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Current cultivation practices for field transplanted potato crops grown from nursery-raised hybrid potato seedlings are mostly borrowed from the tuber-based conventional system. Most studies on field performance of field transplanted seedling crops have largely reported the use of ridged rows and in exceptional cases, the use of beds. It is therefore critical to assess the feasibility of the use of alternative ridge or bed systems for cultivation of field-transplanted nursery-raised potato seedlings considering the differences in physiological behaviour of crops grown from different starting materials. This study assessed the effects of six systems which included bed and ridge systems of different dimensions and planting configurations for field transplanted seedling crops. Field crop establishment, canopy growth and development as well as yield and yield components were assessed. In general, systems that boasted high plant densities resulted in faster canopy development and higher number of tubers and tuber yield. Bed systems (raised and flat beds; 8.0 plants m−2) therefore gave the highest numbers of tubers and tuber yield across all treatments. These systems also produced the most tubers in all tuber size classes resulting in the highest yields in all classes. Standard ridge systems (full- and half ridges; 0.75 m row distance), had the lowest plant populations (5.3 plants m−2) which resulted almost always in fewer tubers and lower yield. Other ridge systems (0.9-m and 0.5-m ridge systems), although having higher plant densities than the standard ridge systems (8.9 and 8.0 plants m−2, respectively) still performed poorer than the bed systems. The small and compact ridges in the 0.5-m ridge system and the compact arrangement of plants in the 0.9-m ridge system caused these effects. Conclusively, based on this study, productivity in field transplanting systems is highly influenced by plant density. Further, cultivation systems boasting higher planting densities should be recommended when the goal for production is to produce large quantities of seed tubers (> 35; ≤ 50 mm). • Higher planting densities favour faster canopy development in seedling-based crops • Bed systems give more tubers and higher tuber yield than ridge systems • Standard ridges are only suitable for tuber-based, not for seedling-based crops • High planting densities are required to produce large quantities of seed tubers [ABSTRACT FROM AUTHOR]

Agricultural production and climate change strongly influence each other and there are significant efforts to minimize negative impacts in both directions. In particular, breeding progress has succeeded in reducing the carbon footprint (CFP) of cereals over time. However, there is widespread certainty that climate change-related weather extremes have led to stagnation of cereal yields in many global production regions. We assume that climate change-related yield stagnation is also evident in variety trials in Germany, which has to date only been shown for on-farm yields. Furthermore, we expect that the stagnation in yields also leads to a stagnation in the downward trend of CFP, and that heat and drought stress in particular increase the CFP of cereals. In addition, we hypothesize that the site-specific soil quality largely determines stress induced increases in CFP. We conduct a partial life cycle assessment (LCA) with German variety trial data from 1993 to 2021 and determine the greenhouse gas emissions per unit of land (GHGL), as well as the CFP of winter wheat, winter rye, and winter barley. Further, we evaluate the time trends of yield, GHGL, and CFP using linear and quadratic plateau models. In addition, we calculate spatio-dynamic weather indices (WIs) for moderate, severe and extreme heat and drought stress. Using mixed models, we estimate the explanatory power and effect size of heat and drought WIs on the CFP. Finally, we present the spatial differences of heat and drought on the CFP at different soil qualities. We show yield plateaus in all crops and stagnating GHGL trends, resulting in a stagnation of the downward trend of CFP, especially for rye and barley. We highlight that heat and drought increase the CFP of all crops. However, the impact of heat and drought on the CFP varies greatly with soil quality across all crops. We conclude that climate change-induced weather extremes are major challenges not only for cereal production and food security but also for climate change mitigation in the agricultural sector, highlighting the importance of high-yield locations, alongside variety selection and resource-efficient management, for climate change mitigation. This study is the first that proves significant yield stagnation in German variety trials. Moreover, this study is the first to analyze the impact of heat and drought stress on cereal CFP, with novel results that proof that climate adaptation will become a crucial aspect of climate change mitigation in field crops. • First study that finds a yield plateau in wheat, rye, and barley variety trial data. • Heat and drought stress increases the Carbon Footprint (CFP) of cereals. • Larger variation in CFP between sites than between years in all crops. • Plateau interrupts downward trend of CFP due to negative E development. • Climate change induced abiotic stress hampers efforts in climate change mitigation. [ABSTRACT FROM AUTHOR]

The utilization of crop nitrogen (N) status as an in-season diagnosis tool for predicting N needs to maximize grain yield (GY) is a well-established concept in agronomy. However, a cross-species comparison including the characterization of yield components, grain number (GN) and grain weight (GW), to understand the physiological basis behind the GY-crop N status relationship is still missing. The main goal of this study was to perform a cross-species comparison for maize (Zea mays L.), rice (Oryza sativa L.), and wheat (Triticum aestivum L.) of the relationship between crop N status around anthesis as a GY and GY components prediction diagnosis method. A systematic literature search was carried out for these major field crops, the final dataset (comprising 629 observations) consisted of 15 publications including information on i) shoot biomass and plant N concentration or N nutrition index (NNI) values at anthesis, ii) GY, and iii) GN and/or GW. An analysis was conducted to assess the sensitivity (slope of the linear models) of GY, GN, and GW to changes in crop NNI status at anthesis. Notably, the crop N status at anthesis demonstrated a strong relationship between both GY (R2 between 0.66 and 0.93) and GN (R2 between 0.58 and 0.94) across all crops, with a slightly weaker relationship with GW (R2 between 0.30 and 0.83). Considerable uncertainty was observed on the GY and GN sensitivity (S) to N deficiency across all crops. Maize showed the greatest sensitivity of GY to NNI (S = 964 g m−2), with lowest sensitivity for wheat crop (S = 496 g m−2). Regarding GN, rice showed the greatest sensitivity to NNI (S = 23859 GN m−2), whereas maize was less sensitive (S = 2673 GN m−2). While maize exhibited a positive association between NNI and GW (although with considerable uncertainty), this relationship was less evident for rice and wheat crops. Our findings demonstrated that crop N status at anthesis is a better predictor of GY and GN than GW in maize, rice, and wheat. Maize showed the greatest range in observed values for relative GW relative to NNI, highlighting the impact of crop N status on GW determination. These findings contribute to improving the understanding of the importance of achieving adequate crop N status at anthesis as key aspect for yield formation, with implications for both breeding programs and the optimization of on-farm crop N management. • Crop N status at anthesis showed a strong relationship with grain number. • Maize showed the greatest sensitivity of grain yield to NNI at anthesis. • Rice showed the greatest sensitivity of grain number to NNI at anthesis. • Maize showed the greatest responses of grain weight to crop N status at anthesis. [ABSTRACT FROM AUTHOR]

Continuing to raise the potential yield of wheat through breeding is essential for global food security. Past progress has largely been associated with greater grains/m2 (GN), the critical period for the determination of which relates to spike growth, with GN often closely related to spike dry weight at anthesis (g/m2). This focussed review outlines the importance of the critical period duration (Ds, in days or °Cdays) and questions how it may be increased genetically, relying partly on the long involvement of the authors in this field, primarily with lower latitude crops of spring-type wheat. Ds is further defined as the interval between flag leaf emergence and first anthesis, each across 50 % of the culms in any crop, a period encompassing most of the accumulation of spike dry matter, in turn determining floret survival and final fertile floret numbers/m2. Natural temperature variation and temperature manipulation, particularly in field crops, confirm the dependence of Ds on temperature, which in °Cdays varies from about 300–500, depending on photoperiod. Evidence points to a stronger influence of night than day temperature on Ds, while maintaining the close positive Ds relationship to GN. However, genetic variation in the response of Ds to temperature appears very minor. Ds is inversely related to photoperiod, again with the expected effects on spike dry weight, fertile florets and GN. Extended photoperiod during the critical period showed the greatest reduction in GN per day advance in anthesis. Ds responses can be related to the major photoperiod sensitivity alleles present. A field experiment with a unique reduced photoperiod treatment demonstrated a strong positive effect on Ds, fertile florets and GN, especially in the fully recessive photoperiod-sensitive isoline. While more recent varieties tend to have a longer Ds, experiments targeting selection for Ds or closely related intervals have delivered little change in Ds, which often showed low heritability. Field photoperiod shortening studies needs further testing as proof of concept. Better selection studies are also needed. At the same time, knowledge of the molecular basis of the leaf response to photoperiod is such that gene editing is surely ripe to tackle the challenge of down-regulating this response only during the critical period, thereby increasing Ds and GN. Exogenous application of plant development regulators at the appropriate stage may also provide a way forward. • Grains per m2 (GN) variation is related to spike dry weight (g/m2) at anthesis. • The critical period (CP) for spike weight is approx. flag leaf emergence to anthesis. • Temp. and ppd. change confirm the importance of CP duration for spike weight. • Genetic sensitivity of CP duration to ppd. may offer a way to increased GN. • Gene engineering could be another plausible route to longer duration. [ABSTRACT FROM AUTHOR]

Popcorn [ Zea mays (L.) var. Everta] is an important field crop in the Midwestern United States. However, hailstorms are a major threat to ensuring high yield because of their effects on leaf photosynthesis, pollination, and stalk lodging. A multi-state study spanning six site-years (2020–2023) was conducted in two locations (Ohio and Nebraska) to determine how defoliation intensity at different stages affects yield loss in popcorn and compare these losses with current values in the National Crop Insurance Service (NCIS) Corn Loss Instructions. At each location the study was conducted in a randomized complete block design with four replicates. The treatments consisted of the combination of four levels of leaf loss (25, 50, 75 and 100 % leaf blade area removal) imposed at five developmental stages: V8 (10-leaf), V13 (15-leaf), VT, R2, and R4. The evaluated traits were plant population, grain yield, stalk lodging, and 100-kernel weight. All evaluated traits were affected by defoliation, except plant population. The treatments 100 % defoliation at VT and R2 stages were the most damaging in terms of grain yield reduction, number of ears per plant and 100-kernel weight for both locations. In Ohio, the greatest stalk lodging was observed at 100 %-R2 and in Nebraska, at 75 %-VT. For both locations, the actual yield losses in the defoliated treatments were lower than values currently listed in the NCIS Popcorn Leaf Loss Chart. These results indicate leaf loss chart values should be updated to accurately reflect yield losses from popcorn defoliation events. This evaluation did not impose damage to stalks (e.g., bruising) or to plant whorls as may be expected in natural events. Future research should incorporate other forms of plant damage such as those described to provide a better emulation of hail damage. • Popcorn plants are most sensitive to defoliation at the VT stage. • Yield losses can exceed 90 % when leaf loss is 100 % at the VT stage. • Yield loss estimates in loss instructions are similar or greater to those observed. [ABSTRACT FROM AUTHOR]

