Pulses are popularly known as poor man’s meat and rich man’s vegetable. They contribute significantly to the nutritional security of the country. Among the pulses, greengram is one of the most ancient and extensively grown pulse crops of India. Pulses are very sensitive to drought, water logging and high temperature. Due to climate change, elevated temperature seriously affects greengram production worldwide. Global temperatures have increased in the past 100 years by an average of 0.86ºC. Elevated temperature stress during sensitive crop growth stages affects yield in greengram and leads to very low productivity. With this background, the present investigation was carried out in CO 8 greengram under elevated temperature stress by raising the temperature upto 2°C and 4°C from the ambient temperature. The experiment was conducted in the open top chambers located at the Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore. The main objective was to investigate the effect of elevated temperature on physiological aspects and yield attributes of greengram by imposing stress at different growth stages. Observations on various physiological parameters viz., chlorophyll index, chlorophyll fluorescence, relative water content, osmotic potential, and yield traits were studied under heat stress. From the results, it was concluded that CO 8 greengram variety exposed to elevated temperature of 2°C and 4°C from the ambient, showed significant changes in its physiology and yield attributes. Elevated temperature stress during flowering phase was critical when compared to other growth stages. Thus, the experiment created innovative views to study the molecular and physiological mechanism in detail to develop stress tolerant genotypes.
Key Words: Chlorophyll index, Chlorophyll fluorescence, Relative water content, Osmotic potential, Yield traits