Description:
Six fungicides were evaluated to control Botrytis blight of western
41 larch in seedbeds at the Coeur d'Alene Nursery. Fungicides were applied
at biweekly intervals during the spring of 1982; test seedlings were
inoculated with spores of B. cinerea twice during the evaluation period.
Seedling mortality and height were recorded in October just prior to
lifting. Because of overall low infection levels, no differences in
seedling mortality were apparent as a result of fungicide treatment.
Low infection was likely due to drier spring weather than when outbreaks
of the disease previously occurred. Most fungicides decreased seedling
height, although no external indications of phytotoxicity were apparent.
Several of the fungicides tested can be considered for use to control
Botrytis blight in larch seedbeds.