Evaluation of Herbicides for Control of Rough Bluegrass, Cheatgrass, Rattail Fescue and Medusahead in Establishment Year and Second Year Kentucky Bluegrass Grown for Seed

Series/Report Number: COARC2016

Abstract: Adequate weed control during the establishment year of Kentucky bluegrass seed production is a challenge, particularly for grassy weeds in a grass crop. This project is a second-year project to evaluate innovative ways to use currently registered products to accomplish this goal, focusing on rough bluegrass, cheatgrass, rattail fescue and medusahead. Treatments and application timings include Callisto pre-emergence between planting and first irrigation, Beacon applied at 0.19 oz/acre, with and without Bronate at 1 pt/acre, at the 2-3 leaf and 4-5 leaf stages, and Beacon at the split application rate of 0.38 oz/acre during a October/November timing. Potential new herbicides, Fierce, Alion and Sharpen were evaluated in a second year stand for control of the same four grassy weeds and for crop safety, compared to two current industry standards. Application timings were pre-emergence and during October/November. Results from establishment year plots indicates significantly less stunting of Kentucky bluegrass when Beacon is applied at 2-3 leaf rather than the 1-2 leaf stage as was done during 2015. Bronate appears to be an effective crop safener when added to Beacon at either 2-3 leaf or 4-5 leaf stages, with similar control of the grassy weeds.

Chapter Number: 5