Increased yield performance of mutation induced Soybean genotypes at varied agro-ecological conditions

In soybean breeding program, continuous selection pressure on traits response to yield created a genetic bottleneck for improvements of soybean through hybridization breeding technique. Therefore an initiative was taken to developed high yielding soybean variety applying mutation breeding techniques at Plant Breeding Division, Bangladesh Institute of Nuclear Agriculture (BINA), Bangladesh. Locally available popular cultivar BARI Soybean-5 was used as a parent material and subjected to five different doses of Gamma ray using Co60. In respect to seed yield and yield attributing characters, twelve true breed mutants were selected from M4 generation. High values of heritability and genetic advance with high genotypic coefficient of variance (GCV) for plant height, branch number and pod number were considered as favorable attributes for soybean improvement that ensure expected yield. The mutant SBM-18 obtained from 250Gy provided stable yield performance at diversified environments. It provided maximum seed yield of 3056 kg ha-1 with highest number of pods plant-1 (56). The National Seed Board of Bangladesh (NSB) eventually approved SBM-18 and registered it as a new soybean variety named ‘Binasoybean-5’ for large-scale planting because of its superior stability in various agro-ecological zones and consistent yield performance.

Cold stress and freezing tolerance negatively affect the fitness of Arabidopsis thaliana accessions under field and controlled conditions

Main conclusion Higher acclimated freezing tolerance improved winter survival, but reduced reproductive fitness of Arabidopsis thaliana accessions under field and controlled conditions. Abstract Low temperature is one of the most important abiotic factors influencing plant fitness and geographical distribution. In addition, cold stress is known to influence crop yield and is therefore of great economic importance. Increased freezing tolerance can be acquired by the process of cold acclimation, but this may be associated with a fitness cost. To assess the influence of cold stress on the fitness of plants, long-term field trials over 5 years were performed with six natural accessions of Arabidopsis thaliana ranging from very tolerant to very sensitive to freezing. Fitness parameters, as seed yield and 1000 seed mass, were measured and correlation analyses with temperature and freezing tolerance data performed. The results were compared with fitness parameters from controlled chamber experiments over 3 years with application of cold priming and triggering conditions. Winter survival and seed yield per plant were positively correlated with temperature in field experiments. In addition, winter survival and 1000 seed mass were correlated with the cold-acclimated freezing tolerance of the selected Arabidopsis accessions. The results provide strong evidence for a trade-off between higher freezing tolerance and reproductive fitness in A. thaliana, which might have ecological impacts in the context of global warming.

Effect of selenium and zinc foliar application to increase the quantitative and qualitative yields of rapeseed at different sowing dates

The sowing date is an important factor for expanding the cultivated area of rapeseed and affects seed yield, oil content, and fatty acid compounds. Micronutrient elements play an important role in improving the vegetative and reproductive growth of the plant, especially under conditions of biological and environmental stresses. A two-year experiment (2014-2016) was performed to study the response of rapeseed genotypes to foliar application of micronutrients on different sowing dates. The treatments were arranged as a factorial-split plot in a randomized complete block design with three replicates. Three sowing dates of 7 (well-timed sowing date), 17, and 27 (delayed sowing dates) October and two levels of foliar application with pure water (control), selenium (1.5%), zinc (1.5%), and selenium+zinc (1.5%) were factorial in the main plots and five genotypes of SW102, Ahmadi, GKH2624, GK-Gabriella, and Okapi were randomized in the subplots (a total of 30 treatments). Seed yield, oil yield and content, oleic acid, and linoleic acid were reduced when rapeseeds were cultivated on 17 and 27 October, while the contents in palmitic, linolenic, and erucic acids, and glucosinolate increased (p < 0.01). a selenium+zinc treatment improved seed yield, oil content and yield (p < 0.01). The oil quality increased due to increased contents of oleic and linoleic acids under the selenium+zinc treatment (p < 0.01). The GK-Gabriella and GKH2624 genotypes are recommended to be sown on well-timed (7 October) and delayed sowing dates (17 and 27 October) and treated with selenium+zinc due to the higher oil yield, linoleic and oleic acids.

