ABSTRACT

Irrigation, is a production tool just like tillage, fertilizer or pesticides. Terminating irrigation at the end of the season is always a difficult decision. The challenge of late season irrigation scheduling arises from the need to deplete the soil profile of available moisture during boll opening. The objective of this study was to determine the optimum timing for terminating LEPA irrigation through the use of COTMAN. Once cutout was achieved, heat units (HU) were accumulated up to the targeted treatment level, at which point the irrigation was terminated. Treatments consisted of, 400 HU past cutout, 600 HU past cutout and 800 HU past cutout. The most economical target for timing the termination of LEPA irrigation appears to be when 600HU past cutout has been accumulated.