Stage sensitivity of mungbean (Vigna radiata L. Wilczek) to an elevated level of carbon dioxide

An experiment was undertaken using open-top chambers to study the effect of CO2 enrichment on crop growth and to assess the variation related to the time of CO2 exposure. In general, enriched CO2 conditions (600 +/- 50 p.p.m.) in the chamber positively affected the growth and development of mungbean (Vigna radiata ), a short-duration (60-65 days) summer pulse crop. However, there was significant variability in the effect of the crop stage/time of CO2 exposure. It was observed that high CO2 exposure at an early growth stage [0-20 days after germination (DAG)] had a larger effect than that at a later growth stage (21-40 DAG). The experiment also provided a means of assessing the short- and long-term effects of elevated CO2 on the carbon exchange rate at both stages of exposure. The study revealed that the sensitivity of plants to high CO2 was more pronounced with respect to net photosynthetic rate. The overall photosynthetic activity gave greater growth and development of plants under high CO2 .