Location: Horticultural Crops Research Unit
2020 Annual Report
Objectives
Evaluate various fungicides, insecticides, and herbicides for phytotoxicity and/or efficacy on floral and nursery crop plants in support of label expansion through the IR-4 regional project.
Approach
Selected floral and nursery crop species will be grown in the greenhouse, ground beds, or field plantings and treated according to specific protocols (timing, concentrations) with selected fungicides, insecticides, or herbicides. In some cases, chemicals will be tested for efficacy, but mostly they will be tested on plants for phytotoxicity. Data will be submitted for inclusion in the IR-4 Minor Use Testing Program.
Progress Report
Researchers in Corvallis, Oregon, have conducted a range of 20-80 crop safety trials per year. These trials are being conducted with different pesticides on a diversity of plant material. The results of these tests are reported annually to the IR-4 project at Rutgers University and are forwarded to the product manufacturer to be used in their request to expand the label to include the tested ornamental plants. In 2020 a total of 80 crop safety trials are being conducted. Eventually, with label expansion, growers should be able to legally use these chemicals on ornamental nursery crops. This information will aid significantly in registering novel fungicides or biologicals for managing diseases of minor crops including ornamentals.
ARS scientists evaluated efficacy of fungicide for control of Phytophthora pathogens on Rhododendron with focus on two pathogens important to nursery production in the Pacific Northwest, Phytophthora plurivora and Phytophthora syringae. Seven chemicals were tested against Phytophthora plurivora. ARS scientists further evaluated the efficacy of select fungicides and biocontrol agents against the foliar pathogen Phytophthora syringae on detached Rhododendron leaves. Seven chemicals were tested for P. syringae. Experiments were conducted by applying fungicides to Rhododendron catawbiense 'Album' plants in one-gallon containers. Disease severity was determined by evaluating lesion area from digital images. Disease development was analyzed and reported. This information improves best management practices for use of fungicides to control plant pathogens of ornamentals.
Accomplishments
