ABSTRACT

Timing of harvest aids continues to be a difficult decision for producers. Producers and crop advisors often are tempted to wait as long as possible on young immature bolls in the top of the plant before making the decision to defoliate. These bolls are often insect damaged, small, and account for little additional gain, but the perception of additional harvestable lint is difficult to overcome. The objective of this study was to validate the heat unit (HU) concept of timing defoliation beyond the last effective boll population as defined by COTMAN to allow producers to make this decision with greater confidence and allow for an earlier harvest. The 850 HU timing beyond cutout allowed the crop to be terminated earlier, without yield loss, and with greater economic returns than conventional harvest aid timings.