Identification of suitable high density planting system genotypes its response to different levels of fertilizers compared with Bt cotton

摘要

The experiments were conducted with objectives to find out suitable genotypes for high density planting system, assess the performance of genotypes under high level of nutrients and also to find out optimum level of nutrients as compared to existing system (RCH 2Bt with conventional spacing (90 x 60 cm) to achieve higher productivity and profitability in cotton at Central Institute for Cotton Research, Coimbatore in 2011-2012 and 2012-2013. The hirsutum earlymaturing compact with short sympodial genotypes viz., Anjali, C1412, and CCH7245 were planted at high density (45 x 15 cm) and compared with RCH 2 Bt planted at conventional spacing (90 x 60 cm). The selected genotypes were combined with four levels (75,100,125 and 150% of RDF) of nutrients tried in sub plot of split plot design and replicated thrice. The conventionally planted RCH2 Bt had been recorded significantly the highest growth and yield attributes (no of bursted bolls (21.8), single plant seed cotton yield (96.4 g) and boll weight (4.7g)).However, relative parameters, the significantly highest number of bolls per unit area (m2) counted (number of bolls of 81.4 and 99.2 at 90 and 120 DAS, respectively) and seed cotton yield (2513 kg/ha) harvested with Anjali planted at 45 x 15 cm followed by CCH7245 and C1412. Higher/plant biometric and yield attributes observed with RCH 2 Bt had not reflected in seed cotton yield because of agronomical advantage associated with high density planting system (45 xl5 cm), which had resulted in 252 to 843 kg/ha higher seed cotton yield than RCH 2 Br.The significantly highest gross return (^1, 04, 780/ha), net return (.60, 231/ha), benefit cost ratio (2.61), water use efficiency (64.4 kg ha-cm ) and water productivity (26.8 /m3 ) were observed with cultivation of Anjali under high density planting system. Higher nutrient uptake was observed with high density planted genotypes. Enhanced application of nutrient levels (75,100,125 and 150%) did not significantly influence growth and yield attributes, seedcotton yield, quality parameters and economic returns except soil available nutrients. The results summarized that high density planting of Anjali (45 x 15 cm) and application of 125 per cent of recommended nutrient level is more productive and profitable.