Planting Date Effects on Soil Temperature, Crop Growth, and Yield of Upland Cotton, 1999

Abstract

A field study was conducted in 1999 at the University of Arizona Marana Agricultural Center (1,974 ft. elevation) to evaluate the effects of three planting dates on yield and crop development for eight Upland varieties. Soil temperature effects associated with date of planting and method of planting (dry or wet planting) were also evaluated in relation to soil temperature at the depth of seed placement. Planting dates ranged from 28 April to 20 May and 821-1157 heat units accumulated since Jan 1 (HU/Jan 1, 86/55o F thresholds). Lint yields generally declined with later dates of planting for all varieties. Soil temperatures associated with the dry planting method, which requires a water-up irrigation, experienced much wider diurnal variations, had slightly lower mean temperatures, and were more strongly coupled to ambient air conditions. Thus, dry planting methods impose more potential risk in terms of seedling stress. Overall, crop growth and development patterns or yield results were not significantly different between the planting methods. Either method can provide satisfactory results if managed appropriately.