Preemergence herbicides are typically applied by broadcasting to the top of raised beds before laying the plastic mulch in plasticulture production systems. Broadleaf and grass emergence is limited to transplant holes in the mulch. As a result, most herbicides are applied under the mulch in locations where weeds cannot emerge and herbicides are unnecessary. To reduce this excessive off-target application, a precision hole-punch sprayer was developed at the University of Florida for use in plasticulture production systems. The technology facilitates the application of herbicides during the hole-punch operation immediately before transplant. Application of napropamide and S-metolachlor in an application volume of 233 L ha–1 of water using the precision hole-punch applicator had no effect on tomato and bell pepper growth and yield. Equipment accuracy ranged from 55% to 90%. Preemergence herbicide use was reduced by 88% to 92% with no reduction in weed control. The hole-punch applicator is an effective way to reduce PRE herbicide use in transplant vegetables grown using the plasticulture production system.
Nomenclature: Napropamide; S-metolachlor; bell pepper, Capsicum annuum L.; tomato, Solanum lycopersicum L.