Submitted to: Agronomy Journal
Publication Type: Popular Publication
Publication Acceptance Date: 4/3/2002
Publication Date: 11/4/2002
Citation: BEDNARZ, C.W., SHURLEY, W.D., ANTHONY, W.S. LOSSES IN YIELD, QUALITY AND PROFITABILITY OF COTTON FROM IMPROPER HARVEST TIMING. AGRONOMY JOURNAL. 2002. 94(5):1004-1011. Interpretive Summary: Net farm income for cotton is not sufficient to sustain cotton production without governmental assistance. The monetary value of cotton is based on both fiber yield per acre and market value or fiber quality. Unfortunately, cotton value to the farmer is a compromise between yield and quality. As farmers delay harvest to increase yield, adverse weathering may reduce fiber quality and lint yield and fiber quality to the extent that economic losses occur for the farmer. The objective of this three-year study was to determine the effects of systematic delayed harvest on cotton lint yield, fiber quality and profitability. Boll enhancers were applied at intervals during the 13 weeks following initial boll opening. Maximum lint yields occurred when harvest aids were applied at when 76.5 to 89.0% of the cotton bolls were open. However, fiber qualities were optimized when harvest aids were applied when 40 to 60% of the bolls were open. Under the current cotton marketing system, the penalty for reduced lint yield is much greater than the penalty for low fiber quality. Therefore, it is more profitable for growers to manage for maximum lint yield at the expense of fiber quality unless adverse discounts are encountered after extreme weathering.
Technical Abstract: Excessive weathering may diminish cotton lint yield and fiber quality to the extent that economic losses occur for the producer. The objective of this investigation was to determine the effects of systematic delayed harvest on cotton lint yield, fiber quality and profitability. Experiments were conducted from 1998 to 2000 at the Coastal Plain Experiment Station in Tifton, GA. The treatments consisted of a standard harvest-aid combination applied at weekly intervals over a thirteen-week period beginning at first open boll. Harvest aids were applied to each plot according to its week after first open boll designation and machine harvested two weeks thereafter. After ginning, fiber quality was determined on lint samples from each plot. High volume instrument (HVI) fiber length uniformity was greatest in 1999 and 2000 when harvest aids were applied between 58 and 88% open boll while the Advanced Fiber Information System (AFIS) short fiber content were lowest when harvest aids were applied from 40.1 to 46.8% open boll. The HVI upper half mean fiber length and the AFIS mean fiber length by number were greatest when harvest aids were applied between 39.1 and 56.7% open boll. In 1999 and 2000 lint yield and adjusted gross income were greatest when harvest aids were applied from 76.5 to 89.0% open boll. Thus, results from this study indicate optimum fiber quality is established earlier during boll opening than lint yield and profitability.