Vol. 8, Issue 12 (2019)

Author(s):
B Santhosh, Ramesh Thatikunta, DVV Reddy, SA Hussain and V Gouri Shankar

Abstract:
Growth and development physiology of cotton cultivars was studied under drought stress. Study was conducted for two consecutive years i.e., Kharif, 2016 -17 and Kharif, 2017-18 in the college farm, College of Agriculture, Rajendranagar, PJTSAU. Results during the boll development stage indicate that photosynthetic rate, stomatal conductance and SCMR were recorded maximum in cultivar WGCV- 48 (26.0 μ mol CO₂ m^-2 s^-1, 584 mmol [H₂O] m^-2 s^-1 and 36.2 respectively) and transpiration rate was maximum in NDLH-1938 (6.1 mol m^–2 s^–1). WGCV- 48 cultivar showed maximum seed cotton yield (1908 kg ha^-1) among all cultivars. Among the spacings studied, 75x10 cm resulted in maximum photosynthetic rate (25.6 μ mol CO₂ m^-2 s^-1), stomatal conductance (626 mmol [H₂O] m^-2 s^-1), transpiration rate (6.15 mol m^–2 s^–1), SCMR (34.7) and seed cotton yield (1639 kg ha^-1). Enhancement of plant density increased the intra specific competition. Though a slight decrease in boll weight identified, overall yield per hectare increased when compared to conventional system of wide density planting.