Alternative Methods of Raspberry Production and Root Rot Control

Root rot (Phytopthora fragriae var. rubi) is of primary concern to all raspberry growers in Washington, and is of particular concern to organic growers who have fewer options for disease control. This trial is focused on organic root rot control, however all raspberry growers will benefit from new disease management strategies.

Our study builds upon research led by Dr. Pete Bristow from 1995 to 1998. That work demonstrated that raised beds reduced the habitat for Phytopthora by increasing drainage, but were not sufficient to control root rot. In spring 1999, in cooperation with Jan Pigman at Pigman's Organic Produce Patch, and with the funding support of the Organic Farming Research Foundation, we began to study six organic treatments for the control of raspberry root rot. In the summer of 1999, we were able to match OFRF funds with funding from the Washington State Commission for Pesticide Registration (WSCPR). We established raspberry research plots at the WSU Vancouver Research and Extension Unit, and included five organic treatments, one chemical treatment, and a control. It is our goal to use the WSU research station site to compare the effectiveness of organic disease control treatments to the standard chemical control treatment.

STUDY OBJECTIVES

• Analyze and compare performance of organic methods to control raspberry root rot at Vancouver REU and in an organic growers' field. • Observe and compare growth and fruit production of raspberry under conventional and organic farming systems.