AVISSAR, I., Institute for Technology, Storage of Agricultural Products, Agricultural Research Organization, The Volcani Center, P. 0, Box 6, Bet Dagan, 50250, Israel
DROBY, S., Institute for Technology, Storage of Agricultural Products, Agricultural Research Organization, The Volcani Center, P. 0, Box 6, Bet Dagan, 50250, Israel
PESIS, E., Institute for Technology, Storage of Agricultural Products, Agricultural Research Organization, The Volcani Center, P. 0, Box 6, Bet Dagan, 50250, Israel

Acetaldehyde (AA) vapour reduced the in vitro growth of the fruit‐infecting fungi Botrytis cinerea and Rhizopus stolonifer, and decreased the respiration of R. stolonifer. Spore germination, germ tube elongation and sporulation were inhibited in both fungi. AA induced the leakage of electrolytes from B. cinerea and R. stolonifer membranes. The conductivity found in the fungal extracts was positively correlated with the AA concentration applied. The leakage of reducing sugars and amino acids suggest that cell membranes are irreversibly disrupted by AA as a first step in inhibition of the fungi in vitro. Copyright © 1990, Wiley Blackwell. All rights reserved