high vol% in growing media blends, but the blends still need further optimization when supplemented with organic fertilizers. Full article
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Article
Beneficial Effects of Silicon Fertilizer on Growth and Physiological Responses in Oil Palm
Agronomy 2022, 12(2), 413; https://doi.org/10.3390/agronomy12020413 - 07 Feb 2022
Cited by 2
Abstract
Vigorous and well-established nursery seedlings are an important component of sustainable oil palm production. We postulated that Si fertilization at the seedling stage could help to achieve improved performance of oil palm seedlings leading to healthy and vigorous nursery establishment. In this study, [...] Read more.
Vigorous and well-established nursery seedlings are an important component of sustainable oil palm production. We postulated that Si fertilization at the seedling stage could help to achieve improved performance of oil palm seedlings leading to healthy and vigorous nursery establishment. In this study, we evaluated the growth and physiological responses of oil palm Tenera hybrid seedlings under three Si fertilization treatments and a control including (i) 0 g Ca2SiO4 (T0), (ii) 0.5 g Ca2SiO4 (T1), (iii) 3.5 g Ca2SiO4 (T2), and (iv) 7.0 g Ca2SiO4 (T3) per plant per month. Ca2SiO4 was used as the Si fertilizer source and was applied for four consecutive months. Nondestructive data including stem diameter, plant height, leaf length, photosynthetic rate, leaf angle, and leaf thickness and destructive data including leaf, stem, and root fresh weight and dry weight, as well as chlorophyll a, Si, and nitrogen contents, were recorded before treatment (0 DAT), as well as 60 (60 DAT) and 120 days after treatment (120 DAT). Results indicated that Si fertilization enhanced Si accumulation in oil palm seedlings, and maximum accumulation was observed in the aerial parts especially the leaves with the highest accumulation of 0.89 % dry weight at T3. Higher Si accumulation stimulated the growth of seedlings; a total fresh weight of 834.28 g and a total dry weight of 194.34 g were observed at T3. Chlorophyll a content (0.83 gm−2) and net photosynthetic rate (4.98 µM CO2·m−2·s−1) were also observed at T3. Leaf morphology was not significantly influenced under Si fertilization, whereas the nitrogen content of seedlings was significantly increased. Correlation analysis revealed a highly significant and positive association among Si accumulation, chlorophyll a content, photosynthetic rate, total fresh weight, total dry weight, and nitrogen content of seedlings, indicating that Si fertilization enhanced the performance of these attributes. On the basis of the research evidence, it was concluded that Si fertilization should be considered for improved nutrient management for oil palm seedling and nursery production. Full article
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Article
Control of Postharvest Gray Mold at Strawberry Fruits Caused by Botrytis cinerea and Improving Fruit Storability through Origanum onites L. and Ziziphora clinopodioides L. Volatile Essential Oils
Agronomy 2022, 12(2), 389; https://doi.org/10.3390/agronomy12020389 - 04 Feb 2022
Abstract
The present research was undertaken to study the antifungal activities of Origanum onites L. and Ziziphora clinopodioides L. essential oils against three different isolates (M1-5, M2-1 and M3-5) of Botrytis cinerea (in vitro tests) and to investigate the vapor contact impacts on fungus [...] Read more.
The present research was undertaken to study the antifungal activities of Origanum onites L. and Ziziphora clinopodioides L. essential oils against three different isolates (M1-5, M2-1 and M3-5) of Botrytis cinerea (in vitro tests) and to investigate the vapor contact impacts on fungus and strawberry fruit quality (in vivo tests). Antifungal activities of these oils were tested by following the poisoned food technique at four different concentrations (0.25, 0.50, 1.00 and 2.00 mL/L) against B. cinerea. In vitro studies suggested that the 0.50 mL/L and 1.00 mL/L doses of O. onites and 1.00 mL/L and 2.00 mL/L doses of Z. clinopodioides provide high mycelial growth inhibition, 85.29–94.12% and 39.12–94.12%, respectively, by direct addition to food. Thus, these doses were tested in in vivo conditions, as a vapor contact treatment against two isolates (M1-5 and M3-5) of B. cinerea inoculated on strawberry cv. Camarosa fruits. Results showed that both O. onites and Z. clinopodioides essential oils have a moderate to high impact on the prevention of gray mold. The oils were also found to have a slight to moderate impact on weight loss and the loss of soluble solids concentration. Overall, the results demonstrated that the tested oils are a potential biodegradable alternative to fungicides. Full article
(This article belongs to the Special Issue Innovative Technologies in Crop Production and Animal Husbandry)
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Article
Spatial Variability of Soil Properties and Its Effect on Maize Yields within Field—A Case Study in Hungary
Agronomy 2022, 12(2), 395; https://doi.org/10.3390/agronomy12020395 - 04 Feb 2022
Abstract
To better understand the potential of soils, understanding how soil properties vary over time and in-field is essential to optimize the cultivation and site-specific technologies in crop production. This article aimed at determining the within-field mapping of soil chemical and physical properties, vegetation [...] Read more.
To better understand the potential of soils, understanding how soil properties vary over time and in-field is essential to optimize the cultivation and site-specific technologies in crop production. This article aimed at determining the within-field mapping of soil chemical and physical properties, vegetation index, and yield of maize in 2002, 2006, 2010, 2013, and 2017, respectively. The objectives of this five-year field study were: (i) to assess the spatial and temporal variability of attributes related to the maize yield; and (ii) to analyse the temporal stability of management zones. The experiment was carried out in a 15.3 ha research field in Hungary. The soil measurements included sand, silt, clay content (%), pH, phosphorous (P2O5), potassium (K2O), and zinc (Zn) in the topsoil (30 cm). The apparent soil electrical conductivity was measured in two layers (0–30 cm and 30–90 cm, mS/m) in 2010, in 2013, and in 2017. The soil properties and maize yields were evaluated in 62 management zones, covering the whole research area. The properties were characterized as the spatial-temporal variability of these parameters and crop yields. Classic statistics and geostatistics were used to analyze the results. The maize yields were significantly positively correlated (r = 0.62–0.73) with the apparent electrical conductivity (Veris_N3, Veris_N4) in 2013 and 2017, and with clay content (r = 0.56–0.81) in 2002, 2013, and 2017. Full article
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Article
Preference of Pollinators over Various Forage Mixtures and Microelement Treatments
Agronomy 2022, 12(2), 370; https://doi.org/10.3390/agronomy12020370 - 01 Feb 2022
Abstract
Low plant species richness and abundance, as well as contamination, can lead to a lack of nutrients in the diets of pollinators. This can cause increased oxidative stress, low resistance to disease and reduced detoxification ability. We proposed three forage mixtures with different [...] Read more.
Low plant species richness and abundance, as well as contamination, can lead to a lack of nutrients in the diets of pollinators. This can cause increased oxidative stress, low resistance to disease and reduced detoxification ability. We proposed three forage mixtures with different botanical compositions, all of which should provide continuous forage for a wide range of pollinators. The monitored mixtures were treated by foliar application with selenium and zinc. Both elements should increase the quality of pollen and nectar. The effect of meadow mixtures and microelements on pollinator abundance, richness, and preference was evaluated using data obtained via the line transect method. Furthermore, the amount of selenium and zinc in the flowers was determined. It was found that the microelement treatment did not have any effect on the abundance and richness of the main pollinator taxa, which were affected only by a botanical composition of meadow mixtures. However, a preference for zinc-treated forage was observed in Apis mellifera, and a preference for selenium-treated forage was observed in Bombus spp. These two eusocial taxa appear to respond to an increased amount of microelements in the treated meadow mixtures. On the contrary, Lepidoptera was tied to untreated forage, where they were probably pushed by social bee species due to the competition. Full article
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Article
The Nitrogen Fixation and Yielding of Pea in Different Soil Tillage Systems
Agronomy 2022, 12(2), 352; https://doi.org/10.3390/agronomy12020352 - 30 Jan 2022
Cited by 1
Abstract
The field experiment was carried out in 2013 and 2014 as part of a long-term experiment to test the influence of different soil tillage systems (conventional, reduced, direct sowing) on (a) the yield of summer pea (Pisum sativum L.) and (b) the [...] Read more.
