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The purpose of this research was to examine the performance of agrivoltaic systems, which produce crops and electricity simultaneously, by installing stilt-mounted photovoltaic (PV) panels on farmland. As PV power stations enjoy remarkable growth, land occupation with the purpose of establishing solar farms will intensify the competition for land resources between food and clean energy production. The results of this research showed, however, that the stilt-mounted agrivoltaic system can mitigate the trade-off between crop production and clean energy generation even when applied to corn, a typical shade-intolerant crop. The research was conducted at a 100-m2 experimental farm with three sub-configurations: no modules (control), low module density, and high module density. In each configuration, 9 stalks/m2 were planted 0.5 m apart. The biomass of corn stover grown in the low-density configuration was larger than that of the control configuration by 4.9%. Also, the corn yield per square meter of the low-density configuration was larger than that of the control by 5.6%. The results of this research should encourage more conventional farmers, clean energy producers, and policy makers to consider adopting stilt-mounted PV systems, particularly in areas where land resources are relatively scarce.

Accurate measurement of leaf chlorophyll concentration (LChl) in the field using a portable chlorophyll meter (PCM) is crucial to support methodology development for mapping the spatiotemporal variability of crop nitrogen status using remote sensing. Several PCMs have been developed to measure LChl instantaneously and non-destructively in the field, however, their readings are relative quantities that need to be converted into actual LChl values using conversion functions. The aim of this study was to investigate the relationship between actual LChl and PCM readings obtained by three PCMs: SPAD-502, CCM-200, and Dualex-4. Field experiments were conducted in 2016 on four crops: corn (Zea mays L.), soybean (Glycine max L. Merr.), spring wheat (Triticum aestivum L.), and canola (Brassica napus L.), at the Central Experimental Farm of Agriculture and Agri-Food Canada in Ottawa, Ontario, Canada. To evaluate the impact of other factors (leaf internal structure, leaf pigments other than chlorophyll, and the heterogeneity of LChl distribution) on the conversion function, a global sensitivity analysis was conducted using the PROSPECT-D model to simulate PCM readings under different conditions. Results showed that Dualex-4 had a better performance for actual LChl measurement than SPAD-502 and CCM-200, using a general conversion function for all four crops tested. For SPAD-502 and CCM-200, the error in the readings increases with increasing LChl. The sensitivity analysis reveals that deviations from the calibration functions are more induced by non-uniform LChl distribution than leaf architectures. The readings of Dualex-4 can have a better ability to restrict these influences than those of the other two PCMs.

Under arid and semi-arid climates, adopting the appropriate tools for alleviating water deficit impacts is a critical factor that affects the physiological characteristics and yield of sunflower. Therefore, in order to find promising field practices in sunflower cultivation, the strip plots design in randomized complete block arrangement was used to examine the effects of two irrigation regimes as 100% (FI) and 85% (DI) of crop evapotranspiration and five antioxidant treatments on physiological and agronomic traits, yield response factor, and irrigation water use efficiency (IWUE) of sunflower. The antioxidant treatments involved two rates of ascorbic acid (150 and 300 mg L−1) and two rates of citric acid (250 and 500 mg L−1), in addition to the check treatment (tap water). The study was conducted for two growing seasons of 2019 and 2020 at the Experimental Farm of Ain Shams University, Egypt, located in a semi-arid environment. Findings showed that exogenous application of higher rate of ascorbic acid, i.e. 300 mg L−1 with FI exhibited the highest increase of chlorophyll a, chlorophyll b and the lowest proline content compared to other interaction treatments. Seed yield was significantly higher with FI plus ascorbic acid 300 mg L−1 and DI plus ascorbic acid 300 mg L−1 treatments than with their counterpart check treatment in both growing seasons. Under DI, IWUE was improved with antioxidant-treated plants compared to untreated plants. Yield response factor as an indicator of crop tolerance to drought was higher than the unit (> 1) under all ascorbic acid and citric acid levels. It could be concluded that ascorbic acid and citric acids partially mitigated the reductions in growth and yield caused by low water supply. However, yield response factor demonstrated that the crop is still sensitive to drought. Thus, other applicable patterns should be adopted to increase the yield potential of sunflower for counteracting the adverse impacts of drought.