Intercropping, a sustainable agricultural practice, is pivotal in enhancing land use efficiency, soil fertility, and overall crop productivity. This study zeroes in on the dynamics of Maize-Cowpea intercropping in the Alluvial Zone of West Bengal, a region characterized by its fertile soil and diverse agro-ecological conditions. The practice of intercropping, particularly in regions like West Bengal, holds immense potential in revolutionizing traditional farming methods by maximizing yield per unit area while ensuring sustainability. The study aims to unravel the complexities and benefits of this practice, especially in the context of the monsoon dependent Kharif season, which is crucial for agricultural productivity in the region. The study aims to evaluate the effects of various Maize-Cowpea intercropping patterns and nutrient management strategies on maize growth, yield, and quality during the Kharif seasons of 2019 and 2020. It hypothesizes that intercropping, combined with optimal nutrient management, can significantly enhance maize performance. Employing a split-plot design, the study analysed 25 treatment combinations of intercropping and nitrogen fertilization under sub-tropical sub-humid conditions. Advanced quantitative methods, including regression analysis and principal component analysis (PCA), were used to assess the interactions between intercropping systems and nutrient management practices. The findings revealed that while sole maize cultivation showed better growth and yield, Maize-Cowpea intercropping, especially in a 1:1 row ratio, significantly increased the total system yield by 13.6%. This method also improved grain quality, notably enhancing crude protein content and nutrient percentage. A combination of 75% recommended dose of nitrogen (RDN) through chemical means with 25% RDN through organic sources, including seaweed, was particularly effective in boosting maize performance. The study confirms the superior performance of Kharif maize in an intercropping setup, particularly when integrated with cowpea. It demonstrates the effectiveness of specific nutrient management strategies in enhancing both quantitative and qualitative traits of maize. This research significantly contributes to the field of sustainable agriculture, particularly in the context of field crops research and practice. The findings offer valuable insights for enhancing crop productivity and sustainability in similar agro-ecological regions globally. The study underscores the benefits of integrating legumes with cereals in intercropping systems, paving the way for innovative agricultural practices that can meet the dual challenges of food security and environmental sustainability. The implications of this research are far-reaching, providing a robust framework for future agricultural strategies in regions facing similar climatic and soil conditions. • Enhanced nutrition from legume intercropping boosts maize yield and quality. • Intercropping enhances total maize yield over sole cropping. • Integration of organic and inorganic nutrient was identified as optimum. [ABSTRACT FROM AUTHOR]

A comparative analysis of grain yield performance of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) under different environments constitutes a way to identify restrictions in yield formation between both crop species. However, most of the previous studies on these field crops have been carried out in Mediterranean environments. This study aims to compare the grain yield performance of wheat and barley across a wide range of temperate environmental conditions. Wheat and barley yield databases from the national network of cultivar evaluation of Argentina were assembled. The database included 191 wheat cultivars (with early-, mid- and late-flowering length cycle), 140 barley cultivars, and 44 combinations of sites and years of the Argentine wheat and barley belt region. Average heading date variation among environments and crops was no more than 10 days. Crop grain yield comparisons were carried out using a regression analysis, benchmarking within each site-year the grain yield of each cultivar against the average grain yield of all crop cultivars (i.e., environmental index). There were no differences in grain yield between wheat and barley for all data, but the behavior between crop species changed with the length of the wheat cycle (i.e., early-, mid-, or late-flowering cultivars). Barley portrayed a greater grain yield than early-flowering wheat under low-yielding environments (< 6060 kg ha−1), but this advantage vanished as the yield environment improved. Mid-flowering wheat showed a similar grain yield to barley across temperate environments. Lastly, late-flowering wheat outperformed barley mainly in high-yielding environments (> 6138 kg ha−1). Grain number m−2 was the main numerical component that explained variability in grain yield. The relative contribution of the yield numerical components differed between species, having barley lower grain number m−2 but a greater grain weight than wheat. The comparison of the grain yield performance between species represents a strategy to adjust the rotation system, being a critical factor in considering the variability in the crop growth cycle. • Yield performance offers valuable insights to select the best crop option into the right environment. • Wheat and barley have similar grain yield performance when they have similar cycle duration. • Barley outyielded early-flowering wheat (shorter season) in low-yielding environments (< 6 Mg ha−1). • Late-flowering wheat (longer season) outyielded barley in high-yielding environments (> 6 Mg ha−1). • Yield variations were governed by changes in grain number per unit area for both crop species. [ABSTRACT FROM AUTHOR]

Yield gap analyses are useful to assess and benchmark the productivity of cropping systems. Often such analyses are performed at higher aggregation levels. As a result, these studies lack the detail to explain yield gaps at field level and hence make it difficult to translate findings into precise recommendations to farmers and extensionists. This study provides a detailed approach for yield gap assessments at field level through coupling frequent field monitoring in farmers' fields with crop growth modelling. We used ware potato production in the Netherlands as a case to study yield gaps at field level, as average productivity is high whilst yields are still highly variable among fields, and as ware potato is an important cash crop for farmers. Over two growing seasons, 96 ware potato fields were monitored throughout the growing season on a biweekly basis, taking measurements on soil, crop growth and yield. The crop growth model SWAP-WOFOST was used to simulate potential and water-limited potential yields. Various statistical methods were used to quantify yield gap explaining factors. The average yield gap ranged from 20 to 31% depending on the year and soil type. Among fields, the yield gap ranged from 0 to 51%. On clayey soils, the yield gap was attributed mostly to oxygen stress. On sandy soils, the yield gap was determined mostly by drought stress in 2020, a relatively dry year, and by reducing factors (pests, diseases and poor agronomic practices) in 2021, an average year in terms of precipitation. The type of reducing factors differed per field. Furthermore, we found that earlier planting and later harvesting can increase yields, as Yp is radiation-limited. Overall, there is limited scope to narrow the yield gap as current ware potato production is already close to 80% of the potential yield, which is assumed to be approximately the maximum farmers can attain. However, yield and resource use efficiency gains are to be made for individual fields. Furthermore, we conclude that frequent field monitoring coupled with crop growth modelling is a powerful way to assess yield gap variability and to get detailed insight in the yield gap explaining factors at field level. This study showed that coupling frequent field monitoring with crop growth modelling allows to gain detailed insight in yield gap variability among fields. This method provides detailed information about yield gap explaining factors which can be used to improve yield and resource use efficiency at field level. [Display omitted] • Yield gaps were decomposed at field level for ware potato crops in the Netherlands. • The yield gap ranged from 0 to 53% among individual fields. • The yield gap was attributed mostly to oxygen stress on clayey soils. • The yield gap was attributed mostly to drought stress and reducing factors on sandy soils. • Our method provided detailed insight in the yield gap variability at field level. [ABSTRACT FROM AUTHOR]

Winter wheat (Triticum aestivum) is one of Switzerland's most important field crops and requires large quantities of nitrogen (N) to produce a high yielding and high-quality crop. However, N is an expensive input for producers that is prone to environmental losses, thus causing pollution and environmental degradation. Furthermore, the N use efficiency (NUE) of wheat remains low. Our goals were to test whether different N fertilizer splits could maximize grain yield and grain N content (a proxy for grain quality) while improving nitrogen use efficiency, identify key variables in determining yield and N grain content, and to determine if variety- and site-specific fertilization recommendations provide additional benefits to nutrient use efficiency. We designed a four-year study across three sites in Switzerland that incorporated five top Swiss varieties of winter wheat and six different N application regimes applied at BBCH 21, 31, and/or 39 that totaled either 0, 80, or 160 kg N ha−1. In addition to mixed model analyses, we used random forest to identify key genetic, environmental, and management variables in determining wheat grain yield and grain N content. Grain N content and yield were found to be maximized at 8000 kg ha−1 and ≈ 2.24% N. Further, more N is required to increase grain N content compared to yield. With respect to nitrogen use efficiency, we found that the total amount of N applied has a greater effect on NUE compared to the rate of the N splits. In general, the rate of the first and second N applications were most important in determining both yield and grain N content, but the rate of the third N application was important in determining the latter. In general, our results did not show broad support for variety-specific fertilization, however site-specific fertilization holds some promise. Creating a winter wheat fertilization system that reduces negative environmental externalities while retaining high yields and quality remains challenging. However, we found that under the conditions tested here, a N regime of 40-40-80 kg N ha−1 may maximize both yield and grain N content, and under some circumstances, improve nitrogen utilization efficiency. This may provide environmental benefits, as well as monetary benefits for producers. Given the current focus on nitrogen use and regulation, research maximizing the utility of nitrogen applications to ensure high grain yield, grain N content, and nitrogen use efficiency is vitally important. This and future work will help producers grow high-quality crops while lessening the environmental impact. • In winter wheat, nitrogen is crucial for attaining both high yield and quality. • In wheat, the efficient use of nitrogen is low, thus impacting profits and the environment. • Swiss top varieties are more similar in yield than grain N content. • Yield and grain N content can be maximized at ≈ 8000 kg ha−1 and ≈ 2.24% N (or ≈ 14% protein). • The efficient use of N is largely controlled by total N applied, rather than different N splits. [ABSTRACT FROM AUTHOR]

