With many growers still actively treating plant bugs, whitefly, bollworm and other cotton pests, it’s also appropriate to look ahead at the proper timing for terminating insecticide treatments.
In a recent UTcrops News Blog, Tennessee Extension Entomologist Scott Stewart offered some thoughts and recommendations for growers to keep in mind as the cotton crop reaches cutout.
“The word ‘cutout’ is synonymous with NAWF5 and occurs when a field averages 5 or fewer nodes above the uppermost first-position white flower,” he says in the post. “The white blooms present at cutout represent the last group of bolls that will likely make it into the picker basket.”
Stewart notes that once cutout is reached, it’s still important to continue to treat for plant bugs until the last harvestable bolls have accumulated 250 DD60s – generally another 10-14 days. He suggests increasing the plant bug threshold from 3 to 5 tarnished plant bugs per drop cloth once cutout is reached. Stink bug and bollworm treatments should continue until 350 DD60s have accumulated.
- For cotton at NAWF5, terminate insecticide applications for plant bugs, stink bugs and bollworms once fields have accumulated more than 350 DD60s. Yet, he says, don’t walk away from fields at that time if significant pest problems are present.
- For late maturing cotton, protect any bolls set by August 15 for another 14-21 days. Look to the first week in September to terminate insecticide applications in late maturing fields, using the NAWF5/350 guideline.