Losses in yield, quality, and profitability of cotton from improper harvest timing

Excessive weathering may diminish cotton (Gossypium hirsutum L.) tint yield and fiber quality to the extent that economic losses occur for the producer. Our objective 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, Tifton, GA, on a Tifton loamy sand (fine-loamy, kaolinitic, thermic Plinthic Kandiudults). The treatments consisted of a standard harvest-aid combination applied at weekly intervals over a 13-wk 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 2 wk 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) fiber length by number coefficient of variation and short fiber content by number 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. Results from this study indicate optimum fiber quality is established earlier during boll opening than lint yield and profitability.