Several narrow or broadband spectral indices can be calculated at varying spatial and spectral resolution, which can then be correlated with the physiological and nutritional status of the leaves. In a three-year trial carried out on fruiting, potted cv. Barbera grapevines subjected to full (N+) or no (N0) nitrogen supply, seasonal evolution of different leaf spectral indices were correlated with non-destructive chlorophyll readings (Minolta SPAD meter), leaf gas exchange, and vine performance. Throughout the entire trial, N starvation resulted in greater-than-proportional limitation of vine yield as compared to vegetative growth (55% compared to 26% less than values measured on N+). Indices calculated within the red-edge spectral domain had highest sensitivity to relative change between N+ and N0, also indicating that the promptest response was recorded at the median shoot zone level. Twelve broadband indices were linearly correlated with leaf blade N concentration at veraison, indicating that N values ≤ 1.8% of dry matter identify a limiting N status. Any of these indices collected at the leaf level can be reliably used as a non-destructive predictor of N availability, albeit due to significant between-year variation in their absolute values at a given N level, readings should always include a well-supplied N treatment. Full article

Beta vulgaris comprise various variety groups that are cultivated for vegetative or reproductive production. As a biennial crop, beets have a photothermal induction requirement for the transition from the vegetative to the reproductive stage. Bolting and flowering are not desirable when beets are cultivated for vegetative production and are suppressed during breeding programs, though these structures are important in seed production. Therefore, the potential of seed hydro priming as an enhancement technique to partially induce vernalization in seeds was evaluated. Following hydro priming, seeds were sown in October 2018 and evaluated during three selected phenological stages. Treating seeds with hydro priming significantly improved the emergence rate in all four tested cultivars. Moreover, treatments significantly lowered the required growing degree days (GDD) for transition to the reproductive stage in all four tested cultivars. Regardless of the treatment effect on an individual developmental stage, the treatment efficiency should be evaluated on the whole production process, depending on the purpose of production. The focus of this study was mainly on improvement of seed production performance. The outcome showed the potential of priming to influence the reproductive stages of the plant life cycle rather than just the germination. Full article

In sustainable farming, the use of organic fertilizers is a costly but environmentally-oriented type of soil–crop system management. Among essential microelements, cobalt (Co) deficiency commonly occurs in arid and semi-arid climatic regions suitable for the growing of moringa (Moringa oleifera Lam), an economically important, multipurpose tree. Therefore, in this study, two pot experiments were conducted to identify the interaction effects of Co and organic fertilizers in modifying the growth, yield, and nutritional composition of moringa. Each experiment consisted of 21 treatments as combinations of seven concentrations of Co (0.0, 2.5, 5.0, 7.5, 10.0, 12.5, and 15.0 mg L⁻¹) and three organic fertilizers (chicken manure, CM; farmyard manure, FYM; and compost, Comp). Co, at 7.5–12.5 mg L⁻¹, in combination with CM, significantly increased the height, leaf number, leaf area, and dry weight of plants, as well as N, P, K, Zn, Cu, protein, total carbohydrate, total soluble solids, total phenolics, carotenoids, and vitamin C in leaves. Co was positively correlated with N, P, K, and the dry weight content in moringa leaves, and this synergistic interaction may underpin the remaining parameters enhanced by Co. The cobalt effect was dose-dependent, so the improved growth, yield, and nutritional composition of moringa can be managed through a proper Co dose in combination with organic fertilizer. Co and organic fertilization could be a promising strategy for improving moringa plant productivity and its biological value in conditions of sandy soils and Co deficiency. Full article

