Cot-Sprayer: A low-cost defoliation sprayer for cotton using pulse width modulation

Spraying is one of the most critical operations in agriculture. Spraying technologies have evolved from simply turning on and off based on the presence or absence of the object of interest into controlling the precise volume of chemicals being sprayed. Different crops have different requirements for chemicals and when it is applied. Cotton defoliation is a natural process of shedding leaves. Still, due to the recent advancement of mechanical harvesting machines, the timing and adequacy of the defoliation have been a problem with farmers harvesting cotton. Farmers often spray defoliant chemicals at least three weeks before harvest to schedule the harvesting equipment properly using a boom sprayer attached to a tractor. Defoliant chemicals are typically sprayed on the top canopy, assuming that the high volume of chemicals will penetrate the bottom of the crops. The Cot-Sprayer is a low-cost solution in defoliating cotton that delivers minimal chemicals to the plant. It focuses on spraying the cotton plants at different sections (top, middle, and bottom) and fully controls each section using pulse width modulation. The sprayer also provides the option only to defoliate part of the plant to facilitate multiple harvest passes, which could maximize the yield and quality of harvested cotton.This work was partially supported by a grant from Cotton Inc. Project No. 17-209 and is based on work supported by NIFA/USDA under project number SC-1700611