The effects of spent mushroom compost and municipal solid waste compost on Phytophthora drechsleri in vivo and in vitro

Abstract

Leached spent mushroom compost (SMC), municipal solid waste compost (MSWC) and their extracts, were tested to suppress Phytophthora drechsleri in cucumber plants. The composts were mixed with sand-loam soil in sterile and non-sterile types and were used to assess suppressiveness against P. drechselri in greenhouse experiments. The extracts of composts, in both sterile and non-sterile types, were applied to evaluate their effect in suppression of pathogen in vitro. The results of the experiments showed that all applications rate of non-sterile SMC were significantly effective in the control of the pathogen. However the sterile SMC amendments did not have a positive effect on the pathogen suppression in vitro or in vivo, as it was expected. In greenhouse experiments, both composts were effective in controlling pathogen at the rate of 15%, but the treatments amended with higher rate of MSWC did not show a positive effect. The treatments amended with MSWC (15%) and SMC (25%) showed the most suppressive effect in controlling the pathogen. The extract of leached-SMC could inhibit P. drechselri in petri dish.

Keywords:

• spent mushroom compost
• municipal solid waste compost
• Phytophtora drechsleri

Acknowledgements

The authors gratefully acknowledge the financial support of Shahid Behashti University and the Iranian Research Institute of Plant Protection. We thank Malard Company for their assistance in spent mushroom compost preparation. We also thank S. Fatemy and H. Saeedi for valuable advice and critical reading of the manuscript.