Inhibitory Activity of Sulfur Dioxide on the Germination of Spores ofBotrytis cinerea

(...) «Molecular» sulfur dioxide (SO 2 ) was present at 0.10-0.11 μg/ml, whereas bisulfite (HSO 3 − ) ranged from 1.6 to 17.1 μg/ml at LD 50 . This confirmed that the «molecular» form of SO 2 was the primary toxic species (...) After a 30-min fumigation with 5,000 or 10,000 ppm SO 2 , the skin and pulp contained 7.6-16.5 and 0.7-0.9 μg/g SO 2 , respectively. Residues on or near the surface of fumigated grapes approached the toxic dosage above 20 C, whereas residues in the pulp were insufficient to kill the spores in dose-mortality tests