25 Jun 2019
Diversity of Phytophthora, Pythium, and Phytopythium Species in Recycled Irrigation Water in a Container Nursery
Neelam R. Redekar, Joyce L. Eberhart, and Jennifer L. Parke (Oregon State University)
Plant nurseries may irrigate with surface or recycled water that is contaminated with plant pathogens. At an Oregon nursery we filtered or baited irrigation water, followed by next generation DNA sequencing, to identify multiple oomycete pathogens occurring together. Baits were more effective than filters at capturing pathogenic species. Pathogens were more abundant in recycled water than in the source water, but chlorination was effective at killing them. Pythium and Phytopythium species were prominent in summer, whereas Phytophthora species were observed year-round. Growers should regularly test irrigation water for pathogens and disinfest water before use in irrigation.
Read the article here: https://doi.org/10.1094/PBIOMES-10-18-0043-R
26 Apr 2018
Test Your Irrigation Water for Phytophthora
Redekar, N.R. and Parke, J.L. (Oregon State University)
Phytophthora is a plant pathogen that can infect a wide variety of nursery plant species, and it spreads in irrigation water. In this article, we will describe how you can test your irrigation water for Phytophthora using baits. We present a case study of a large nursery where baiting was used to test the efficacy of their water treatment. Although this nursery recycles 90% of their irrigation water, we showed that they were successful at controlling Phytophthora contamination with their chlorination treatments.
Haga clic aquí para leer el artículo en español.
American Nurseryman Redekar and Parke 2018 (657 KB)
6 Apr 2018
Phytophthora Communities in a Western Oregon (USA) River
Redekar, N., Eberhart, J., and J.L. Parke (Oregon State University)
One source of oomycete (Phytophthora and Pythium) contamination in nurseries and greenhouses is the use of untreated water from ponds and rivers. Next generation DNA sequencing was used to detect species of Phytophthora and Pythium in irrigation water originating from a river. Research highlights: 1) Pythium and Phytophthora are the most abundant oomycete genera found in river water, 2) the oomycete species in river water fluctuate seasonally, 3) leaf baiting is the best method to detect active plant pathogens, particularly Phytophthora species, and 4) next generation sequencing technology is a very effective, sensitive and semi-quantitative method for detecting Phytophthora and Pythium in water or soil.
Take home message for growers: 1) surface water (rivers and ponds) are almost always contaminated with Phytophthora and Pythium species, 2) water can be tested using leaf baiting to determine if Phytophthora is present https://youtu.be/SJx7gzXyXoM 3) water should be disinfested before use in irrigation.
Poster IUFRO Redekar et al (724 KB)