Gibberellic acid (GA₃) application after anthesis is an important practice in hybrid rice seed production, and it plays diverse roles in seed quality and seed yield. The main objective of this study was to determine (1) the effects of GA₃ application after anthesis on seed vigor and (2) the optimal GA₃ dosage applied to Indica hybrid rice seed production. Field experiments of different GA₃ dosages (15 g hm⁻² and 30 g hm⁻², respectively) after anthesis were conducted in 2016 and 2017, and seed vigor parameters, stigma vigor index, and seed yield were determined. We found that significant differences in seed vigor parameters by a standard germination test and a cool germination test were observed among different GA₃ dosages after anthesis. Compared with the water spraying treatment, the germination percentage (GP) increased by 2.5–6.3%, and the vigor index (VI) increased by 8.9–19.8% from GA₃ application after anthesis, respectively. Moreover, the stigma vigor index of the female parent was enhanced with an increasing GA₃ dosage, and there were significant increases (7.5–16.0%) between the water spraying treatment and GA₃ spraying treatments. There were positive significant relationships between the VI and stigma vigor index. Additionally, the seed yield of the GA₃ application with 30 g hm⁻² was 3.9% higher on average than that of the water spraying treatment. Therefore, our study suggests that seed vigor can be increased by GA₃ application after anthesis, and GA₃ application should be applied at a rate of 30 g hm⁻² to improve seed vigor and maintain seed yield in Indica hybrid rice seed production. Full article

In this study, we aimed to investigate the effect of processing methods and storage time on selected parameters of quality in the purees of blue honeysuckle berries. We investigated the content of bioactive compounds such as anthocyanins, L-ascorbic acid, and total polyphenols (TPs). We tested four processing methods and two varieties of blue honeysuckle berry (Lonicera caerulea L.var. Sineglaska and Volshebnica). The purees were analyzed immediately after production, and after two and four months of storage at 20 °C without exposure to light. According to our results, thermal treatment of the fruits for 5 min resulted in obtaining purees with a higher content of anthocyanins and TPs, but lower content of L-ascorbic acid. However, sieving fruits that were not thermally treated resulted in a higher content of L-ascorbic acid. Furthermore, purees prepared from the fruits of the Volshebnica cultivar were richer in bioactive compounds than that of purees prepared from the Sineglaska cultivar. In addition, the content of anthocyanins, L-ascorbic acid, and TPs decreased with storage time. Full article

Manipulation of planting density and choice of variety are effective management components in any cropping system that aims to enhance the balance between environmental resource availability and crop requirements. One-time fertilization at first flower with a medium plant stand under late sowing has not yet been attempted. To fill this knowledge gap, changes in leaf structural (stomatal density, stomatal length, stomata width, stomatal pore perimeter, and leaf thickness), leaf gas exchange, and chlorophyll fluorescence attributes of different cotton varieties were made in order to change the planting densities to improve lint yield under a new planting model. A two-year field evaluation was carried out on cotton varieties—V₁ (Zhongmian-16) and V₂ (J-4B)—to examine the effect of changing the planting density (D₁, low, 3 × 10⁴; D₂, moderate, 6 × 10⁴; and D₃, dense, 9 × 10⁴) on cotton lint yield, leaf structure, chlorophyll fluorescence, and leaf gas exchange attribute responses. Across these varieties, J-4B had higher lint yield compared with Zhongmian-16 in both years. Plants at high density had depressed leaf structural traits, net photosynthetic rate, stomatal conductance, intercellular CO₂ uptake, quenching (qP), actual quantum yield of photosystem II (ΦPSII), and maximum quantum yield of PSII (F_v/F_m) in both years. Crops at moderate density had improved leaf gas exchange traits, stomatal density, number of stomata, pore perimeter, length, and width, as well as increased qP, ΦPSII, and F_v/F_m compared with low- and high-density plants. Improvement in leaf structural and functional traits contributed to 15.9%–10.7% and 12.3%–10.5% more boll m⁻², with 20.6%–13.4% and 28.9%–24.1% higher lint yield averaged across both years, respectively, under moderate planting density compared with low and high density. In conclusion, the data underscore the importance of proper agronomic methods for cotton production, and that J-4B and Zhongmian-16 varieties, grown under moderate and lower densities, could be a promising option based on improved lint yield in subtropical regions. Full article

