ABSTRACT
A field experiment was conducted at Siddapur research farm, Regional Agricultural Research Station, Warangal, Telangana, India during kharif 2022 to investigate the effect of plant geometry and cultivars on growth and yield of cotton under high plant density system. The results revealed that plant height (102.7 cm) and drymatter production (6499 kg ha-1) were significantly higher at ultra narrow spacing of 90 x 15 cm (74,074 plants ha-1) than medium and wider spacings of 90 x 30 and 90 x 60 cm, respectively but, was on par with narrow spacing of 90 x 20 cm (55,555 plants ha-1). Though sympodial branches plant-1 (16.4) and number of bolls plant-1 (24.0) were significantly greater with wider spacing (90 x 60 cm: 18,518 plants ha-1), adoption of high plant density method of 90 x 15 cm spacing (74,074 plants ha-1) (2707 kg ha-1) and 90 x 20 cm (55,555 plants ha-1) (2498 kg ha-1) resulted in significantly higher seed cotton yield. The yield from 90x15 cm was 26.2% and 11.7% higher than that of 90 x 30 cm (2391 kg ha-1) and 90 x 60 cm (1998 kg ha-1), respectively. In case of cultivars, though growth and yield attributes were not significantly influenced, but, the boll weight (5.2) and seed cotton yield (2845 kg ha-1) were significantly higher with NCS 2778 over other cultivars viz., Bt Suraj (2151 kg ha-1), WGCV-79 (2310 kg ha-1) and ADB-39 (2288 kg ha-1).
ABSTRACT
Plants fumigated with 40ppbv, 80ppbv and 120ppbv concentrations of O3 exhibited significant reduction in total chlorophyll content, RuBP carboxylase activity and net photosynthesis. The reduction in total chlorophyll activity ranged from 12 to 36% in Bauhinia variegata, 11 to 35% in Ficus infectoria and 3 to 26% in Pongamia pinnata on fumigation with O3, while the RuBP carboxylase activity was reduced by 10 to 32% in Bauhinia variegata, 10 to 23% in Ficus infectoria and 9 to 15% in Pongamia pinnata. The net photosynthesis was also reduced by 6 to 26% in B. variegata, 16 to 39% in F. infectoria and 7 to 31% in P. pinnata on fumigation with 03. The relative higher sensitivity of tropical trees to O3 suggests that the ambient air quality standards in tropical tree areas need to be stringent to prevent vegetation from air pollution.