What is coming down the pike in defoliation technology?

Andrade is in the early test stages of proximal sensing technology tests to improve the efficiency and effectiveness of chemical applications in cotton.

For several years, Andrade, a precision agriculture specialist, and UA research specialist John Heun, have conducted trials with proximal sensing using optical spectral sensors to measure canopy color reflectance in field crops including wheat.

The goal is to determine the field areas slower in plant development and then apply extra nitrogen and other inputs to speed the plants to optimal development.

Andrade and Heun are applying the same principle to cotton in the early-mid season, but with a secondary benefit at defoliation time.

During the defoliation spray process, sensors mounted on the front of a rig would record the latest color-based plant development information. The “electronic eyes” detect areas where plants remain physiologically active by looking at the absorption of red light by the green leaves. The defoliation sprayer, located on the back of the rig, would apply higher rates of defoliant so the entire field is defoliated more effectively.

Andrade and Heun are also testing infrared thermometry to detect active growth in the plant by examining cooler canopy temperatures. The goal is to combine canopy temperature and light reflectance information to enhance the real-time detection of active growth in the cotton plant. This research is financially supported by Cotton Incorporated.

“In the early-mid season, our sensor-based approach is looking into ways to improve crop management to help the crop develop healthy growth with high yield potential in terms of defoliation management,” Andrade said. “The greatest benefit of this technology will come from time efficiencies. The chemical defoliation process would be more effective with the first application of defoliant so growers can more quickly move into harvest.”