Consecutive Crops Research Articles

Effect of One-Time Application of Biochar and Compost on Soil and Maize During 5-Time Consecutive Periods of Crop Cultivation

This study evaluates the impact of a single-time biochar application during initial cultivation on the performance of five consecutive crop cycles. The research compares the effects of biochar alone versus biochar combined with soybean compost on maize yield and soil properties over a period of 2.8 years. Fundamental soil properties—including pH, cation exchange capacity, organic matter content, and macronutrient levels—were assessed before each planting cycle and at the end of the fifth cycle. Maize yield and productivity were evaluated based on the number of maize ears, kernel biomass, and both fresh and dry kernel weights. Five experimental plots, each with four replicates, were established with the following treatments: compost applied at 0.56 kg/sq m (TM), cassava stem (CS) biochar applied alone at 2.5 kg/sq m (TB2.5) and 3.0 kg/sq m (TB3.0), and combinations of compost at 0.56 kg/sq m with CS biochar at 2.5 kg/sq m (TMB2.5) and 3.0 kg/sq m (TMB3.0). Results indicated that the sole application of biochar and its combination with compost positively affected soil properties and maize yield. Biochar applications alone significantly improved soil nutrient levels and maize yields compared to the compost alone. Notably, the beneficial effects of biochar on maize and soil were observed from the first cultivation and persisted throughout all five cycles. Based on these findings, it is recommended to apply biochar at 3.0 kg/sq m, in combination with compost at 0.56 kg/sq m, every three crop cycles to sustain nutrient levels and enhance maize yields effectively. Doi: 10.28991/ESJ-2025-09-01-07 Full Text: PDF

Univariate and multivariate genomic prediction for agronomic traits in durum wheat under two field conditions.

Genomic prediction (GP) has been evaluated in durum wheat breeding programs for several years, but prediction accuracy (PA) remains insufficient for some traits. Recently, multivariate (MV) analysis has gained much attention due to its potential to significantly improve PA. In this study, PA was evaluated for several agronomic traits using a univariate (UV) model in durum wheat, subsequently, different multivariate genomic prediction models were performed to attempt to increase PA. The panel was phenotyped for 10 agronomic traits over two consecutive crop seasons and under two different field conditions: high nitrogen and well-watered (HNW), and low nitrogen and rainfed (LNR). Multivariate GP was implemented using two cross-validation (CV) schemes: MV-CV1, testing the model for each target trait using only the markers, and MV-CV2, testing the model for each target trait using additional phenotypic information. These two MV-CVs were applied in two different analyses: modelling the same trait under both HNW and LNR conditions, and modelling grain yield together with the five most genetically correlated traits. PA for all traits in HNW was higher than LNR for the same trait, except for the trait yellow index. Among all traits, PA ranged from 0.34 (NDVI in LNR) to 0.74 (test weight in HNW). In modelling the same traits in both HNW and LNR, MV-CV1 produced improvements in PA up to 12.45% (NDVI in LNR) compared to the univariate model. By contrast, MV-CV2 increased PA up to 56.72% (thousand kernel weight in LNR). The MV-CV1 scheme did not improve PA for grain yield when it was modelled with the five most genetically correlated traits, whereas MV-CV2 significantly improved PA by up to ~18%. This study demonstrated that increases in prediction accuracy for agronomic traits can be achieved by modelling the same traits in two different field conditions using MV-CV2. In addition, the effectiveness of MV-CV2 was established when grain yield was modelled with additional correlated traits.

Looking back to look forward: Explorations on water scenario in Bundelkhand, Central India

At present, India is suffering from the worst water crisis in its history, and millions of lives and livelihoods are under threat. As per NITI Aayog's Water Index Report (2018), 40% of the population will have no access to drinking water by 2030. A 2016 report by Down To Earth (DTE) stated that 116,000 water harvesting structures were constructed between 2006 and 2015, and 15,000 crore rupees were spent on drought-proofing measures in Bundelkhand, Central India. Still, the region had 15th consecutive crop loss and 13 droughts in the past 15 years. Water historians like Elizabeth Whitcombe, Rohan D'Souza, and others have demonstrated how British imperialism led to the replacement of traditional water harvesting structures and systems, severely altering existing water-society relationships. On the contrary, Ian Stone, David Mosse, and Esha Shah argued that the ‘pre-colonial equilibrium’ versus ‘colonial hydrology’ framework is an exaggeration. Within this context, the research reveals the tangled roots of various causes and variables, and practically informing policy circles to tackle contemporary water issues and challenges and achieve SDG 6: Clean Water and Sanitation.