The field experiment was carried out in 2013 and 2014 as part of a long-term experiment to test the influence of different soil tillage systems (conventional, reduced, direct sowing) on (a) the yield of summer pea (Pisum sativum L.) and (b) the amount of biologically reduced atmospheric nitrogen (N), which was determined using the 15N dilution method (ID15N). Spring barley was used as a reference plant. Climatic conditions did not have a significant influence on the yield of pea seeds (mean value 4.56 t ha−1), post-harvest residues (3.76 t ha−1) and total biomass (8.33 t ha−1). Soil tillage system was found to have a significant impact on all components of the pea yield in years of experiment, with the highest average seed yield values observed with the conventional system (5.19 t ha−1) and significantly lower values observed with reduced tillage (4.34 t ha−1) and direct sowing (4.17 t ha−1). The content of total N was greatest in the pea biomass that was harvested in the conventional system (202 kg ha−1) and lowest with direct sowing (155 kg ha−1). Nitrogen accumulated in the pea seeds from three sources: atmosphere (mean value 35.2%), fertilizers (6.8%) and soil (57.9%), equating to 48.6, 9.9, and 85.4 kg ha−1, respectively. Soil tillage system was found to have a significant impact on the amount of N that was fixed from the atmosphere by the peas: 17.7% in conventional tillage, 37.9 in reduced system and 50.2% in direct sowing, which equates to a harvested seed yield of 28.9, 52.0 and 64.4 kg ha−1, respectively. In the post-harvest residues, the amount of N fixed from the atmosphere by the pea crop was also modified by the soil tillage system in range: 20.2% in conventional tillage and 32.6% in direct sowing (which equates to 7.4 and 8.5 kg N ha−1, respectively), but the difference was not significant. Full article
(This article belongs to the Special Issue Sustainable Tillage and Sowing Technologies)
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Article
Long-Term Decline in Harvester Termites in Madagascar following Multiple Barrier Treatments with Fipronil against Migratory Locust
Agronomy 2022, 12(2), 310; https://doi.org/10.3390/agronomy12020310 - 25 Jan 2022
Cited by 1
Abstract
Mounds of the harvester termite Coarctotermes clepsydra (Sjöstedt) (Isoptera: Termitidae, Nasutitermitinae) are a typical feature of savanna woodlands in Madagascar. With densities of up to 300 termitaria ha−1, this species provides key ecosystem services and is an important food source for [...] Read more.
Mounds of the harvester termite Coarctotermes clepsydra (Sjöstedt) (Isoptera: Termitidae, Nasutitermitinae) are a typical feature of savanna woodlands in Madagascar. With densities of up to 300 termitaria ha−1, this species provides key ecosystem services and is an important food source for wildlife. Following large-scale aerial blanket and barrier treatments with the insecticide fipronil to control an outbreak of migratory locust in the late 1990s, evidence emerged that C. clepsydra and related food webs were adversely affected. However, neither the scale nor the duration of the effects were known. The present ex post study investigated the recovery of C. clepsydra populations subjected to multiple barrier treatments against hopper bands in 1998 and 1999 at estimated cumulative dose rates of 1.7–3.4 g fipronil ha−1. At the time of the survey in 2007, both the density of occupied termitaria (30.2 versus 106.8 mounds ha−1) and mound occupancy (24.3% versus 70.0%) were significantly lower in repeatedly sprayed so-called hotspots than in unsprayed areas. The overall adverse effect (mortality in sprayed areas corrected for mortality in unsprayed areas) was E = 64.4%. The main outcome of this study is a strikingly low resilience of C. clepsydra populations, which did not recover in hotspots within eight years, with likely repercussions on food webs. This study shows that the environmental benefits of barrier treatments are forfeited if the same areas are treated repeatedly during the same campaign. Recommendations are given for the mitigation of these risks. Full article
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Article
Optimal Fertilization Level for Yield, Biological and Quality Traits of Soybean under Drip Irrigation System in the Arid Region of Northwest China
Agronomy 2022, 12(2), 291; https://doi.org/10.3390/agronomy12020291 - 24 Jan 2022
Cited by 1
Abstract
Soybean is one of the most important oilseed crops worldwide. Fertilization severely restricts the yield potential of soybean in the arid regions of Northwest China. A two-year field experiment was conducted to investigate the effects of fertilization on soybean yield in arid areas [...] Read more.
Soybean is one of the most important oilseed crops worldwide. Fertilization severely restricts the yield potential of soybean in the arid regions of Northwest China. A two-year field experiment was conducted to investigate the effects of fertilization on soybean yield in arid areas under a drip irrigation system. The treatment consisted of 14 fertilizer combinations comprising of four rates each of nitrogen (N) (0, 225, 450, and 675 kg ha−1), phosphorus (P) (0, 135, 270, and 405 kg ha−1), and potassium (K) (0, 75, 150, and 225 kg ha−1). The results revealed that grain yield was more sensitive to N fertilizer than to P and K fertilizers. The P and K fertilizers influenced harvest index and biomass, respectively. The optimized combination of fertilizers for high yield, as well as biological and quality traits was obtained by quadratic polynomial regression analysis. The theoretical grain yields based on the performed statistical calculations and plant biomass were greater than 7.21 tons ha−1 and 16.38 tons ha−1 with 300,000 plants ha−1 and were obtained under a fertilization combination of 411.62–418.39 kg ha−1 N, 153.97−251.03 kg ha−1 P2O5, and 117.77−144.73 kg ha−1 K2O. Thus, our findings will serve as a guideline for an effective fertilizer application in order to achieve a balance between grain yield and plant biomass as well as to contribute to the promotion of large-scale cultivation of soybean under drip irrigation. Full article
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Article
Soil Sustainability: Analysis of the Soil Compaction under Heavy Agricultural Machinery Traffic in Extensive Crops
Agronomy 2022, 12(2), 282; https://doi.org/10.3390/agronomy12020282 - 22 Jan 2022
Abstract
Crop establishment depends mostly on the soil preparation and sowing methods used. Our main goal was to evaluate soil compaction and its effects on wheat (Triticum aestivum L.) and soybean (Glycine max L.) yields and seedling emergence with two different tillage [...] Read more.
Crop establishment depends mostly on the soil preparation and sowing methods used. Our main goal was to evaluate soil compaction and its effects on wheat (Triticum aestivum L.) and soybean (Glycine max L.) yields and seedling emergence with two different tillage methods: no-tillage (NT) and conventional tillage (CT). The study was done in the Western Pampas Region during three cropping seasons. The soil of the study site is a Mollisol. The variables measured were: (1) cone index (CI), (2) dry bulk density (DBD), (3) seedling emergence (SE), and (4) crops yield (CY). For both crops, seedling emergence was slower in NT than in CT, but results were similar 22 days after sowing. After 3 years, the results show that in NT the DBD and CI reached values of 1653 kg m−3 and 3210 kPa, respectively (between 275 and 300 mm). While in CT the values of DBD and CI reached were 1540 kg m−3 and 2300 kPa respectively at the same depth. The highest yields were found in CT (3.31 and 4.10 tons/ha−1, for soybean and wheat, respectively) compared to NT (2.91 and 3.53 tons/ha−1). Topsoil horizon has to be tilled to improve crop yields. In spite of the high number of equipment passes in CT, both tillage systems caused subsoil compaction. Full article
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Article
Response of Winter Wheat (Triticum aestivum L.) to Fertilizers with Nitrogen-Transformation Inhibitors and Timing of Their Application under Field Conditions
Agronomy 2022, 12(1), 223; https://doi.org/10.3390/agronomy12010223 - 17 Jan 2022
Abstract
Winter wheat is a widely cultivated crop that requires high inputs of nitrogen (N) fertilization, which is often connected with N losses. The application of fertilizers with nitrification (NI) and urease inhibitors (UI) is an opportunity to eliminate the risk of N losses [...] Read more.
Winter wheat is a widely cultivated crop that requires high inputs of nitrogen (N) fertilization, which is often connected with N losses. The application of fertilizers with nitrification (NI) and urease inhibitors (UI) is an opportunity to eliminate the risk of N losses and improve N availability to plants. The aim of this study is to compare the effect of conventional nitrogen fertilizers with fertilizers containing nitrogen-transformation inhibitors as well as to evaluate the timing of their application on the wheat-grain yield and quality under the conditions of a three-year field experiment. The examined fertilizers with inhibitors were applied in a single dose or in a split application in combination with conventional fertilizers. The single application of urea with NI and/or UI resulted in a relatively average increase in the grain yield, while protein content and the Zeleny-test values were significantly increased compared to the split N application. The more significant effect of urea with NI and UI was found under the moisture-rich conditions compared to the drier conditions. A significant increase in the grain yield (by 6.3%) and in the Zeleny-test value (by 16.5%) was observed after inhibited urea application comparing to the control treatment (without inhibitors). Full article
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Article
Estimating Nutrient Uptake Requirements for Melon Based on the QUEFTS Model
Agronomy 2022, 12(1), 207; https://doi.org/10.3390/agronomy12010207 - 15 Jan 2022
Abstract
Imbalanced and excessive fertilizer application has resulted in low yields and reduced nutrient use efficiency for melon production in China. Estimating nutrient requirements is crucial for effectively developing site-specific fertilizer recommendations for increasing yield and profit while reducing negative environmental impacts. Relationships between [...] Read more.
