The Economic Value of Pelargonic Acid as a Natural Herbicide in Sweet Bell Peppers

Abstract

Pelargonic acid, although not certified as organic, is naturally occurring in many plants, animals, and foods. It is also phytotoxic to plants as a contact herbicide, injuring and killing plants by destroying the cell membrane. Vegetable producers would benefit from additional herbicide options that are safe to the crop, naturally occurring, and provide effective weed control. Research was conducted in southeastern Oklahoma to determine the impact of pelargonic acid on weed control efficacy, crop injury, green pepper (Capsicum annuum) yields, and the cost/benefits associated with the various levels of this herbicide. The experiment included pelargonic acid applied unshielded post-directed at 5, 10, and 15 lb/a, plus an untreated weedy control and an untreated weed-free check. The 15 lb/a (9% v:v) pelargonic acid treatment resulted in the maximum smooth crabgrass control (56%) and broadleaf weed control (66%) at 1 day after the initial spray treatment (DAIT), and 33% yellow nutsedge control at 3 DAIT. Only the 15 lb/a pelargonic acid application produced greater fruit per acre (58,012 fruit/acre) and yields (10,204 lb/acre) than the weedy control (14,516 fruit/acre and 3,409 lb/acre). The highest level of pelargonic acid (15 lb/a) provided 2.8 times the gross revenue as that of the weedy control.