Impact of Elevated CO2 and Temperature on Growth, Physiology and Yield of Black Gram (Vigna mungo L. Hepper) Genotypes

Abstract:
Climate change significantly impacts crop production and productivity, particularly in leguminous crops like black gram, which are primarily cultivated under rainfed conditions. The present study evaluated the response of four black gram genotypes (Vigna mungo L. Hepper) to elevated CO2 (eCO2) and elevated temperature (eT) using the Carbon dioxide and Temperature Gradient Chamber (CTGC) facility at ICAR-CRIDA. The experimental conditions included ambient temperature (aT), eCO2 (550 ± 50 ppm), and three gradients of elevated temperature (eT1 = aT+1.5°C, eT2 = aT+3.0°C, eT3 = aT+4.5°C) individually and in combination with eCO2. Results revealed that eCO2 significantly improved biomass accumulation, photosynthetic rate, and yield traits of all the black gram genotypes, while temperature at higher gradients negatively impacted plant growth and yield. The combined treatment of eCO2 + eT had a mitigating effect, particularly at eT1+eCO2, where plants exhibited improved photosynthetic rate, water-use efficiency, and biomass accumulation. However, this amelioration effect declined at eT2+eCO2 and became negligible at eT3+eCO2. The negative effects of elevated temperature counteracted the advantage of elevated CO2. However, at eT3, the negative effects of temperature stress outweighed the benefits of eCO2, leading to reduced yield. Among the genotypes, PLU-826 exhibited the highest photosynthetic rate (Anet) under eCO2, while PSRJ-95016 showed improved performance under eT1+eCO2. Yield parameters such as pod number and seed weight significantly declined under eT3, highlighting the importance of selecting climate-resilient genotypes to sustain black gram productivity under changing environmental conditions.

Keywords:
Black gram (Vigna mungo L. Hepper), climate change, elevated CO2, genotypes, temperature, yield.

Article Info:
Received: 03 Aug 2025; Received in revised form: 02 Sep 2025; Accepted: 06 Sep 2025; Available online: 19 Sep 2025

Cite this Article: