Issues with Fuller Rose Beetle Foliar Treatments
One of the requirements of the Fuller rose beetle program for shipping fruit to Korea is application of a foliar spray by Oct 15. I am in the process of testing various products for efficacy against Fuller rose beetle to find insecticides to recommend, in addition to Actara. While several other products (Kryocide, Lorsban Advanced, Sevin XLR) show good efficacy, they do not have MRLs established or the MRLs for Korea are substantially lower than the US. There are two products I tested that include the active ingredient in Actara - thiamethoxam: Agri-Flex 8.5 oz (thiamethoxam + abamectin) and Voliam Flexi 7 oz (thiamethoxam + chlorantraniliprole). These products could be used as the foliar FRB treatment, if used at a rate that provides a similar level of thiamethoxam.
Numerous questions have come up about combining the FRB Actara treatment with a gibberellin spray or a Copper-Lime-Zinc spray. This morning a test was conducted at Lindcove REC and Gibb was not found to alter pH. In contrast, the lime treatment raised the pH to an unacceptable level (from 7.5 to 12.2) and so should not be combined with Actara. Additional tests are underway to see if these treatments reduce the efficacy of Actara against FRB in the field.