Wall rocket (Diplotaxis erucoides) is a wild vegetable with the potential to become a crop of high antioxidant quality. The main bioactive compounds include ascorbic acid (AA), sinigrin, and a high content of total phenolic compounds (TP). It also accumulates nitrates. Since these compounds are affected by environmental conditions, adequate crop management may enhance its quality. Eleven accessions of wall rocket were evaluated under field and greenhouse conditions during two cycles (winter and spring) and compared to Eruca sativa and Diplotaxis tenuifolia crops. The three species did not differ greatly. As an exception, sinigrin was only identified in wall rocket. For the within-species analysis, the results revealed a high effect of the growing system, but this was low among accessions. The highest contents of AA and TP were obtained under field conditions. In addition, the levels of nitrates were lower in this system. A negative correlation between nitrates and antioxidants was determined. As a counterpart, cultivation in the field–winter environment significantly decreased the percentage of humidity (87%). These results are of relevance for the adaptation of wall rocket to different growing conditions and suggest that the field system enhances its quality. The low genotypic differences suggest that intra-species selections in breeding programs may consider other aspects with greater variation. Full article

With the rise of plant factories around the world, more and more crops are cultivated under artificial light. Studies on effects of lighting strategies on plant growth, such as different light intensities, photoperiods, and their combinations, have been widely conducted. However, research on application of multi-segment light strategies and associated plant growth mechanisms is still relatively lacking. In the present study, two lighting strategies, multi-segment light intensity and extended photoperiod, were compared with a constant light intensity with a 12 h light/12 h dark cycle and the same daily light integral (DLI). Both lighting strategies promoted plant growth but acted via different mechanisms. The multi-segment light intensity lighting strategy promoted plant growth by decreasing non-photochemical quenching (NPQ) of the excited state of chlorophyll and increasing the quantum yield of PSII electron transport (PhiPSII), quantum yield of the carboxylation rate (PhiCO₂), and photochemical quenching (qP), also taking advantage of the circadian rhythm. The extended photoperiod lighting strategy promoted plant growth by compensating for weak light stress and increasing light-use efficiency by increasing chlorophyll content under weak light conditions. Full article

The bioavailability of trace elements (TEs) is one of the major factors for successful plant production and environmental protection. The aim of this study was to determine the extent to which TEs are bioavailable and which of the basic soil parameters affect bioavailability. The survey included agricultural soil samples taken from 240 locations on the territory of the Republic of Serbia, where the soil analytics were carried out. On the basis of the analyzed data the prediction models were derived based on the Freundlich model, showing the dependence between trace elements (TEs) extracted using the DTPA buffer solution in relation to the trace elements extracted using an aqua regia, the organic matter content (SOM), the clay fractions content, and soil pH. On one part of the samples, the prediction models were separated on the basis of a suspension for determining the pH in H₂O and 1M KCl. The model was applied for the following TEs: Mn, Ni, Pb, Zn, and Cu. The content of the pseudo total forms of TEs statistically significantly influenced the bioavailability of TEs in all prediction models for all studied elements. The pH value statistically significantly affected the bioavailability of Ni, Mn, Pb, and Cu also in all prediction models. The impact of SOM and clay varied depending on the model and TEs. Multiple linear regression showed that the prediction models for TE Cu (R² = 0.763–0.848) were the most reliable and that the bioavailability of Cu was significantly influenced by all the studied soil parameters except clay. Reliable results were also shown by the prediction models for TE Pb, but the values of the determination coefficient and investigated parameters that influenced the bioavailability varied depending on the model. The derived models for TE Mn, Zn, and Ni were less reliable (R² is approximately 50% or less), and the effect of the tested parameters on bioavailability varied depending on the model and TEs. Full article

