Shifting Gears For Plant Bugs
TPB nymph
DR. SCOTT STEWART
JACKSON, TENN.
We need to make some adjustment in managing plant bugs as we near bloom. Much of the cotton is at or beyond the third week of squaring, and thus, the suggested sweep net threshold can be relaxed to 15 bugs/100 sweeps. However, you should be more aggressive in situations where overall square retention is at or below 80 percent.
How do you know if a field has reached the third week of squaring? A pretty good indicator is if the average plant has five or more squaring branches. It takes about 3 days to put on a new node, so five nodes indicates a plant has been squaring for about 15 days.
You should also consider some different insecticides if a field is within a few days of first bloom or blooming has just begun. This might be a good time to include Transform or Diamond in the mix, particularly if immature plant bugs are becoming more obvious. I suggest not using neonicotinoids like imidacloprid or Centric once blooming has begun. ∆
DR. SCOTT STEWART: IPM Extension Specialist, University of Tennessee