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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research » Research » Research Project #431569

Research Project: Improving Plant Health for Nursery Production in the Pacific Northwest

Location: Horticultural Crops Research

Project Number: 2072-22000-043-21-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Sep 15, 2016
End Date: Sep 14, 2021

1. Characterize impact of irrigation, nutrition, and fungicide application on disease development and physiology of nursery crops. 2. To evaluate the effect of different Phytophthora species on nursery crop health.

The effects of different cultural practices on diseases caused by Phytophthora and Pythium with be investigated in a series of experiments with woody perennial nursery crops. Using different Rhododendon cultivars and isolates of Phytophthora cinnamomi, Ph. plurivora, and Pythium irregulare we will assess how (1) altering the frequency and volume of irrigation effects disease and the ability of plants to withstand water stress; (2) fertilizer type and application method effects disease and the ability of plants to absorb and use nutrients; and (3) fungicide formulation and application method effects disease severity and plant health. Experiments will be performed in greenhouses and under nursery production conditions and will be replicated across and within seasons to evaluate seasonal changes in plant susceptibility and pathogen activity. This project will be expanded to evaluate the effect of other Phytophthora species on nursery crop health. In addition to the Phytophthora species identified above (Ph. cinnamomi and Ph. plurivora), three other Phytophthora species will be inoculated onto Rhododendron to evaluate their ability to cause disease.