Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 10/31/2004
Publication Date: 11/3/2004
Citation: Bynum, J., Cothren, T., Lemon, R., Mahan, J.R. 2004. Nodes above white flower and heat units as indicators of cotton harvest aid timing[abstract]. American Society of Agronomy Meetings.
Technical Abstract: Management strategies to optimize cotton yields may be achieved by fine-tuning current practices. Various methods are currently used to determine timing of harvest aid application. One method is the use of growing degree-day units and/or heat units (HU). This concept triggers harvest aid application based on accumulated heat units following cutout, which is defined as the time when the nodes above white flower equals five (NAWF=5). A guideline has been set for harvest aid timing to occur at 850 HU after cutout. In some regions, it appears that this guideline calls for harvest aid application prematurely, and may potentially reduce overall yield. A study was conducted at the Texas Agricultural Experiment Station in Burleson County, Texas, to assess proper timing of harvest aid application. The study was arranged in a split-plot design with four replications. Treatments consisted of evaluating HU accumulations of 650, 750, 850, 950 and 1050 once the crop has reached NAWF = 3, 4 or 5. There were significant differences in percent open boll counts at defoliation for both NAWF and HU. NAWF = 4 and 950 HU most closely coincided with the 60 percent open boll method of harvest aid timing. Significant differences occurred between NAWF and HU for percent open boll at harvest. No significant differences were observed between NAWF for lint yield; however, there were differences in lint yield for HU with 950 and 1050 yielding more than the other treatments.