Wet Year Prompts Weed Challenges in Crops

By Kay Ledbetter

Uncharacteristically wet weather this year has left many producers across the state with a growing weed problem, according to a Texas A&M AgriLife Extension Service expert.

Scott Nolte, Ph.D., AgriLife Extension state weed specialist and associate professor in the Texas A&M Department of Soil and Crop Sciences, Bryan-College Station, said widespread drought during previous seasons allowed producers to keep weed growth in check. However, moisture is becoming a challenge this year due to weed growth and producers' inability to control it.

"Some areas, like the South Plains, have had good moisture, but it has kept them out of their fields," Nolte said. "They don't typically have that this time of year, so they have been delayed probably a month getting cotton planted."

Another problem, he said, is some production areas were dry early, and preemergence herbicide applications did not get good activation. Now, producers are relying on postemergence treatment, but it has been difficult to access fields between rains to spray or cultivate.

Delayed canopy production allows weed growth

Good growing conditions in the Coastal Bend helped crops to reach canopy faster than usual, which prevented many weeds from establishing themselves. But not all areas were able to plant the crops on schedule.

Canopy development typically reduces the amount of sunlight available for weeds to germinate and grow, Nolte said. But repeated rainfall and delays in planting put canopy development behind the rapid growth of weeds in some regions.

Now, producers need to make postemergence herbicide applications to clean up weeds after preemergence herbicide applications were no longer effective and plantings were delayed.

"Typically, we have drier conditions going into July, and it slows weed growth down, giving the canopy time to close up, which takes care of this problem," he said. "In areas with more rainfall than normal, we're getting a lot more germination of weeds later in the middle of July."