ENHANCEMENT OF PLANT-GROWTH BY ZYGORRHYNCHUS-MOELLERI

Cucumber, tomato, two flowering annuals and a flowering perennial produced plants of greater weight in soilless compost infested with Zygorrhynchus moelleri than in uninfested compost. In Z. moelleri-infested compost the annuals commenced flowering 4 to 10 days earlier, cucumbers produced mature fruits more rapidly and a greater weight (20%) of fruit was harvested from 15-wk-old tomato plants. Leaves of 11 and 15-wk-old tomato plants grown in infested compost contained more chlorophyll than leaves from plants in uninfested compost. Z. moelleri was isolated from 99% of segments cut from roots of tomato plants grown in infested compost and it suppressed the growth of Trichoderma spp. at the root surface. Propagules of Z. moelleri remained viable in air-dried compost for at least 12 months. In axenic culture, Z. moelleri enhanced lateral root development in tomato and cucumber seedlings.