Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 1, 2006
Publication Date: July 5, 2006
Citation: Funk, P.A., Armijo, C.B., Showler, A., Fletcher, R.S., Brashears, A.D., McAlister III, D.D. 2006. Cotton harvest preparation using thermal energy. Transactions of the ASABE. 49(3):617-622. Interpretive Summary: The yields and fiber values of cotton prepared for harvest by conventional chemical and experimental heat treatments were compared over two years and three production practices in three states, six locations and seven varieties. Fiber value and yield were not significantly different by treatment, indicating that heat treatment does not hurt the cotton. Cotton prepared for harvest using heat treatment can be harvested in a day or two (compared to a week or two with chemical desiccants and defoliants) allowing producers to make better use of machinery by giving them more time to harvest. Early harvest may prevent weather related losses such as from a hurricane. The experimental heat treatments eliminated late season sucking insect pests by removing their food supply. A single application was sufficient to prevent increases in aphid and whitefly stickiness. Heat treatment can be applied in combination with chemical boll openers to enhance yields. Thermal defoliation is an effective harvest preparation tool that complies with organic labeling rules.
Technical Abstract: Cotton is prepared for mechanical harvest using desiccant and defoliant chemicals. Conventional chemical defoliation is not effective immediately, it requires a period of good weather, and it is restricted in organic production. This study was conducted to determine what impact thermal defoliation has on fiber value, yield and gross returns. A thermal defoliation machine that used propane to heat treatment air was tested on several varieties at various locations in three states over two years. A mixed statistical model was used to compare thermal defoliation to conventional chemical defoliation and harvesting two or three days after treatment to harvesting two or three weeks after treatment. There were no statistically significant differences in yield or value between treatments or harvest dates. Thermal defoliation does not negatively impact fiber value or yield, and thermally defoliated cotton may be harvested early without reducing gross returns.