Imbalanced and excessive fertilizer application has resulted in low yields and reduced nutrient use efficiency for melon production in China. Estimating nutrient requirements is crucial for effectively developing site-specific fertilizer recommendations for increasing yield and profit while reducing negative environmental impacts. Relationships between the yield and nutrient uptake requirements of above-ground dry matter were assessed using 1127 on-farm observations (2000–2020) from melon production regions of China. The quantitative evaluation of fertility of tropical soils (QUEFTS) model was used to estimate nutrient requirements. It predicted a linear increase in yield at balanced nutrient uptake levels until the yield reached approximately 60–80% of the potential yield. In order to produce 1000 kg of fruit, 2.9, 0.4 and 3.2 kg/ha of N, P and K (7.2:1.0:7.8), respectively, were required for above-ground parts, while the corresponding nutrient internal efficiencies were 345.3, 2612.6 and 310.0 kg per kg N, P and K, respectively, whereas 1.4, 0.2 and 1.9 kg of N, P and K were required to replace nutrients removed after harvest. The corresponding fruit absorption rates were 47.0%, 59.5% and 58.2%, respectively. Field validation experiments confirmed the consistency between observed and simulated uptake rates, indicating that this model could estimate nutrient requirements. These findings will help develop fertilizer recommendations for improving melon yield and nutrient use efficiency. Full article
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Article
Effect of Different Tillage Systems on Soil Organic Carbon and Enzymatic Activity
Agronomy 2022, 12(1), 208; https://doi.org/10.3390/agronomy12010208 - 15 Jan 2022
Cited by 2
Abstract
The aim of the study was to compare the effect of conventional, simplified, and organic farming systems on changes in the content of soil organic carbon, organic matter fractions, total nitrogen, and the enzymatic activity. The research was conducted from 2016–2018 on arable [...] Read more.
The aim of the study was to compare the effect of conventional, simplified, and organic farming systems on changes in the content of soil organic carbon, organic matter fractions, total nitrogen, and the enzymatic activity. The research was conducted from 2016–2018 on arable land in the south-eastern part of Poland. The selected soils were cultivated in conventional tillage (C_Ts), simplified tillage (S_Ts), and organic farming (O_Fs) systems. The analyses were performed in soil from the soil surface layers (up to 25 cm depth) of the experimental plots. The highest mean contents of soil organic carbon, total nitrogen, and organic matter fractions were determined in soils subjected to the simplified tillage system throughout the experimental period. During the study period, organic carbon concentration on surface soil layers under simplified tillage systems was 31 and 127% higher than the soil under conventional tillage systems and organic farming systems, respectively. Also, the total nitrogen concentration in those soils was more than 40% and 120% higher than conventional tillage systems and organic farming systems, respectively. Moreover, these soils were characterised by a progressive decline in SOC and Nt resources over the study years. There was no significant effect of the analysed tillage systems on the C:N ratio. The tillage systems induced significant differences in the activity of the analysed soil enzymes, i.e., dehydrogenase (DH) and catalase (CAT). The highest DH activity throughout the experiment was recorded in the O_Fs soils, and the mean value of this parameter was in the range of 6.01–6.11 μmol TPF·kg−1·h−1. There were no significant differences in the CAT values between the variants of the experiment. The results confirm that, regardless of other treatments, such as the use of organic fertilisers, tillage has a negative impact on the content of SOC and organic matter fractions in the O_Fs system. All simplifications in tillage reducing the interference with the soil surface layer and the use of organic fertilisers contribute to improvement of soil properties and enhancement of biological activity, which helps to maintain its productivity and fertility. Full article
(This article belongs to the Special Issue Biotechnology of Microorganisms in the Agriculture Environment)
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Article
Exercise, Urban Food Production, Preparation and Consumption: Implications, Benefits and Risks to Grow-Your-Own (GYO) Gardeners
Agronomy 2022, 12(1), 181; https://doi.org/10.3390/agronomy12010181 - 12 Jan 2022
Abstract
This study is the first to consider, and estimate, the influence of gardening routines on exposures to both health benefits and health risks. This holistic approach helped to contrast the healthy lifestyle of gardening with health risks from exposures to potentially toxic elements [...] Read more.
This study is the first to consider, and estimate, the influence of gardening routines on exposures to both health benefits and health risks. This holistic approach helped to contrast the healthy lifestyle of gardening with health risks from exposures to potentially toxic elements such as Cd and Pb in urban environments. A total of 120 participants who grew their own produce in an urban setting were recruited to the study. A detailed questionnaire was developed that included sections on gardening activity, cultivation and consumption of produce, consumption of commercially grown produce, and other lifestyle factors. Administered alongside the questionnaire was the Short Form 36 (v2) as a standardised tool for measuring physical and mental health. Fruit and vegetable consumption was found to be correlated with the amount of gardening individuals did in autumn/winter and was greater than fruit and vegetable consumption, on average, in the UK general population. Levels of physical activity were also found to be higher in our study than regional averages, whilst BMI was lower than average. This is the first study to find a relationship between gardening more regularly (in autumn/winter) and the physical component of the Short Form 36, and this relationship was elevated compared to non-gardening populations. The physical component scores from this study were also significantly higher for older participants, compared to means from a Western population. This finding supports studies suggesting that gardening may be more beneficial for the elderly generation. These benefits were assessed in the context of potential exposures estimated from the type and frequency of produce being consumed. The benefit of maintaining a healthy lifestyle is likely to outweigh the health risks of gardening on soils mildly contaminated with Cd and Pb but requires formal consideration within a risk management framework. Full article
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Article
Apple Autotetraploids—Phenotypic Characterisation and Response to Drought Stress
Agronomy 2022, 12(1), 161; https://doi.org/10.3390/agronomy12010161 - 10 Jan 2022
Cited by 1
Abstract
Polyploidization is an important source of variability for plant breeding. Polyploids are often characterised by increased resistance to biotic and abiotic stresses. Since drought and pathogen attack are the main threats to apple cultivation, obtaining new sources of resistance is an important issue [...] Read more.
Polyploidization is an important source of variability for plant breeding. Polyploids are often characterised by increased resistance to biotic and abiotic stresses. Since drought and pathogen attack are the main threats to apple cultivation, obtaining new sources of resistance is an important issue for apple breeding. The newly obtained autotetraploid clones of apple cv. ‘Redchief’ showed superior resistance to fire blight. The aim of the presented research was the in-depth phenotypic characterisation of ‘Redchief’ tetraploids and assessment of their response to drought at the physiological and genetic level. The growth of own-rooted five-year-old trees of ‘Redchief’ tetraploids was poor compared with diploids; all growth parameters—the number and length of current season shoots, the total length of current season shoots per tree and the cross-section area of the trunk—were reduced in tetraploid clones. Grafting on M9 rootstock improved the growth characteristics of ‘Redchief’ tetraploids. Compared with diploid plants, the leaves of tetraploids were thicker, with altered shape, higher chlorophyll content, and larger stomata, but the stomatal density decreased. The leaf anatomical structure of tetraploids was changed, the adaxial and abaxial epidermis and both types of mesophyll were significantly thicker than in diploids. Moreover, the pollen grains of tetraploids were larger, but their viability and germination were reduced. Under conditions of limited water supply, the reduction in growth parameters was smaller and the physiological parameters were higher in the ‘Redchief’ tetraploid clone 4x-25 than in diploid plants. The expression of APX gene was higher in tetraploids than in diploids 15 days after drought stress induction. The results suggest the enhanced drought tolerance of the studied ‘Redchief’ autotetraploid clone compared with its diploid counterpart. Full article
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Article
Effect of Up-Converting Luminescent Nanoparticles with Increased Quantum Yield Incorporated into the Fluoropolymer Matrix on Solanum lycopersicum Growth
Agronomy 2022, 12(1), 108; https://doi.org/10.3390/agronomy12010108 - 02 Jan 2022
Abstract
The influence of light conversion induced by glasses coated with up-converting luminescent nanoparticles on Solanum lycopersicum cultivation was studied. Nanoparticles of Sr0.46Ba0.50Yb0.02Er0.02F2.04 solid solution were used as the up-converting luminophore. These nanoparticles were able [...] Read more.
