Effects of defoliation timings on yield and fiber quality of cotton planted at different dates

This study was conducted to determine the effects of defoliation, harvest-aid treatments, timings by using application method of nodes above cracked boll on yield and fiber quality of cotton planted at different dates in Diyarbakır conditions.Planting timing main effects was found to be significant for seed cotton yield, gin turnout, lint yield, fiber fineness and yellowness. Early plantings compared to later plantings produced higher seed cotton yield, gin turnout, lint yield, fiber fineness and yellowness values. Defoliation timing affected seed cotton yield, gin turnout, lint yield, fiber length, fiber strength, fiber fineness, reflectance and yellowness. Highest yields, lint percentage and reflectance values were obtained when cotton was defoliated at 4 NACB.. Fiber length, fiber strength and fiber fineness values were higher for cotton defoliated at 6 NACB.