Damping-Off Suppressiveness of Vermicomposted-Bamboo Powder microorganisms (Elvira et al. 1998). The feedstocks that are commonly used for vermicomposting include animal manure and vegetable or fruit scraps from kitchens or farms (Atiyeh et al. 2000, Garg et al. 2006). Many kinds of vermicompost are known to be used as a component of nursery potting media (Scheuerell et al. 2005) owing to their ability to control plant pathogens such as Pythium ultimum Trow var. ultimum, Rhizoctonia solani Kuhn, and Verticillium sp. (Chaoui et al. 2002). Owing to their effective disease suppression, vermicomposts have become a promising alternative to chemical pesticides. However, vermicomposts produced from different feedstocks vary in disease suppressiveness. Szczech & Smolińska (2001), for example, showed that vermicomposts produced from

A series of experiments in laboratory, greenhouse, and field were conducted to compare the nematode suppressive effect of vermicompost tea (VCT) prepared from vermicompost with mosobamboo (Phyllostachys edulis (Carrière) J. Houz.) and kudzu (Pueraria lobata (Willd) Ohwi) as feed stock (weed VCT) to that prepared from vegetable food waste (vegetable VCT) against Meloidogyne incognita and Rotylenchulus reniformis. Two laboratory trials were conducted by incubating eggs of M. incognita and R. reniformis in weed VCT or vegetable VCT over 1 wk. These trials revealed that although both VCTs suppressed M. incognita egg hatching compared to water control, only weed VCT suppressed R. reniformis egg hatching. In addition, both VCTs suppressed the mobility of second stage juveniles (J2s) of M. incognita equally compared to water control though suppression from weed VCT performed inconsistently between the trials. When root penetration of M. incognita on cucumber drenched with VCT on one side of a split-root system in a greenhouse sterile sand-soil mix was examined, weed VCT suppressed root penetration of M. incognita on the other side of the root in two trials, but vegetable VCT was only effective in one trial. However, both VCTs did not suppress R. reniformis root penetration. When the effect of the VCTs was examined in two cowpea (Vigna unguiculata) field trials, drenching of VCTs did not affect cowpea growth and yield, but weed VCT reduced root-gall index compared to the water control in both trials. Although both VCTs did not reduce the number of M. incognita and R. reniformis in soil, weed VCT did increase omnivorous nematodes in the second trial, indicating a gradual improvement of soil food web structure through VCT drenching over time. Overall, performance of weed VCT was more consistent than vegetable VCT for plant-parasitic nematodes suppression.

A strain of Pythium oligandrum isolated from soybean, grown in a commercial field in Osaka, Japan, was characterized by species identification and suppression of soybean damping off caused by P. aphanidermatum and P. myriotylum. The morphology and hyphal growth temperature of the P. oligandrum strain corresponded with those of the original description of P. oligandrum. rDNA-ITS sequences of the P. oligandrum strain were highly matched to those of the type strain of the species. The P. oligandrum strain was mycoparasitic toward P. aphanidermatum and P. myriotylum, and significantly suppressed soybean damping off caused by them. This is the first report of the effectiveness of P. oligandrum on soybean damping off pathogens.

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