Sulphur dioxide fumigation for control of botrytis storage rot of kiwifruit

Abstract

Abstract Spores of Botrytis cinerea and kiwifruit (Actinidia deliciosa) inoculated with B. cinerea spores were exposed to sulphur dioxide (SO2) gas ranging from 200 to 3200 ppm for 10, 20, and 30 min at 17°C. Germination of spores was completely inhibited at concentrations of 400–3200 ppm but some germination occurred at 200 ppm. The level of control of botrytis storage rot on fruit increased with increasing SO2 concentration. Botrytis rot was almost completely controlled in fruit treated with 1600–3200 ppm. Fumigation at 200–400 ppm was ineffective. Most of the SOO2 absotption by kiwifruit occurred within the first 2 min of fumigation. AbSOtption was greater at 3200 ppm than 400–1600 ppm SO2. No SO2 injury was detected on fruit at any concentration tested. Fruit firmness was not affected by the treatments.