BIOLOGICAL METHODS IN RELATION TO APPLE REPLANT PROBLEM

Phytotoxic micromycetes were appeared to be responsible for apple replant problem.
Inoculation of apple seedlings with Agrobacterium radiobacter reduced the amount of phytotoxic micromycetes in rhizosphere soil and also reduced the inhibition of growth of apple seedlings in soil with apple replant problem.
Introduced bacteria persisted in the rhizosphere throughout the 30-months test period. A. radiobacter not only reduced the amount of phytotoxic micromycetes, but also other components of the soil microbial community.
Occurrence of dinitrogen-fixing bacteria of the genus Azospirillum was positively influenced.
These bacteria could serve also as antagonists against phytotoxic fungi. Agrobacterium radiobacter was more antagonistic than Azospirillum brasilense. It is suggested that the ratio of bacterial Azospirillum colony forming units (CFU) to phytotoxic micromycetes can be used as an indicator of the degree of apple replant problem.

Workshop on Replant Problems with Fruit Trees

V. Catská

https://doi.org/10.17660/ActaHortic.1988.233.7