Link to home

Fluctuations of Phytophthora and Pythium spp. in Components of a Recycling Irrigation System

December 2003 , Volume 87 , Number  12
Pages  1,500 - 1,506

Elizabeth A. Bush , Chuanxue Hong , and Erik L. Stromberg , Virginia Polytechnic Institute and State University, Department of Plant Pathology, Physiology and Weed Science, Blacksburg 24061



Go to article:
Accepted for publication 4 August 2003.
ABSTRACT

Stringent standards of water quality have prompted many horticultural enterprises to limit pollutant discharge associated with nutrient and pesticide applications. Collecting and recycling effluent is a method that has been implemented by many operations to contain pollutants; however, plant pathogens may be spread through recycled effluent. In this study, Phytophthora and Pythium spp. present in a water-recycling irrigation system at a perennial container nursery in southwestern Virginia were characterized using filtering and baiting techniques with two selective media. Members of Phytophthora were identified to species, whereas Pythium spp. were identified to genus only. Pythium spp. were recovered more frequently and in greater numbers than Phytophthora spp. Phytophthora capsici, P. citricola, P. citrophthora, P. cryptogea, P. drechsleri, and P. nicotianae were recovered in filtering assays. Only P. cryptogea and P. drechsleri were identified from baits placed on the surface of the irrigation reservoir, whereas P. cactorum, P. capsici, P. citricola, P. citrophthora, P. cryptogea, and P. drechsleri were recovered at depths, specifically at 1 and 1.5 m. This research provides data for development of detection technology and management practices for plant pathogens in irrigation water and may lead to improvements in conventional assay protocols.


Additional keywords: chlorination, recycled irrigation water

© 2003 The American Phytopathological Society