The Potential of Sulfosulfuron to Control Troublesome Weeds in Tomato1

Abstract

There are few efficient and cost-effective methods for controlling weeds in processing tomatoes. Sulfosulfuron is a sulfonylurea herbicide developed for controlling weeds in wheat. In previous studies, we have demonstrated the efficacy of sulfosulfuron in selectively controlling Orobanche aegyptiaca in tomato. The objective of the present study was to elucidate the potential of sulfosulfuron to selectively control troublesome, nonparasitic weeds in tomato. In the greenhouse, sulfosulfuron efficacy at 37.5, 75.0, and 112.5 g ai/ha applied preplant incorporated (PPI), preemergence (PRE), and postemergence (POST) was tested. Sulfosulfuron when applied PPI and POST was highly selective in controlling weeds without causing injury to tomato. The weeds that were efficiently controlled, even at low rates of application, included purple nutsedge, black nightshade, mustard, pigweed, and bindweed. PRE application resulted in the most efficient weed control but was phytotoxic to tomato at high rates.Nomenclature: Sulfosulfuron; black nightshade, Solanum nigrum L. #3 SOLNI; field bindweed, Convolvulus arvensis L., # CONAR; purple nutsedge, Cyperus rotundus L. # CYPRO; redroot pigweed, Amaranthus retroflexus L. # AMARE; tomato, Lycopersicon esculentum Mill. # LYPES; wheat, Triticum aestivum L.; wild mustard, Sinapis arvensis L. # SINAR.Additional index words: Acetolactate synthase inhibitors, sulfonylurea herbicides, weed management.Abbreviations: ALS, acetolactate synthase; DAA, days after application; DAP, days after planting; POST, postemergence; PPI, preplant incorporated; PRE, preemergence.