The influence of light conversion induced by glasses coated with up-converting luminescent nanoparticles on Solanum lycopersicum cultivation was studied. Nanoparticles of Sr0.46Ba0.50Yb0.02Er0.02F2.04 solid solution were used as the up-converting luminophore. These nanoparticles were able to transform IR radiation into visible light (λem = 660 nm with minor peaks at 545 nm and 525 nm). By applying the “variable” chlorophyll fluorescence (ΔF), it was shown that the cultivation of tomatoes under the photoconversion glasses stimulated changes in the rate of plant adaptation to ultraviolet radiation. The restoration time of values of effective quantum yield of photosystem II photochemical reactions and photochemical quenching of chlorophyll fluorescence (reflecting disappearance of imbalance between photosynthetic electron transport and the utilization of NADPH) was reduced from three weeks to three days in the case of control and photoconversion films, respectively. As a result, plants grown under photoconversion glass had an increased leaf number (12.5%), total leaf area (33%), stem length (35%) and chlorophyll content in the leaves (two-fold). It is assumed that an increase in the proportion of red light in the growing spectrum has a positive effect on photosynthetic activity and plant growth. Full article
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Article
The Effect of the Application of Stimulants on the Photosynthetic Apparatus and the Yield of Winter Wheat
Agronomy 2022, 12(1), 78; https://doi.org/10.3390/agronomy12010078 - 30 Dec 2021
Cited by 1
Abstract
The use of stimulation preparations seems to be a promising means for mitigating the effects of abiotic and biotic stressors. Their significance includes plant organism stimulation and metabolism optimisation, water regime, and nutrition during periods of stress. They help bridge it over and [...] Read more.
The use of stimulation preparations seems to be a promising means for mitigating the effects of abiotic and biotic stressors. Their significance includes plant organism stimulation and metabolism optimisation, water regime, and nutrition during periods of stress. They help bridge it over and create conditions for rapid regeneration. In a field experiment, the effect of the application of stimulation preparations on cultivars Triticum aestivum L. with different genetic composition was evaluated (donor of blue aleurone colour KM-72-18; donor of a multi-row spike (MRS) KM-94-18). Our results show a predominantly positive effect of the application of stimulants on the yield and thousand-grain weight (TKW). The results obtained were influenced by the year, based on different temperatures and precipitation. Higher yields were achieved in 2020 with higher total precipitation during the grain filling period and with a higher maximum quantum yield of the photosystem II (Fv/Fm). In 2019, this period was significantly dry and warm, which was reflected in a lower yield and TKM, higher proline content in the leaves, and lower Fv/Fm values. In both experimental years, there was a higher yield of the cultivar with blue aleurone (KM-72-18). In the case of cultivars with coloured grains, the promising use of the content substances in cultivars as natural means of increasing resistance to abiotic and biotic stressors seems to be promising. Full article
(This article belongs to the Special Issue Alternative Cropping Systems for Climate Change)
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Article
Yield of Winter Oilseed Rape (Brassica napus L. var. napus) in a Short-Term Monoculture and the Macronutrient Accumulation in Relation to the Dose and Method of Sulphur Application
Agronomy 2022, 12(1), 68; https://doi.org/10.3390/agronomy12010068 - 28 Dec 2021
Cited by 1
Abstract
The objective of this study was to assess the yield efficiency of sulphur-enhanced fertilisers, depending on the dose and application method, in a short-lived (three-year) monoculture of winter oilseed rape under the climate and soil conditions of south-eastern Poland. The experiment was carried [...] Read more.
The objective of this study was to assess the yield efficiency of sulphur-enhanced fertilisers, depending on the dose and application method, in a short-lived (three-year) monoculture of winter oilseed rape under the climate and soil conditions of south-eastern Poland. The experiment was carried out between 2010 and 2013 on winter oilseed rape (Brassica napus L. var. napus) of the Orlando variety, fertilised with different sulphur doses—0, 20, 40 or 60 kg S ha−1 applied in different method—soil application sowing, foliar application in the spring, and soil application sowing + foliar application in the spring (combined application). Following the harvest, seed and straw yields and the content of macroelements (N, S, P, K, Ca and Mg) in the seed and straw samples were determined. The harvest indices were also established for each of these elements. The impact of sulphur on winter oilseed rape yield depended significantly on both the dose and the application method. Even at the lowest dose (20 kg·ha−1), sulphur materially increased seed yield, regardless of the application method. With autumn soil application and foliar application, differences between the lowest dose and the higher doses (40 and 60 kg·ha−1) were not significant. However, with combined application, the highest dose (60 kg·ha−1) significantly increased yield compared to the lower doses. In general, all the fertilisation approaches significantly increased the N, P, K, Ca and Mg contents compared to the control sample, but the differences between them were not substantial. Each of the sulphur application approaches decreased the harvest index for sulphur. The foliar application of each of the doses decreased the harvest indices for N, P, K and Ca. The soil application of 20 kg·ha−1, and the mixed application of 40 and 60 kg·ha−1, all increased the harvest indices for P, K and Ca. Full article
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Article
Biofortification of Diverse Basmati Rice Cultivars with Iodine, Selenium, and Zinc by Individual and Cocktail Spray of Micronutrients
Agronomy 2022, 12(1), 49; https://doi.org/10.3390/agronomy12010049 - 27 Dec 2021
Cited by 2
Abstract
Given that an effective combined foliar application of iodine (I), selenium (Se), and zinc (Zn) would be farmer friendly, compared to a separate spray of each micronutrient, for the simultaneous biofortification of grain crops, we compared effectiveness of foliar-applied potassium iodate (KIO3 [...] Read more.
Given that an effective combined foliar application of iodine (I), selenium (Se), and zinc (Zn) would be farmer friendly, compared to a separate spray of each micronutrient, for the simultaneous biofortification of grain crops, we compared effectiveness of foliar-applied potassium iodate (KIO3, 0.05%), sodium selenate (Na2SeO4, 0.0024%), and zinc sulfate (ZnSO4∙7H2O, 0.5%), separately and in their combination (as cocktail) for the micronutrient biofortification of four Basmati cultivars of rice (Oryza sativa L.). Foliar-applied, each micronutrient or their cocktail did not affect rice grain yield, but grain yield varied significantly among rice cultivars. Irrespective of foliar treatments, the brown rice of cv. Super Basmati and cv. Kisan Basmati had substantially higher concentration of micronutrients than cv. Basmati-515 and cv. Chenab Basmati. With foliar-applied KIO3, alone or in cocktail, the I concentration in brown rice increased from 12 to 186 µg kg−1. The average I concentration in brown rice with foliar-applied KIO3 or cocktail was 126 μg kg−1 in cv. Basmati-515, 160 μg kg−1 in cv. Chenab Basmati, 153 μg kg−1 in cv. Kisan Basmati, and 306 μg kg−1 in cv. Super Basmati. Selenium concentration in brown rice increased from 54 to 760 µg kg−1, with foliar-applied Na2SeO4 individually and in cocktail, respectively. The inherent Zn concentration in rice cultivars ranged between 14 and 19 mg kg−1 and increased by 5–6 mg Zn per kg grains by foliar application of ZnSO4∙7H2O and cocktail. The results also showed the existence of genotypic variation in response to foliar spray of micronutrients and demonstrated that a foliar-applied cocktail of I, Se, and Zn could be an effective strategy for the simultaneous biofortification of rice grains with these micronutrients to address the hidden hunger problem in human populations. Full article
(This article belongs to the Topic Plant Nutrition Biofortification)
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Article
Biochemical and Rapid Molecular Analyses to Identify Glyphosate Resistance in Lolium spp.
Agronomy 2022, 12(1), 40; https://doi.org/10.3390/agronomy12010040 - 25 Dec 2021
Abstract
Lolium spp. are troublesome weeds mainly found in winter cereal crops worldwide, including Europe. In recent years resistant mechanisms have been evolved to several important herbicides. In this study we investigated the mechanisms responsible for conferring glyphosate resistance in some Lolium spp. populations. [...] Read more.
Lolium spp. are troublesome weeds mainly found in winter cereal crops worldwide, including Europe. In recent years resistant mechanisms have been evolved to several important herbicides. In this study we investigated the mechanisms responsible for conferring glyphosate resistance in some Lolium spp. populations. A holistic approach was used, based on dose-response experiments, determination of shikimic acid concentration in plant leaf tissue, as well as molecular analyses. More specifically, in three Lolium spp. populations the existence of a mutation in the Pro-106 codon of the 5-enolpyruvylshikimate-3 phosphate synthase (EPSPS) gene was investigated as well as the relative transcript levels of four ABC-transporter genes were monitored at three time points after glyphosate application. The results demonstrated that glyphosate resistance is a multifactor phenomenon. Relative transcript levels of the ABC-transporter genes were abundant at very early time points after glyphosate treatments. Dose-response experiments and shikimate analyses were in accordance with the findings of the quantitative PCR (qPCR) analyses. We suggest that relative expression ratio of ABC-transporter genes can be a useful tool to rapidly identify Lolium spp. populations resistant to glyphosate. Full article
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Article
Interactive Effects of Biochar, Nitrogen, and Phosphorous on the Symbiotic Performance, Growth, and Nutrient Uptake of Soybean (Glycine max L.)
