ESTIMATION OF PANTOEA AGGLOMERANS E325 STIGMA SURVIVAL DURING THINNING PROGRAMS USING DECISION ANALYSIS TOOLS

The survival of a biological antagonist such as Pantoea agglomerans E325 or the pathogen Erwinia amylovora on an apple blossom depends upon many environmental factors.
In addition commercial orchard practices such as blossom thinning can confound the understanding of this survival.
Proper integrated pesticide management programs need to understand this survival so that biological tools to suppress disease can be adequately deployed.
Using decision analysis it can be shown that application of antagonist before thinning will result in low antagonist coverage at the end of bloom without post thinning antagonist applications.
Post thinning antagonist application at 60% bloom will result in predictions of 49% blossom colonization at full bloom.
When the post thinning antagonist application is done at 90% bloom, the overall coverage is predicted to be 80%. One recommendation from this analysis could be that biological antagonists should be applied as recommended early in the orchard but that a second application should be made to blossoms that come after thinning activities in the orchard.
Addition of pathogen colonization and risk models will help predict optimum timing of treatments to be analyzed.

XII International Workshop on Fire Blight

C. Wend

fire blight, decision analysis, Pantoea agglomerans E325

https://doi.org/10.17660/ActaHortic.2011.896.77