Field crops, irrigated and rain-fed, constitute the majority of cropland worldwide. An important agricultural variable determining their biomass production is planting density. The objective of the study was to explore the relationships between the biomass (dry matter) and planting density for either major individual field crops or all field crops, combined, and to suggest empirical models describing them. This article describes a meta-analysis of the literature data on biomass per unit area or plant versus planting density for 8 major field crops: 4 cereals (corn, wheat, sorghum, and pearl millet) and 4 forbs (soybean, sunflower, rapeseed, and buckwheat). When data from all 8 field crops are combined, it seems that areal biomass production is practically independent of planting density, apparently obeying the constant final yield hypothesis. By contrast, analyzing each of the 8 crops separately, there is a clear rising trend of areal biomass with increasing planting density, with a mean intraspecific allometric exponent of about 0.25, and individual exponents that increase systematically with a decrease in the average planting density. Applying a planting density-dependent allometric exponent improves the predictability of the interspecific biomass–planting density relationship for field crops. A bounding, exponential model that describes the biomass–planting density relationship in the agricultural range of 1–1000 plants per m2 better than power-law allometric equations is proposed. Although the biological meaning of a derived generic expression relating areal biomass to single-plant biomass for field crops is not clear, the deviation of the outliers probably reflects already utilized or remaining breeding potential for increased areal biomass and agricultural yields. A good understanding, quantification, and prediction of the biomass–planting density relationship is essential for both plant breeding and management of crop production. Plant breeders need this knowledge to choose between strategies for either increasing the single-plant biomass or increasing the plants' tolerance to high planting density. Agronomists and extensionists need it to optimize planting density for a particular variety under given environmental and agricultural (GxExM) conditions. • Planting density is one of the major factors that determine biomass production and agricultural yields of field crops. • Results for 8 major field crops show a clear rising trend of areal biomass with increasing planting density for each crop. • The intraspecific allometric exponent increases with decreasing crop planting density. • A bounding exponential function is superior to a power function for describing the biomass-planting density relationship. • Reported results have implications for agronomic and economic optimization of planting density. [ABSTRACT FROM AUTHOR]

• Continuous cropping decreased seed yield most in the second cropping. • Sesame yield depended on the field conditions and cropping. • Seed mineral quality of crude protein and N, P, Fe, Zn and Mn were significantly decreased in the second cropping. • 'Gomazou' and 'Maskin' showed high seed yield despite continuous cropping obstacle. Sesame (Sesamum indicum L.) is an important oilseed crop that is negatively affected by continuous cropping but there is still limited research on this phenomenon. A three-year field experiment was conducted from 2012 to 2014 at Tottori, Japan, on an upland field converted from a paddy to determine the effect of continuous cropping on seed yield, crude protein and mineral nutrient contents of four sesame cultivars ('Maruhime', 'Nishikimaru', 'Gomazou', 'Masekin') and identify cultivars adaptable to continuous cropping obstacle. Seed yield, crude protein and mineral nutrient contents were negatively affected in the second cropping: however, the level of response differed among the cultivars. In the first cropping, the intercultivar yield differences were not significant whereas seed yield showed significant differences among the cultivars in the second cropping. Averaged over years, seed yield was significantly lowest in 'Maruhime' and 'Nishikimaru' compared with 'Gomazou' (588.3 kg ha−1) and 'Masekin' (450.3 kg ha−1). Averaged across cultivars, the seed crude protein and N, P, Fe, Zn and Mn contents decreased by 7.5, 10.0, 19.4, 14.7, and 13.6% in the second cropping compared with the first cropping. Although 'Maruhime' yields in the second cropping were lower than those of the other cultivars, its crude protein, N, P, and Fe contents were generally highest. Changes in the soil nutrients N and available P partially explained the decrease in the yield and seed mineral contents. The variation in the seed yield, crude protein and mineral nutrient contents in the second cropping reflected differences in the cultivar response to continuous cropping that influence the seed composition. To minimize this yield reduction, adoption of two sesame cultivars 'Gomazou' and 'Masekin' could be recommended to overcome continuous cropping obstacle on upland fields converted paddy. [ABSTRACT FROM AUTHOR]

• Increased vernalisation requirement of canola proposed as mechanism to improve yield. • Spatial modelling shows yield advantage in 3.7 Mha from increased vernalisation. • New winter × spring crosses could lift canola production by 10% in Southern Australia. • Winter × spring canola lines provide intermediate maturity between spring and winter types. • Longer season canola will provide opportunities for earlier sowing of crops. Long season, winter-type canola cultivars have the potential for significantly higher yields than short-season, spring-type canola, yet until recently, breeding of new canola cultivars in Australia has focussed on spring-type canola. This has been to accommodate the typically drier, warmer conditions across the Australian cropping belt where long-season varieties do not perform well due to delayed flowering and risk of water-stress during grain fill. However, as cropping continues to expand into the Australian High Rainfall Zone (500–900 mm, HRZ), breeders have become increasingly interested in developing winter-spring crosses (not yet commercially available) which have an intermediate phenology between that of a spring and winter-type canola. As the vernalisation requirement for these crosses is lower than winter-type canola, the areas where such cultivars can be grown profitably in Australia is potentially much wider than for winter-type canola. Field experimentation and crop simulation studies across the potential cropping region of southern Australia were used to determine the yield potential of these winter-spring canola crosses compared with currently available spring-type and winter-type cultivars. Our analysis showed that the four winter-spring crosses evaluated had a range of vernalisation requirements which were between the small requirements of spring-types and the large requirement of winter-types. In this study the Catchment Analysis Tool (CAT) spatial modelling framework was used to determine the expected canola yields of four cultivars across the entire cropping region of southern Australia. These cultivars were the spring-type 45Y88CL, winter-type Hyola® 970CL and two winter-spring crosses K50057 and K50058 with vernalisation requirements at the higher end and the lower end of the range of winter-spring crosses, respectively. The potential benefit of some increase in the vernalisation requirement, based on the area currently sown to canola, was an additional 381 M tonnes per year (based on 50-year average) of canola, if K50058 was sown in areas where it proved superior to 45Y88CL. At the 5-year average canola price of $486 t−1, this would provide an additional AUD 185 Mil/annum for the industry. In general, the modelled yield advantage from canola cultivars with increased vernalisation requirement was greater in the areas of southern Australia that had milder climates and higher rainfall. The value to the Australian canola industry of substituting spring cultivars (e.g. 45Y88CL) with winter x spring (K50057) or winter (Hyola970CL) cultivars where they had a yield advantage, was AUD 82.8 M and AUD 29.2 M, respectively. [ABSTRACT FROM AUTHOR]

While crop breeding represents a key factor in terms of effectiveness and affordability in the adaptation of agriculture to stress conditions, phenotyping is perceived as a major bottleneck to achieving genetic advance. Crops in the field experience the simultaneous occurrence of multiple stresses, which vary depending on the location, year and management conditions. Even under the so-called "optimal agronomic conditions", crops under field conditions may experience some degree of stress. The review addresses the methodology of field phenotyping in environments with multiple stresses where genotype by environment (and even by management) interactions are common, the ideotypes that may work, and the phenotypic traits that characterise such ideotypes that are the most useful for identifying better adapted genotypes. Mediterranean wheat is taken as a case study. Integrative phenotypic traits have intrinsic value in terms of information about crop adaptability to growing conditions in a wide sense, thus inherently accounting for the occurrence of "hidden" stresses. Indeed, this has implications when considering genotype by environment interactions. Thus, such integrative traits, when evaluated under real (i.e. field) conditions, account for the crop's performance under scenarios where the interaction between environmental growing conditions is the norm. Three categories of traits may comprise the ideotypic characteristics when phenotyping wheat for Mediterranean environments: phenology, water status and plant growth. While these characteristics are not fully independent of each other, they should represent the crop's performance reasonably well over a wide range of Mediterranean scenarios. It is in such a context that this review examines the case of wheat and other small grain cereals growing under Mediterranean conditions and illustrates how a few phenotyping traits, related to crop growth, water status and phenology, may define ideotypes well adapted to a wide range of environmental conditions, where non-crossover interactions exist. This is despite the fact that across such a range of environmental conditions, multistressors are present and are variable in nature, intensity and timing. Thus, for a wide range of Mediterranean conditions, the genotypes chosen correspond to ideotypes that exhibit more effective use of water and stronger growth. It is not only the characteristics of the ideotypes, but also the appropriate phenotypic traits characterising these ideotypes that are integrative in nature, meaning that they inform about crop performance over time (e.g. stable carbon isotope composition) and/or at the highest organisational level (e.g. canopy assessed via remote sensing). At the functional level, these traits guide improvements in the capture of resources such as water or radiation, rather than how efficiently these resources are being used. • Crops in the field experience simultaneous occurrence of multiple stresses. • Ideotypes can be formulated based on characters phenotyped with integrative traits. • A few traits may define wheat ideotypes that are well adapted to a wide range of Mediterranean conditions. • Classical ways to display GxE interaction help to assess trait performance across growing conditions. • These traits guide improvements in the capture of resources, rather than how efficiently they are being used. [ABSTRACT FROM AUTHOR]