Sources and splitting of special fertilizers application in coffee crop

This study assesses special and mineral fertilizers and the splitting of fertilizer application in coffee - a crop with high nutritional requirements for full yield potential. A 4 × 3 factorial scheme was implemented with four fertilizers [mineral, mineral with polymer, organomineral with cellulosic residue (OM-CR), or sugarcane filter cake (OM-FC)] and three application times, or splits (100% at once, 50%+50%, 33.3%+33.3%+33.3%). Coffee plant height, canopy diameter, plagiotropic branch growth, leaf chlorophyll, nutrient contents in the soil and leaves, and harvest yield after fruit maturation were evaluated in two consecutive crop cycles. The results indicated that organomineral fertilizers performed similarly to other fertilizers regarding coffee leaf chlorophyll and plant height. Only one fertilizer application effectively increased canopy diameter in both crop cycles. In the first crop cycle, OM-FC and conventional mineral fertilizers were significantly better for coffee foliar N content. In contrast, in the second crop cycle, mineral-P, OM-CR, and OM-FC achieved satisfactory results with one fertilizer application, whereas conventional mineral fertilizer required three applications for superior results. There are no differences in leaf P content among different sources and frequencies of application. Still, mineral-P and OM-CR had better soil P content than the conventional mineral fertilizer. OM-CR required two applications to reach high levels of leaf K content, while other fertilizers achieved it with one application. Organomineral and protected mineral fertilizers performed similarly in both crop cycles, with two applications resulting in greater coffee yield in the second cycle, regardless of the fertilizer used.

Soil Microorganism Interactions under Biological Fumigations Compared with Chemical Fumigation.

Biological fumigation, a potential alternative to chemical fumigation, shows a wide range of prospective applications. In this study, we carried out biological fumigation experiments to evaluate its effect on alleviating consecutive cropping problems (CRPs) when compared with chemical fumigation. We designed five treatments, namely, CR (no treatment), LN (chemical fumigation with lime nitrogen), Ta (fumigation with marigold), Ra (fumigation with radish), and Br (fumigation with mustard), for soils for replanting eggplant and measured the crop's growth status, soil bacterial and fungal communities, and soil physicochemical properties. The results showed that the Br and Ra treatments formed similar microbial communities, while the Ta treatment formed unique microbial communities. The genera Olpidiomycota and Rozellomycota could be used as indicator species for the transformation process of soil microbial communities after the Br and Ta treatments, respectively. When compared with the CR and LN treatments, the soil's physicochemical properties were optimized under the Br treatment, and the soil organic matter content increased by 64.26% and 79.22%, respectively. Moreover, under the Br treatment, the soil's biological properties enhanced the bacterial and fungal alpha diversity, and the saprotrophic fungi increased with the depletion of pathotrophic fungi, while some specific probiotic microorganisms (such as Olpidiomycota, Microascales, Bacillus, etc.) were significantly enriched. In contrast, under the Ta treatment, soil nutrient levels decreased and the soil's biological indices deteriorated, whereas the bacterial diversity decreased and the pathogenic fungi increased. Among these three biological fumigation methods, the Br pre-treatment was the best way to alleviate the crop's CRPs and may be a good substitute for chemical fumigation in some situations. However, the Ta treatment also had some risks, such as the loss of land quality and reduced productivity.

Priming of Exogenous Salicylic Acid under Field Conditions Enhances Crop Yield through Resistance to Magnaporthe oryzae by Modulating Phytohormones and Antioxidant Enzymes.

