Weed control in vegetable seed crops

By Barry Tickes, UA Area Agriculture Agent

Season-long weed control in many vegetable seed crops is a challenge. Most fresh market vegetable crops are grown within two to four months and soil residual herbicides can control many annual weeds during the entire growing season.

Vegetable seed crops can be in the ground for eight months or longer. Few soil active herbicides are effective for this length of time. Even if there were herbicides that persisted this long, almost nothing is registered for use on these minor acreage, high-value crops.

Fields that are weed free now can look ugly by May when many of the crops are harvested. An application made now of a soil residual herbicide will help keep weeds in check until the crop is harvested. After the crop has made seed heads, cultivation equipment is difficult to fit into the field.

Growers should anticipate weed emergence emerging in the spring that will mature by harvest. Some of the emerging spring weeds, including clover, are the same size and weight as the crop seed (cole crops) and very difficult to clean out. Hand labor is the only weed control option.

Although few herbicides are registered for vegetable seed production, anything registered for use on that crop may be used unless the label specifically excludes use for seed production.

Contact Tickes: (928) 580-9902 or btickes@ag.arizona.edu.

Can Bagrada bugs feed on seed?

John Palumbo was asked if the Bagrada bug feeds on seeds and can reduce a plant stand. Click this link for the answer: Bagrada Bug Seed Damage