Location: Horticultural Crops Research2012 Annual Report
1a. Objectives (from AD-416):
1. Develop and assess new controls for perennial weeds in cranberry beds. 2. Develop and assess controls for blackvine weevil in cranberry beds. 3. Assess organophosphate alternatives for insecticide management on cranberry beds.
1b. Approach (from AD-416):
Field trials will be implemented across numerous growers’ cranberry beds infested with yellow loosestrife (Lysimachia terrestris). Trials will consist of mesotrione, rimsulfuron and quinclorac applied alone and in all herbicide combinations. Research will be conducted to assess adulticides and larvicides for the control of blackvine weevil. Adulticides - each treatment will be applied at the first sign of adult emergence. Larvicides - treatments will be applied to weevil-infested cranberry beds at the end of egg laying in August. Research will be conducted to assess if any of the new alternative insecticide chemistries are as effective for fireworm control as organophosphates when applications are made via chemigation. Documents Grant with Washington State University. Formerly 5358-22000-032-15G (12/10). Formerly 5358-22000-036-04G (8/2011).
3. Progress Report:
Results on herbicide screening trials in 2012 indicate that the herbicide indaziflam provided excellent long-term pre-emergent control of several important weeds in cranberries with no crop phytotoxicity. This chemistry, because of its efficacy, crop safety, and registrant support, has excellent registration potential for cranberries. The herbicides chlorimuron and quinclorac provided year after treatment control of Lysimachia terrestris, the main cranberry weed pest in PNW cranberries. A Section 18 in OR and WA was obtained for quinclorac and Section 4 for chlorimuron. Both herbicides received rapid widespread adoption by the industry. Trials were conducted to assess efficacy of blackvine weevil larvicides and adulticides. Neither PFR-97, soil microbial insecticide, nor clothianidin was efficacious as spring-applied larvicides. Dinotefuran and indoxacarb both had adulticidal activity, but dinotefuran was not as efficacious as the industry standard, indoxacarb. Multiple whole farm trials for chemigation treatment of blackheaded fireworm (BHFW) using rynaxypyr, methoxyfenozide and spinetoram, were conducted. All chemistries had excellent efficacy as larvicides. These trials were conducted as paired studies comparing conventional OP insecticides. Efficacy was comparable, but the reduced-risk farms had greater populations of beneficial insects. Rynaxypyr also had significant ovicidal activity when applied during peak adult fireworm flight. These results have had both immediate and long-term economic and environmental impacts. This project has and will continue to result in significant improvement in the quality of surface water running off cranberry beds. Because of continued water quality violations, the Washington Department of Agriculture has enforced mandatory restrictions on the use of organophosphates on the majority of cranberry farms in Washington. Without replacement of OP chemistries, these farms would no longer have any legal pest control options and could quickly become non-economical. This work provides the research results that will allow growers to make that transition successfully. This research was conducted in support of objective 304 2B, Control.