This study explores the impact of exogenous salicylic acid (SA) alongside conventional treatment by farmers providing positive (Mancozeb 80 % WP) and negative (water) controls on rice plants (Oryza sativa L.), focusing on antioxidant enzyme activities, phytohormone levels, disease resistance, and yield components under greenhouse and field conditions. In greenhouse assays, SA application significantly enhanced the activities of peroxidase (POX), polyphenol oxidase (PPO), catalase (CAT), and superoxide dismutase (SOD) within 12-24 h post-inoculation (hpi) with Magnaporthe oryzae. Additionally, SA-treated plants showed higher levels of endogenous SA and indole-3-acetic acid (IAA) within 24 hpi compared to the controls. In terms of disease resistance, SA-treated plants exhibited a reduced severity of rice blast under greenhouse conditions, with a significant decrease in disease symptoms compared to negative control treatment. The field study was extended over three consecutive crop seasons during 2021-2023, further examining the efficacy of SA in regular agricultural practice settings. The SA treatment consistently led to a reduction in rice blast disease severity across all three seasons. Yield-related parameters such as plant height, the number of tillers and panicles per hill, grains per panicle, and 1000-grain weight all showed improvements under SA treatment compared to both positive and negative control treatments. Specifically, SA-treated plants yielded higher grain outputs in all three crop seasons, underscoring the potential of SA as a growth enhancer and as a protective agent against rice blast disease under both controlled and field conditions. These findings state the broad-spectrum benefits of SA application in rice cultivation, highlighting its role not only in bolstering plant defense mechanisms and growth under greenhouse conditions but also in enhancing yield and disease resistance in field settings across multiple crop cycles. This research presents valuable insights into the practical applications of SA in improving rice plant resilience and productivity, offering a promising approach for sustainable agriculture practices.

Characterisation of ‘giant’ cysts of the potato cyst nematode, Globodera rostochiensis, present in potato fields in Kenya

Summary Potato production in East Africa is seriously impacted by the potato cyst nematode (PCN), Globodera rostochiensis, where it has been recorded in at least three countries. In Kenya, it is widespread in all major potato-growing regions, often at very high densities. Consecutive cropping of potato on the same land and a sub-tropical climate have influenced PCN biology. For example, unusually large cysts have been regularly recovered. We have analysed the biological properties of these ‘giant cysts’. The giant cysts contained more eggs than those recovered from UK fields. Egg size did not differ from UK populations and there was no difference in overall lipid content or lipid profile in J2 from giant cysts, compared to control samples. The nematodes in giant cysts were also genetically indistinguishable from any other G. rostochiensis sampled. When grown under UK glasshouse conditions, the offspring of nematodes from giant cysts were no different in size from those grown from control cysts, indicating that gigantism is not a heritable trait and may simply reflect favourable conditions for PCN under Kenyan farming systems. To date, all the PCN tested from Kenya, including those from giant cysts, are avirulent on potato cultivars containing the resistance gene.

Comparative analysis of different Karnal bunt disease prediction models developed by machine learning techniques for Punjab conditions.

Timely prediction of pathogen is important key factor to reduce the quality and yield losses. Wheat is major crop in northern part of India. In Punjab, wheat face challenge by different diseases so the study was conducted for two locations viz. Ludhiana and Bathinda. The information regarding the occurrence of Karnal bunt in 12 consecutive crop seasons (from 2009-10 to 2020-21) in Ludhiana district and in 9 crop seasons (from 2010-11 to 2018-19) in Bathinda district, was collected from the Wheat Section of the Department of Plant Breeding and Genetics at Punjab Agricultural University (PAU), located in Ludhiana. The study aims to investigate the adequacy of various methods of machine learning for prediction of Karnal bunt using meteorological data for different time period viz. February, March, 15 February to 15 March and overall period obtained from Department of Climate Change and Agricultural Meteorology, PAU, Ludhiana. The most intriguing outcome is that for each period, different disease prediction models performed well. The random forest regression (RF) for February month, support vector regression (SVR) for March month, SVR and BLASSO for 15 February to 15 March period and random forest for overall period surpassed the performance than other models. The Taylor diagram was created to assess the effectiveness of intricate models by comparing various metrics such as root mean square error (RMSE), root relative square error (RRSE), correlation coefficient (r), relative mean absolute error (MAE), modified D-index, and modified NSE. It allows for a comprehensive evaluation of these models' performance.

Dry matter production and nutrient extraction by three successive crops fertilized with serpentinite rock as a soil remineralizer

The incorporation of new sources of fertilizers is important to of the food production security. The use of rock powders still needs investigation to address their agronomic efficiency and the safety for the users and for the consumers. This work aimed to study the dry matter production and the nutrient extraction after three consecutive crops, in two soils fertilized with serpentinite rock powder. The experiment was carried in a greenhouse, with three sequential crops, with seven treatments, two soils and four replications. After 40 days of growth, the whole plants were harvested and sent to measure the dry weight and for the chemical analyses. The use of the serpentinite did not increase the total dry matter biomass weight, compared to the fertilized controls. The magnesium extraction was not different between the control treatment with dolomitic limestone and the serpentinite treatment at higher dose for the clayed soil, indicating that the serpentinite was able to supply the magnesium for the plants in the experimental condition, and also a significant dose related effect suggests that the magnesium from the powder has been released. The use of the serpentinite also increased the extraction of other nutrients, like calcium, phosphorus, zinc and iron.

