Dr. Phillip Roberts, UGA Cotton Entomologist, just sent out the newest information about the cotton jassid to county Extension agents. The bottom line is to please do not underestimate this pest. Below are a few highlights on thresholds, insecticide observations and a few common questions. The whole cotton jassid agent update is available below. It contains 14 day after treatment (DAT) from on farm and other trials.
Below is a new updated threshold.
Comments on insecticide selection.
Cotton Jassid Common Questions
• How long before we will need to retreat a field? This is dependent on insecticide used and how much migration or reinfestation is occurring. Scout! Some fields have required a second application.
• How long do we need to protect cotton from jassids? We need green leaves to fill top bolls. Based on observations that jassids can crash a field in 2 weeks our thoughts are: Protect cotton up to 14 days before the earliest you could defoliate a field (60% open) and the field is still green. This generally corresponds to about 20-25 percent open boll and the field is still green. If the field is yellowing and beginning to show symptoms I would still spray even at 20-25 percent open. If the field is crashing, leaves are yellow and beginning to turn red and brown, it is likely over, and treatment may not be of a benefit.
If you have questions please contact your local county Extension agent.