Agronomy 2022, 12(1), 27; https://doi.org/10.3390/agronomy12010027 - 24 Dec 2021
Abstract
Numerous studies reported the positive effect of soil amendment with biochar on plant development. However, little is known about biochar and its interrelation with nitrogen (N) and phosphorous (P) additions and their impact on plant growth. We carried out greenhouse experiments to understand [...] Read more.
Numerous studies reported the positive effect of soil amendment with biochar on plant development. However, little is known about biochar and its interrelation with nitrogen (N) and phosphorous (P) additions and their impact on plant growth. We carried out greenhouse experiments to understand the interactive effects of nitrogen and phosphorus supply, as well as biochar amendment, on the symbiotic performance of soybean (Glycine max L.) with Bradyrhizobium japonicum, and plant growth and nutrient uptake. The biochar was produced from maize by heating at 600 °C for 30 min and used for pot experiments at an application rate of 2%. Plants were fertilized with two different concentrations of P (KH2PO4) and N (NH4NO3). Biochar application significantly increased the dry weight of soybean root and shoot biomass, by 34% and 42%, under low nitrogen and low phosphorus supply, respectively. Bradyrhizobium japonicum inoculation enhanced the dry weight of shoot biomass significantly, by 41% and 67%, in soil without biochar and with biochar addition, respectively. The nodule number was 19% higher in plants grown under low N combined with low or high P, than in high N combinations, while biochar application increased nodule number in roots. Moreover, biochar application increased N uptake of plants in all soil treatments with N or P supply, compared with B. japonicum-inoculated and uninoculated plants. A statistical difference in P uptake of plants between biochar and nutrient levels was observed with low N and high P supply in the soil. Our results show that the interactions between nitrogen, phosphorus, and biochar affect soybean growth by improving the symbiotic performance of B. japonicum and the growth and nutrition of soybean. We observed strong positive correlations between plant shoot biomass, root biomass, and N and P uptake. These data indicated that the combined use of biochar and low N, P application can be an effective approach in improving soybean growth with minimum nutrient input. Full article
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Article
Changes in Soil Organic Carbon and Its Labile Fractions after Land Conversion from Paddy Fields to Woodlands or Corn Fields
Agronomy 2022, 12(1), 29; https://doi.org/10.3390/agronomy12010029 - 24 Dec 2021
Cited by 1
Abstract
Land use change could significantly affect soil organic carbon (SOC) and other soil chemical properties. However, the responses of soil labile C fractions at different soil depths to land-use change are not still clear. The aim of this study was to investigate the [...] Read more.
Land use change could significantly affect soil organic carbon (SOC) and other soil chemical properties. However, the responses of soil labile C fractions at different soil depths to land-use change are not still clear. The aim of this study was to investigate the effect of paddy field conversion on woodlands or corn fields on total soil organic C (TOC) and its labile C fractions including particulate organic C (POC), microbial biomass C (MBC), and potassium permanganate-oxidizable C (KMnO4–C) along a 0–100 cm soil profile. Our results indicate that soil TOC concentrations increased by 3.88 g kg−1 and 3.47 g kg−1 in the 0–5 cm soil layer and 5.33 g kg−1 and 4.68 g kg−1 in the 5–20 cm soil layer during 13 years after the conversion from paddy fields to woodlands and corn fields, respectively. In the 20–40 cm soil layer, the woodlands had the highest TOC concentration (12.3 g kg−1), which was 5.13 g kg−1 and 3.5 g kg−1 higher than that of the paddy and corn fields, respectively. The increase in TOC was probably due to the absence of soil disturbance and greater root residue input into the woodland soil. In corn fields, pig manure addition contributed to the increase in soil organic C concentrations. In addition, the proportion of soil KMnO4–C increased after conversion from paddy fields to woodlands or corn fields in the 0–40 cm soil layer, ranging from 39.9–56.6% for the woodlands and 24.6–32.9% for the corn fields. The soil POC content was significantly higher in woodland and corn field soils than in paddy field soils at lower soil depths (5–40 cm). However, there were no differences in MBC contents in the whole soil profile between the woodlands and paddy fields. The KMnO4–C and MBC was the most important factor affecting the CMI values through the whole 0–100 cm soil profile. Overall, converting paddy fields to woodlands or corn fields increased the TOC and labile C fractions in the 0–40 cm soil layer. Future studies should focus on the response of the deeper soil C pool to land-use change. Full article
(This article belongs to the Special Issue Applied Research and Extension in Agronomic Soil Fertility)
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Article
Estimation of Stagnosol Hydraulic Properties and Water Flow Using Uni- and Bimodal Porosity Models in Erosion-Affected Hillslope Vineyard Soils
Agronomy 2022, 12(1), 33; https://doi.org/10.3390/agronomy12010033 - 24 Dec 2021
Abstract
Erosion has been reported as one of the top degradation processes that negatively affect agricultural soils. The study objective was to identify hydropedological factors controlling soil water dynamics in erosion-affected hillslope vineyard soils. The hydropedological study was conducted at identically-managed Jastrebarsko (location I), [...] Read more.
Erosion has been reported as one of the top degradation processes that negatively affect agricultural soils. The study objective was to identify hydropedological factors controlling soil water dynamics in erosion-affected hillslope vineyard soils. The hydropedological study was conducted at identically-managed Jastrebarsko (location I), and Jazbina (II) and (III) sites with Stagnosol soils. Soil Hydraulic Properties (SHP) were estimated on intact soil cores using Evaporation and WP4C methods; soil hydraulic functions were fitted using HYPROP-FIT software. For Apg and Bg/Btg horizons, uni- and bimodal soil hydraulic models could be well fitted to data; although, the bimodal model performed better in particular cases where data indicated non-uniform pore size distribution. With these SHP estimations, a one-year (2020) water flow scenario was simulated using HYDRUS-1D to compare water balance results obtained with uni- and bimodal hydraulic functions. Simulation results revealed relatively similar flux distribution at each hillslope position between the water balance components infiltration, surface runoff, and drainage. However, at the bottom profile at Jastrebarsko, bimodality of the hydraulic functions led to increased drainage. Soil water storage was reduced, and the vertical movement increased due to modified soil water retention curve shapes. Adequate parameterization of SHP is required to capture the hydropedological response of heterogenous erosion-affected soil systems. Full article
(This article belongs to the Special Issue Land Management Impacts on Soil Properties and Soil Erosion Processes)
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Article
Ecological Adaptability of Some Cultivars and Breeding Samples of Origanum vulgare L.
Agronomy 2022, 12(1), 16; https://doi.org/10.3390/agronomy12010016 - 23 Dec 2021
Abstract
Since the registry of common oregano (Origanum vulgare L.) cultivars does not involve regionalization, a comprehensive study of cultivars bred by different institutions in the intended cultivation region is valuable and relevant. The objective of the research was to assess the possibility [...] Read more.
Since the registry of common oregano (Origanum vulgare L.) cultivars does not involve regionalization, a comprehensive study of cultivars bred by different institutions in the intended cultivation region is valuable and relevant. The objective of the research was to assess the possibility of using various indices of ecological adaptability originally developed for grain crops for their use in the most adapted genotypes’ selection (breeding samples and cultivars) of Origanum vulgare L. to the temperate climate of the Crimean Peninsula. The research was carried out in the piedmont zone of Crimea from 2016 to 2019. The study material consisted of breeding samples No. 10 and No. 82 from the collection of FSBSI “Research Institute of Agriculture of Crimea”, as well as cultivars Zima, Raduga, and Slavnitsa selected by the All-Russian Scientific Research Institute of Medicinal and Aromatic Plants (ARSRIMAP). Genotype had the greatest influence on yield of fresh oregano material (43%) with the influence of the weather conditions of the year being 2%. On the contrary, meteorological conditions had a much greater effect on the essential oil accumulation and its areal yield, which were 30% and 25%, respectively. In terms of the coefficient of ecological variation of fresh yield, sample No. 82 and Slavnitsa cultivar were the best (11.47–16.7%). The local genotypes No. 10 and No. 82 varied less by the essential oil content and its yield. The genotype effect value was greater than 0 in the Raduga cultivar and local genotype No. 82 for the yield, but only in No. 82 genotype for the other two characteristics. Cultivars Zima and Raduga were classified as intensive (bi > 1) by the environmental flexibility of fresh yield, while local genotype No. 82 and Slavnitsa cultivar formed the group of intensive ones by essential oil content and essential oil yield. Local genotypes No. 10 and No. 82 were better than the introduced cultivars in terms of essential oil content homeostability and essential oil yield (Hom = 1.91–2.18). Thus, local genotypes proved to be more adapted to the region’s conditions in terms of essential oil accumulation. However, they were inferior to the registered cultivars of ARSRIMAP breeding in terms of fresh yield. Full article
(This article belongs to the Special Issue Innovative Technologies in Crop Production and Animal Husbandry)
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Article
Improving Nitrogen Status Estimation in Malting Barley Based on Hyperspectral Reflectance and Artificial Neural Networks
Agronomy 2021, 11(12), 2592; https://doi.org/10.3390/agronomy11122592 - 20 Dec 2021
Abstract
Malting barley requires sensitive methods for N status estimation during the vegetation period, as inadequate N nutrition can significantly limit yield formation, while overfertilization often leads to an increase in grain protein content above the limit for malting barley and also to excessive [...] Read more.