Nitrogen use efficiency in bread wheat: Genetic variation and prospects for improvement.

Nitrogen (N) is one of the primary macronutrients required for crop growth and yield. This nutrient is especially limiting wheat yields in the dry and low fertile agro-ecologies having low N in the root zone soil strata. Moreover, majority of farmers in India and South Asia are small to marginal with meagre capacity to invest in costly nitrogen fertilizers. Therefore, there is an immense need to identify lines that use nitrogen efficiently. A set of 50 diverse wheat genotypes consisting of indigenous germplasm lines (05), cultivars released for commercial cultivation (23) and selected elite lines from CIMMYT nurseries (22) were evaluated in an alpha-lattice design with two replications, a six-rowed plot of 2.5m length for 24 agro morphological, physiological and NUE related traits during two consecutive crop seasons in an N-depleted precision field under two different N levels of 50%-N50 (T1) and 100%-N100 (T2) of recommended N, i.e., 100 kg/ha. Analysis of variance revealed significant genetic variation among genotypes for all the traits studied. About 11.36% yield reduction was observed at reduced N levels. Significant correlations among NUE traits and yield component traits were observed which indicated pivotal role of N remobilization to the grain in enhancing yield levels. Among N-insensitive genotypes identified based on their yielding ability at low N levels, UASBW13356, UASBW13358, UASBW13354, UASBW13357 and KRL1-4 showed their inherent genotypic plasticity toward N application. The genotypes with more yield and high to moderate NUtE can be used as parents for the breeding of N efficient genotypes for marginal agro-ecologies. Low N tolerant genotypes identified from the current investigation may be further utilized in the identification of genomic regions responsible for NUE and its deployment in wheat breeding programs. The comprehensive data of 24 traits under different nitrogen levels for diverse genotypes from India and global sources (mainly CIMMYT) should be useful for supporting breeding for NUE and thus will be of great help for small and marginal farmers in India and South Asia.

Mulch alleviates the continuous crop barriers of Codonopsis pilosula (Franch.) Nannf. by regulating the soil bacterial community

AbstractCodonopsis pilosula (Franch.) Nannf. is an essential traditional medicinal herb in China. Soil sickness caused by continuous cropping is the main reason for the yield reduction of C. pilosula. However, because of the lack of systematic research on the mechanism of continuous cropping obstacles in C. pilosula, there is a lack of effective measures to reduce or even restrain the disorder of continuous cropping obstacles in C. pilosula. The root system, inter‐root soil microorganisms and non‐inter‐root soil of C. pilosula under a continuous cropping system (e.g. crop rotation, two consecutive crops and three consecutive crops) as well as under different mulching methods (the mulched film and the uncovered) were used as experimental materials for the study. The plant growth of C. pilosula was significantly inhibited when continuous cropping reached 2 years. At the same time, the mulched film significantly (p < .05) promoted the development of C. pilosula under continuous cropping and considerably mitigated the plant death rate of C. pilosula in all fields. The content of soil nutrients, such as organic matter and inorganic nitrogen, decreased with increasing years of continuous cropping. In contrast, the mulched film improved this soil nutrient in continuous cropping. There was a tendency for the number of endemic operational taxonomic units (OTUs) to decrease in continuous cropping. Additionally, the mulched film altered the distribution of shared and endemic OTUs in the samples and had a recruiting effect on inter‐root microorganisms in continuous cropping. Betaproteobacteriales flora abundance decreased with increasing years of continuous cropping, which showed a strong positive correlation with the immune system and environmental adaptation function. The mulched film increased the abundance of beneficial microorganisms, such as AKAU4049, Betaproteobacteriales and Gaiellales, to adapt and improve the continuous crop disorder of C. pilosula. In conclusion, mulching can enhance the soil environment and facilitate the growth and development of C. pilosula during continuous cultivation.

Response of soil microbial glycoside hydrolase family 6 cellulolytic population to lignocellulosic biochar reveals biochar stability toward microbial degradation.

