Evaluation of Two Commercially Available Composts for Managing Phytophthora Fruit Rot of Pumpkin

Abstract

The goal of this project was to evaluate commercially available composts for managing Phytophthora fruit rot of pumpkin. Five composts were screened for disease suppressiveness against common soil borne disease organisms in the greenhouse. One product stood out as highly suppressive. This compost (Nutribrew) was then applied to two fields with a history of Phytophthora capsici. In one field, no disease occurred. Pumpkin growth and yield was significantly improved where compost was applied, and 20 tons/a was adequate to achieve this improvement. The compost contributed to both nutrients as well as moisture conservation. In the other field, the disease pressure was high, and compost applications did not reduce the disease level. These results may suggest the need for several years of application before diseases may be reduced.