Chromatic Validation of Herbicides Used in Vegetable Production

Herbicides are necessary for successful vegetable production in the Southeastern United States. Along with bare-ground production, low density polyethylene (LDPE) mulches are often utilized to produce multiple crops (2–4) by rotation over the course of a 12-to-24-month period. These include fresh market tomato, pepper, cucurbits, eggplant, and cabbage. For LDPE mulch vegetable production, between each crop growers must apply contact and residual herbicides to mitigate weeds. However, these herbicides can remain on the mulch and injury transplants. Herbicides are often soil applied for bare soil production as well as under the LDPE mulch. Herbicide carryover in soil using these vegetable production methods can also result in management issues. Proper quantification analyzing the dissipation is critical in the decision-making process for growers to prevent unnecessary crop losses. A series of experiments have been conducted to quantify the dissipation of the herbicides flumioxazin, fomesafen, ammonium-glufosinate, glyphosate, halosulfuron-methyl, paraquat, S-metolachlor, and sulfentrazone over time using UPLC/MS and bioassay methods. These methods are presented.