The seed production and quality of soybean (Glycine max L.) gets affected due to erratic rainfalls during the season, leading to exploration in off-season cultivation to meet out the demand. Therefore, the experiment was conducted to identify the optimal sowing window for off-season seed production of soybean during the years 2022–23 and 2023–24 in the North Eastern Dry Zone of Karnataka. The experiment was laid out in a split-plot design with three replications, comprising two varieties (JS 335 and DSB 21) and six sowing dates. Results revealed that sowing during the first fortnight of November (D1) consistently recorded superior performance in both the years and pooled analysis. This treatment significantly improved key phenological parameters, including longer duration from planting to one open flower at any node on the main stem, extending reproductive phase (R1: Beginning bloom to R8: Full maturity), and higher days to 50% flowering in both varieties. The favourable growth period under D1 contributed to better crop development and efficient resource utilisation. Consequently, the highest seed yield/plot was also recorded under this sowing window, with JS 335 outperforming DSB 21. Therefore, it can be concluded that sowing soybean during the first fortnight of November may be the most suitable window for off-season seed production in the North Eastern Dry Zone of Karnataka, ensuring better growth and higher seed yield.
A field experiment was conducted to evaluate the bio-efficacy and phytotoxicity of pre-emergence herbicide mixtures on weed growth and yield in transplanted rice (Oryza sativa L.) cv. ‘Samba Mahsuri’ (BPT-5204) during kharif 2023 with nine treatments replicated thrice at the Agricultural Research Farm, Banaras Hindu University, Varanasi, Uttar Pradesh. The weed flora in the trial comprised of grasses (Cynodon dactylon, Echinochloa colona, Paspalum distichum), sedges (Cyperus rotundus, Fimbristylis miliacea, Cyperus difformis), and broad-leaved weeds (Ipomoea aquatica, Sagittaria guayanensis, Marsilea quadrifolia, Eclipta prostrata, Rotala densiflora). Among all the treatments, oxidiazon + pretilachlor @520 + 150 mL a.i./ha (T9) recorded significantly lowest weed density (355 weeds/m²) and weed dry weight (197.46 g/m²) at 60 DAA. It also recorded significantly highest yield attributes, effective tillers, panicle weight, filled grains/panicle and test weight resulting in the highest grain yield, net return and BC ratio with slight to moderate phytotoxicity symptoms at 7 and 14 DAA but the crop recovered completely by 21 days without any lasting effect on growth or productivity. It also registered lowest weed density and weed dry weight, highest yield attributes viz., effective tillers (413/m2), panicle weight (3.3 g), filled grains/panicle (168) and test weight (19.01 g), resulting in the highest grain yield (5.41 t/ha), net return (₹90,944/ha) and benefit-cost ratio (3.83) in transplanted rice. It may, therefore, be concluded that application of oxidiazon + pretilachlor @520 + 150 mL a.i./ha can be recommended as an effective and economically viable pre-emergence herbicide mixture for weed management in transplanted rice under the agro- climatic conditions of Varanasi region.
One of the most significant factors influencing global crop production is salt stress. Plants adapt to salinity stress using a variety of physiological, morphological and molecular mechanisms. Microbial agents, particularly bacterial endophytes, have shown to enhance salinity tolerance, thereby improving plant growth, survival and physiological performance under saline stress. The present study was carried out during 2023–25 at Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu to evaluate the efficacy of bacterial endophyte seed biopriming for enhancing tomato (Solanum lycopersicum L.) growth, physiological performance and salinity tolerance under saline conditions to find the most efficient endophyte and to elucidate the biochemical mechanism by profiling the root exudate metabolites using Gas Chromatography-Mass Spectrometry (GC-MS). Tomato cv. PKM 1 seed were bioprimed with Bacillus firmis (1:1), Bacillus paralicheniformis (undiluted broth), Bacillus amyloliquefaciens (undiluted broth) and Bacillus velezensis (1:1) along with water (hydropriming) for 12 h. Non-primed seeds were used as control. The primed and control seeds were sown in pots with different levels of salinity (0 mM, 25 mM, 50 mM and 75 mM NaCl). Among the tested isolates, B. paralicheniformis performed the best followed by B. firmis under different salinity levels at different durations such as 30, 45 and 60 days. B. paralicheniformis recorded highest leaf area (85.7 cm), chlorophyll content (2.0 mg/g) and relative water content (77.5%) at 60 days. The best-performed isolates (B. paralicheniformis suspension, B. firmis suspension) along with the control under pot culture were selected and raised for 15 days using hydroponic method. The root exudates were collected and analysed through GC-MS. The seeds primed with paralicheniformis recorded more biomolecules such as niacinamide, 2,4-di-tert-butylphenol, α-terpinyl acetate and fatty acid derivatives such as methyl cis-13,16-docosadienoate and hexadecanoic acid butyl ester which possess stress-protective and antioxidant properties that may be responsible for phytohormone production, stimulation of antioxidant activity and resulted in improved physiological performance of tomato seedlings under salinity.
