Kulvir Singh
Abstract
Field experiments were conducted to determine the productivity potential of American cotton (Gossypium hirsutum L.) as altered by harvest-aid chemicals i.e Dropp ultra® and Ethrel, their optimal dose and suitable time of application in three genotypes. Bt hybrids MRC7361 and MRC7017 resulted in significantly improved seed cotton yield than variety F1861. Dropp ultra® @ 200 mL/ha revealed statistically highest yield (3071.1 kg/ha) followed by Ethrel @ 2000 ppm and control, while significantly least yield (2586.3 kg/ha) was observed with higher dose of Dropp ultra® @ 225ml/ha. Harvest-aid chemicals applied at 150 days after sowing (DAS) resulted statistically better lint and seed yield as compared to early application at 140DAS owing to significant improvement in yield attributes. Dropp ultra® @ 200 ml /ha lead to significantly better net returns ( 81173/ha) and B:C ratio (2.47) over other treatments. Improved water and fertilizer use efficiency coupled with better B: C ratio for Dropp ultra® @ 200 ml/ ha at 150 DAS clearly indicated its superiority over other harvest-aid chemicals. Application of harvest-aid chemicals at 150DAS resulted in statistically improved net returns ( 76264/ha) as compared to earlier application ( 70056/ha). Therefore, for maximizing productivity and net returns, cotton growers should opt for MRC7361 and apply Dropp ultra® @ 200 ml/ha at 150DAS to reap higher benefits under semi-arid conditions of north-western India.