- Fruits: berries (brambles)
- Pest Management: chemical control, disease vectors, integrated pest management
In the Pacific Northwest region, an emerging complex of virus diseases in raspberry has caused symptoms of crumbly fruit, resulting in lowered fruit quality, crop loss and shortened life of the field. As a result, control of these viruses has consistently been one of the top priorities of the Washington Red Raspberry Commission and the Northwest Center for Small Fruit Research. One of the viruses implicated in these symptoms is raspberry leaf mottle virus (RLMV), a closterovirus that is transmitted by the large raspberry aphid, Amphorophora agathonica. RLMV is widespread in the top raspberry producing counties of Washington, which produce 95% of the processed red raspberries in the U.S. Infection rates of 100% are commonly seen in fields only four years of age and contribute to the loss of the raspberry crop and short life of the field. Control of RLMV depends on effective management of the aphid vector by targeting life stages that are most responsible for virus spread to new areas, such as the winged morph of the aphid, or broadly exposed life stages, such as the overwintering egg. To improve current management of this aphid vector, this study proposes to: 1) determine if control of the fall flight period of A. agathonica is required for control of virus spread, and 2) evaluate organic fungicides and oils for their efficacy in suppressing egg hatch.
Project objectives from proposal:
1. Determine the late-season interval when control of aphids is important for reducing raspberry leaf mottle virus (RLMV) in raspberry and if there is a date after which aphid control is unnecessary.
2. Evaluate the effectiveness of lime sulfur, lime sulfur with dormant oil and neem oil for suppressing aphid egg hatch.
3. Disseminate results of these studies both in scientific journals and to growers throughout the region using field days, meetings and online tools.