Source: Syngenta news release
MINNETONKA, MINN. - June 13, 2011 — With the recent USDA deregulation of herbicide tolerant alfalfa, many growers are now wondering how to manage their new crop. Glyphosate-tolerant alfalfa allows for a broad spectrum of weed control while also providing growers additional flexibility with application timing.
“One or two applications of glyphosate should provide excellent weed control,” said Cole Anderson, Syngenta field agronomist. “You can apply glyphosate-based herbicides, such as the Touchdown® family of herbicides, at various stages of the plant’s growth cycle, so growers can determine the timing that works best for their management practices.”
Glyphosate can be applied to glyphosate tolerant alfalfa at any stage of growth from preplant to five days before cutting. However, according to a study conducted by the Panhandle Research and Extension Center, Scottsbluff, Neb., if weeds were removed using glyphosate shortly after alfalfa emergence and again in several weeks after later flushes of weeds had emerged, the alfalfa plant could be protected from weed interference and stand establishment could be further enhanced.
“This study found that removal of weeds at the unifoliate and again at the fourth trifoliate growth stages provided the greatest alfalfa yield,” Anderson continued. “Of course, the more weeds removed, the higher the quality and yield potential in your establishment year.”
A small percentage of seeds in the bag may not have the herbicide tolerance trait, therefore an early application of glyphosate-based herbicide, like a Touchdown brand, is encouraged to remove these plants prior to becoming a dominant plant within the stand.
Please talk to your local agronomist or seed dealer to understand how to implement an integrated weed management practice in your alfalfa stand. The amount of glyphosate used should be dictated by the type and density of weeds so always read product labels for appropriate rates by weed species.