Weed Management in Grapes during the Winter
Effective weed management is a critical part of Helena’s Grape Wise™ program. Weeds under the vine rows can cause a number of problems throughout the season. Besides directly competing with the vines for water and nutrients, weeds can also influence the presence of harmful insects, mites, nematodes and diseases. Weeds also provide habitat and food for vertebrate pests like gophers, ground squirrels and voles. In order to limit the negative influence of weeds on vine health, growers must manage those weeds in a manner that best compliments their farming practices.
Integrated weed management techniques can vary from site to site based on a number of reasons, including soil type, slope, vine age and farming practice (conventional, sustainable, organic, etc). In California, weed growth can be broken up into two simple time frames: fall-winter and spring-summer. The fall-winter weed growth is influenced by winter rainfall while the spring-summer growth is generally initiated with the warmer temperatures and irrigation water. For this article, we will focus on the conventional/sustainable vineyard during the fall-winter time period.
Weed management during the fall-winter depends heavily on how effectively the spring-summer program managed weeds. If the under-vine berms are clean and weed-free, either with post-emergent herbicide control or under-vine cultivation, your fall-winter program will be much simpler. However, if there is a large amount of residual weed growth/escapes, additional measures must be implemented. Assuming we have clean under-vine berms because you have implemented a strong Grape Wise weed management program, the key tool for fall-winter weed control is the pre-emergent herbicide application. Pre-emergent herbicides can be very effective weed management tools if they are applied correctly. Keys to successful pre-emergent herbicide applications include: properly calibrated spray equipment, material applied to bare dirt, soil incorporation utilizing natural rainfall or overhead irrigation, and the correct herbicide for the weed mix present in the vineyard.
The pre-emergent of choice for Grape Wise growers is Centrus™, the only dual-action pre-emergent herbicide on the market today. Centrus is a pre-emergent herbicide for grape growers that combines two industry-proven herbicides to provide long, residual weed control, plus complimentary burndown. Helena’s exclusive formulation offers one convenient choice for impactful, seasonal-long control of grasses and broadleaf weeds such as Italian ryegrass, filaree, fleabane and marestail. The combination of active ingredients in Centrus is unlike any other herbicide in the marketplace. One active ingredient complements burndown activity by starving the plant and inhibiting cell division in the soil during germination. The other active ingredient inhibits seed germination and root development. The combination provides safe and effective control of weeds for up to six months, while also reducing the potential for future retreatments, saving you time and money. Centrus offers a strong solution to put control back in your hands, allowing you to focus on other aspects of the business besides weed control.
For control to the core, contact your local Helena Grape Wise representative for more information about Centrus.
- Paul W. Crout, CCA, PCA, Senior Product Manager/Agronomist