ABSTRACT
Cotton was planted on April 27, 1998 at the University of Georgia Ponder Farm in Tift County. Harvest aid applications were initiated when the crop was 5% open bolls and continued each week thereafter for a total of 13 weeks. Net return was calculated for each of the 13 treatments or harvest weeks. The measure of net return used for this study was defined as the "Adjusted Gross Income" which considered differences in yield and quality. Maximum cotton yield of 1,409 pounds per acre was achieved by defoliating the first week of 100% open boll (OB). The highest net return was achieved at 42% open boll. This plot yielded 1,313 pounds per acre (96 pounds per acre less than the maximum) but received no discounts for quality. Delay in defoliation and harvest resulted in a maximum loss of $167 per acre in net return. On average, delay in defoliation and harvest resulted in losses of $68 per acre. A trendline representing the average relationship for all the data shows maximum net return by defoliating at 50-60 percent open bolls. Historical data of crop harvest in Georgia indicates that 60% open bolls would occur around mid-September on average. This would be at the very early stage peanut harvest. For this reason, it is likely that most Georgia cotton is defoliated at more than 50-60% open bolls and harvest is delayed even further.
|