Malting barley requires sensitive methods for N status estimation during the vegetation period, as inadequate N nutrition can significantly limit yield formation, while overfertilization often leads to an increase in grain protein content above the limit for malting barley and also to excessive lodging. We hypothesized that the use of N nutrition index and N uptake combined with red-edge or green reflectance would provide extended linearity and higher accuracy in estimating N status across different years, genotypes, and densities, and the accuracy of N status estimation will be further improved by using artificial neural network based on multiple spectral reflectance wavelengths. Multifactorial field experiments on interactive effects of N nutrition, sowing density, and genotype were conducted in 2011–2013 to develop methods for estimation of N status and to reduce dependency on changing environmental conditions, genotype, or barley management. N nutrition index (NNI) and total N uptake were used to correct the effect of biomass accumulation and N dilution during plant development. We employed an artificial neural network to integrate data from multiple reflectance wavelengths and thereby eliminate the effects of such interfering factors as genotype, sowing density, and year. NNI and N uptake significantly reduced the interannual variation in relationships to vegetation indices documented for N content. The vegetation indices showing the best performance across years were mainly based on red-edge and carotenoid absorption bands. The use of an artificial neural network also significantly improved the estimation of all N status indicators, including N content. The critical reflectance wavelengths for neural network training were in spectral bands 400–490, 530–570, and 710–720 nm. In summary, combining NNI or N uptake and neural network increased the accuracy of N status estimation to up 94%, compared to less than 60% for N concentration. Full article
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Article
The Perfect Match: Adjusting High Tree Density to Rootstock Vigor for Improving Cropping and Land Use Efficiency of Sweet Orange
Agronomy 2021, 11(12), 2569; https://doi.org/10.3390/agronomy11122569 - 17 Dec 2021
Cited by 1
Abstract
The rise in the productivity of sweet orange in Brazil has been related to the use of superior rootstocks and higher tree density, among other factors. In order to investigate whether the cropping system and the land use efficiency would benefit from more [...] Read more.
The rise in the productivity of sweet orange in Brazil has been related to the use of superior rootstocks and higher tree density, among other factors. In order to investigate whether the cropping system and the land use efficiency would benefit from more intensive cultivation, the performance of Valencia sweet orange was evaluated over nine years on four rootstocks, which induced contrasting vigor, at 513, 696 and 1000 trees·ha−1. Agronomic Institute of Campinas (IAC) 1697 and IAC 1710 citrandarins, and diploid and allotetraploid (4×) Swingle citrumelos were classified as semi-dwarfing, super-standard, standard, and dwarfing rootstocks, respectively. The fruit yield per tree was decreased at higher tree densities, notably for more vigorous rootstocks. Conversely, the cumulative productivity was increased over the evaluation period by 27% at 1000 trees·ha−1, irrespective of the rootstock, and the most vigorous rootstock resulted in 2.5 times higher production than the dwarfing one on average. Most fruit quality parameters were seldom influenced by the tree density, while the rootstock was a decisive factor in improving the quality and the soluble solids content. Dwarfing rootstocks allowed for harvesting 17% more fruit per minute by manual pickers. Because the tree row volume per area is lower with such rootstocks, even at higher tree density, spray volume can be reduced, although appropriate equipment should be developed for better spray coverage on smaller trees. Nine years after planting under strict vector control, the cumulative incidence of huanglongbing-symptomatic trees on IAC 1710 was double that on Swingle 4×. Taken together, the results suggested that the land use efficiency in the citrus industry can be further improved by planting vigorous rootstocks at moderate to high tree densities. Nevertheless, obtaining highly productive semi-dwarfing and dwarfing rootstocks is the sine qua non for making high-density pedestrian sweet orange orchards more profitable. Full article
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Article
Yield Assessment of Maize Varieties under Varied Water Application in Semi-Arid Conditions of Southern Mozambique
Agronomy 2021, 11(12), 2541; https://doi.org/10.3390/agronomy11122541 - 14 Dec 2021
Abstract
Maize is one of the most important staple food crops in Mozambique. Its production is country-wise dominated by smallholder farmers (more than 90%) under rain-fed conditions, where the risk of crop failure is high, especially under semi-arid conditions in southern Mozambique. Several maize [...] Read more.
Maize is one of the most important staple food crops in Mozambique. Its production is country-wise dominated by smallholder farmers (more than 90%) under rain-fed conditions, where the risk of crop failure is high, especially under semi-arid conditions in southern Mozambique. Several maize genotypes have been developed for the broad agro-ecological zone adaptation but lack strong evidence about their productivity and yield stability to support decision-making in farming systems. In order to assess the yield and yield stability of maize genotypes under different environments, five identical on-station trials were implemented in the period 2017 to 2019, covering summer and winter seasons in the semi-arid region of southern Mozambique. The trials were established at the experimental station of the Universidade Eduardo Mondlane (UEM) in Sábie and at the Instituto de Investigação Agrária de Moçambique (IIAM) in Chókwe. A strip-plot design in a randomized complete block arrangement with 15 maize genotypes, and three water application (rainfall plus irrigation) levels in four replications was followed in a line-source irrigation arrangement. The water application levels varied from 151 mm to 804 mm, covering different water regimes. Under well-watered summer conditions, the genotypes G6 and G12 showed high yield and high grain yield stability. In the drier conditions, either in summer or winter, the G2 and G11 genotypes produced higher grain yield but with low stability. Both groups of genotypes have a high potential to be included in technology transfer packages to smallholder farmers to address food security or large-scale commercial farmers differently. Full article
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Article
Genetic Mapping of Quantitative Trait Loci for End-Use Quality and Grain Minerals in Hard Red Winter Wheat
Agronomy 2021, 11(12), 2519; https://doi.org/10.3390/agronomy11122519 - 11 Dec 2021
Cited by 2
Abstract
To meet the demands of different wheat-based food products, traits related to end-use quality become indispensable components in wheat improvement. Thus, markers associated with these traits are valuable for the timely evaluation of protein content, kernel physical characteristics, and rheological properties. Hereunder, we [...] Read more.
To meet the demands of different wheat-based food products, traits related to end-use quality become indispensable components in wheat improvement. Thus, markers associated with these traits are valuable for the timely evaluation of protein content, kernel physical characteristics, and rheological properties. Hereunder, we report the mapping results of quantitative trait loci (QTLs) linked to end-use quality traits. We used a dense genetic map with 5199 SNPs from a 90K array based on a recombinant inbred line (RIL) population derived from ‘CO960293-2’/‘TAM 111’. The population was evaluated for flour protein concentration, kernel characteristics, dough rheological properties, and grain mineral concentrations. An inclusive composite interval mapping model for individual and across-environment QTL analyses revealed 22 consistent QTLs identified in two or more environments. Chromosomes 1A, 1B, and 1D had clustered QTLs associated with rheological parameters. Glu-D1 loci from CO960293-2 and either low-molecular-weight glutenin subunits or gliadin loci on 1A, 1B, and 1D influenced dough mixing properties substantially, with up to 34.2% of the total phenotypic variation explained (PVE). A total of five QTLs associated with grain Cd, Co, and Mo concentrations were identified on 3B, 5A, and 7B, explaining up to 11.6% of PVE. The results provide important genetic resources towards understanding the genetic bases of end-use quality traits. Information about the novel and consistent QTLs provided solid foundations for further characterization and marker designing to assist selections for end-use quality improvements. Full article
(This article belongs to the Section Crop Breeding and Genetics)
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Article
Phenylalanine Ammonia-Lyase (PAL) Genes Family in Wheat (Triticum aestivum L.): Genome-Wide Characterization and Expression Profiling
Agronomy 2021, 11(12), 2511; https://doi.org/10.3390/agronomy11122511 - 10 Dec 2021
Cited by 5
Abstract
Phenylalanine ammonia-lyase (PAL) is the first enzyme in the phenylpropanoid pathway and plays a vital role in adoption, growth, and development in plants but in wheat its characterization is still not very clear. Here, we report a genome-wide identification of TaPAL genes and [...] Read more.