Biochar produced from lignocellulosic biomass offers an opportunity to recycle waste into a valuable soil amendment. The application of biochar has been proposed to mitigate climate change by sequestering carbon in the soil. However, the field impact of biochar treatment on the cellulolytic microbial populations involved in the earlier steps of cellulose degradation is poorly understood. A field trial spanning three consecutive crop cycles of Zea mays was conducted in a degraded tropical Ultisol of Peninsular Malaysia. The soil was amended with two contrasting biochar made from oil palm kernel shells (pyrolyzed at 400°C) and rice husks (gasified at 800°C) with or without fertilizer supplementation. Soil samples were taken at each harvesting stage and analyzed for total organic carbon, labile active organic carbon, total cellulase, and β-glucosidase. Microbial glycoside hydrolase family 6 (GH6) cellulase genes and transcripts, involved in the early steps of cellulose degradation, were quantified from the extracted soil deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), respectively. Total organic carbon, labile active organic carbon, and β-glucosidase activity were significantly increased, while no effect on total cellulase activity was found. Both biochars stimulated the total population (DNA-derived) abundance of soil microorganisms harboring the GH6 cellulase genes. The biochar amendment did not affect the active population (RNA-derived) of the GH6 cellulolytic community, showing no significant changes in transcript expression. This indirectly corroborates the role of biochar as a potential carbon sequester in the soil.

QTL mapping: insights into genomic regions governing component traits of yield under combined heat and drought stress in wheat.

Drought and heat frequently co-occur during crop growth leading to devastating yield loss. The knowledge of the genetic loci governing component traits of yield under combined drought and heat stress is essential for enhancing the climate resilience. The present study employed a mapping population of 180 recombinant inbred lines (RILs) derived from a cross between GW322 and KAUZ to identify quantitative trait loci (QTLs) governing the component traits of yield under heat and combined stress conditions. Phenotypic evaluation was conducted across two consecutive crop seasons (2021-2022 and 2022-2023) under late sown irrigation (LSIR) and late sown restricted irrigation (LSRI) conditions at the Indian Council of Agricultural Research Institute-Indian Agricultural Research Institute (ICAR-IARI), New Delhi. Various physiological and agronomic traits of importance were measured. Genotyping was carried out with 35K SNP Axiom breeder's genotyping array. The linkage map spanned a length of 6769.45cM, ranging from 2.28cM/marker in 1A to 14.21cM/marker in 5D. A total of 35 QTLs were identified across 14 chromosomes with 6B containing the highest (seven) number of QTLs. Out of 35 QTLs, 16 were major QTLs explaining the phenotypic variance greater than 10%. The study identified eight stable QTLs along with two hotspots on chromosomes 6B and 5B. Five QTLs associated with traits thousand-grain weight (TGW), normalized difference vegetation index (NDVI), and plant height (PH) were successfully validated. Candidate genes encoding antioxidant enzymes, transcription factors, and growth-related proteins were identified in the QTL regions. In silico expression analysis highlighted higher expression of transcripts TraesCS2D02G021000.1, TraesCS2D02G031000, TraesCS6A02G247900, and TraesCS6B02G421700 under stress conditions. These findings contribute to a deeper understanding of the genetic architecture underlying combined heat and drought tolerance in wheat, providing valuable insights for wheat improvement strategies under changing climatic conditions.

Impact of foliar application of iron and zinc fertilizers on grain iron, zinc, and protein contents in bread wheat (Triticum aestivum L.).

