1a.Objectives (from AD-416):
1. Development of decision-making tools.
2. Develop sustainable management systems.
1b.Approach (from AD-416):
Through a combination of laboratory and field experiments we will develop decision-making tools and sustainable management systems for the control of Phytopthora spp. and plant-parasitic nematodes in raspberry production systems. Specifically we will use molecular techniques to characterize and determine virulence of Phytophthora spp. in raspberry. We will establish field trails in nematode-infested fields to identify raspberry plants resistant or tolerant to Pratylenchus penetrans. We will also begin to develop sustainable pest management systems for raspberry by establishing field trials in northern Washington that evaluate alternative was to broadcast fumigation to manage soil borne pathogens prior to establish a raspberry crop.
United States raspberry (Rubus idaeus) production is heavily concentrated in the Pacific Coast states, with over 90% of total fresh market production coming from California and over 90% of total processing production grown in Washington. The soil borne pathogen Phytophthora rubi and the plant-parasitic nematode Pratlylenchus penetrans are both important, difficult to manage pests in these production systems. The goal of this multi-state, collaborative research is to develop tools for raspberry growers to better manage these organisms. The objectives of this project are to. 1)characterize the virulence and population dynamics of Phytophthora species,. 2)identify sources of plant resistance to P. penetrans, and. 3)evaluate novel preplant management practices to control these organisms and permit successful raspberry establishment. To achieve the first objective, 20 raspberry fields in Washington, Oregon, and California were sampled for Phytophthora species and three isolation methods were evaluated to optimize recovery. For objective 2, a field trial was established in Washington to evaluate the response of eight raspberry varieties, as well as two Rubus species closely related to raspberry, to P. penetrans; nematode population dynamics and plant performance are being evaluated. Finally, for objective 3, novel preplant management practices such as bed fumgation alone and in combination with cover crops are being compared to the industry standard of broadcast fumigation in a replicated, on-farm trial. All of these experiments are in progress and will continue to be conducted/monitored over a 3 to 4 year period.
This research was conducted in support of objective 303 3B: Biologically-Based and Integrated Disease Management.