Variability in biomass production poses a challenge for growers when using cover crops for weed control. However, most methods for assessing cover crop biomass are laborious and impractical on a field scale. The goal of the present study was to determine the feasibility of using Structure-from-Motion (SfM) photogrammetry to estimate biomass in cereal rye (Secale cereale L.) and winter wheat (Triticum aestivum L.) cover crops by correlating biomass with 3-D point cloud pixel density and crop height. Point clouds were generated using a SfM algorithm from RGB (red, green, and blue) videos collected by a hand-held GoPro camera over sixteen crop fields in North Carolina, Iowa, and Maryland, USA, throughout two growing seasons (2021–2023). Crop height, leaf area index (LAI), and photosynthetically active radiation (PAR) were also measured. Biomass was positively correlated with crop height for both cereal rye (R 2 = 0.621) and wheat (R2 = 0.55). LAI was positively correlated with biomass accumulation and crop height for both species, increasing linearly in rye and exponentially in wheat. Conversely, PAR penetration below the canopy decreased with biomass accumulation and crop height in both species, with a more rapid extinction in wheat than rye. Point cloud pixel density showed a positive linear relationship with biomass in rye but saturated after 2.5 tonnes ha−1 (2500 kg ha−1). In wheat, point cloud pixel density was weakly and negatively correlated with biomass due to a denser canopy causing faster saturation of tissue detection by SfM point clouds. However, considering crop height and point cloud density integrating them both in the model allowed obtaining a positive relationship with biomass through levels of 8 tonnes ha−1 (8000 kg ha−1) in both species. When models were validated with independent data, predicted and measured biomass were positively correlated for both rye (R2 = 0.86) and wheat (R2 = 0.78). Based on the results, using SfM to generate 3-D point clouds can provide a more accurate estimation of biomass than canopy height alone by capturing species-level differences in canopy architecture. The results of this study suggest that SfM can potentially be used as a non-destructive tool for growers to monitor biomass production in cereal cover crops other systems such as energy/forage crops, which can help inform management decisions and conserve resources. • Variable biomass production in cover crops is a challenge for weed suppression. • 3-D point clouds from Structure-from-Motion (SfM) can estimate cover crop biomass. • A camera and SfM were used to visualize canopy structure. • SfM may provide growers with a simple tool for monitoring cover crop performance. [ABSTRACT FROM AUTHOR]

Barley is one of the most relevant crops worldwide and an essential component of agriculture in Europe in general, and in the Mediterranean region in particular. As cropping areas will hardly rise in the future, yield must be improved to enhance global crop production. Naturally, understanding how yield is affected by environmental and genetic factors in two- and six-rowed barley can help us to develop more efficient management and breeding strategies to increase current yield gains. We aimed to determine the relative importance of genetic and environmental factors on numerical and physiological components of GN for two- and six-rowed barley types. To generate a large and unbiased database, we compiled data of yield and its numerical and physiological components from crop-based experiments (i.e., excluding controlled-conditions experiments and/or approaches using isolated plants) reported in figures and tables in every single paper having the word "barley" in the title published over 25 years in four rigorous and prestigious international journals: Field Crop Research, European Journal of Agronomy, Crop Science and Crop and Pasture Science (formerly Australian Journal of Agricultural Research) between January 1996 and December 2021, both inclusive. Spike number (SN) was the most relevant numerical component explaining GN regardless of the source of variation. Regarding physiological components, it seemed that when the driving force was environmental factors, spike dry weight at flowering (SDW F) was more relevant than fruiting efficiency (FE); whilst when the differences were due to genotypic factors, clearly the FE was the component mostly responsible for the changes in GN. When the analysis was restricted to two- and six-rowed barley types, GN improvements were mainly explained by changes in SN for both two- and six-rowed barley types. However, when the physiological components were considered, the responsiveness of GN was more related to SDW F than to FE in two-rowed genotypes, while the opposite was true for the six-rowed type. In barley, SN always explained the responses of GN better than grain number per spike (GNS), regardless the source of variation and the type of barley. Respect to the physiological components, environmental factors affected GN mainly through affecting SDW F , while genotypic factors affected GN through affecting FE. SDW F and FE were more relevant for explaining changes in GN two- and six-rowed barleys, respectively. Breeders and agronomists can be aware that it will be more likely to achieve significant gains in yield through focusing more on SN than on GNS regardless of the barley type, whilst regarding the physiological components it would be more relevant to focus on SDW F in two-rowed barley, and on FE in six-rowed barley. • We quantified grain number components depending on source of variation in barley. • Spike number (SN) explaining grain number regardless of the source of variation. • Spike dry weight (SDW F) was the most relevant component for environment factor. • Fruiting efficiency was more relevant for genotypic factor. • Grain number was more related to SDW F in two-rowed, while FE in six-rowed type. [ABSTRACT FROM AUTHOR]

Whilst mineral fertiliser is required to meet nearly 50% of global crop demand, its production is energy intensive and contributes close to 2% of the global emissions of greenhouse gases. The aim of this study is to evaluate the efficacy of a novel fertiliser to meet crop demand and its impacts on soil health. This novel fertiliser incorporates point source carbon dioxide captured into organic matter balanced with mineral fertiliser. It is hypothesised that this carbon capture-based organo-mineral fertiliser (CCOMF) will mineralise and release nutrients adequate to meet demand of cereal crops. Two field trials were conducted to evaluate the performance of CCOMF on winter wheat and winter barley. Each field trial compared three concentrations of CCOMF (5% N, 10% N, and 15% N) to a conventional mineral fertiliser treatment and an unfertilised control. Each fertiliser treatment was applied at the recommended application rate for the crops (270 kg/ha N and 180 kg/ha N, for winter wheat and winter barley, respectively). Each field trial included three additional application rates for each fertiliser treatment of 50% less, 50% more, and double the recommended rate in order to obtain a yield response curve. This totalled 160 experimental plots (2 field sites, 5 fertiliser treatments, 4 doses, with 4 replicates). All treatments were organised into a randomised block design with 4 replicates in both sites. The impact of the fertilisers on yield, soil nutrients, and root development were established by comparing baseline soil analysis and root measurements taken before the first application of fertiliser to samples taken at harvest. The results showed that the CCOMFs produced winter wheat and winter barley yields (7.49 ± 0.74 t/ha and 5.85 ± 0.29 t/ha, respectively for the 10% N) comparable to those produced following mineral fertilisers (7.40 ± 0.50 t/ha and 5.35 ± 0.16 t/ha, respectively). There was no significant fertiliser impact on soil organic carbon, microbial biomass, or pH. In terms of nutrients, there was also no significant difference in residual concentrations. There was also no significant difference in root development between the treatments. This study showed that CCOMFs are a promising alternative to conventional mineral fertilisers as they produce comparable yields with no additional negative impacts in the short term. This study is the first of its kind in a field context showing feasibility of using carbon capture technology to formulate sustainable fertilisers adopting a circular economy approach. • This is the first study testing novel carbon-capture based organo-mineral fertilisers (CCOMF) at a field scale. • Winter wheat and barley yields were comparable between CCOMF and conventional mineral fertilisers. • Nutrients from CCOMF were readily utilised by the crops, with no residual effects on soil. [ABSTRACT FROM AUTHOR]

Large-scale vegetation construction has generally led to soil desiccation in arid and semi-arid regions. Energy crops with high biomass and water use efficiency are generally beneficial to agriculture and the environment. It is necessary to understand how to maintain the dynamic balance of soil moisture and biomass production on herbaceous energy croplands. In this study, soil moisture data at different depths of soil were obtained from long-term field observations for two energy crops, i.e., Panicum virgatum and Miscanthus sinensis , and a forage crop- Medicago sativa . Relative aridity of the soil and plant biomass were compared among different vegetation types, transects, and cultivation years. Medicago sativa soil was severely, even extremely, desiccative with increasing cultivation years, whereas there was nearly no desiccation in the soil of energy crops. The values of compared soil water storage compensation indexes in deep soil layers were higher than those in shallow soil layers, with the evaluated soil water storage compensation index being the smallest in the 40–80 cm layer. Energy crops had significantly higher aboveground biomass, mostly exhibiting more than 2.6 kg m −2 , while the aboveground biomass of M. sativa was only above 0.5 kg m −2 . Furthermore, the water use efficiencies of energy crops were obviously higher than that of M. sativa (P < 0.05). Our results indicated that deep soil moisture conditions were mainly determined by field crop types. Energy crops may be suitable candidates for compensating soil water storage and maintaining high biomass production in semi-arid regions. [ABSTRACT FROM AUTHOR]

Lodging is a major limiting factor for high-yielding wheat production due to its negative impact on yield and quality. However, little is known about the relationship between different planting patterns and the lodging resistance of wheat. Different planting patterns alter the precise spatial distribution of crops in the field, which can further affect growth and grain yield. Compared with conventional row planting, more orderly use of growth resources by bunch planting contributed to plant growth and dry matter production. Stem growth is not only related to yield but also to lodging resistance. Based on this, we hypothesise that benefits in crop growth due to bunch planting pattern will promote stem growth to increase its lodging resistance and yield in the field. In this study, a three-year field experiment was conducted with two planting methods (bunch planting and row planting) at two planting densities (normal density, 3.00 × 106 seeds ha−1 (ND); appropriately increased density, 4.50 × 106 seeds ha−1 (ID)) using the multiple-spike wheat variety XN538 and heavy-spike wheat variety LKAZ8 to investigate the effect of bunch planting on wheat yield and lodging resistance and to assess the suitability of bunch planting for wheat production. The results showed that high yields were obtained with both varieties under bunch planting, and overall bunch planting increased wheat yields safety factor by 3.2% and 26.5% respectively. Increasing the planting density further increased the yield of XN538 under bunch planting but reduced the yield of LKAZ8. Bunch planting promotes the morphological development of the basal stem, leading to higher stem diameter, stem wall thickness and stem density per unit length. It also promotes the accumulation of structural and non-structural carbohydrates, leading to lignin, cellulose, soluble sugar and starch contents increased by 23.3%, 28.6%, 26.2%, 54.3%, respectively. The altered morphological characteristics and chemical properties of the stem contributed to the higher mechanical strength and lodging safety factor of wheat under bunch planting at both densities. These results suggest that bunch planting could increase wheat yields and improve lodging resistance. Our study provides insights into the relationship between planting pattern and crop lodging resistance, which may be of interest for field wheat production. • We compared two wheat planting patterns: bunch planting and row planting. • Bunch planting improves stem lodging resistance. • Bunch planting maintains the high-yielding performance of wheat. • Bunch planting boosted stem mechanical strength by promoting stem development and carbohydrate accumulation. [ABSTRACT FROM AUTHOR]