Phenylalanine ammonia-lyase (PAL) is the first enzyme in the phenylpropanoid pathway and plays a vital role in adoption, growth, and development in plants but in wheat its characterization is still not very clear. Here, we report a genome-wide identification of TaPAL genes and analysis of their transcriptional expression, duplication, and phylogeny in wheat. A total of 37 TaPAL genes that cluster into three subfamilies have been identified based on phylogenetic analysis. These TaPAL genes are distributed on 1A, 1B, 1D, 2A, 2B, 2D, 4A, 5B, 6A, 6B, and 6D chromosomes. Gene structure, conserved domain analysis, and investigation of cis-regulatory elements were systematically carried out. Chromosomal rearrangements and gene loss were observed by evolutionary analysis of the orthologs among Triticum urartu, Aegilops tauschii, and Triticum aestivum during the origin of bread wheat. Gene ontology analysis revealed that PAL genes play a role in plant growth. We also identified 27 putative miRNAs targeting 37 TaPAL genes. The high expression level of PAL genes was detected in roots of drought-tolerant genotypes compared to drought-sensitive genotypes. However, very low expressions of TaPAL10, TaPAL30, TaPAL32, TaPAL3, and TaPAL28 were recorded in all wheat genotypes. Arogenate dehydratase interacts with TaPAL29 and has higher expression in roots. The analysis of all identified genes in RNA-seq data showed that they are expressed in roots and shoots under normal and abiotic stress. Our study offers valuable data on the functioning of PAL genes in wheat. Full article
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Article
Conceptual Design of a Comprehensive Farm Nitrogen Management System
Agronomy 2021, 11(12), 2501; https://doi.org/10.3390/agronomy11122501 - 09 Dec 2021
Cited by 3
Abstract
Data that are required for nutrient management are becoming increasingly available in digital format, leading to a high innovation potential for digital nitrogen (N) management applications. However, it is currently difficult for farmers to analyze, assess, and optimize N flows in their farms [...] Read more.
Data that are required for nutrient management are becoming increasingly available in digital format, leading to a high innovation potential for digital nitrogen (N) management applications. However, it is currently difficult for farmers to analyze, assess, and optimize N flows in their farms using the existing software. To improve digital N management, this study identified, evaluated, and systematized the requirements of stakeholders. Furthermore, digital farm N management tools with varying objectives in terms of system boundaries, data requirements, used methods and algorithms, performance, and practicality were appraised and categorized. According to the identified needs, the concept of a farm N management system (FNMS) software is presented which includes the following modules: (1) management of site and farm data, (2) determination of fertilizer requirements, (3) N balancing and cycles, (4) N turnover and losses, and (5) decision support. The aim of FNMS is to support farmers in their farming practices for increasing N efficiency and reducing environmentally harmful N surpluses. In this study, the conceptual requirements from the agricultural and computer science perspectives were determined as a basis for developing a consistent, scientifically sound, and user-friendly FNMS, especially applicable in European countries. This FNMS enables farmers and their advisors to make knowledge-based decisions based on comprehensive and integrated data. Full article
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Article
Improvement of Nitrogen-Fertilizer Recommendation by Consideration of Long-Term Site and Cultivation Effected Mineralization
Agronomy 2021, 11(12), 2492; https://doi.org/10.3390/agronomy11122492 - 08 Dec 2021
Abstract
Organic matter (OM) and nutrient nitrogen (N) play vital roles in the fertility and production of soil in accordance with goals of efficient environmental protection. This study aimed to show the extent to which N delivery can contribute to improving nitrogen fertilizer requirements [...] Read more.
Organic matter (OM) and nutrient nitrogen (N) play vital roles in the fertility and production of soil in accordance with goals of efficient environmental protection. This study aimed to show the extent to which N delivery can contribute to improving nitrogen fertilizer requirements (NFR) through comparative analysis of OM and N. Systems determining the NFR in agricultural practices have thus far been challenged to estimate the annual rate of mineralization of the soil. OM and N turnover was investigated through an available evaluation consisting of 546 representatively distributed permanent test and observation plots (TP) of the German Federal State of Saxony farms. A solid database of at least 10-year field plot card records from 2001 to 2010 was selected for the analysis. A program (BEFU) widely used in agricultural practice, along with the simplified process model CCB, were applied. For the calculation of the amount of mineral N fertilizers used, the results of three different methods for determining the NFR were compared with each other. The determination of the farmers’ demand (=actual condition of the TP) with a mean value of 132 kg N ha−1 did not show a large difference between the calculated values with 137 kg N ha−1 by the BEFU program. Based on the available results for the most important crop species cultivated in Saxony, there were clear differences in the considerations of the N delivery from the soil. The BEFU program was able to calculate an average N delivery of 17 kg N ha−1 from tabulated data, whereas with the CCB process model, 66 kg N ha−1 of mineralization was determined with a distinct higher deviation by taking into account the 10-year field histories. Using the N delivery of the TP by the CCB model, a clear reduction of the mean N fertilization level, to about 80 kg N ha−1, was therefore achieved. These differences were particularly large for TP with organic fertilization (livestock), at a relatively low N fertilization level, and for certain crop species. With a high standard deviation, the average savings potential of mineral N fertilizers was 52–57 kg N ha−1. After including the corrected values for the N mineral fertilization, a decrease in the N balances by an average of 20–25 kg N ha−1 was ultimately achieved. In particular, the heavily oversupplied plots with D and E classification decreased by approximately 50%. The results of our study demonstrate clear improvements; therefore, increased efforts should be made in the future to optimize the determination of NFR using applicable methods that consider N mineralization in agricultural practice and consultation. Full article
(This article belongs to the Special Issue Nitrogen Cycle in Farming Systems)
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Article
The Impact of Forest Fungi on Promoting Growth and Development of Brassica napus L.
Agronomy 2021, 11(12), 2475; https://doi.org/10.3390/agronomy11122475 - 06 Dec 2021
Abstract
Inoculation of plants with fungi has been shown to increase yields by improving germination, seedling vigor, plant growth, root morphogenesis, photosynthesis, and flowering through direct or indirect mechanisms. These mechanisms include solubilization and mineralization of nutrients, facilitating their uptake by plants, regulation of [...] Read more.
Inoculation of plants with fungi has been shown to increase yields by improving germination, seedling vigor, plant growth, root morphogenesis, photosynthesis, and flowering through direct or indirect mechanisms. These mechanisms include solubilization and mineralization of nutrients, facilitating their uptake by plants, regulation of hormone balance, production of volatile organic compounds and microbial enzymes, suppression of plant pathogens, and mitigation of abiotic stresses. In the presented experiments, the effect of selected forest soil fungi on the growth and development of Brassica napus L. seedlings was investigated. Inoculation was carried out in vivo and in pot experiments with ectomycorrhizal fungi typical for forest soils: Collybia tuberosa, Clitocybe sp., Laccaria laccata, Hebeloma mesophaeum, and Cyathusolla. It was shown that all analyzed fungi produced IAA. In the in vitro experiment, B. napus inoculated with L. laccata showed stimulated root growth and greater number of leaves compared to control plants. A similar stimulatory effect on lateral root formation was observed in cuttings grown in pots in the presence of the C. olla fungus. In the pot experiment, the seedlings inoculated with the L. laccata fungus also showed increased growth of shoots and biomass. The effect of inoculation with the tested fungal strains, especially C. olla, on the growth and development of oilseed rape was probably indirect, as it also contributed to an increase in the number of microorganisms, especially soil bacteria. The expression of the metallothioneins in B. napus (BnMT1-BnMT3) varied depending on the fungal species. The presence of C. olla significantly increased BnMT2 expression in oilseed rape. It was found that BnMT1 expression increased and BnMT3 transcripts decreased in plants growing in the presence of L. laccata. This indicates the involvement of BnMT in the adaptation of oilseed rape to growth in fungi presence. Full article
(This article belongs to the Section Soil and Plant Nutrition)
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Article
Computational Interaction Analysis of Sirex noctilio Odorant-Binding Protein (SnocOBP7) Combined with Female Sex Pheromones and Symbiotic Fungal Volatiles
Agronomy 2021, 11(12), 2461; https://doi.org/10.3390/agronomy11122461 - 02 Dec 2021
Cited by 2
Abstract
Sirex noctilio, a major forestry quarantine pest, has spread rapidly and caused serious harm. However, existing methods still need to be improved because its olfactory interaction mechanisms are poorly understood. In order to study the role of male-specific protein SnocOBP7 in the [...] Read more.
