Impact of foliar herbicide application on cotton with selected insecticide seed treatments

With insecticide seed treatments not working as well as they have in the past, many growers have questions about seed treatment efficacy.  The objective of this research study was to continue this work using insecticide-treated seed to examine efficacy changes after herbicide application.  One preliminary trial was planted on June 7th.  Various rates of Gaucho and Cruiser seed treatments were tested.  Foliar applicaton of Dual Magnum herbicide was made on 2-4 leaf cotton.  Thrips densities, both before and after herbicide application, were counted.  Plant height and stand counts were monitored 5-7 days post treatment.  Plant injury (necrosis or chlorosis) was also recorded at this time.  After these data were collected, all trials were treated identically for pests the remainder of the season.  Nodes above white flower were made once just prior to cutout to determine differences in maturity.  Efficacy of seed treatments was disrupted by application of an over-the-top herbicide.  Gaucho and Cruiser seed treatments showed differences in control before and after herbicide applciation, with Gaucho treatments having a greater loss in efficacy after herbicide application but greater control before herbicide application.  Future evaluation of this disruption will be expanded through experiments with different herbicides and multiple seed treatments.