Submitted to: Western Society of Crop Science Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 12/1/2006
Publication Date: 8/1/2007
Citation: Kadir, S., K. Al-Khatib, R. A. Boydston, T. Lanini, and T. Miller. KSU12800; A new herbicide for vineyards and orchards. Proceedings of the Western Society of Weed Science 60:14-115. 2007. Interpretive Summary:
Technical Abstract: KSU12800 is a new heteroaryl azole herbicide that controls selected broadleaf and grass weeds. It controls several important weeds including pigweeds, lambsquarters, hairy nightshade, mustards, clovers, and thistles. In addition, KSU12800 is active against several grasses. KSU12800 has soil and foliar activities. KSU12800 is a hydrophobic molecule that has limited movement in the soil, therefore it may be used to control weeds in perennial crops, including grapes and tree fruit. Six field studies were conducted to evaluate the efficacy of KSU12800 in vineyards and apple orchards in Washington; and Davis, California. Apple orchard experiments were conducted at Prosser and Mount Vernon, Washington. At all sites, KSU12800 was applied early in the spring before bud break in grapes and apple trees. KSU12800 was applied at 255 and 340 g ai/A and a standard herbicide treatment was included at each site. No injury symptoms were observed on apple trees or grapevines treated with KSU12800. However, slight injury to grape suckers form the base of a vine was observed. Injury symptoms consisted of bleaching of the leaves. No injury symptoms were observed in grape shoots that emerged after the treatment, indicating that KSU12800 did not move into the vines. Weed control with KSU12800 at all sites was greater than the standard herbicide treatment. At Davis site, general weed control at the end of the growing season was 99 and 61% with KSU12800 and oryzalin, respectively. At Wamego and Eudora site, general weed control was greater than 90% wit KSU12800 compared to 40 and 50% with oryzalin at Wamego and Eudora, respectively. At Prosser, site, broadleaf weed control was near perfect with KSU12800 and was not different form the standard herbicide treatment of flumioxazin. This research showed that KSU12800 is safe on grapes and apple trees and provides excellent season-long weed control.