Predicted increase in temperature variability can result in short duration of heat stress episodes coinciding with vulnerable reproductive processes leading to significant reduction in floret-fertility in crops. Recent knowledge on alternations in the pollen and stigmatic morphology, pollen biochemical and lipid composition, variable sensitivity of floral reproductive organs and differential temperature thresholds across crops advances the knowledge on heat stress induced reduction in seed-set and harvest index. Rapid increase in night-time temperature, leading to narrowing diurnal temperature amplitude is a major emerging threat to sustain crop productivity. Interestingly, wild wheat ( Aegilops spp.) with higher heat-tolerance and wild rice ( Oryza officinalis ) escaping damage by completing flowering during early morning hours, are examples of novel opportunities to breed field crops resilient to heat stress. Information on mechanisms leading to heat stress induced sterility is biased towards rice, wheat and sorghum, while the same across other field crops is limited. Hence, increasing research efforts in this direction is critical and timely. [ABSTRACT FROM AUTHOR]

Increasing the production of grain legumes in Europe will contribute to protein self-sufficiency and provide direct and indirect environmental benefits, e.g., delivering ecosystem services such as N input via biological N 2 fixation (BNF). Faba bean (Vicia faba L.) is the main grain legume cultivated in Europe with increasing interest from the organic sector. Agronomic and economic obstacles exist to the inclusion of grain legumes in cropping systems but could be counterbalanced by accounting for the provision of ecosystem services. Thus, variations in productivity and BNF under different management need to be investigated. We assessed productivity, yield stability and BNF in a common faba bean variety (Boxer), grown for four years (2015–2018) in a long-term crop rotation field experiment at Foulum, Denmark. We compared conventional and organic cropping systems with spring cereals and faba bean, with and without long-term use of animal manure and cover crops. N derived from atmosphere (%Ndfa), determined with the 15N isotope dilution method, varied from 78% to 93% with significant effects of year and cropping system. Conventional treatments had the highest %Ndfa and yield, but the lowest yield stability. Organic treatments had problems with pests and diseases, mainly towards the end of the growing season. Quantity of BNF (qBNF) in aboveground biomass was on average 255 kg N ha−1 in the organic and 334 kg N ha−1 in the conventional systems, which would have been underestimated by up to 50 and 100 kg N ha−1 respectively using standard literature %Ndfa values. A correct estimation of N input via BNF has economic and environmental implications (e.g., fertilization of following crops, N losses); thus, we recommend to account for the effect of management on %Ndfa and qBNF. • Higher yield and N 2 -fixation in conventional than organic faba bean. • Higher yield stability in organic than conventional faba bean. • Organic faba bean yield was as or more stable than organic spring cereals. • N derived from atmosphere range was 78–93% and 199–399 kg N ha−1 aboveground. • N 2 -fixation was underestimated with standard values, disregarding management effect. [ABSTRACT FROM AUTHOR]

Remotely estimating plant nitrogen concentration (PNC) at the vegetative growth stage plays a crucial role in the precision N management of field crops. However, the great challenges still remain on how to overcome the impact of canopy structure variation and the 'N-dilution' effect on the accuracy of PNC assessment using spectral indices (SIs). This study was to apply machine learning (ML) algorithms fed with the optimized spectral indices (OSI), sensitive spectral bands (SSB), and full-spectrum (FS) to improve the prediction accuracy of PNC in critical vegetative growth stages of wheat, maize, rice, potato and the across crops. Four ML algorithms including the partial least squares regression (PLSR), random forest (RF), support vector regression (SVR), and artificial neural network (ANN) were compared for their efficacies in predicting PNC from ten field trials in different locations from 2005 to 2016. The input variable had a non-negligible influence on the performance of ML models. The OSI was the most efficient input variable for the tested ML algorithms in predicting PNC. The OSI-based RF models showed consistent outperformance compared to other models regardless of crops. The coefficient of determination (R 2) was 0.51˗0.85 and the root means square error (RMSE) was 0.15% ˗ 0.34% in the experimental validation datasets. By choosing PNC-related spectral features across crops, the OSI-based RF models increased prediction accuracy by 10–31% compared with the best OSI-simple regression models, which was because the OSI-based RF models may be independent of canopy structure or the "N-dilution" impact. The simulated datasets based on the PROSAIL model and satellite multispectral bands further validated the results. Our study concludes that the OSI-based RF is a robust and effective model to predict crop PNC at the vegetative growth stage. The results of this study may provide insights into how to improve PNC assessment using the OSI-based RF models and deploy ML-based N recommendation models in the next generation of crop sensors. [Display omitted] • We propose a novel method to predict plant nitrogen concentration (PNC). • The method combines machine learning (ML) and optimized spectral indices (OSI). • The method successfully predicted PNC of wheat, maize, rice and potato. • The method reduces the impact of canopy structure and N dilution effect. [ABSTRACT FROM AUTHOR]

Climate change is affecting agricultural crop production, but there is little information to date from climate change experiments on agricultural ecosystems over the long-term. Data from a ten-year experimental arable field using several climate change factors and their interactions were analyzed with respect to their impacts on crop biomass and harvestable yield production. From a crop rotation of wheat, barley, and oilseed rape was exposed to increased soil temperature (+2.5 °C), reduced summer precipitation amount (−25%), and frequency (−50%) in a multifactorial design. Depending on the growing period, aboveground biomass and crop yield of spring wheat, winter wheat, and spring barley were either increased or unaffected under soil warming. In moist years with high cumulative ambient precipitation, cereal productivity was enhanced due to soil warming, whereas no effect was visible in dry years. Experimental reductions in summer precipitation amount had only minor effects on aboveground biomass and yield of wheat, barley, or oilseed rape, possibly due to an increase in those crops' water use efficiency under water scarcity. However, a reduction in summer precipitation frequency had no effects on aboveground biomass and yield of the selected crops. The results illustrate that effects of climate change on plant development and yield also depend on the immediate weather conditions during the growing period. This underscores the need for long-term climate change experiments under field conditions where, in addition to manipulated experimental treatments, annual variations in precipitation and temperature can be studied. • Year-to-year weather variations studied in ten-year climate change field experiment. • Inter-annual variations in precipitation explained soil warming effects on cereals. • Soil warming enhanced cereal (wheat, barley) biomass and yield in moist years. • Whereas in dry years soil warming showed no effects on biomass and yield of cereals. [ABSTRACT FROM AUTHOR]

Late-season nitrogen (N) application has been proposed to boost grain yield and grain protein concentration (GPC) in cereals; however, its effects on bread and durum wheat have been inconsistent in field experiments. We performed a meta-analysis to (i) assess the effect of N applications to wheat after flag leaf visible (GS 37) on grain yield and GPC; and to assess the variation in these responses with (ii) N fertiliser management, (iii) environmental factors, and (iv) physiological traits. We searched ' Agronomy Journal ', ' Crop Science ', ' European Journal of Agronomy ', and ' Field Crops Research ' for articles published between 1980 and 2021 that allowed for a direct comparison of wheat yield and GPC between N application after GS 37 to an otherwise equally managed crop that received basal N fertilisation. We also collected other traits such as stover biomass and N uptake at plant maturity, and dough rheological properties, when available. The search resulted in 38 articles that, in addition to one unpublished trial from our group, evaluated 542 pairwise comparisons in 127 environments. Across studies, grain yield ranged from 1.15 to 10.63 Mg ha−1 and showed a negative relation with GPC, which ranged from 65 to 189 g kg−1. Late-season N fertilisation was consistently neutral for grain yield (I2, proportion of the overall variance due to variation in real effects rather than chance, 26.2 %) and increased GPC with a pooled estimate of 3.96 %. The response of GPC was heterogeneous (I2 = 84 %), suggesting the need for exploration of potential moderators of the response. Meta-regression suggested that increasing the proportion of late N relative to the total available N positively associated to increases in GPC, and the residuals of this analysis suggested that later applications increased GPC response, with no effect of N fertiliser source or placement. Environments with low temperature, high photothermal quotient, and long duration of the critical period associated with greater GPC response to late-season N applications. The relative response of GPC to late fertilisation correlated with the relative response of both stover N uptake and nitrogen concentration in stover at maturity, but not with stover biomass at maturity. Alveogram index and dough extensibility increased when late-season N increased GPC. Enhancing GPC through late N applications should consider associations between management, environmental, and physiological factors. Future research should focus on forecasting GPC response to late N, based on GPC response drivers identified in the current research. • Meta-analysis highlighted physiological drivers of wheat response to late N • Grain yield was unaffected by late N across a broad range of environments • Late N increased protein by 3.96% and its effects were heterogeneous • Protein increased linearly with the proportion of late N and with later applications • Higher protein response to late N associated to favourable growing conditions [ABSTRACT FROM AUTHOR]

