Initial growth responses of blackgram (Vigna mungo L. Hepper) under elevated CO₂and moisture stress

Abstract

An attempt was made to understand the interactive effect of the elevated CO 2 and moisture stress on germination and initial growth responses of blackgarm (Vigna mungo L. Hepper). Four open top chambers (OTCs) were used for different conditions: irrigated with ambient CO 2 (365 ppm), irrigated with elevated CO 2 (600 ppm), moisture stress with ambient CO 2 and moisture stress with elevated CO 2 . The percentage of germination, germination speed, emergence index, and vigor index were measured on the 5 th and 6 th day after sowing (DAS). Plants were harvested at different time intervals, i.e. on 7, 14, 21 and 28 DAS; leaf area and dry weights of the seedlings were recorded. It was observed that moisture stress in general reduced the germination in all the conditions and affected seedling growth of blackgram. Germination percentage, emergence index, germination speed and vigor index were increased with elevated CO 2 under both irrigated and moisture stress conditions. Plants grown with elevated CO 2 were taller and attained a greater leaf area along with more biomass than ambient CO 2 levels under irrigated and moisture stress conditions at all time intervals. The increase in the germination, larger leaf area and dry matter of root, shoot and leaf proved that CO 2 enrichment of the atmosphere will be beneficial for the crops for better establishment and greater productivity.

Potential impact of future climate change on spatial variability of blackgram yield over Tamil Nadu

“…The relative deviation in mean annual rainfall projection over Tamil Nadu for the mid-century was found to be 27.7 per cent. Blackgram being simulated under rainfed condition, precipitation might be the major contribution towards yield deviation; similar finding was reported by Vanaja et al, (2006). In specific, higher decrease in yield during the mid-century might be due to increase in extreme rainfall events during crop season or coincidence of extreme temperature event at the reproductive stage of the crop leading to reduction in pollen production and fertility which in turn reduces the yield (Mondal et al, 2013).…”

“…The elevation in maximum and minimum temperature is not so high which this crop could not adapt. Since Blackgram is a C3 crop, the impact of this mild heat stress might be counteracted by CO 2 increment (Vanaja et al, 2006). The increase in CO 2 concentration favours growth, physiology and biochemical processes (Ziska and Ebi, 2021) including increase in net photosynthesis (Rao et al, 2015).…”

Drought tolerance potential of Vigna mungo L. lines as deciphered by modulated growth, antioxidant defense, and nutrient acquisition patterns

“…Black gram (Vigna mungo L.) is an important pulse crop of Fabaceae family and cultivated in different agro-ecological zones of rainfed areas of South Asian countries including India, Pakistan, Bangladesh, Nepal, Thailand, and Korea (Vanaja et al 2006). In Pakistan, V. mungo is grown on an area of 45.7 thousand hectares with a 25.6 thousand tons production annually, making 563 kg/ha average yield (Anonymous 2001).…”