Micronutrient deficiencies, particularly iron (Fe) and zinc (Zn), are prevalent in a large part of the human population across the world, especially in children below 5 years of age and pregnant women in developing countries. Since wheat constitutes a significant proportion of the human diet, improving grain Fe and Zn content in wheat has become important in improving human health. This study aimed to quantify the effect of foliar application of iron sulfate heptahydrate (FeSO4.7H2O) and zinc sulfate heptahydrate (ZnSO4.7H2O) and their combination on grain Fe and Zn concentrations, as well as grain protein content (GPC). The study also aimed to assess the utility of these applications in large field conditions. To address this issue, field experiments were conducted using 10 wheat cultivars and applying a foliar spray of FeSO4.7H2O (0.25%) and ZnSO4.7H2O (0.50%) separately (@400 L of solution in water per hectare during each spray) and in combination at two different crop growth stages (flowering and milking) for three consecutive crop seasons (2017-2020). The study used a split-plot design with two replications to assess the impact of foliar application on GFeC, GZnC, and GPC. In addition, an experiment was also conducted to assess the effect of soil (basal) @ 25 kg/ha ZnSO4, foliar @ 2 kg/ha, ZnSO4.7H2O (0.50%), and the combination of basal + foliar application of ZnSO4 on the grain micronutrient content of wheat cultivar WB 02 under large field conditions. GFeC increased by 5.1, 6.1, and 5.9% with foliar applications of FeSO4, ZnSO4, and their combination, respectively. GZnC increased by 5.2, 39.6, and 43.8% with foliar applications of FeSO4, ZnSO4, and their combination, respectively. DBW 173 recorded the highest increase in GZnC at 56.9% with the combined foliar application of FeSO4 and ZnSO4, followed closely by HPBW 01 at 53.0% with the ZnSO4 foliar application, compared to the control. The GPC increased by 6.8, 4.9, and 3.3% with foliar applications of FeSO4, ZnSO4, and their combination, respectively. Large-plot experiments also exhibited a significant positive effect of ZnSO4 not only on grain Zn (40.3%, p ≤ 0.001) and protein content (p ≤ 0.05) but also on grain yield (p ≤ 0.05) and hectoliter weight (p ≤ 0.01), indicating the suitability of the technology in large field conditions. Cultivars exhibited a slight increase in GFeC with solitary foliar applications of FeSO4, ZnSO4, and their combination. In contrast, a significant increase in GZnC was observed with the foliar application of ZnSO4 and the combined application of FeSO4 and ZnSO4. In terms of GPC, the most significant enhancement occurred with the foliar application of FeSO4, followed by ZnSO4 and their combination. Data demonstrated the significant effect of foliar application of ZnSO4 on enhancing GZnC by 39.6%. Large plot experiments also exhibited an increase of 40.3% in GZnC through the foliar application of ZnSO4, indicating the effectiveness of the technology to be adopted in the farmer's field.

Post-harvest cleaning, sanitization, and microbial monitoring of soilless nutrient delivery systems for sustainable space crop production.

Bioregenerative food systems that routinely produce fresh, safe-to-eat crops onboard spacecraft can supplement the nutrition and variety of shelf-stable spaceflight food systems for use during future exploration missions (i.e., low earth orbit, Mars transit, lunar, and Martian habitats). However, current space crop production systems are not yet sustainable because they primarily utilize consumable granular media and, to date, operate like single crop cycle, space biology experiments where root modules are sanitized prior to launch and discarded after each grow-out. Moreover, real-time detection of the cleanliness of crops produced in spacecraft is not possible. A significant paradigm shift is needed in the design of future space crop production systems, as they transition from operating as single grow-out space biology experiments to becoming sustainable over multiple cropping cycles. Soilless nutrient delivery systems have been used to demonstrate post-harvest sanitization and inflight microbial monitoring technologies to enable sequential cropping cycles in spacecraft. Post-harvest cleaning and sanitization prevent the buildup of biofilms and ensure a favorable environment for seedling establishment of the next crop. Inflight microbial monitoring of food and watering systems ensures food safety in spaceflight food systems. A sanitization protocol, heat sterilization at 60°C for 1 h, and soaking for 12 h in 1% hydrogen peroxide, developed in this study, was compared against a standard hydroponic sanitization protocol during five consecutive crop cycles. Each cropping cycle included protocols for the cultivation of a crop to maturity, followed by post-harvest cleaning and inflight microbial monitoring. Microbial sampling of nutrient solution reservoirs, root modules, and plants demonstrated that the sanitization protocol could be used to grow safe-to-eat produce during multiple crop cycles. The cleanliness of the reservoir and root module surfaces measured with aerobic plate counts was verified in near real time using a qPCR-based inflight microbial monitoring protocol. Post-harvest sanitization and inflight microbial monitoring are expected to significantly transform the design of sustainable bioregenerative food and life support systems for future exploration missions beyond low earth orbit (LEO).

