Weeds management is one of the greatest concerns of growers during the first four weeks of growth. Weed control at this time is essential to maximize returns from sunflowers. Foxtails are late spring emerging weeds. Foxtail plants can be numerous in a sunflower field, but can easily be controlled with most herbicides. Wild mustard can continue to emerge with timely rains and continues to be a problem throughout the season.
Herbicides used in rotations with other crops are the best means for control in sunflower fields.
No chemical selectively controls Canada thistle in sunflower. However, glyphosate is registered for preemergence use and use with shielded sprayer between sunflower rows. Fall herbicide applications, herbicide use in rotations with other crops, and selecting fields low in populations of Canada thistle are good management practices. Common cocklebur is an annual that emerges later in the growing season. No chemical selectively controls common cocklebur in sunflower.