What is in this article?:
- Early season pests mean trouble for stressed crops
- Gaines County
- Spider mites and thrips are the primary early targets in cotton.
- Use tactics that protect beneficials insects.
- Climate-stressed cotton can’t afford pest injury.
Gaines County IPM agent Manda Anderson is also seeing thrips pressure on cotton.
“Thrips numbers have been below threshold levels in the IPM scouting program fields,” so far, she says. “However, we have seen a few fields in which the threshold should be lowered because the plants are already suffering from environmental damage, such as wind and blowing sand. In these cases, producers may consider lowering their thresholds to one-halfthrips per true-leaf if they are seeing immature thrips in the already damaged fields.” She says typical treatment threshold is one thrips per true leaf through the fifth true-leaf stage.
Anderson says presence of immature thrips indicate that thrips are reproducing in the field. She agrees that cotton farmers can’t afford the damage. “Thrips’ feeding damage, along with the environmental damage, will set the plants back and slow growth and development.”
Farmers should monitor fields. “Weekly scouting will help you to accurately monitor thrips populations and help determine whether leaf damage is being caused by thrips feeding, wind or blowing sand, or a combination of the two. Never make a treatment based solely on leaf damage; only treat if thrips are still present and the population has reached the economic threshold.”
She says thrips are out and looking for an attractive crop.
She’s also found evidence of Kurtomathrips but says growers should not panic. “Earlier this week I found an adult Kurtomathrips on a cotton plant at the cotyledon stage, so we could see Kurtomathrips earlier this year, and a large Kurtomathrips population would likely be devastating on young cotton plants.
“Seed treatments would likely control this pest until the treatment starts wearing off. In 2011, we conducted three insecticide trials in Gaines County. Our data suggest that Trimax Pro (imidacloprid), Orthene (acephate), Intruder (acetamaprid), and Centric (thiamethoxam) all have excellent activity on Kurtomathrips.”
Vandiver says farmers should continue to be vigilant for herbicide resistant weeds. “I have received several reports of potential glyphosate resistant pigweed,” he says. “We need to be diligent in managing weeds using multiple and timely tactics.”