How Does Quinoa (Chenopodium quinoa Willd.) Respond to Phosphorus Fertilization and Irrigation Water Salinity?

Soil salinity is a major problem in arid and semi-arid regions, causing land degradation, desertification, and subsequently, food insecurity. Salt-affected soils and phosphorus (P) deficiency are the common problems in the sub-Sahara, including the Southern region of Morocco. Soil salinity limits plant growth by limiting water availability, causing a nutritional imbalance, and imparting osmotic stress in the plants. The objective of this study was to determine the positive effects of P on growth and productivity and understand the major leaf mineral nutrient content of quinoa (Chenopodium quinoa Willd.) cv. “ICBA Q5” irrigated with saline water. A field experiment applying three salinity (Electrical Conductivity, EC) levels of irrigation water (ECw = 5, 12, and 17 dS·m−1) and three P fertilizer rates (0, 60, and 70 kg of P2O5 ha−1) were evaluated in a split-plot design with three replications. The experiment was conducted in Foum El Oued, South of Morocco on sandy loam soil during the period of March–July 2020. The results showed that irrigation with saline water significantly reduced the final dry biomass, seed yield, harvest index, and crop water productivity of quinoa; however, P application under saline conditions minimized the effect of salinity and improved the yield. The application of 60 and 70 kg of P2O5 ha−1 increased (p < 0.05) the seed yield by 29 and 51% at low salinity (5 dS·m−1), by 16 and 2% at medium salinity (12 dS·m−1), and by 13 and 8% at high salinity (17 dS·m−1), respectively. The leaf Na+ and K+ content and Na+/K+ ratio increased with irrigation water salinity. However, the leaf content of Mg, Ca, Zn, and Fe decreased under high salinity. It was also found that increasing P fertilization improved the essential nutrient content and nutrient uptake. Our finding suggests that P application minimizes the adverse effects of high soil salinity and can be adopted as a coping strategy under saline conditions.

The Effect of Mineral N Fertilization and Bradyrhizobium japonicum Seed Inoculation on Productivity of Soybean (Glycine max (L.) Merrill)

Soybean yields can be considerably improved by inoculation with selected Bradyrhizobium japonicum strains and fertilization. The aim of this study was to assess the productivity of two soybean cultivars depending on the applied N mineral fertilizers and seed inoculation with B. japonicum. The study showed that on average, for both cultivars, the soybean yield was most favorably affected by the combined use of inoculation and nitrogen fertilization (increase in seed yield by 42%, protein yield by about 28%). The application of mineral nitrogen at the dose of 30 or 60 kg·ha−1 allowed the increase in the seed yield by about 17% and protein content by about 14% compared to the control. Inoculation of soybean seeds with B. japonicum increased the yield of soybeans by about 20%, proteins by about 10% compared to the control, and inoculation of Hi®Stick Soy favored a better yield than Nitragina. Inoculation of seeds with Nitragina or Hi®Stick Soy and fertilization with mineral nitrogen increased the content of protein and fiber in seeds of both soybean cultivars, as well as reduced the amount of ash and fat. The seeds of cv. Aldana had a higher amount of protein and ash than cv. Annushka, but a similar amount of fat and fiber.

Enhancement of Soybean (Glycine max L.) Productivity through Sowing Methods and Seed Rates in Telangana State