Bihar hairy caterpillar [Spilarctia obliqua (Walker)], a voracious defoliator of green gram, inflicts significant economic losses in pulse production. Biocontrol agents such as entomopathogenic fungi provide a sustainable alternative for managing defoliating pests; however, their efficacy often falls short when compared to chemical insecticides. To maximise their biocontrol potential, this study was designed to assess the nano-biocontrol combination between the entomopathogenic fungus Beauveria bassiana and biosynthesised silver nanoparticles (AgNPs) against S. obliqua in green gram [Vigna radiata (L.) R. Wilczek]. The study was carried out during 2023 at College of Agriculture, Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, Uttarakhand. Different AgNPs concentrations (1.25, 2.5, 5, 10, 20 and 40 ppm) with and without B. bassiana were evaluated including control. Laboratory assays confirmed that AgNPs up to 10 ppm inhibited less than 50% growth of B. bassiana according to Hassan’s toxicity classification index, inferring mutual compatibility. The nano-biocontrol combination of B. bassiana (6.1 × 108 conidia/ mL) with AgNPs (40 ppm) attained LC50 value of 11.16 ppm and LT50 of 77.31 h, demonstrating 2.85-fold higher toxicity than AgNPs alone (LC50: 31.90 ppm; LT50: 106.31 h) against S. obliqua. Under nethouse conditions, this combination achieved 100% mortality of S. obliqua by the 8th day after treatment on green gram plants. The findings suggest that nano-biocontrol combinations have the potential to improve efficacy of microbial biocontrol agents and contribute to the sustainable management of insect-pests.
Phosphorus (P) is an essential macronutrient for wheat (Triticum aestivum L.) growth and productivity. However, indiscriminate use of P fertilisers poses environmental and economic challenges. To address this, a field experiment was conducted to evaluate the effectiveness of humic acid (HA) and phosphate solubilising bacteria (PSB) in enhancing phosphorus use efficiency under reduced phosphorus fertilisation. The experiment comprised three phosphorus levels (control, 50%, and 100%, corresponding to 0, 30, and 60 kg of P2O5/ha) and four phosphate solubiliser treatments (control, HA @10 kg/ha, PSB biofertiliser @10 g/kg seed, and HA @10 kg/ha + PSB biofertiliser @10 g/kg seed) arranged in a factorial randomised block design (F-RBD) with three replications. Application of 100% phosphorus recorded the highest plant height (98.8 cm), tiller number (390.8/m2), dry matter accumulation (890.5 g/m2), spike count (366.7/m2), grain yield (5.48 t/ha), straw yield (9.15 t/ha), total phosphorus uptake (41.45 kg/ha), gross returns (₹136.71 × 103/ha), and net returns (₹97.35 × 103/ha). Among phosphate solubiliser treatments, HA + PSB significantly improved plant height (96.3 cm), tiller number (362.4/m2), dry matter accumulation (879.3 g/m2), spike count (342.7/ m2), grain yield (5.10 t/ha), straw yield (8.60 t/ha), and total phosphorus uptake (37.22 kg/ha). A significant interaction between phosphorus levels and phosphate solubilisers was observed for spike count, grain yield, and straw yield. Notably, 50% phosphorus combined with HA + PSB produced 331.0 spikes/m2, 4.97 t/ha grain yield, and 8.47 t/ ha straw yield, which were statistically comparable to the sole application of 100% phosphorus (338.0 spikes/m2, 5.09 t/ha grain yield, and 8.91 t/ha straw yield). The results demonstrate that integration of HA and PSB can reduce phosphorus fertiliser requirements by 50% without significant yield reduction, thereby improving phosphorus use efficiency and supporting economically viable and environmentally sustainable wheat production.
