Effect of selective mycoflora amended vermicompost on suppression of root rot pathogens of tomato.

摘要

Ten decomposition promoting fungal isolates from rhizosphere of different plants were evaluated in various combinations to determine their effect on the biological productivity of earthworms and subsequent suppression of tomato diseases by the vermicast. Earthworm population, weight and size, and vermicast recovery were higher in fungal-amended vermicompost over the unamended control. Aqueous extracts of various combinations of fungal-amended vermicompost inhibited as well as promoted the growth of Pythium aphanidermatum (causing damping off disease of tomato), whereas similar combinations had inhibitory effect on mycelial growth of Fusarium oxysporum (causing root rot disease of tomato). Mycelial growth of Trichoderma virens was inhibited by fungal-amended vermicompost while mixed response was recorded in case of Paecilomyces lilacinus. Vermicompost prepared from fungal combinations of Aspergillus niger+Trichoderma virens+Paecilomyces lilacinus+Humicola grisea stimulated almost all the biological parameters of the plant and was highly suppressive towards pre-emergence disease incidence and also towards total disease severity. Fungal combinations of A. niger+T. virens+P. lilacinus+H. grisea+Cladosporium cladosporioides+Penicillium purpurogenum used in vermicompost preparation was superior to other combinations in reducing the post emergence disease incidence.