Effect of Sulfosulfuron on Fenncross Creeping Bentgrass Seedlings When Applied Before or After Seeding

摘要

Sulfosulfuron is labeled for roughstalk bluegrass (Poa trivialis L.) control in creeping bentgrass (Agrotis stolonifera L.) fairways. Between or following applications, managers often overseed creeping bentgrass to repopulate bare or thin areas left by dying roughstalk bluegrass. Our objective was to establish safe application intervals for sulfosulfuron before or after seeding creeping bentgrass. Treatments were arranged in a 3 ?8 factorial with three sulfosulfuron application rates (13, 26, or 52 gai/ha) and eight application times [-3, -2, -1, 0, 1, 2, 3, and 4 weeks after seeding (WAS)]. Sulfosulfuron at 13 g ai/ha applied -3 WAS was the safest of all the pre-seeding herbicide treatments at 5 WAS in 2004, with creeping bentgrass cover equal tothat of the untreated control and > 20% higher than any other treatment. Seeding creeping bentgrass should be delayed at least two weeks after the last application of sulfosulfuron at 13 g ai/ha and this rate of sulfosulfuron should not be applied to seedling creeping bentgrass sooner than three weeks after seeding. Applications at 26 g ai/ha can be safely applied three weeks before or four weeks after seeding creeping bentgrass. Sulfosulfuron applied at 52 g ai/ha was not safe on creeping bentgrass seedlings at any application timing assessed in this study.