Information regarding the pattern of sulphur (S) accumulation in shoots is scarce for field crops and few comprehensive analysis were performed on N:S stoichiometry. Particularly, the need to study the patterns of uptake, allocation and stoichiometry of S and N in soybean is two-fold. First, the main areas for soybean production in the world have been recently reported as S-deficient. Second, S concentration (%S) and N:S ratios are relevant for diagnosing S deficiency. The aim of this work was to analyze, in a gradient of S availability, the dynamics of nitrogen concentration (%N), %S and N:S ratio in soybean lamina, stem and shoots during vegetative growth. Experiments were performed at Balcarce, Argentina during two growing seasons. Two soybean cultivars were evaluated: DM2200 (maturity group II) and DM4970 (maturity group IV), sown in optimum dates for the region (mid-November). DM2200 was also sown late (early January). We sampled crops between biomass ≈ 1 Mg ha −1 and R5. Shoots were separated in lamina, stem and petiole, and pod. The adjusted S dilution curve for S-sufficient treatments was attenuated in soybean (S = 2.8 W −0.11 ), with no differences among cultivars of maturity groups II and IV, and sowing dates from November to January. For the same treatments, the N:S ratio was stable in shoots during vegetative growth (N:S = 12.2), supporting the use of a unique threshold for diagnosing the S status during this period. Sulphur concentration in stems was more responsive to the availability of S than%S in lamina. In addition, the concentration of N in stem tended to be constant with variation in %S while %N and %S correlated in lamina. This produced a greater response of N:S in stem than in lamina. Thus, the determination of%S and N:S in stem are good candidates as indicators of S status of soybean. [ABSTRACT FROM AUTHOR]

Machine learning approaches are attracting more attention in predicting the economic optimum nitrogen rate (EONR) for field crop production. However, the robustness in fertilizer recommendations appeared to be less responsive to extreme abiotic stress conditions, due to the lack of post-fertilization seasonal weather information. This study employed four machine learning models, namely, support vector machine (SVM), gradient boosting (GB), random forest (RF), and ridge regression (RR) to predict the site-specific EONR values of canola crops, based on a 22-site-year field study across eastern Canada. Model performance was assessed using the 'leave-one-out' approach under three scenarios, i.e., different combinations of input variables, including current seasonal weather data before N topdressing, 10-year historical weather records, and field management and crop traits. Results of this study showed that including historical weather data highly improved prediction accuracy for EONR in a variety of canola growing environments. The RF model outperformed other models in predicting site-specific EONRs, with a Pearson correlation coefficient of 0.9, a standard deviation of 23 kg N ha−1 and a relative error of 2%. For 16 of the 22 test environments, the EONR predicted using RF fell within its confidence range, indicating that the prediction has a 73% chance of being an acceptable recommendation. Overall, incorporating historical weather data is essential for successfully predicting crop N requirements under normal and stressful growing conditions. The results indicate that with a base fertilizer of 50 kg N ha−1, the recommended topdressing application rate varied from 50 to 110 kg N ha−1 in moist seasons, but decreased to 20–50 kg N ha−1 in hot and dry years, for sustainable canola production in eastern Canada. Appropriately incorporating historical weather data and soil properties into machine learning-based algorithms can be used to precisely guide fertilizer N management on canola crops under diverse climatic stress conditions. This approach promises to optimize seed yield and reduce nitrogen losses to the environment for sustainable canola production in Canada. • Four machine learning models were compared to predict economic optimum nitrogen rate (EONR). • Historical weather conditions were essential to predict the site-specific EONR. • Random forest model performed the best in recommending EONR by integrating weather data, field management and crop features. • A rate of 50 kg N ha−1 at planting plus 20–110 kg N ha−1 at the 4–6 leaf stage is recommended for canola production. [ABSTRACT FROM AUTHOR]

The aim of the study was to examine the variation and breeding effects on the stay-green traits, and to identify the relationship between the different growing seasons and grain yield of the Pannonian winter wheat. The experiment was carried out with a historical set of 25 winter wheat cultivars during four growing seasons, in a typical Pannonian location at the experimental field of the Institute of Field and Vegetable Crops, Novi Sad, Serbia. The results demonstrated a linear wheat grain yield progress at the rate of 45.7 kg ha−1 yr−1, along with significant variations observed in most stay-green traits due to increased capability of modern wheat cultivars to retain prolonged crop greenness. Furthermore, significant positive correlations between the onset and mid senescence and grain yield in three out of four studied seasons showed that the prolonged senescence led to grain yield increase. Modern wheat cultivars showed an increase of crop greenness at anthesis, onset and mid senescence, and the stay-green interval, as well as a faster senescence rate. Moreover, the stay-green interval was positively correlated with grain yield in each growing season, while the senescence rate was significantly positively correlated with grain yield in the three growing seasons. Furthermore, all examined traits, except the endpoint of senescence (N10), were significantly negatively correlated with anthesis time during all growing seasons. Knowledge about the positive correlations between the prolonged stay-green traits and grain yield could be used for adjusting post-anthesis senescence traits and implemented in winter wheat breeding programs under the climate conditions of the Pannonian Plain. • Significant progress in grain yield over the year of cultivar release. • Modern cultivars have higher NDVI values and prolonged stay green duration compared to the older cultivars. • Close relationship between the stay-green duration indicators with grain yield. • Anthesis date is negatively related to the duration of senescence stages. [ABSTRACT FROM AUTHOR]

Most of the required increases in food production over the next decades are expected to be achieved through increases in crop yield. As wheat is essential for food security it is worrying that its yield gains over the last two decades were small. To achieve further yield increases it is critical to continue increasing number of grains per unit area (GN m-2), the trait best related to yield. In this context, it is relevant to identify the main determinants of GN m-2 in response to genetic and environmental factors as well as the trade-offs between them. In the present study we compiled a large database across the literature to analyse the relative importance of components when affected by genetic or environmental factors, producing small or large changes in GN m-2 and its components, either numerical (the number of spikes per m2, SN m-2; and the number of grains per spike, GN spike-1) or physiological (spike dry weight at anthesis, SDWa; and fruiting efficiency, FE) determinants. The database included 367 papers published in: (i) Field Crop Research (FCR), (ii) European Journal of Agronomy (EJA), (iii) Crop Science (CS) and (iv) Crop and Pasture Science (CPS, formerly Australian Journal of Agricultural Research) between 1990 and 2020. The complete dataset was split into classes, depending on the source of experimental variation, environment or genotype and was normalised to remove the differences between experiments and determine the environmental and genotypic effects within each experiment. Normalised data showed that the responsiveness of GN m-2 was similarly explained by changes in both SN m-2 and GN spike-1, but in terms of physiological components SDWa was more relevant than FE for explaining the variations in GN m-2. Considering the numerical components of GN m-2 genotypic and environmental factors modified more GN spike-1 than in SN m-2. On the other hand, physiological components were differently modified by genotype and environment: for genotypic effects FE was more critical than SDWa and the other way around for environmental factors. A trade-off between numerical and physiological components was observed although was greater between physiological than between numerical components. • We quantified physiological/numerical components (and trade-offs) of grains/m-2 in wheat. • We recognised differences depending on magnitude and source of variation (genetic/environmental). • Grains/spike-1 explained better grains/m-2 than spikes/m-2, particularly for genotypes. • Genotypes affected more fruiting efficiency than spike-dry-weight-at-anthesis, environments the opposite. • Trade-offs seemed more relevant for physiological than for numerical components. [ABSTRACT FROM AUTHOR]

Accurate estimation of yield gaps is only possible for locations where high quality local data are available, which are, however, lacking in many regions of the world. The challenge is how yield gap estimates based on location-specific input data can be used to obtain yield gap estimates for larger spatial areas. Hence, insight about the minimum number of locations required to achieve robust estimates of yield gaps at larger spatial scales is essential because data collection at a large number of locations is expensive and time consuming. In this paper we describe an approach that consists of a climate zonation scheme supplemented by agronomical and locally relevant weather, soil and cropping system data. Two elements of this methodology are evaluated here: the effects on simulated national crop yield potentials attributable to missing and/or poor quality data and the error that might be introduced in scaled up yield gap estimates due to the selected climate zonation scheme. Variation in simulated yield potentials among weather stations located within the same climate zone, represented by the coefficient of variation, served as a measure of the performance of the climate zonation scheme for upscaling of yield potentials. We found that our approach was most appropriate for countries with homogeneous topography and large climate zones, and that local up-to-date knowledge of crop area distribution is required for selecting relevant locations for data collection. Estimated national water-limited yield potentials were found to be robust if data could be collected that are representative for approximately 50% of the national harvested area of a crop. In a sensitivity analysis for rainfed maize in four countries, assuming only 25% coverage of the national harvested crop area (to represent countries with poor data availability), national water-limited yield potentials were found to be over- or underestimated by 3 to 27% compared to estimates with the recommended crop area coverage of ≥50%. It was shown that the variation of simulated yield potentials within the same climate zone is small. Water-limited potentials in semi-arid areas are an exception, because the climate zones in these semi-arid areas represent aridity limits of crop production for the studied crops. We conclude that the developed approach is robust for scaling up yield gap estimates from field, i.e. weather station data supplemented by local soil and cropping system data, to regional and national levels. Possible errors occur in semi-arid areas with large variability in rainfall and in countries with more heterogeneous topography and climatic conditions in which data availability hindered full application of the approach. [ABSTRACT FROM AUTHOR]

We examined twelve cotton ( Gossypium hirsutum L.) cultivars that were released in Australia between 1973 and 2006, in three field experiments, harvested in 2009, 2010 and 2012. Crop biomass and nutrient uptake were measured at 160 days after sowing and lint yield at crop maturity. Crop nutrient use-efficiency was determined by dividing lint yield by nutrient uptake. Lint yield increased by 40% ( P < 0.001) for cultivars released between 1973 and 2006; crop biomass increased by 25%; N, S uptake increased by 20%, and 26% respectively; 33% for Ca, Mg and Na; and 22% for trace elements Fe, Mn, B, Zn and Cu (all P < 0.001). With the release of improved cultivars, the use-efficiency increased for N (20%, P < 0.001), P (23%, P < 0.001) and K (24%, P < 0.01). Similar increases were found for trace elements Fe, Cu and Zn ( P < 0.05–0.001). Newer cultivars also had substantial improvements in lint fraction, fibre strength and fibre length. We conclude that crop nutrient use-efficiency has increased relatively slowly, crop nutrient uptake has increased faster but neither has increased as quickly as lint yield. Improved use-efficiencies of N, P, K, Fe, Zn and Cu have occurred through selective breeding for lint yield over the past three decades. Based on nutrient demand, it is calculated that further increases in yield will require improved nutrient use-efficiency, and probably with better internal redistribution of nutrients. Such research should be done using a soil type and growing system capable of producing high-yielding cotton. [ABSTRACT FROM AUTHOR]

