Impact of Sowing Time and Plant Density on Selected Traits and Yield of Cotton Genotypes in Pakistan

Impact of Sowing Time and Plant Density on Cotton

Abstract

Extremely diversified cropping environments prevail in most cotton-growing areas of Pakistan due to prevailing rainfed conditions, prolonging the crop’s cultivation period. To contribute to the development of desired breeding traits for effective breeding programs, this study examined the production and growth pattern of 8 cotton genotypes. Four experiments were conducted in 2018 and 2019 at 2 locations in Dera Ismail Khan, Pakistan, to evaluate the performance of the studied genotypes at 3 plant densities and 2 sowing dates. Traits such as days to first flower opening, flowering duration, monopodial branches per plant, plant height at harvest, height-to-node ratio, fruiting branch length, and boll retention at the first fruiting branch position were investigated. Results showed that CIM-632 had a higher yield in late sowing and at high plant density, as shown by less growth of vegetative branches, early start of flowering, short flowering duration, and lower boll retention at the first fruiting branch position. In addition, CIM-663 and CIM-343 performed outstandingly in early sowing and at low plant density, as shown by more growth of vegetative branches, delayed flowering, lengthy flowering duration, and higher boll retention at the first fruiting branch position. Based on these findings, ideotypes with high heritability for days to first flower opening, plant height at harvest, height-to-node ratio, and fruiting branch length, and with medium heritability for monopodial branches per plant, flowering duration, and boll retention at the first fruiting branch position are recommended to be used in breeding programs for cotton genotypes that are adaptable to different growing conditions.