Reducing Phytophthora

Authors: Parke, Jennifer (OSU) Date: 2010

Phytophthora species are some of the most problematic plant pathogens in nursery production systems. The quarantine pathogen Phytophthora ramorum has received the most notoriety, but many Phytophthora species pose a challenge for nursery growers.

These pathogens cause trouble because of their persistence and spread in infested soil and water, and their ability to attack a wide variety of plants. Some species cause root rot, whereas others cause foliar blight and shoot dieback. Several species can infect plant parts both above and below the ground.

In collaboration with Niklaus Grünwald and Val Fieland of the USDA-ARS Horticultural Crops Research Laboratory, Carrie Lewis and I (Oregon State University) recently completed a three-year project to determine the most common sources of Phytophthora contamination in nurseries. We applied a systems approach to identify three critical control points in nursery production systems: contaminated soil/gravel beds, contaminated irrigation water, and used pots. Another potential source of Phytophthora spp., not included in our study, is nursery stock brought in from off site.

So what is the take home message for growers? Here are the top 10 practical tips for nursery growers:

Download (PDF): Reducing Phytophthora (2MB)

Use of Mycorrhizae for Native Plant Production

Author: St. John, T.

The mycorrhizal symbiosis is well known, but not yet in widespread use in the com- mercial nursery trade. The often-cited mycorrhizal growth response is in not the most signi cant mycorrhizal effect. Instead, the important effects are performance in the eld and improved nutrition and disease resistance in the nursery. These bene ts may be of use in meeting regulatory requirements related to fertilizer runoff and pesticide use. A nursery mycorrhiza program requires modi cation of some current practices and careful choice of appropriate fungi.

Download (PDF): Use of Mycorrhizae for Native Plant Production (120KB)

Nursery Manual for Native Plants: a Guide for Tribal Nurseries

Authors: Dumeroese, Luna & Landis (eds.) Date: 2009

This handbook covers all aspects of managing a native plant nursery, from initial planning through crop production to establishing trials to improving nursery productivity into the future. It was written to assist Native Americans in growing native plants and draws extensively on tribal activities for the many photos and specific examples in the text.

Download (PDF): Nursery Manual for Native Plants: a Guide for Tribal Nurseries (3.7MB)