Evaluation of different insecticides for the suppression of rice leaf folder and their impact on rice yield under field condition

The study was conducted at the Adaptive Research Farm in Sheikhupura, Punjab, Pakistan, over three crop seasons (Kharif-2020, 2021, and 2022). The goal was to assess both new and existing insecticides' effectiveness against leaf folders in rice crops. The results showed that all the experimental units treated with insecticides successfully reduced leaf folder damage and populations, with significant variations among them. Over three years, the insecticides Chlorantraniliprole, Flubendiamide, Fipronil, Gamma-cyhalothrin, and Lambda-cyhalothrin caused varying levels of pest mortality, ranging from 44.0% to 90.2%. Chlorantraniliprole had the most significant impact, with a mortality rate of 89.0% to 94.1%, followed by Flubendiamide (84.6% to 90.4%) and Fipronil (72.2% to 87.0%). Lambda-cyhalothrin had the lowest effect, with a mortality rate of 29.0% to 53.5% over the control treatment across all three years. The application of insecticides significantly improved grain yield, productive tillers, and paddy yield compared to the control. In terms of paddy yield, Chlorantraniliprole treatment had the highest production with yields of 4293.3, 3583.0, and 4540.0 kgha-1 in the years 2020, 2021, and 2022. It was followed by Flubendiamide (4166.7, 3566.7, and 4476.7 kgha-1) and Fipronil (4030.3, 3483.3, and 4493.3 kgha-1) for the respective years. The lowest paddy yield was observed in the check plot, with yields of 3650.0, 3200, and 3973.3 kgha-1 over the three consecutive crop seasons.

Host-virus interaction between tobacco mild green mosaic virus strain U2 and tropical soda apple resulting in systemic hypersensitive necrosis and the host range, survival, spread, and molecular characterization of the virus.

Tobacco mild green mosaic virus strain U2 (TMGMV-U2) is a registered active ingredient in a bioherbicide to control tropical soda apple (TSA), Solanum viarum, an invasive weed. As required for registration, we developed empirical data on the host-virus interaction and the virus's host range, survival, spread, and genomic sequence. TMGMV-U2 killed TSA plants by causing systemic hypersensitive necrosis (SHN). It elicited local lesions in inoculated leaves which was followed by the plant's wilting and death. It moved from inoculated terminal leaves through the vasculature to roots and then to newly developed leaves. Phloem death was implicated in wilting and plant death. The SHN response was attenuated in plants grown at constant 32 °C. TMGMV-U2 titer in TSA was low compared to a systemically susceptible tobacco. The virus remained infective for up to 6 months in infected dead TSA tissues and in soil in which infected plants had grown. Susceptible tobacco and pepper plants grown in soil that previously had infected dead TSA or in soil amended with the virus remained asymptomatic and virus-free. A susceptible pepper crop grown in a field block following two consecutive crops of TMGMV-U2-infected susceptible tobacco grew disease-free and virus-free and without yield loss. Purified TMGMV-U2 was infective for 1 year when stored at -20 °C or 5 °C and for 1 month at room temperature. No virus spread was found in the field. Genomic analyses confirmed the registered isolate to be a U2 strain and free of satellite TMV. The TMGMV-U2-susceptible species preponderantly belonged to the Solanaceae. A few hosts that were killed belonged to this family. Several new hosts to TMGMV-U2 were found. These data enabled registration of TMGMV-U2. TMGMV-U2 can be used safely as a bioherbicide without risks to nontarget plants and the environment. © 2023 Society of Chemical Industry.

Prevalence and spatial distribution of cranberry fruit rot pathogens in British Columbia, Canada and potential fungicides for fruit rot management.

Twenty-eight cranberry farms in southwestern British Columbia were investigated for the prevalence and spatial distribution of fungal pathogens that contribute to fruit rot incidence. Farms were selected from six regions where most cranberry production is concentrated. Flowers, and green and ripe fruit (var. 'Stevens') samples, collected during two consecutive crop seasons, were analyzed for fruitrot pathogens. The most frequently isolated pathogens were identified asAllantophomopsis cytisporea, Botrytis cinerea, Coleophoma empetri, Colletotrichum fioriniae, Colletotrichum gloeosporioides, Fusicoccum putrefaciens, Glomerella sp., Phomopsis vaccinii, Phyllosticta elongata, Phyllosticta vaccinii and Physalospora vaccinii. The pathogens Allantophomopsis cytisporea, Phyllosticta spp., and Physalospora vaccinii were found at high incidence. These pathogens were present in all cranberry growing regions, although their mean percentage incidence varied from farm-to-farm and region-to-region. Amongst the pathogens from three phenological stages of cranberry crop examined, ripe fruit had the highest percentage incidence of fruit rot pathogens compared to that of flowers or green fruit; thus, indicating their presence at the early stages of crop development. The efficacy to inhibit the mycelial growth and spore germination of the fruit rot pathogens by twenty six fungicides, belonging to nine different modes of actions, were evaluated in vitro. The copper-based fungicides and captan of group M, flutriafol, triforine, difenoconazole, prothioconazole and propiconazole of group 3, benzovindiflupyr of group 7, and fosetyl-Al of group 33 demonstrated a high degree of efficacy in inhibiting the mycelial growth of all fruit rot pathogens. The fungicides chlorothalonil of group M, fenbuconazole of group 3, pyrimethanil and cyprodinil of group 9, and fludioxonil of group 12 also demonstrated activity against most fruit rot pathogens. The copper-based fungicides, chlorothalonil, captan, flutriafol, triforine, difenoconazole, prothioconazole, propiconazole, benzovindiflupyr, and fosetyl-Al effectively prevented the spore germination of most fruit rot pathogens. This demonstrated activity of the fungicides towards cranberry fruit rot pathogens should be assessed for efficacy in planta under field conditions. The current study identified the most critical fungal pathogens causing fruit rot of cranberry in British Columbia and potential fungicides that could be used in the management of fruit rot and to improve fruit quality and yield.

