Effect of fungi associated with roots on the growth of continuously cropped upland rice

Pyrenochaeta sp. enriched on and in roots of upland rice through its continuous cropping, was shown to have an ability to inhibit the growth of upland rice in quartz or partially sterilized soil. It was established that the microorganism produced some substance inhibiting the growth of seedlings of upland rice or/in roots of the plant. The results suggested that Pyrenochaeta sp. produced this inhibitor even on/in roots of upland rice continuously cropped on the field, and may play a role in the appearance of upland rice soil sickness.