Abstract
Experiments were conducted to develop a microbial soil amendment for controlling plantparasitic nematodes using Streptomyces isolates NA-128, -150, -303, -359, -369 and -494. The acetone extracts of the cultured broth of these isolates suppressed the motility of secondstage juveniles of Meloidogyne incognita. These nematode-controlling Streptomyces isolates (NS isolates) are expected to control root-knot nematodes in the field. We examined how NS isolates could be maintained on various agricultural materials (carrier), and found that paperpulp compost and vermiculite could maintain them at a high density for a long time. In a pot experiment in a greenhouse, treatments with NS isolates fixed on paper-pulp compost increased the shoot length and fresh shoot weight of cucumber plants, and suppressed gall formation as compared to the NS untreated control. These effects became more remarkable by using paperpulp compost as a carrier for fixation of NS. There was a significant interaction effect involving NS treatments and the carrier type on cucumber growth. In addition, NA-494 treatment with paper-pulp compost had the most remarkable effects on cucumber growth.
