A field experiment was conducted at Water Technology Centre, College of Agriculture, PJTSAU, Rajendranagar, Hyderabad during summer 2020-21 on “Optimization of irrigation and nitrogen levels under drip fertigation in okra (Abelmoschus esculentus L.) during summer” 2020-21. The experiment was laid out in a split-plot design with Radhika hybrid (40 cm x 45 cm) and replicated thrice. The treatments comprise of three irrigation levels through drip scheduled at 0.75 Epan, 1.0 Epan and 1.25 Epan as main-plots and four nitrogen levels viz., 75 % RDN (112.5 kg N ha-1), 100 % RDN (150 kg N ha-1), 125 % RDN (187.5 kg N ha-1) and 150 % RDN (225 kg N ha-1) as sub-plots. Experimental soil was sandy clay in texture, alkaline in reaction, medium in organic carbon content, low in available nitrogen, high in available phosphorous and available potassium, respectively. The results indicated that optimized drip irrigation scheduling significantly improved NUE, with the highest efficiency observed at 1.00 Epan (I2) irrigation scheduling and 75 % RDN (N1) nitrogen level. Phenological development, including days to first flowering, days to 50 % flowering, days to first and final picking was not influenced influenced by irrigation scheduling and nitrogen supply. The number of branches per plant increased with 1.00 Epan (I2) and 100 % RDN (N2) nitrogen application, contributing to higher biomass and potential yield. Soil nitrogen content varied across treatments, with initial and final measurements providing insights into nitrogen uptake and residual soil fertility.
Fusarium wilt, caused by Fusarium oxysporum f. sp. melongenae (Fomg), has emerged as a serious disease limiting brinjal productivity. Soil-borne nature of the pathogen, limited reproducibility and environmental variability complicate the use of the laborious traditional screening methods for resistance to Fusarium wilt in breeding programs. To facilitate reliable screening and rapid phenotyping, we resorted to a novel hydroponic approach. In this study, 90 brinjal genotypes, including diverse cultivated and wild accessions, were grown in Hoagland solution and inoculated with Fomg, isolated from a Fusarium wilt-endemic field at the host institute. Disease indices (DI), area under disease progress curve (AUDPC) and area under disease progress stairs (AUDPS) were used to identify resistant genotypes and study disease progression. Host phenotypic trait assessments and histopathological studies were also used to characterize resistant sources. Five genotypes, namely BR-40-7, Pink, Bouldar, S. sisymbriifolium, and S. torvum were found immune to Fusarium wilt, while fifteen genotypes each were found highly resistant and resistant to the disease. Genotypes immune to the disease were asymptomatic. Highly resistant genotypes were late-wilters, while the resistant genotypes were slow-wilters. Highly susceptible genotypes exhibited early, rapid and severe wilting. Resistant genotypes exhibited superior root and shoot development compared to susceptible genotypes. The broad applicability of the hydroponic screening method to diverse plant species and root pathogens underscores its potential to address critical challenges in agriculture. This study is the first to use Fusarium-specific screening of germplasm in hydroponic brinjal and wild Solanum cultures.
The experiment was carried out at the Instructional Farm of JNKVV-College of Agriculture, Rewa (M.P), during the Rabi season 2020-2021 on cabbage. The experiment was laid out in a Randomized Block Design with nine treatments, including Chlorantraniliprole 18.5 SC at 10 g a.i./ha, Fipronil 5% SC @ 40 g a.i./ha, Indoxacarb 14.5 SC @ 40 g a.i./ha, Spinosad 45 SC @ 100 g a.i./ha, Novaluron 10 EC @ 75 g a.i./ha, Emamectine benzoate 5 SG @ 10 g a.i./ha, Neem oil 0.15% @ 4.5 g a.i./ha , Bt 5% WP @ 25 g a.i./ha and untreated control and three replications against diamondback moth two sprays of insecticide were done at 15 and 35 days after transplanting of the crop. The effect of insecticide was recorded on 3, 7, 10 and 15 days after the insecticide. The mean population of DBM after two sprays showed that Spinosad 45 SC proved to be the most effective and superior treatment, recording the lowest population of DBM (0.55 larvae/plant). The order of efficacy of insecticides was found in order T4 (Spinosad 45 SC) > T1 (Chlorantraniliprole 18.5 SC) > T6 Emamectin benzoate > T3 (Indoxacarb 14.5 SC) >T2 (Fipronil 5% SC) > T5 (Novaluron 10 EC) >T8 (Bt 5% WP )> T7 (Neem oil 0.15%). The untreated control recorded a maximum DBM larval population (3.35 larvae/plant). Resulting in the head yield 320.00 q/ha Spinosad 45 SC @ 100 g a.i./ha with maximum C:B ratio (1:21.31) was recorded from Chlorantraniliprole 18.5 SC treatment followed by Indoxacarb 14.5 SC (1:18.20).
Salinity is a major abiotic stress that impacts plant growth and crop yields, particularly in saline-prone regions. The main objective of this work is to determine the optimum NaCl concentration for screening salt tolerance using the Salt Injury Index (SII) by analyzing the effects of NaCl-induced salinity on germination and seedling growth in 30 cowpea (Vigna unguiculata L. Walp.) genotypes. Cowpea seeds were exposed to six NaCl concentrations (0, 75, 100, 150, 200, and 250 mM) in petri plates. Seedling growth parameters such as germination, shoot and root length, seedling length, dry weight, and vigour indices (I & II), were recorded to evaluate the effects of salinity stress. A consistent decline in all measured parameters was observed as NaCl concentration increased. Linear regression of the Salt Injury Index values revealed NaCl concentrations caused a 50% reduction in specific traits, including 215 mM affecting germination, 180 mM for shoot, 210 mM for root, 200 mM for seedling length and dry weight, and 130 and 160 mM for Vigour Index-I and -II, respectively, with an average threshold of 183.57 mM. Consequently, 200 mM NaCl was identified as the optimal concentration to evaluate salt tolerance levels, offering a standardized benchmark for assessing cowpea genotypes under saline conditions.
