ABSTRACT

The introduction of new cultivars and changes in technology and production practices may have altered the optimal planting time for cotton (Gossypium hirsutum, L) in the mid-South U.S.A. A field experiment was conducted in 2002 on Gigger silt loam to define planting date (PD) effects on selected cotton cultivars. Six cultivars (Deltapine DP555BR, Deltapine Pearl, PSC 355, SureGrow SG215BR, SureGrow 821, Stoneville ST4892BR) were no-till planted at eight PD (25 March; 4, 15, and 24 April; 2, 13, and 23 May; 3 June). Data were collected on seedling emergence, plant height, main stem node number, nodes above white flower, boll size, lint percentage, lint yield, soil and air temperature and rainfall. Although cultivars affected most plant variables and yield, there was little or no interaction between PD date and cultivar. Seedling emergence averaged 11% at the 25 March and 4 April PD; 34 percent at the 15 April PD and greater than 50 percent at all other PD. Low soil temperature, minimal DD60s and high rainfall combined to reduce seedling emergence and survival at early PD. Plants were shortest at the 25 March PD (29 inches) and increased to a maximum of 67 inches at the 23 May PD. Boll weight averaged 5.3 g and was not affected by PD. Lint percentage was higher at early PD (43.4) and decreased at later PD (41.7). Highest lint yield (1526 lb/acre) was produced from PD between 15 April and 2 May. Cotton planted at the 13 May PD had significantly lower yields than cotton planted at the 2 May PD. Planting dates later than 13 May had lower yields due in part to adverse weather from two tropical systems that caused prolonged cloudy, rainy periods and high winds. In this study, the optimal PD was earlier than in previous studies and cotton planted later than the optimal date was at risk from adverse weather.