By Dr. Henry Wu, Technical Sales Support Representative, Chemtura AgroSolutions
Since harvest has wound down, for the past several weeks we’ve been talking about weed management as part of an overall vineyard management system. That’s because plants on the vineyard floor can have a significant impact on other pests like leafhoppers, mealybugs, mites, nematodes and diseases.
Therefore, it’s a good time to make sure your weed control strategy is up-to-date and able to address potential challenges during the upcoming growing season.
Keep in mind that a weed management program should start before new vines are planted. The more difficult-to-control weeds, particularly perennials, are easier to manage before vines are planted. That’s because weeds reduce vine growth and yields by competing for water, nutrients, and sunlight. Competition is most severe during the first four years of the vine's life or where root growth is limited.
University of California experts remind growers that weeds around the grapevine trunk not only compete directly with vine growth, but provide a good habitat for field mice or voles, which can girdle and kill young vines. Gophers are most prevalent in non-tilled vineyards and are common where broadleaf weeds, such as field bindweed and perennial clovers, predominate. These animals feed on the roots and weaken or kill young vines. For optimum yields and vine health, control weeds, especially in the area next to the base of young vines.
After about the third year, the effect of competition from weeds is somewhat lessened as vines become established, and shading from the vineyard canopy reduces weed growth.
But that doesn’t mean you should let up on weed control. In older vineyards, weed growth can interfere with cultural practices and harvest. For example, tall weeds can disrupt the application pattern of water from low-volume spray emitters. Frequent cultivation near vines can injure vine roots or the base of the vine trunk. Vine trunk injuries can encourage crown gall or collar rot infections.
Furthermore, dry weed growth is a fire hazard.
Firestorm® from Chemtura AgroSolutions is a contact herbicide for control or suppression of a broad spectrum of emerged weeds and grasses and is a good partner in your weed control program. It features 3 lbs. of active ingredient per gallon and when applied in a tank mixture with a residual preemergence herbicide, Firestorm will either control glyphosate-resistant weeds or prevent them from surviving and producing seeds that will emerge the following season. It is compatible with other herbicides, insecticides and liquid fertilizers and is reliable in all weather conditions with no detrimental effect on efficacy.
Click here for more information from the University of California on integrated weed management.