Premium
Effects of time and temperature on the fungistatic action of mercury‐containing and other compounds on conidia of Botrytis fabae Sardiña
Author(s) -
McINTOSH A. H.
Publication year - 1961
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.1961.tb03636.x
Subject(s) - incubation , nuclear chemistry , chloride , biology , bromide , pentachlorophenol , mercury (programming language) , botrytis , zoology , chemistry , horticulture , biochemistry , organic chemistry , botrytis cinerea , ecology , computer science , programming language
SUMMARY The in vitro fungistatic action of nineteen compounds was measured on conidia of two strains of Botrytis fabae Sardiña in slide‐germination tests, at two or three incubation temperatures in the range 10–25° C.; the effects were assessed at intervals up to 14 days from the start of each test. In general, the ED 50's increased as incubation time passed, finally approaching or reaching steady values. With each compound, an increase in incubation temperature increased the speed of action (i.e. decreased the time taken for the ED 50 to reach a steady value), and increased the ultimate toxicity. Temperature coefficients were calculated as ratios of ED 50's and were ‘positive’ or ‘negative’ according to whether the toxic action was greater or less at the higher temperature. The conidia of the two strains of B. fabae behaved similarly, but the temperature coefficients were larger with one strain (A) than the other (B). Mercuric cyanide, chloride, bromide, acetate and thiocyanate gave positive coefficients which increased in size as incubation time passed. In these tests, which lasted for only 3 days, the largest 10:25° C. coefficient (+ 35) was given by the cyanide after 3 days (strain A); the corresponding figures for the chloride and bromide were + 10.5 and +6.0. Phenyl mercury acetate, methyl mercury nitrile, silver nitrate, copper sulphate, 8‐hydroxyquinoline, acetamide, p ‐nitrophenol, 2,4‐dinitrophenol and pentachlorophenol gave coefficients which were usually small and positive (about + 1.3), and changed only slightly in size as incubation time passed. t ‐Butyl alcohol, pyridine, 3‐picoline, phenol and p ‐chlorophenol gave coefficients which changed from negative (‐ 3.9 to ‐1.5) to positive (+1.3 to +3.2) after 2–7 days (strain B). There was little evidence that spores are more resistant to fungicides at their optimum temperature for germination, i.e. the temperature at which maximum germination is reached soonest (15–20° C. for B. fabae ). Mercuric cyanide, chloride and bromide, which are scarcely ionized in aqueous solution, also resembled non‐electrolytes in that the sizes of their positive temperature coefficients were inversely related to their solvent: water partition coefficients, i.e. the temperature coefficients increased with decrease in the presumed rates at which lipoid membranes are penetrated by diffusion. This correlation did not extend to other compounds.