CHEMICAL CONTROL OF PARASITIC STORAGE DISEASES ON APPLE AND PEAR

Several fungi are involved in storage rots on apple and pear. Chemical control was mainly based on the use of benzimidazoles during the last six weeks before harvest. These systemic fungicides are particularly interesting because of their activity against a great number of fungi causing storage rots like Gloeosporium, Botrytis, Penicillium and Monilia.

However, some fungi species are naturally resistant against the benzimidazoles such as e.g. Phytophthora or Alternaria; others have developed resistance like e.g. Botrytis cinerea which causes more than 90% of the storage rots on pear. In order to prevent resistance or a shift in dominance, a combination or an alternation of fungicides with a different mode of action is recommended.

In the past the same control schedule was applied for apple and for pear; now, more specific schedules will be followed for both fruit' species. On pear, the control schedule will be directed on Botrytis, on apple, on the contrary, Gloeosporium will be the first objective.

In order to avoid resistance build up of some storage fungi a shift of pre-harvest towards post-harvest treatments should be considered.