|Brandenberger, Lynn - TX AGRIC EXT SVC-WESLACO|
Submitted to: Journal of Vegetable Crop Production
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 8, 2000
Publication Date: N/A
Interpretive Summary: The herbicide sulfentrazone was applied postemergence to cabbage at five single application dosage levels and at three dosage levels with a split application at the 2-4 leaf stage of cabbage growth and again at the 6-8 leaf stage of growth for broadleaf weed control at one location each year for two consecutive years. Split applications of sulfentrazone consistently caused crop injury, plant yellowing and reduced cabbage head size and weight. Single applications of 23, 46, and 93 g a.i. ha-1 did not injure the cabbage but provided 95% or better postemergence weed control for palmer amaranth and yellowtop. Sulfentrazone effectively and safely controlled broadleaf weeds when applied postemergence to cabbage and did adversely impact crop yield or quality at application rates of 23, 46, or 93 g a.i. ha-1.
Technical Abstract: A relatively new herbicide which has selective postemergence potential for use in cabbage is sulfentrazone. Sulfentrazone was applied postemergence to 2-4 leaf stage cabbage at 23, 46, 93, 140, and 187 g active ingredient (a.i.) ha-1 and also applied as a split application to both 2-4 leaf stage of growth and again to 6-8 leaf growth stage with 23, 46, and 93 g a.i. ha-1. Crop injury and leaf discoloration was minimal at 3 days after treatment (DAT) but was substantial at 28 DAT with 93, 140, and 187 g a.i. ha-1 and with all the split applications for both years of the study. Palmer amaranth (Amaranthus palmeri) and yellowtop (Verbinsina enceluloides) were effectively controlled with all dosage levels when applied postemergence to cabbage except the lowest rate of sulfentrazone (23 g a.i. ha-1). Leaf yellowing and crop stunting occurred with the higher dosage levels of sulfentrazone (140 and 187 g a.i. ha-1) as well as with some of the split applications. The cabbage head (core growing point length) was reduced with 140 and 187 g a.i. ha-1 sulfentrazone only in the 1998-99 season but not in 1999-2000 season. Height of cabbage heads, circumference, and head weight were reduced by 187 g a.i. ha-1 in both seasons. When sulfentrazone was applied postemergence to cabbage at dosage levels of 23 to 93 g a.i. ha-1 crop injury, stunting, yellowing, or cabbage size or weight were not adversely impacted. Dosages of 46 and 93 g a.i. ha-1 of sulfentrazone effectively controlled yellowtop and Palmer amaranth, which currently are not effectively controlled by any other registered herbicide. Sulfentrazone did effectively control weeds and did not decrease crop size or quality at dosages of 46 and 93 g a.i. ha-1.