Forage crops provide micronutrients as well as energy, protein and fibre to ruminants. However, the micronutrient concentrations of forage plant species differ, legumes generally having higher concentrations than grasses. In addition to that there are also strong effects of soil type. Typically, the concentrations of one or several micronutrients in forage are too low to meet the nutritional requirement of dairy cows. We hypothesized that the overall micronutrient (Co, Cu, Fe, Mn, Mo, Zn) concentrations of forage mixtures are affected by the red clover dry matter (DM) proportion and site effects. This hypothesis was tested at three contrasting sites. The results showed that increased red clover proportion increased the overall concentrations of several micronutrients in the mixtures at all sites. At the site with the widest range of red clover proportion (0–70%) in the mixture, the Co, Cu and Fe concentrations more than doubled between the lowest and highest red clover DM proportion. At the other two sites a smaller increase in red clover proportion (from 10% to 25% or from 25% to 50%) also increased the overall concentrations of Co by up to 80% but less for other micronutrients. One of the sites generally had higher micronutrient concentrations in the crop and removed larger amounts of micronutrients with the harvested biomass compared to the other two sites. This could be explained by differences in pH and micronutrient concentrations of the soils at the sites. We conclude that increased red clover proportion in the sward has the potential to increase the overall micronutrient concentrations but that the effect of the soil is also a controlling factor. [ABSTRACT FROM AUTHOR]

The present reported study was designed to assess the interactive effects between film fully-mulched ridge–furrow (FMRF) cropping and the presence of a crop on soil moisture. Four treatments were evaluated in 2011 and 2012 at a rainfed semi-arid site: (1) no mulch + no crop planting, (2) mulch + no crop planting, (3) no mulch + crop planting, and (4) mulch + crop planting. Narrow and wide ridges were alternated in all treatments and maize ( Zea mays L . ) was seeded in furrows only for the crop planting treatments. In 2011, soil water storage in the 0–100 cm layer was higher at all measurements after sowing under mulched compared to unmulched treatment with no maize planting, whereas it increased at measurements in the first two and a half months only under mulched compared to unmulched treatment with maize planting. This indicated that the effect of mulch on soil–water storage was associated with increased transpiration. Mulch under no maize planting increased water storage to the field holding capacity by the end of one growing season, conserving 100 mm more water in the 0–170 cm layer than no mulch. This highlighted that FMRF was very efficient at conserving rainwater in soil. In 2012, soil moisture dynamics under the four treatments were different from those in 2011 because of residue effects and higher precipitation. Compared to no mulch, mulch increased grain yield and water use efficiency by 70–72% and 57–77%, respectively, over the two experiment years. The results suggest that increased transpiration under mulch contributes to increased grain yield and water use efficiency compared with no mulch. [ABSTRACT FROM AUTHOR]

Cover crops and mulches can be used for increasing sustainability in winter cereal cropping systems. We performed a 2-year field experiment in Central Italy with the aim of finding a suitable spatial arrangement for durum wheat ( Triticum durum Desf.) and subclover ( Trifolium subterraneum L.) as a living mulch system in order to provide a high cereal grain yield and a sufficient subclover reseeding following the wheat harvest. Experimental treatments consisted of: (i) five cropping patterns [wheat and subclover mixed in the same row, with rows 15 cm apart (same row); 2 rows of wheat and 1 row of subclover at a distance of 10 cm between rows (narrow rows); 2 rows of wheat and 1 row of subclover with a distance of 10 cm between the wheat rows and 17.5 cm between the wheat and subclover rows (wide rows); durum wheat sole crop and subclover sole crop, both in rows 15 cm apart]; (ii) two nitrogen fertilization levels (0 and 100 kg ha −1 of N); (iii) and two weed management levels (weed-free and weedy). The wheat grain yield was not reduced by the intercropped subclover in narrow rows, while it was around 14% lower in same row and wide rows compared to the one in the pure crop treatment. When intercropped with subclover, wheat was the competitively superior species and its competitive advantage was greater when it was closer to the legume and/or in presence of nitrogen fertilization. A strong negative relationship between wheat aggressivity and subclover seed production was observed. Following the wheat harvest, the legume reseeding was sufficient to regenerate a cover crop in the autumn of the second year regardless the spatial arrangement, even if the density of the subclover seedlings was almost twice in wide rows compared to the one in the same row. Although the intercropped systems were characterized by an increase in plant density compared to the sole crops (100% of wheat + 50% of subclover), the competitive ability of the wheat-subclover system against the weeds was higher than the wheat sole crop only in narrow rows where a significant reduction of both weed density and weed biomass was observed. When the subclover is used as living mulch in durum wheat, a moderate separation between the two species could be a suitable spatial arrangement for obtaining an adequate wheat grain yield, ensuring satisfactory subclover reseeding, controlling the weeds more effectively. [ABSTRACT FROM AUTHOR]

Tree-crop mixtures may increase yield and revenue especially during the early years of tree plantations. Jujube is grown widely in China for their fruits, and cotton is gaining popularity as an understory crop in young jujube plantations. There is a need for information on productivity and optimal planting densities of cotton in these mixed systems. Field experiments were carried out in 2012 and 2013 in Hetian, Xinjiang, China. Three cotton plant densities (13.5, 18.0 and 22.5 plants m −2 ) were tested in 6–7 years old jujube plantations, in which the cotton was grown in a 6 m-wide space between the tree rows. Cotton leaf area index increased but plant height decreased with plant density. Cotton light interception increased with density, but at early and mid-season, the difference in light interception between 18.0 and 22.5 plants m −2 was only marginal. Increasing plant density modified the distribution pattern of the light within the canopy, thus affected overall cotton light interception and use efficiency. The highest yield and light use efficiency of cotton were achieved at 18.0 plants m −2 . Spatial distributions of light intensities and extinction coefficients were affected by the shading of jujube trees within the cotton canopy in the intercrop. Jujube growth, yield and light utilization were not significantly affected by cotton plant density. We conclude that the productivity and light utilization of cotton in jujube-cotton intercropping can be increased by optimizing cotton plant density. [ABSTRACT FROM AUTHOR]

Boron (B) deficiency is becoming a common problem in water-saving rice production systems of South Asia. Boron nutrition can potentially improve the crop performance. This two-year field study was conducted to evaluate the potential of pre-optimized B application through various methods in improving the performance of rice grown in aerobic culture, alternate wetting and drying and flooded systems. Boron was delivered as seed priming (0.1 mM B), foliar spray (200 mM B), and soil application (1 kg B ha −1 ); no B application and hydropriming were taken as control. Boron nutrition by either method improved the plant water relations, total chlorophyll contents, morphological and yield related traits in different rice production systems. In addition to improvement in kernel yield, boron application also improved the kernel quality. Foliar application of boron in flooded rice and alternate wetting and drying gave maximum net returns than all other treatment combinations. In crux, B application through foliar spary or seed priming may be an economically viable option to reduce panicle sterility, improve kernel quality, rice growth and yield. Improvement in rice yield by B application is attributed to increase in kernel size and decrease in panicle sterility. [ABSTRACT FROM AUTHOR]

The nexus of climate change and food security challenges currently facing humanity requires better understanding of how to balance food production needs with climate change mitigation. Life cycle assessment methods provide a way to quantify the climate impacts of a food product by accounting for all greenhouse gas (GHG) emissions associated with its production, including upstream and downstream from the farm. This study modeled life cycle GHG emissions for one kg of milled, unpackaged rice produced in California, USA, a state that achieves some of the highest rice yields in the world. The goal was to (1) provide an assessment of life cycle GHG emissions of a comparatively intensive production system, using local field emissions data, (2) identify emissions hotspots, and (3) create a model that elucidates the life cycle-wide consequences of potential changes in field management practices. Study parameters are based on an annual cropping cycle, with continuous flooding during the growing season and soil incorporation of straw post-harvest, and yields of 9.3 Mt ha −1 dried paddy rice. Field emissions (growing and fallow seasons) were estimated with empirical data while other emissions were calculated using an engineering model coupled with life cycle inventory datasets and vehicle emission models. The 100-year global warming potential (GWP, based on CO 2 , CH 4 and N 2 O) was 1.47 kg CO 2 -equivalent (CO 2 e) kg −1 of milled rice; of which field emissions contributed 69%. These results are relatively low when compared to life cycle studies in other parts of the world, due in large part to higher grain yields and lower field emissions. When using IPCC Tier 1 estimates of field emissions, the GWP increased to 3.60 CO 2 e kg −1 rice, highlighting the importance of using direct field measurements as we have in this study. Due to their large contributions to life cycle GWP, reducing field CH 4 emissions through different field management practices, optimizing N fertilizer use, and increasing fuel efficiency or reducing use of farm machinery present the greatest opportunities to reduce life cycle emissions. Because of high variability and uncertainty in estimating field emissions, they should also be targeted for improved measurement and modeling. [ABSTRACT FROM AUTHOR]

