Abstract
Aims
A study on the effectiveness of replanting in “inter-row” to minimize replant disease in apple orchards was performed focusing on the plant-microorganism relationship.
Methods
Simulation of a post transplant period with M9 rootstock plantlets was performed in soil samples taken from five third-generation orchards. Plant growth and root health, root colonizing fungi and bacteria of rhizospheric soil were evaluated at the end of the post-transplant simulation.
Results
Plant growth did not differ across the orchards, but was highest (
P
> 0.01) in the “inter-row”. Root colonizing fungi composition differed from one orchard to the other, but not between row and inter-row.
Fusarium solani
and
F. oxysporum
were the most represented species followed by
Cylindrocarpon
spp, binucleate
Rhizoctonia
sp., and
Fusarium
spp.
Cylindrocarpon
spp and binucleate
Rhizoctonia
sp. were pathogenic and occurred everywhere. Rhizosphere bacteria differed across orchards, but their position within the orchards did not. As plant growth response to the row and inter-row varied through the orchards, findings suggest that microbial interaction and pathogen host specificity play a role in plant health.
Conclusions
Replanting in inter-row can minimize replant disease but potential fungal pathogens are endemic in soil, therefore replanting should be associated with strategies increasing soil suppressiveness in established orchards.