Issue (Who cares and why?)
Kentucky bluegrass is a significant weed problem throughout Nevada wherever alfalfa is grown under pivot irrigation. The frequent light irrigation that is delivered in the area nearer to the pivot irrigation tower provides an ideal environment for the dense sod-forming Kentucky bluegrass to dominate over alfalfa and other tap-root or bunchgrass plant growth forms. Kentucky bluegrass not only negatively affects crop yields, decreases the relative feed value of the forage, but also influences the price downward to buyers of high quality feeds for diary cattle because of the appearance. The purpose of this project is to determine a cost-effective herbicide management program to control Kentucky bluegrass in alfalfa under pivot irrigation in Nevada.
What has been done?
A fall application of Kerb® herbicide was applied in a randomized complete block design and was irrigated into the soil. The precision application equipment was donated by the Tri-County Weed Program in Ely, Nevada. In the early spring the following year, a spring-tooth harrow was used across the trial area. After emergence of the Kentucky bluegrass various rates of the grass herbicides (Poast and/or Select) were applied.
Impact
Investigator have completed the Kentucky bluegrass trials and were happy to find that Kerb® herbicide at 2 pounds / acre give is over 90% control and we keep suppression of Kentucky bluegrass down to 1 pound / acre. As a result of this investigation, Dow AgriSciences are now planning on introducing new Kerb® herbicide product especially designed to control Kentucky bluegrass in alfalfa. Specifically targeting irrigated alfalfa fields throughout the western United States. Local alfalfa producers were given the information at a field day in Eureka during the summer and again at an indoor workshop in October of 2006.