Cotton Planting date: yield, seedling survival, and plant growth
New cultivars, changes in technology and production practices, and climate change may have altered the optimal planting time for cotton (Gossypium hirsutum L.) in the midsouthern United States. A field experiment was conducted from 2002 through 2005 on Gigger silt loam to define planting date (PD) effects on selected cotton cultivars. Six cultivars in 2002 (Deltapine DP555BR and Delta Pearl, Phytogen PHY355, SureGrow SG215BR and SG821, and Stoneville ST4892BR) and eight cultivars in 2003 through 2005 (DP555BR, DeltaPearl, PSC355, DP444BR, Fibermax FM960BR, PHY410RR, ST4892BR, and ST5599BR) were planted on or near eight PDs (25 March; 5, 15, and 25 April; 5, 15, and 25 May; and 5 June). Data were collected on seedling emergence, plant height, main stem node number, nodes above white flower, lint percentage, lint yield, fiber properties, soil and air temperature, rainfall, and photosynthetically active radiation (PAR). Planting date and cultivar affected most measured variables, and although there were some significant PD x Cultivar interactions, these were very small in relation to the main effects. Low soil temperature, few heat units, and rainfall combined to reduce seedling survival at early PD to <15%. For lint yield, the optimal PD was earlier than in previous studies and the highest average yield (1700 kg ha–1) was produced from a PD between 15 April and 5 May. Cotton planted at a PD later than 5 May did not benefit from recent changes and improvements in technology and, therefore, incurred yield declines similar to those reported in the 1970s.