Sunday, June 19, 2016

Start of Summer Update

As we begin the summer season there are not any significant pest problems to report in corn and sorghum. Blayne Reed has reported treatable thrips levels on cotton in some fields in Hale and Swisher counties, and Katelyn Kowles is reporting lower levels in fields in Lubbock and Crosby counties. Regardless of the reports, all cotton should be scouted for thrips through the 5th true leaf stage.

Foremost in our thoughts is when sugarcane aphid will colonize sorghum. We know the insect overwintered in Hale County and near Lamesa, and we found it on Johnsongrass in Lubbock County on May 3rd, but as yet it has not appeared on sorghum. The beneficial insect activity in wheat was higher than average this year (due to higher aphid numbers in wheat), and it is possible these beneficials found some or most of the early aphid colonies on Johnsongrass and provided suppression. However, the Hill Country and areas south of the High Plains do have aphids in significant numbers, and it is reasonable to expect winged aphids to arrive soon. Last year the first find of sugarcane aphids on the High Plains was in Lubbock County on June 27th. So for sugarcane aphids we are in a period of watching and waiting. When it does arrive we will begin the several control and economic threshold trials that we have pending.

Things are quiet in corn and the only real insect of note has been fall armyworm on non-Bt corn. The most recent trap counts are pictured below. I have not heard of any non-Bt fields with an economically important fall armyworm infestation. Hopefully all late planted corn is with a good Bt trait to blunt the high numbers of fall armyworms we traditionally have later in the season.

Because most of our corn is rotated, the risk of corn rootworm is nonexistent in these fields. The few non-rotated fields may be getting root injury at this time.