Effect of elevated temperature stress on growth, yield and yield attributes of mungbean (Vigna radiata) in semi-arid north-west India

A field experiment was conducted consecutively during the kharif season of 2014 and 2015 at the New Delhi, India to assess the effects temperature on early and late sown mungbean (Vigna radiata (L.) Wilczek) in rain-fed conditions across natural seasonal temperature gradient and elevated temperatures. Elevated temperatures where imposed on mungbean by use of a polyethylene sheds at specific growth stages. Average ambient temperature differences between normal and late sowing dates was 2–3°C. Elevated temperatures >44/34°C significantly affected P_N at all stages. A departure from the normal seasonal temperatures by 8–10°C resulted in shortened phenological stages specifically vegetative phase leading to earlier maturity (50–57 DAS) compared to the control that reached maturity between 70–77 DAS under normal summer seasonal temperature. Increase in temperature negatively reduced number of pods per plant as well as the test weight of mungbean. Protein content in seeds was higher in stressed plants. Yield was sensitive to temperature with a 13.6% decrease in overall yield in 2015 from 2014 correspondingly to a 3°C temperature increase. The least yield was obtained from mungbean stressed at flowering stage in both seasons. Results are discussed in context of climate change and improved mungbean yield production in monsoon season.