Processing tomato is an important worldwide horticultural crop. It is generally grown in high-input systems; nevertheless, plant responses to nitrogen fertilization, in terms of the effects on dry matter production and allocation to different plant organs, have yet to be investigated in depth. Moreover, information on the crop marginal net return and global warming potential (as an index of the environmental impact of crop cultivation) at different nitrogen rates is still scarce. Therefore, the aim of this work was to study the effects of different nitrogen rates (0, 50, 100, 150, 200, and 250 kg of N ha⁻¹) on the agronomic, economic, and environmental aspects of processing tomato grown under conventional management in the Mediterranean area. The results of the two-year trials indicated 200 kg of nitrogen ha⁻¹ as the best rate, ensuring the highest values of marketable and total yields, brix ton ha⁻¹, and marginal net return and the lowest global warming potential per ton of marketable yield. However, since plants fertilized with 200 kg of N ha⁻¹ did not record the highest values of nitrogen use efficiency and nitrogen uptake efficiency, our finding suggest the possibility to select better-performing cultivars for these physiological parameters by adopting specific tomato breeding programs. Full article

Bread-making quality is a crucial trait for wheat and triticale breeding. Several genes significantly influence these characteristics, including glutenin genes and the wheat bread-making (wbm) gene. World wheat collection screening showed that only a few percent of cultivars carry the valuable wbm variant, providing a useful source for wheat breeding. In contrast, no such analysis has been performed for triticale (wheat (AABB genome) × rye (RR) amphidiploid) collections. Despite the importance of the wbm gene, information about its origin and genomic organization is lacking. Here, using modern genomic resources available for wheat and its relatives, as well as PCR screening, we aimed to examine the evolution of the wbm gene and its appearance in the triticale genotype collection. Bioinformatics analysis revealed that the wheat Chinese Spring genome does not have the wbm gene but instead possesses the orthologous gene, called wbm-like located on chromosome 7A. The analysis of upstream and downstream regions revealed the insertion of LINE1 (Long Interspersed Nuclear Elements) retrotransposons and Mutator DNA transposon in close vicinity to wbm-like. Comparative analysis of the wbm-like region in wheat genotypes and closely related species showed low similarity between the wbm locus and other sequences, suggesting that wbm originated via introgression from unknown species. PCR markers were developed to distinguish wbm and wbm-like sequences, and triticale collection was screened resulting in the detection of three genotypes carrying wbm-specific introgression, providing a useful source for triticale breeding programs. Full article

The use of nematicides with reduced toxic side-effects against non-target free-living nematodes is a favorable option for farmers to control plant-parasitic nematodes. The nematicide fluensulfone was registered in several countries for the control of the root-knot nematodes, Meloidogyne spp. among other plant-parasitic nematodes. This study aimed to evaluate the nematicidal activity of fluensulfone against non-target nematode fauna in four field experiments, each under different conditions (soils types and plant hosts). Nematodes extracted from soil samples were classified and counted based on their morphological characters. Fluensulfone significantly reduced damage caused by root-knot nematodes to tomato and sweet potato plants, while overall non-target free-living nematode population densities were maintained at the same level as those in control. Different diversity indices (e.g., Shannon-Wiener H’, Simpson’s D, species richness, evenness J’, maturity indices) and principal component analyses in the four experiments showed that fluensulfone treatment kept a similar diversity level of non-target free-living nematode fauna to that of the non-treated control. The results suggested that fluensulfone may have minimal impact to free-living nematode fauna in both population density and diversity when the nematicide was applied to control Meloidogyne spp. Full article

In maize-based cropping systems, leaching of nitrate-nitrogen (NO₃-N) to drainage tile and groundwater is a significant problem. The purpose of this study was to assess whether a winter rye cover crop planted after silage maize or soybean harvest and injected with liquid manure could decrease soil NO₃-N without reducing the yield of the following maize crop. An experiment was conducted at 19 sites with predominant occurrence of Mollisols (15 out of 19 sites) in the upper Midwest USA immediately after soybean or maize silage harvest to compare a drilled rye cover crop and a non-cover crop control. Later in the fall, liquid swine or dairy manure was injected into the cover crop and control plots. Rye was terminated the following spring using herbicide, usually before reaching 20 to 25 cm in height, and incorporated with tillage at most sites, after which maize was planted and harvested as silage or grain. Across sites, soil NO₃-N at rye termination was reduced by 36% (range = 4% to 67%) with rye compared to no rye. Nitrogen in aboveground rye biomass at termination ranged from 5 to 114 kg N ha⁻¹ (mean = 51 kg N ha⁻¹). Across sites, there was no significant difference in yield of maize silage or grain between treatments. These results demonstrate in a Mollisol-dominated region the potential of a winter rye cover crop planted before manure application to effectively reduce soil NO₃-N without impacting yield of the following maize crop, thereby reducing risk of negative environmental impacts. Full article

