Hembree stresses the importance of complying with herbicide label recommendations and operating spray equipment properly

“Grape vines are extremely sensitive to herbicides,” he says. “For best possible product efficacy and to protect your vineyard from herbicide damage, follow the label instructions about when, where and how to apply these products.”

Hembree offers these tips for using and spraying herbicides:

Timing is key

He recommends applying contact herbicides at two to three weeks after weeds emerge. That’s when the plants are most susceptible to the chemicals.

Mix things up

“To help slow development of herbicide resistance in the weeds, it’s really important to tank mix at least two products, each with different modes of chemical action,” Hembree says.

Keep spray pressure in the range of 30 to 40 psi.

This is the range in which the newer spray nozzles are designed to provide the optimum spray droplet size and spray pattern while reducing drift, Hembree says.

Use only the type of nozzle specified on the product label.

Operate the spray rig at a ground speed of 2 to 3 mph.

Ensure spray operators know how to use the equipment and apply products properly.

“Make sure the applicator knows not only how and where to apply the products but also how to spot any equipment malfunctions, such as plugged nozzles, poor spray patterns or excessive drift, and how to correct them,” Hembree says. “It’s especially important to be aware of wind conditions and to use shields and drift reduction nozzles when spraying during canopy and fruit development.”