Due to its rusticity and feasibility of use, oat (Avena sativa L.) represents a crucial agronomic and economic resource for many semiarid environments. Presently, the recourse to new commercial varieties has caused a dramatic lowering of areas covered with the traditional local genotypes, and a severe risk of genetic erosion is emerging. To deepen the knowledge about the autochthonous oat populations, an activity of collection and cataloging across semiarid cropping areas was carried out. Sixteen oat populations were collected from different areas of Sicily and put in a field study for two consecutive years (2014 and 2015) in the experimental farm “Sparacia” (Cammarata, Italy). In both years and all populations, 21 morphological characters, related to different aspects of the whole plant or plant parts, were measured as described in the guidelines Community Plant Variety Office—Office Communautaire des Varietes Vegetales (CPVO‐OCVV) (rif. CPVO‐TP/020/2). Multivariate analysis (MA) was applied to assess the similarity/dissimilarity level among populations, also evaluating the relative discriminatory importance of each selected plant character. Although a strong variability between years did not allow perfect discrimination among genotypes, an association between oat groups emerged based on their prevalent utilization form. Among categorical characters, measurements on glumes and grain provided the best characterization of the populations in both years. Core Ideas In Sicily, many oat landraces are grown and multiplied by local farmers, mostly for animal feeding. There is no certainty about the actual extent of difference/similarity among the locally grown populations. We analyzed 21 morphological quantitative‐qualitative descriptors on 16 oat populations in a 2‐year cultivation. We used multifactorial analysis (MFA) to assess the relative importance of morphological traits for full characterization of populations. A strong variability showed up between cropping years for most of the examined variables.

Core Ideas Cover crops improve soil microbial biomass compared to no cover crop and influence soil microbial community structure.Soil microbial communities change both spatially and temporally.Results of the study imply that integration of CC in a regular corn–soybean rotation can improve soil quality and environmental benefits. Although cover crops (CC) are believed to play a major role in soil quality improvement, the effects of CC on microbial populations and community structure is not well understood. The objective of this study was to quantify CC effects on soil microbial biomass and community structure under a corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] rotation. The study was conducted at the Chariton County Cover Crop Soil Health Research and Demonstration Farm (CCSH) in Missouri, USA, where CC were first established in 2012. Soils were sampled in 2016, 2017, and 2018 from the 0‐ to 10‐cm depth layer using a grid sampling design and phospholipid fatty acid (PLFA) profiles were determined. Microbial biomass and microbial community structure (total fungi, total bacteria, rhizobia, gram (−), and actinomycetes biomass), as estimated from the PLFA biomarkers, were significantly greater (P < 0.05) in the CC treatment compared to no cover crop (NCC) in 2016 and 2018 (2.4‐ and 1.7‐fold larger, respectively). Within the CC treatment, differences by soil type were also observed, finding that the silt loam soil supported greater total microbial biomass than the loam soil in 2018. Spatial distribution patterns of total microbial biomass, bacteria biomass and fungi biomass differed with time. Overall, this study demonstrated that the CC treatment affected the soil microbial community biomass and structure, which has potential environmental, production, and soil quality benefits.

Cymbopogon winterianus Jowitt. is cultivated worldwide for its industrial and pharmaceutical applications. The economic value for this crop is due to its herbage, essential oil yield, and citronellal content. Therefore, this study was conducted to identify the traits that are important to increase the economic yield and to estimate the variability among the Cymbopogon winterianus germplasm necessary for selection of superior genotypes. In this study, a total of 72 accessions of Cymbopogon winterianus were collected from different parts of Northeast India and planted in the experimental farm of CSIR‐NEIST, Jorhat, Assam, India. Divergence and association studies among the nine characters were estimated from the 3‐yr pooled data. The genotypic coefficient of variation was slightly lower than the phenotypic coefficient of variation for all the traits studied. High genetic advance with high heritability (H2BS) estimates were observed in tillers per bush, herbage yield, citronellal, and essential oil content. Path coefficient analysis also supported that the leaves per bush, tillers per bush, leaf breadth, and length of basal sheath were the major contributing characters for the herbage yield. Tillers per bush, leaves per bush, and herbage yield were the direct and indirect factors affecting the essential oil content. Divergence study partitioned the germplasm into 15 different clusters in which tillers per bush, leaves per bush, plant height, leaf length, and herbage yield contributed more towards variability. All the parameters studied could be considered as selection criterion to improve economic yield of C. winterianus and in estimating variability necessary for breeding program.

