Monday, May 14, 2012

Thrips Damge in Cotton

Thrips pressure is quite variable based on the location and field. The two most significant factors affecting thrips damage seem to be planting date and rainfall. Thrips trials at Prattville, AL, planted on April 16, are showing low to moderate thrips injury even without a foliar application on top of seed treatments at planting. Trials planted a week earlier, April 9, are showing heavy thrips injury behind all seed treatments. Rainfall occurred on all trials during 5 of the first 10 days of May.

Most April-planted cotton should be out of the thrips damage window within 10 days or less. Cotton planted in April had three true leaves or more with the fourth or fifth emerging on May 11.

Growers planting behind the rainfall that occurred between May 7 and May 11 will likely not have to be concerned about making a foliar spray for thrips at the first true leaf stage. Seed treatments alone should provide adequate thrips control.

Cotton up and growing should be beyond grasshopper damage. The concern about pill bug damage in the one field in Talladega County this week turns out to be primarily damage from slugs and not pill bugs.