Initial growth responses of blackgram (Vigna mungo L. Hepper) under elevated CO<sub>2</sub>and moisture stress

Abstract

An attempt was made to understand the interactive effect of the elevated CO<sub>2</sub> 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<sub>2</sub> (365 ppm), irrigated with elevated CO<sub>2</sub> (600 ppm), moisture stress with ambient CO<sub>2</sub> and moisture stress with elevated CO<sub>2</sub>. The percentage of germination, germination speed, emergence index, and vigor index were measured on the 5<sup>th</sup> and 6<sup>th</sup> 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<sub>2</sub> under both irrigated and moisture stress conditions. Plants grown with elevated CO<sub>2</sub> were taller and attained a greater leaf area along with more biomass than ambient CO<sub>2</sub> 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<sub>2</sub> enrichment of the atmosphere will be beneficial for the crops for better establishment and greater productivity.