The increased availability and high adoption rate of glyphosate-tolerant crops have selected for several glyphosate-resistant weed species. The response of representative weed species to glyphosate was assessed to provide insights and tools for optimizing glyphosate use for economic, agronomic and environmental reasons. Anoda cristata, Chenopodium album, Digitaria sanguinalis, Eleusine indica and Portulaca oleracea were grown outdoors in pots containing commercial potting medium. An increasing dose of glyphosate was applied to these species at three growth stages. Weed response was evaluated visually compared to the nontreated control and shoot dry weights were recorded. Fecundity was also determined. Based on visual evaluations, the dose of glyphosate required to attain 90% control of the species tested exhibited an application rate margin up to 28.5-fold compared to recommended rate, denoting a potential for rate optimization. Except for A. cristata, the recommended dose of glyphosate could be reduced by 30%–60% and still achieve 90% or greater control. The order of species sensitivity, based on effective dose 50 (ED₅₀ )values, was E. indica > C. album > D. sanguinalis > P. oleracea > A. cristata. The ratio of ED₉₀/ED₅₀ was constant, indicating that increasing the glyphosate dose 8.7-fold would reduce weed biomass 1.8-fold. In most cases, the fecundity-avoidance biomass threshold (i.e., the maximum allowable weed biomass for herbicide application in order to prevent weed seed production and dispersal) for glyphosate was below the ED₉₀ value. Complimentary measures such as fecundity-avoidance biomass threshold will improve herbicide evaluation procedures and preserve the effectiveness of herbicides, including glyphosate, on sensitive species, an important issue particularly when action to reduce herbicide resistance development is highly required. Full article

Grain number and weight within a spikelet are major yield components which determine the grain yield in wheat. The objective of this study was to explore genetic gains in grain performance within wheat spikelets at the individual grain level and its effect on grain yield and evaluate genetic progress in stem internode length and other yield-related traits. We conducted field experiments across three growing seasons in the western Yellow and Huai Valley of China; incorporating 17 bread wheat cultivars released from 1948 to 2012. Yields were significantly correlated with year of release. Yield gains equated to 3.95 g m⁻² yr⁻¹ in response to increases in total grain weight per m² (GW) in proximal (G1 and G2) and distal (G3 and G4) grains, despite a decline in the proportional contribution of proximal grains to yield and increase in the proportional contribution of distal grains to yield with year of release. Grain number per m² (GN), thousand-grain weight (TGW), and harvest index (HI) increased with year of release, but plant height decreased. Both grain number per spikelet of proximal and distal grain contributed to the increase in total GN. However, the contribution ratio of GN in proximal grains to total GN declined, and the proportion in distal grains increased. Average single grain weight (SGW) increased linearly at G1, G2, G3, and G4 with year of release and contributed to the increase in TGW. The G3 and G4 grain positions had much lower individual grain weights but increased at a faster rate than G1 and G2. At G1, G2, and G3 grain positions, from bottom to top spikelets, the newly released cultivars had the heaviest grains and the old cultivars had the lightest grains. New cultivars had more spikelets than old cultivars and the number of grains (proximal and distal grains) in the apical spike increased with year of release. The length of five internodes decreased significantly with year of release, more so in the upper than lower internodes, all of which contributed to the decline in plant height. In summary, increasing the number and weight of distal grains could increase grain yield, TGW, and GN. Full article