Abstract
The effects of Pratylenchus neglectus, Bacillus megaterium and oil radish or rapeseed green manure crops on Meloidogyne chitwoodi reproduction on potato were investigated in greenhouse and field microplot experiments. B. megaterium reduced the population densities of M. chitwoodi and P. neglectus by up to 50% on potato plants. There was a three-way interaction (P< 0.05) of B. megaterium x P. neglectus x green manure on M. chitwoodi population control on potato. The Population density of M chitwoodi was suppressed by B. megaterium more in pots with green manure of oil radish or rapeseed than in pots with no green manure. M. chitwoodi generally suppressed P. neglectus numbers, but not in the presence of B. megaterium in pots amended with Oil radish green manure. In field microplots, the main effects of green manure and nematode species on potato yield and nematode population density were significant (P< 0.05). Oil radish or rapeseed green manure treatments increased tuber yield compared to non-amended soil. Tuber yield from oil radish green manure treated plots was greater than from aldicarb treated plots. Tuber size was also greater in oil radish and rapeseed treatments than in aldicarb and non-amended treatments. Tuber yield from microplots inoculated with M. chitwoodi alone or in combination with P. neglectus was significantly lower than the non-inoculated control. Population densities of both the nematode species on potato plants were suppressed when they were inoculated together, compared to individual inoculation. The presence of P. neglectus also reduced tuber infection by M. chitwoodi.