Background: With the unparalleled growth in area and production, soybean has established itself as a leading oilseed crop of India. The crop is mainly grown under rainfed conditions, and the distribution of rainfall plays an important role in yield realization. The changed landform management with broad-bed furrow seed drill is gaining popularity as the system helps in in situ moisture conservation and draining out excess rainwater. A field experiment was conducted at Regional Sugarcane and Rice Research Station, Rudrur. The yield advantage by adoption of broad-bed and furrow (BBF) method over flat bed was 7.06%. Seed rate of 50 kg ha-1 recorded significantly higher mean seed yield of 2804 kg ha-1 over 75, 38, 20 kg ha-1. The total benefit from adoption of BBF method recorded net returns of ₹ 53,233 ha-1 and B:C ratio of 2.58 over flatbed planting. Seed rate of 50 kg seed ha-1 recorded the highest net returns and B:C ratio this was followed by 75 kg ha-1 seed rate. Methods: A field experiment was conducted for three years (2017-19) at Regional Sugarcane and Rice Research Station, Rudrur, situated at an altitude of 286.3 m above mean sea level at 18°49’41" N latitude and 78°56’ 45" E longitude. Indeterminate variety of soybean ASB 22 was selected. The experimental plots (6m × 6m= 36m2) were laid out with split plot design with three replications. Main plot treatments were methods of planting: M1- Flat bed, M2- Broad bed and Furrow, and sub plot treatments were : seed rates; S1- 75 kg ha-1 (30 × 10 cm), S2- 50 kg ha-1 (30 × 15 cm), S3- 38 kg ha-1 (30 × 20 cm), S4- 20 kg ha-1 (30 × 30 cm). Result: The grain yields, water productivity, harvest index and economics of soybeans under BBF method of planting (in-situ water conservation) and flatbed practices were studied. BBF method increased seasonal soil water storage by 5.37%, 5.78% and 6.20% respectively compared with flatbed planting for 2017, 2018 and 2019 respectively. Seed rate of 50 kg ha-1 recorded significantly higher mean seed yield of 2804 kg ha-1 over 75, 38, 20 kg ha-1. The yield advantage by adopting seed rate of 50 kg ha-1 was 16.08%, 56.02% and 67.6% over 75, 38 and 20 kg ha-1 respectively. The total benefit from adoption of BBF method recorded net returns of ₹ 53,233 ha-1 and B:C ratio of 2.58 over flatbed planting. Seed rate of 50 kg ha-1 recorded the highest net returns and B:C ratio this was followed by 75 kg ha-1. Broad bed and furrow method of planting and optimum seed rate in soybean will enhance the soybean productivity.

Yield and Seed Quality of Summer Green Gram as Influenced by Weed Management under Zero Tillage

Background: Weeds are primary factors that adversely affect growth, yield and seed quality of summer green gram, which can be minimized with adoption of proper weed management practices. This field experiment was conducted to find out the effective weed management practice in summer green gram (Vigna radiata) under zero tillage condition. Methods: In this field-laboratory investigation conducted during summer season 2019 on different herbicides were applied to manage weeds in summer green gram. Eight treatments were applied based on various application windows. In the field and laboratory, the collected samples were determined for growth parameters, nutrient uptakes, seed yield and seed quality of summer green gram. Result: The result revealed that weed free treatment recorded higher growth parameters like, plant height, number of branch/plant, number of leaves/plant and root biomass which was statically at par with Shaked (Propaquizafop + Imezathyper) as post-emergence (POE) at 20 DAS and Pendimethalin as pre-emergence (PE) followed by one hand weeding 20 DAS. Same trends were also observed in seed yield, nutrient content and uptake by seeds. Seed quality parameters like germination per cent (98.00), shoot (25.63 cm) root (14.20 cm) and seedling length (39.83 cm), seedling dry weight (0.16 g), vigour index I (3903.33) and vigour index II (14.96) was higher under weed free followed by Shaked (Propaquizafop + Imezathyper) and Pendimethalin as (PE followed by one hand weeding 20 DAS over weed check.

​Nodulation, Yield Attributes and Yield of Mungbean [Vigna radiata (L.)] Influenced by Different Level of Potassium Humate and Fertility Levels

