A sprayer for under-canopy application of herbicide sprays

Herbicides applied postemergence to crops planted in rows must reach the target weed species to be effective, In numerous cases, the targeted species may be covered by leaves of a crop canopy, Our objective was to develop an apparatus that could be used effectively to apply directed herbicides postemergence to under-canopy areas of crops planted in narrow rows (less than or equal to 20 in.) so that the herbicide would reach the target species. We designed and constructed a sprayer that will attach to a 40- to 100-hp row-crop tractor having a PTO and standard Category (Cat.) II three-point hitch attachment. This unit delivers herbicide sprays beneath the canopy of crops so that the maximum amount of herbicide spray reaches the target species. Each nozzle that is directed to cover the space in a single between-row area is mounted on a wheel-supported frame so that the height of application is constant regardless of terrain. Use of this sprayer to direct herbicide sprays underneath the canopy reduces the effect of wind that causes drift in over-the-top applications. Thus, use of this sprayer ensures that the maximum amount of spray solution of any herbicide applied postemergence will contact the target weed species that may be partially overshadowed by leaves of the crop, and will be confined to the intended area of application.