Possibility for fungicidal control of kiwifruit fungal storage rots

The shelf life of cool‐stored kiwifruit ( Actinidia chinensis Planch.) can be reduced by fungal rots which appear after the fruit is removed from storage. The activity of 3 fungicides, benomyl, captafol, and mancozeb was tested against spore germination and hyphal growth of decay fungi, Phoma sp., Glomerella ( Colletotrichum ) sp., and Diaporthe ( Phomopsis ) sp., commonly isolated from rotting kiwifruit. ED 50 values for inhibition of spore germination were 5 μg/ml‐100 μg/ml for benomyl, <0.1 μg/ml for captafol, and 2 μg/ml‐43 μg/ml for mancozeb. ED 50 values for inhibition of hyphal growth were <0.1 μg/ml‐2 μg/ml, 0.6 μg/ml‐11 μg/ml, and >100 μg/ml, for benomyl, captafol, and mancozeb respectively. A spray programme with captafol (150 g/100 litre) applied at 2‐weekly intervals from blossom improved the shelf life, compared with unsprayed fruit, of kiwifruit stored for 21 weeks at 0–1°C and then held at room temperature (18–22°C) for 4 weeks. The proportion of fruit affected by rots during 5 weeks at ambient temperature increased as the period of storage at 0–1°C lengthened from 11 weeks to 27 weeks.