An experiment on aonla-soybean intercropping was conducted at the experimental farm of the Department of Silviculture and Agroforestry, College of Horticulture and Forestry, Neri–Hamirpur, H.P., India during the year 2020–21 with an objective to determine the effect of aonla trees on growth, yield and quality parameters of soybean crop. The experiment was laid out in randomised complete block design (02 factorial) to determine the effect of the trees on growth and yield parameters of soybean crop in four directions (east, west, north and south) at three distances (1, 2 and 3 m) from the trees. The quality parameters of soybean were estimated at three distances (1, 2 and 3 m) from aonla trees having composite sample from all the directions, distance wise and in open grown crop with total four treatments. The treatments were replicated five times and data were analysed using randomised complete block design. In another experiment, the agroforestry system comprising aonla + soybean was compared with the sole soybean cropping system employing student’s t-test. The results showed that the growth and yield of intercropped soybean increased with an increase in the distance of crop from aonla trees and revealed significantly higher values at 3 m distance from trees as compared to the sole crop. Among directions, the highest yield was obtained in the east direction. The biochemical analysis exhibited that the photosynthetic pigments (total chlorophyll and carotenoids) of soybean leaves were lower under aonla as compared to sole cropping. The contents of total soluble protein and total carbohydrates were significantly higher in the seeds of soybean crop raised underneath aonla over the sole crop. Overall, aonla + soybean system revealed positive interactions between the components, therefore recommended for the farmers from ecological and economical perspective.

The Soil Management Assessment Framework (SMAF) has successfully been tested as an objective tool to quantify land use and management effects on soil health, including under some Brazilian soil conditions. Thus, the objective of this study was to evaluate soil quality under five land uses, including: three types of agroforestry systems, a degraded pasture, and a secondary forest in Southeastern Brazil. The study was conducted at an experimental farm in Sapucaia, state of Rio de Janeiro, where diverse management practices had been implemented on plots with similar soil properties and management history prior to the establishment of three distinct agroforestry systems. We collected soil samples in the dry and rainy seasons, and assessed biological (soil organic carbon, β-glucosidase, microbial biomass carbon), chemical (pH, phosphorus, and potassium), and physical (bulk density, macroaggregation) soil properties. Using the SMAF scoring curves, the measured values were transformed (0–1 range) and an overall soil health index was calculated. We found overall SMAF scores values of 0.87, 0.88 and 0.87 for AS1, AS2, AS3, respectively, 0.83 for pasture, and 0.82 for forest, and the values differed significantly between land uses. The establishment of agroforestry systems over areas previously occupied with extensive pasturelands enhances soil fertility (12.79%) and soil physical indicators (6.5%). Our results show that AS not only enhance the provision of key soil ecological functions, but also restore soil quality of unmanaged pastureland.

Coffee is one of Brazil’s main commodities. Among the goals of crop improvement, the search for drought-tolerant materials has stood out, mainly due to the water scarcity of the producing regions. The knowledge of genetic diversity and the morphophysiological analysis of plants allow the identification of genotypes with potential use in genetic improvement. Thus, this study aimed to evaluate the diversity, by morphophysiological characteristics, in 173 genotypes of Coffea canephora, from populations of contrasting crosses regarding the drought tolerance of the breeding program of Incaper, and to identify the relative importance of traits, subsidizing the selection for drought tolerance, based on the factor analysis index (FAI). The experiment was conducted in three evaluation periods, under field conditions without irrigation at the Incaper Experimental Farm of Marilândia, in the state of Espírito Santo. There was great variability between and within populations, which was affected by the evaluation season. Based on the traits of greater relative importance identified in this work (LL, LW, SLA, LAR, LT, TLA, PBL, CHL, NO3−, TSP, PRO, A, and iWUE), the FAI identified the genotypes 76 × 48 − 1, 76 × 48 − 10, 76 × 48 − 16, 76 × 48 − 76, 76 × 48 − 77, 76 × 48 − 83, 76 × 48 − 90, 76 × 48 − 128, 76 × 04 − 1, and 76 × 04 − 32 as more promising, from the ideotype of lower LL, LW, SLA, and LAR, and higher LT, TLA, PBL, CHL, NO3−, TSP, PRO, A, and iWUE.

AbstractAnthracnose lima beans, caused by Colletotrichum truncatum can cause severe losses in production. Although there are difficulties in controlling the pathogen, studies concentrate on genetic resistance through local varieties with high genetic resistance to the pathogen. The objective of this work was to evaluate the temporal progress of lima beans anthracnose under field conditions. The experiments were carried out in the experimental farm Chã de Jardim, Federal University of Paraíba, Areia, Brazil in 2015 and 2017. Nine creole varieties of lima beans (Phaseolus lunatus) represented by UFPB02, UFPB04, UFPB05, UFPB06, UFPB11, UFPB13, UFPB14, UFPB19 and UFPB20, were tested at seven day intervals to determine incidence and severity, considering the natural occurrence of anthracnose in plants. Area under the anthracnose progress curve and disease index were assessed. The productivity components of the varieties were obtained at the end of the crop cycle. The experimental design was randomized blocks with four replicates. We found an interaction between local varieties and environments, creating favorable and unfavorable environments to disease development. Genetic variability among lima bean varieties was observed regarding resistance to C. truncatum, where the UFPB04 and UFPB20 varieties were considered more resistant to the pathogen and able to be used in breeding programs.