Comparative study of univariate and multivariate selection strategies based on an integrated approach applied to oilseed rape breeding

AbstractChoosing the right method to discover superior genotypes is always one of the major challenges that oilseed rape (Brassica napus L.) researchers deal with. This work aimed to compare the univariate and multivariate selection indices utilizing variance‐based, additive main effects and multiplicative interaction based, best linear unbiased prediction based, and genotype × environment/trait based strategies to determine the best‐performing (regarding stability, yield, and agronomic traits) oilseed rape genotypes. Utilized indices were categorized into five general methods, including univariate performance selection index (UPSI: mean performance), univariate stability selection indices (USSIs: environmental variance, Shukla's stability variance, AMMI stability value, modified AMMI stability value, modified AMMI stability index, and weighted average of absolute scores), multivariate performance selection indices (MPSIs: genotype by trait [GT], genotype by yield × trait [GYT], and ideotype‐design index [FAI‐BLUP]), univariate performance and stability selection indices (UPSSIs: coefficient of variability, harmonic mean of genotypic value [HMGV], relative performance of genotypic value [RPGV], WAASBY [WAASB and mean performance {Y}], and genotype + genotype × environment interaction [GGE]), and multivariate performance and stability selection index (MPSSI: MTSI). Data from 18 oilseed rape genotypes and two checks were obtained from trials conducted at eight locations in Iran during two consecutive crop years from 2018 to 2020. The grain yield (GY) and agronomic traits were evaluated. The significant genotype × environment interaction was found for GY and agronomic traits in the combined analysis of variance. In terms of GY, the selection indices GGE, HMGV, and RPGV (6.51), GYT (6.43), GT (5.35), MTSI (4.95), FAI‐BLUP (4.64), and WAASBY (3.97) achieved better‐than‐average genetic gains (GSs). Using an optimized model of USSIs (O‐USSIs), GS increased from −0.15 to 3.26 on average, which shows the efficiency of O‐USSIs in high‐yielding and stable genotypes selection. Based on Spearman's ranking correlation, a positive relationship was found among MPSIs, MPSSI, UPSSIs, and UPSIs, but not for USSIs. Based on an integrated model of selection indices, genotypes G2, G10, G11, G14, and G20 were detected as superior genotypes with high‐yielding, high‐stability, and desirable agronomic traits. It could be concluded that combining different approaches of genotype selection based on an integrated model can provide better answers to oilseed rape breeders.

Influence of genetic and interannual factors on the fatty acids profile of virgin olive oil.

Among olive oil nutritional benefits, it is worth mentioning its fatty acids composition with predominance of monounsaturated fatty acids (MUFAs). We have evaluated the influence of the cultivar and interannual factors on the fatty acids profile of virgin olive oil samples obtained from 45 and 71 cultivars along three and two consecutive crop seasons, respectively. The cultivars were classified in two groups according to the fatty acids composition: (1) high content in MUFAs and moderate content in saturated and polyunsaturated fatty acids (SFAs and PUFAs, respectively) and (2) moderate content in MUFAs and high content in SFAs/PUFAs. We also observed variations in the fatty acids content with the climate conditions, which can significantly alter the saturated and unsaturated profiles. Thus, a significant decrease in MUFAs and an increase in SFAs/PUFAs concentrations was found when the precipitation accumulated within the June-October period was reduced.