Physiology, Growth, and Productivity of Spring–Summer Black Gram (Vigna mungo L. Hepper) as Influenced by Heat and Moisture Stresses in Different Dates of Sowing and Nutrient Management Conditions

Abstract

Heat and soil moisture stress account for serious abiotic constraint in black gram (Vigna mungo (L.) Hepper) production during spring–summer under Gangetic plains of Eastern India. Concurrence of these two can bring about early completion of phenophases that hampers normal metabolism of legumes by disrupting their defense mechanism, leading to poor seed set. The field experiment was conducted with two different sowing dates as the main plot, soil application of cobalt (Co) as subplots and foliar sprays of potassium (K) and boron (B) either alone or in combination as sub–sub plot treatment in a split–split plot design during spring–summer seasons of 2020 and 2021 with black gram (variety: Pant U 31). The study was aimed at evaluating the impact of sowing time and nutrients application alleviating adversities of abiotic stress during reproductive development of black gram. The March first week sown crop took significantly higher days to complete its life cycle compared to March third week sown one (82.0 vs. 78.2 and 81.8 vs. 78.8). This in turn relatively allowed a broader window for leaf area expansion, flowering, and seed filling in the first crop compared to the second one leading to the attainment of superior yield in the normal sown crop during the consecutive years. Crop growth rate (CGR), net assimilation rate (NAR), pod number per plant, seed yield, and harvest index were significantly higher (p ≤ 0.05) with soil Co @ 4 kg ha−1 and foliar 1.25% K + 0.2% B applications through stress mitigation by stimulating chlorophyll biosynthesis, nitrate reductase activity, proline accumulation, and cell membrane stability, irrespective of the years. Fluctuations in per plant pod number explained about 96 and 94% variations in seed yield through linear regressions in respective years. Optimum sowing date along with soil Co application combined with foliar K+B sprays manifested immense potential to achieve higher black gram production. In addition, this nutrient schedule proved to be efficient enough to promote satisfactory growth and optimum seed yield of late sown blackgram through relief of stress during the spring–summer season.

Plant Nutrition: An Effective Way to Alleviate Abiotic Stress in Agricultural Crops

“…Proline accumulation is one of the major mechanisms of drought tolerance in plants [ 113 , 114 ]. Stress tolerance through the accumulation of proline has been reported to be intensified through the foliar spray of K [ 115 , 116 ]. Potassium deficiency has also been linked to a significant reduction in the rate of photosynthetic CO 2 fixation, partitioning and use of photosynthates in moisture-deprived conditions [ 117 , 118 ].…”

“…Boron (B) application has a significant impact on reducing the negative effects of abiotic stress, improving yield, and nutrient uptake. Boron plays a vital role in the overall metabolism and transport system of carbohydrates as well as synthesis and functional aspects of cellular integuments [ 116 , 210 ]. Application on B mitigates the negative effects of saline environments by maintaining internal K + balance through retaining cell wall elasticity and recovery of proper levels of K + [ 211 ].…”

Effect of Sowing Windows and Nutrient Levels on Growth Parameters of Sunnhemp (Crotalaria juncea)

“…Higher plant height produced more leaves which lead to higher leaf area index in delayed sowing. Banerjee et al [11] [12], who reported as increased dosage of fertilizers (37.5:75:37.5 NPK kg ha -1…”

Morpho-physiological Variability and Yield Determinants for Drought Tolerance in Blackgram [Vigna mungo (L.) Hepper]

“…More than 87% of the area under pulses is presently rainfed and moisture stress is the main reason for crop failure or for low yield realization. Water deficit stress can lead to various physiological peculiarities in plants, getting in the way of their growth and production (Banerjee et al, 2021). In fact, this abiotic stress appearing at the reproductive phase of plants may pose serious threats to the maturing of leguminous crops by means of leaf area and chlorophyll content ultimately culminating into poor production (Banerjee et al, 2021).…”

“…Water deficit stress can lead to various physiological peculiarities in plants, getting in the way of their growth and production (Banerjee et al, 2021). In fact, this abiotic stress appearing at the reproductive phase of plants may pose serious threats to the maturing of leguminous crops by means of leaf area and chlorophyll content ultimately culminating into poor production (Banerjee et al, 2021). Improved varieties of different pulse crops hold promise to increase productivity by 20-25% (Ali and Gupta, 2012).…”