Background: Optimum crop growth and yield is result of interlinking of several factors. In semi- tropical soil in central plateau and hills zone are deficit in organic carbon and NPK content; therefore inadequate fertilization may leads to pure quality and also lower crop productive capacity of soil. For the maintenance of sustainable and productive production, maintaining soil health is a critical factor. Under low fertility levels, mungbean gives low seed yield. Potassium humate, nitrogen and phosphorus (RDF) application may be increase yield of mungbean in this zone. Method: A field experiment was conducted to study, “Nodulation, yield attributes and yield of mungbean [Vigna radiata (L.)] influenced by different level of potassium humate and fertility. The experiment was carried out in factorial randomized block design with three replications and sixteen treatment combination. Result: Result showed that total number of root nodules, effective nodules, fresh and dry weight of root nodules, leghaemoglobin, nodule index, no. of pods/plant, no. of seeds/pod, test weight, seed and straw yield were observed significantly higher with application of potassium humate @ 4.5 kg/ha. Among different fertility level, the application of 100% RDF significantly increased the total number of root nodules and effective nodules, fresh and dry weight of root nodules, leghaemoglobin, nodule index, no. of pods/plant, no. of seeds/pod and test weight, seed and straw yield. With combined application of potassium humate @ 3.0 kg/ha + 75% RDF significantly higher no. effective nodules, dry weight of root nodules and seed yield were observed, as well as saving of 25% RDF and 1.5 kg potassium humate were also observed.

Genetic study of terminal heat stress in indigenous collections of Indian mustard (Brassica juncea L.) germplasm

Aim: The present study was carried out to evaluate 145 genotypes of Indian mustard for terminal heat stress under late sown irrigated conditions. Methodology: One hundred and forty five genotypes of Indian mustard were evaluated for terminal heat tolerance, along with six checks in augmented block design. The effect of heat stress was assessed on different agro-morphological traits. Data were recorded on five randomly selected plants for 12 different quantitative traits for each genotype. Results: Terminal heat stress caused significant reduction in performance of all traits, except oil content and fruiting zone length. Seed yield per plant showed highest reduction (33.92%) followed by 1000-seed weight (21.28%). Thousand-seed weight and secondary branches per plant were found associated with seed yield under late sown conditions. Based on yield under stress, yield index, geometric mean productivity and stress tolerance indices, five lines viz., DRMR-59, DRMR-2094, DRMR-2129, DRMR-2071, DRMR-2136 were identified as high yielding and terminal heat stress tolerant. Whereas, based on heat stress susceptibility index, DRMR-1347, DRMR-1154, DRMR-1190 were top performing lines tolerant to terminal heat stress. Interpretation: Selection of high yielding lines under stress condition can be done using correlated traits. Yield under stress was found significantly correlated with YSI, YI, MP, STI and GMP suggesting to use these indices for selection of high yielding and heat tolerant lines. However, further re-validation is very much needed for effective use of these indices for selection of heat tolerant lines in Indian mustard.

Path-coefficient and correlation analysis in Bambara groundnut (Vigna subterranea [L.] Verdc.) accessions over environments

In a breeding program, studies of genotypic and phenotypic relationships among agricultural crop traits are useful to design, evaluate, and develop selection criteria for desirable traits. Using path coefficient analysis, the present study was executed to estimate the phenotypic, genotypic, and environmental correlation coefficients between yield and yield-related traits and to determine the direct and indirect effects of yield-related traits on yield per plant. A total of 30 genotypes of Vigna subterranea were studied under tropical conditions at two sites over two planting seasons (considered as four environments). The experiment at each site used a randomized complete block design with three replicates. Data were collected on vegetative and yield component attributes. Based on analysis of variance, pooled results showed that there were positive and highly significant differences (p ≤ 0.01) among the 30 genotypes for all attributes studied. Highly significant and positive strong correlation at phenotypic level was observed for dry seed weight (0.856), hundred seed weight (0.754), fresh pod weight (0.789), and total pod weight (0.626) with yield in kg per hectare, while moderate positive correlations were observed for harvest cut (0.360) and days to maturity (0.356). However, a perfect positive correlation was observed for the dry weight of pods with seed yield. In contrast, days to 50% flowering (− 0.350) showed a negative significant relationship with yield per hectare. The dried pod weight attribute (1.00) had a high positive direct effect on yield. Fresh pod weight had the greatest indirect effect on yield per hectare, followed by the number of total pods by dry pod weight. As a result, dry pod weight, hundred seed weight, number of total pods, and fresh pod weight could be used as selection criteria to improve the seed yield of Bambara groundnut (Vigna subterranea).