Different planting date and potassium fertility effects on cotton yield and fiber properties in the Cukurova region, Turkey

Late planting causes the crop to flower later and pushes boll development into the cooler weather, resulting in reduced yields. Potassium deficiency associated with the 0 kg K treatment elicits some of the same responses in cotton as delayed planting. Together, these stresses may affect the yield and quality beyond the individual effects of late planting and K deficiency. The objective of this research was to determine the effects of planting date and K fertilization on yield and fiber properties of cotton. The experiment was designed as a split-plot with four replications with planting dates as the main plots. Subplots were levels of potassium. Data collected in 2000 and 2001 indicate that planting date and K fertilization produced significant differences in seed cotton yield, lint yield and earliness. Potassium application in early planted cotton gave the highest boll weight while potassium deficiency related with the 0 kg K treatment produced the lowest boll weight. On average, the best yield response of cotton to planting date treatments was when the crop was sown early. Lint yield was 11.2% higher for the early planting date than for the late planting date. The K fertilization rate had an impact on earliness only in 2001. Averaged across years, soil applications of 150 kg K2O/ha decreased the number of days required from planting to open first boll 1.8% compared with the no potassium control treatment. Late planted cotton without the K treatment gave the greatest number of days to boll opening. It is concluded that cotton grown in this region can benefit from K treatments. While current soil K rates are sufficient, reductions in lint yield and some fiber quality characteristics may result if sowing occurs after mid-May. (C) 2002 Elsevier Science B.V. All rights reserved.