Petiole-NO 3 , leaf N and chlorophyll (SPAD) meter readings are good in-season indicators of the N status of the uppermost part of cotton ( Gossypium hirsutum L.) plants. Petiole-NO 3 , particularly is widely used in the USA as an in-season plant N test that guides N fertilizer recommendations in cotton. However, these N status indicators do not take account of plant biomass, canopy width or percent cover. The objectives of this study were to assess the effect of N fertilizer rates on the commonly used indicators of plant N status; leaf N, petiole sap NO 3 and chlorophyll meter (SPAD) readings and the plant growth measurements; plant height, canopy width, and percent ground cover, and determine to inter-correlations among the them. Irrigated field studies were conducted at Lubbock, TX USA in 2010 and 2011, New Deal, TX in 2010, and at Halfway, TX in 2011. Zero-N and a full N fertilizer rate of 134, 101, and 112 kg N ha −1 were used at Lubbock, New Deal, and Halfway, respectively. The 2010 cotton growing season in West Texas was much wetter than average, and the 2011 season was much drier than normal. As a result, plant height, canopy width, and ground cover were greater in the 2010 sites than in 2011. The effects of N fertilizer were greatest for the two cultivars in subsurface drip irrigation (SDI) at New Deal in 2010 for all three N status indicators, and for the three plant growth measures compared to the other site-years. Correlation analysis indicated that among the three plant N indicators, leaf N was the most sensitive to plant parameters. These effects were positive in 2010 and negative in the 2011 dry year. Petiole NO 3 was the plant N indicator that was the most insensitive to plant growth, but the marked seasonal decline pattern reduces its usefulness for late-season N management. [ABSTRACT FROM AUTHOR]

In this study, we aimed to investigate the effects of nitrogen (N) management and polyaspartic acid urea (PASP-urea) on N utilization and soil N balance of midseason rice in southwest China. Field experiments with no N treatment, famer's fertilizer practice (FFP), three optimized nitrogen managements (ONMs), and three PASP-urea treatments (PASPTs) were conducted at Shehong and Wenjiang, Sichuan Province, in 2013. The results showed that the N fertilizer increased crop N uptake and total N output, but intensified the apparent N losses. Compared to FFP, ONMs and PASPTs (excluding ONM2 and PASPT1 at Shehong) increased N accumulation in plant organs before anthesis, which significantly ( p < 0.05) increased crop N uptake and N recovery efficiency (NRE), but reduced N production efficiency and N physiological efficiency (NPE), as well as apparent N losses at both the sites. However, the effectiveness of N treatments on N utilization and soil N balance was associated with the initial soil N min (amount of inorganic N accumulation). ONM3 (a 15% increase in the N rate over that used in the FFP) increased N accumulation, NRE, and N agronomy efficiency (NAE) of rice at Shehong, whereas ONM2 (a 15% reduction in the N rate over that used in the FFP) reduced N loss but significantly ( p < 0.05) increased NPE, NAE, and N partial factor productivity at Wenjiang. PASP-urea, especially PASPT3 (PASP urea spilt-applied in four stages), significantly ( p < 0.05) reduced apparent N surplus before anthesis and N deficit after anthesis, resulting in higher crop N uptake and N use efficiency. Therefore, split-application of N at an optimal rate and PASP-urea could improve the balance between plant N requirement and N input and thus enhance N use efficiency and/or reduce N losses. [ABSTRACT FROM AUTHOR]

Upland rice cropping has become a familiar part of the landscape in Madagascar's central highlands, a densely populated region mainly characterized by resource poor family farmers and cold climatic conditions. A survey of 485 farmers conducted in 2011–2012 revealed that 71% of them cultivated upland rice although the crop was absent in this region before the first cold tolerant varieties were released in 1995. It also revealed that a single variety, Chhomrong Dhan (CD) originating from Nepal and released in 2006 was by far the most widely cultivated variety and accounted for 82.5% of the total acreage of upland rice. Farmers appreciate CD for its relatively high yield under low input conditions. However, this dominance raises concerns about the resilience of upland rice agro-systems in the face of changes in climatic conditions or in pathogen populations. To identify key varietal adaptive traits that should be taken into account in the breeding of new upland rice varieties in this context, we compared a panel of improved varieties including CD under low input management over two cropping seasons. A strong positive correlation between leaf area index (LAI) before harvest and yield was observed. Varieties with the highest yield, including CD, are of long duration, produce high biomass yields, have a high LAI and the highest harvest index. A significant negative correlation was observed between the LAI of rice varieties and that of weeds, showing that a high LAI also helps limit competition for resources by weeds. In the context of subsistence family farming and in the cold conditions of Madagascar's tropical highlands, new improved varieties should combine high LAI, high harvest index and long duration, as these traits help compete with weeds and contribute to high yield potential under low input management, on the one hand, and resistance to blast, cold tolerance and reduced crop duration, traits that prevent yield losses, on the other hand. The trade-off between crop duration and the risk of cold-induced sterility specific to the cold conditions of Madagascar highlands has to be taken into account. [ABSTRACT FROM AUTHOR]

Understanding the changes in soil potassium (K) and crop yield under K fertilization and straw return is important for proper K fertilizer management. A field experiment involving a wheat ( Triticum aestivum L.)–maize ( Zea mays L.) rotation was conducted to study the effects of long-term (20-year) K fertilization and straw return on soil K and crop yield in north-central China. Fertilization treatments included: nitrogen and phosphorus fertilizers (NP), NP plus wheat straw (NPS), NP and K fertilizers (NPK), and NPK plus wheat straw (NPKS). Annual soil K budget increased with increasing K inputs (including fertilizer K and straw K) in the order of NP < NPS < NPK < NPKS, and further increased after maize straw returned since 2008. The NP and NPS treatments decreased soil available K and slowly available K below the initial levels, K fertilization and/or straw return increased available K and slowly available K in the top 30 cm soil over the NP treatment. Fertilization did not significantly alter total K in the 0–100 cm depths, but in the 0–10 cm soil layer, the NP, NPS, and NPK treatments decreased total K by 4.3%, 3.4%, and 0.4% than the initial concentration, respectively. Compared with the NP treatment, K fertilization and/or straw return increased crop yields in most cases, and the effect of K inputs on yield increase was greater for maize than wheat. Additionally, increased straw return enhanced soil organic carbon (SOC) beyond the NP treatment, and SOC decreased with depths between 0 and 40 cm soil; however, fertilization did not change SOC below 40 cm. In conclusion, K fertilization and/or straw return alleviated soil K depletion and increased soil K fertility; crop yields increased with increasing K inputs, and yield response of maize to K fertilization was greater than wheat. [ABSTRACT FROM AUTHOR]

Highlights: [•] The suitability of two QTLs was confirmed to be utilized in improving the resistance of japonica rice varieties to sheath blight disease. [•] The pyramiding effect of the two QTLs was significantly larger than that of either of them, and no genetic interaction was found between the two QTLs. [•] The introgression of both QTLs could achieve a 14% reduction in yield loss under serious disease condition. [ABSTRACT FROM AUTHOR]

Highlights: [•] The LINGRA model for timothy was evaluated using a field trial data set from the Nordic region. [•] The biomass yield prediction was affected by the data that were used for model calibration. [•] Multi-site calibration resulted in better yield predictions overall across the region than single-site calibration. [•] Single-site calibration resulted in better yield predictions at the specific location of calibration than multi-site calibration. [•] The LINGRA model was sensitive to changes in initial tiller density. [ABSTRACT FROM AUTHOR]

Highlights: [•] An attempt to compile a validation guideline for in vivo field methods is presented. [•] The guideline is derived by adapting norms from chemistry. [•] A case study for indirect determination of rice nutritional status is presented. [•] The applicability and effectiveness of the proposed procedure is discussed. [ABSTRACT FROM AUTHOR]

Highlights: [•] In general, hybridisation decreased DM production of white clover. [•] Backcross 1 hybrids had smaller leaves, shorter internodes, and were more prostrate. [•] Many traits showed variation among individual hybrid families. [•] Variation in key white clover traits could be used to select elite hybrid populations. [•] Hybridisation did not affect nitrogen fixation. [ABSTRACT FROM AUTHOR]

Highlights: [•] Differences of rice lodging affected by nitrogen (N) under different eco-sites were significant. [•] For the lower lodging index (LI) rice populations, N primarily decreased the stems stiffness. [•] For the higher LI rice populations, N mainly impacted the morphological parameters of the basal stems. [ABSTRACT FROM AUTHOR]

Highlights: [•] A set of maize traits that could help farmers on selection for yield was identified. [•] A new ear value formula that better estimates the yield potential was obtained. [•] A new instance ranking measure to be used for evaluating ear ranks is proposed. [•] A new method to be used in participatory research and pre-breeding is proposed. [ABSTRACT FROM AUTHOR]

Highlights: [•] qDTY2.2 and qDTY2.3 were identified in MTU1010 and R64 backgrounds respectively for grain yield under drought. [•] Both QTLs showed consistent effect across two seasons of testing for the trait under varying severities of drought. [•] Consistent effect of these QTLs may allow the improvement of these mega varieties for drought tolerance. [ABSTRACT FROM AUTHOR]

Abstract: Field Crops Research focuses on both experimental and modelling research at the field, farm and landscape level on temperate and tropical crops and cropping systems, with a focus on crop ecology and physiology, agronomy, plant genetics and breeding. Emphasis is on species more relevant to ensuring global food security and on their performance in the field. An increasing number of manuscripts dealing with genetics and breeding also deal with trait phenotype and individual components contributing to the total phenotypic variance. Some of these either fail to deliver new scientific insight, have experimental deficiencies or use inappropriate tools for analysis. A lack of explicit theoretical frameworks is common. The aims of this article are to identify research gaps and new scientific developments, highlight common experimental and analytical deficiencies, and outline editorial criteria addressing this specific area, where the journal would favour: (1) rigorous account and interpretation of the components of phenotypic variance, (2) closing the gap between phenotypic and genotypic characterisation of crop traits, (3) developing and applying advanced approaches for quantitative environmental characterisation; (4) linking with appropriate theories to improve genetic, agronomic, physiological and ecological interpretations of the phenotype and its drivers, and (5) methods for efficient screening of plant populations and segregating progenies for yield potential and stress adaptation, with an emphasis on biological mechanisms. [Copyright &y& Elsevier]