Dr. David Kerns and I have been receiving more phone calls regarding spider mites in cotton. Mite problems are exacerbated by hot, dry weather and applications of broad-spectrum insecticides for early season pests.
Do not wait for spider mite treatments in cotton if populations are found scattered throughout the field or if mites are moving in from field borders. When making applications, correct nozzles and high water volumes are essential for adequate coverage and application rates should reflect mite severity.
Miticide application rates should be adjusted for population severity with higher rates used for more severe infestations. Some control options available for spider mite control include Oberon, Portal, Abamectin, Athena and Zeal. Below is a brief description of each product and recommended use.
Oberon, a slower acting miticide, may to take 5-7 days before mortality is observed in the field.
Portal has given satisfactory results when applied at 16-20 oz/acre, lower rates in large cotton may not give complete control. Portal is a contact miticide but one should still allow 5-7 days to assess effectiveness.
Abamectin has been widely used for mite control across the Northeast region with multiple applications required for control of severe infestations. However, producers and consultants should consider rotating chemistries on fields that have had numerous abamectin applications for resistance management and if efficacy has decreased.
If mixed populations of bollworms and mites are in a field, Athena a premix of bifenthrin and abamectin, is another available control option. Ten ounces of Athena is equivalent to 3.8 ounces of bifenthrin 2E and 7.5 ounces of abamectin. For effective bollworm control, Athena should be supplemented with more bifenthrin and ½ lb of acephate should be added to increase efficacy on any tarnished plant bugs and pyrethroid tolerant worms.
Zeal is one of our most effective options for controlling spider mites in cotton. Because we are limited to 1 application of Zeal per season, we usually prefer to save our Zeal shot for more troublesome mite problems.
If you have any questions or concerns, do not hesitate to contact Sebe Brown or Dr. David Kerns for more information.
Sebe Brown Cell: 318-498-1283 Office: 318-435-2903
Dr. David Kerns Cell: 318-439-4844 Office: 318-435-2157