Sirex noctilio, a major forestry quarantine pest, has spread rapidly and caused serious harm. However, existing methods still need to be improved because its olfactory interaction mechanisms are poorly understood. In order to study the role of male-specific protein SnocOBP7 in the protein–ligand interactions, we selected it as the object of computational simulation and analysis. By docking it with 11 ligands and evaluating free binding energy decomposition, the three best binding ligands were found to be female sex pheromones ((Z)-7-heptacosene and (Z)-7-nonacosene) and symbiotic fungal volatiles ((−)-globulol). Binding mode analysis and computational alanine scanning suggested that five residues play key roles in the binding of each female sex pheromone to SnocOBP7, whereas two residues play key roles in (−)-globulol binding. Phe108 and Leu36 may be the crucial sites via which SnocOBP7 binds female sex pheromones, whereas Met40 may regulate the courtship behavior of males, and Leu61 may be related to mating and host finding. Our studies predicted the function of SnocOBP7 and found that the interaction between SnocOBP7 and pheromone is a complex process, and we successfully predicted its binding key amino-acid sites, providing a basis for the development of new prevention and control methods relying on female sex pheromones and symbiotic fungi. Full article
(This article belongs to the Special Issue Biological Interactions of Pests)
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Article
Influence of Substrate Composition and Container Size on the Growth of Tissue Culture Propagated Apple Rootstock Plants
Agronomy 2021, 11(12), 2450; https://doi.org/10.3390/agronomy11122450 - 30 Nov 2021
Abstract
Substrate composition and container size are considered crucial for apple rootstock grown in a plug seedling system. This study investigated the effect of substrate material’s proportion and different container volumes on the growth of apple rootstock (M-9) plants propagated by tissue culture. In [...] Read more.
Substrate composition and container size are considered crucial for apple rootstock grown in a plug seedling system. This study investigated the effect of substrate material’s proportion and different container volumes on the growth of apple rootstock (M-9) plants propagated by tissue culture. In substrate composition, three different ratios of peat moss (PM): vermiculite (VL): perlite (PL) at 1:1:1 (S1), 1:2:3 (S2), 3:1:2 (S3) were used. For container size, plants were grown in 1000 mL (C1), 500 mL (C2), and 300 mL (C3) containers filled by 1:1:1 mixture of PM, VL and PL. In both cases, plants were treated eleven weeks in a green house. Our results demonstrate that the plant height, number of leaves, leaf area, shoot fresh weight and root fresh weight of apple rootstock were significantly higher in substrate composition S3 compared with S1 composition. However, chlorophyll content (SPAD) and photosynthesis rate were unaffected by variation of substrate composition. Furthermore, rootstock grown in C1 container showed plant height, number of leaves, leaf area, number of nodes, root length, shoot and root’s fresh and dry weight were significantly higher than those grown in C2 and C3 volume containers. The chlorophyll content and transpiration rate were not significantly affected by the different container volumes. These results suggest that the substrate ratio 3:1:2 of PM:VL:PL and container size 1000 mL were more favorable than other treatments for initial growth and development of the tissue culture propagated apple rootstock plants. Full article
(This article belongs to the Special Issue In Vitro Multiplication and Seed Production Technology)
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Article
Towards a Socio-Economic Model for Southwest Asian Cereal Domestication
Agronomy 2021, 11(12), 2432; https://doi.org/10.3390/agronomy11122432 - 29 Nov 2021
Cited by 1
Abstract
Mechanisms of selection for domestication traits in cereals and other annual plants are commonly explained from agro-technological and genetic perspectives. Since archaeobotanical data showed that domestication processes were slow and protracted, research focused on genetic constraints and hypothetical ‘non-selective’ management regimes to explain [...] Read more.
Mechanisms of selection for domestication traits in cereals and other annual plants are commonly explained from agro-technological and genetic perspectives. Since archaeobotanical data showed that domestication processes were slow and protracted, research focused on genetic constraints and hypothetical ‘non-selective’ management regimes to explain the low selection rates. I argue that these factors only partially explain the observed patterns and develop a model that contextualises the archaeobotanical data in their socio-economic settings. I propose that developments towards individual storage by small household units and the gradual increase in storage capacities with the development of extended households represent key factors for establishing the conditions for selection, as these practices isolated individually managed and stored cereal subpopulations and gradually reduced the need to replenish grain stocks with grains from unmanaged populations. This genetic isolation resulted in stronger and more persistent selection rates and facilitated the genetic fixation of domestication traits on a population level. Moreover, individual storage facilities within buildings reflect gradual developments towards households as the social units that mobilised agricultural labour, which negotiated new sharing principles over cultivated resources and drove the intensification of cultivation practices. In this sense, selection rates and the slow domestication process can be understood as a function of limited food sharing networks and increased labour-inputs into early arable environments—socio-economic processes that also unfolded gradually over a protracted period of time. Full article
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Article
Plant Disease Identification Using Shallow Convolutional Neural Network
Agronomy 2021, 11(12), 2388; https://doi.org/10.3390/agronomy11122388 - 24 Nov 2021
Cited by 5
Abstract
Various plant diseases are major threats to agriculture. For timely control of different plant diseases in effective manner, automated identification of diseases are highly beneficial. So far, different techniques have been used to identify the diseases in plants. Deep learning is among the [...] Read more.
Various plant diseases are major threats to agriculture. For timely control of different plant diseases in effective manner, automated identification of diseases are highly beneficial. So far, different techniques have been used to identify the diseases in plants. Deep learning is among the most widely used techniques in recent times due to its impressive results. In this work, we have proposed two methods namely shallow VGG with RF and shallow VGG with Xgboost to identify the diseases. The proposed model is compared with other hand-crafted and deep learning-based approaches. The experiments are carried on three different plants namely corn, potato, and tomato. The considered diseases in corns are Blight, Common rust, and Gray leaf spot, diseases in potatoes are early blight and late blight, and tomato diseases are bacterial spot, early blight, and late blight. The result shows that our implemented shallow VGG with Xgboost model outperforms different deep learning models in terms of accuracy, precision, recall, f1-score, and specificity. Shallow Visual Geometric Group (VGG) with Xgboost gives the highest accuracy rate of 94.47% in corn, 98.74% in potato, and 93.91% in the tomato dataset. The models are also tested with field images of potato, corn, and tomato. Even in field image the average accuracy obtained using shallow VGG with Xgboost are 94.22%, 97.36%, and 93.14%, respectively. Full article
(This article belongs to the Special Issue Applications of Deep Learning in Smart Agriculture)
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Article
Establishment and First Year Yield of Interseeded Alfalfa as Influenced by Corn Plant Density and Treatment with Prohexadione, Fungicide and Insecticide
Agronomy 2021, 11(11), 2343; https://doi.org/10.3390/agronomy11112343 - 19 Nov 2021
Cited by 1
Abstract
Interseeding alfalfa (Medicago sativa L.) into a silage corn (Zea mays L.) companion crop can increase the yield and profitability of forage production and reduce the risk of nutrient and soil loss from cropland, but unreliable establishment of alfalfa hampers the [...] Read more.
Interseeding alfalfa (Medicago sativa L.) into a silage corn (Zea mays L.) companion crop can increase the yield and profitability of forage production and reduce the risk of nutrient and soil loss from cropland, but unreliable establishment of alfalfa hampers the adoption of this practice on dairy farms. This study evaluated plant survival, foliar health, and dry matter yields of two alfalfa varieties when established in corn sown at populations ranging from about 47,500 to 100,000 plants per ha−1 and when treated with prohexadione (PHD), PHD followed by fungicide and insecticide (PHD-FI), or not treated with agrichemicals. The plant density of alfalfa during establishment was adversely impacted by above average precipitation and high corn populations, but substantially improved by PHD-FI treatment, which limited alfalfa etiolation, disease, and defoliation. First-cut dry-matter yields of interseeded alfalfa after corn were maximized at a stand density of approximately 200 plants m−2 or 850 stems m−2 and total first year yield exceeded conventionally spring-seeded alfalfa by 59 to 75%. Overall, our results indicated that PHD-FI treatment promoted good establishment and subsequent forage production of interseeded alfalfa. Applications of PHD-FI must, however, be fine-tuned, and additional management practices must be developed to ensure both good yields of corn silage and reliable establishment of interseeded alfalfa, especially during wet growing conditions. Full article
(This article belongs to the Special Issue Multifunctional Forages)
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