Comparison the Effect of Some Fungicides in Control of Gray Mould on Tomato in Greenhouses

Bara’a Mhrez
General Commission for Scientific Agricultural Research-
Lattakia Research Center
Tishreen University, Faculty of Agriculture
 2007

Abstract

Botrytis cinerea (pers.fr) was isolated from infected tomato of various greenhouses in the Syrian coast. Thirteen isolates were examined for their sensitivity to some fungicides that are used to control gray mold on tomato (carbendazim, pyrimethanil, diethofencarb, procymidon) and the mixture of (cyprodinil+fludioxonil).
The results showed that all isolates were sensitive to the mixture of (cyprodinil + fludioxonil), and there were high rate of isolates that were sensitive to procymidone which had not the growth hyphe at  100.0 ppm.
For pyrimethanil, most isolates  were sensitive to it with one which isolate has mean sensitivity to pyrimethanil. Isolates showed high resistance to diethofenocarb with little rate sensitivity, and there were resistant isolates for diethofencarb that were sensetive to carbendazim.
In vitro, the mixtures didnt give good result, but the mixture (cyprodinil + fludioxonil) gives clear result as compared to every substance used alone.
For germination of spores, the mixture (cyprodinil + fludioxonil) was the most efficient on spore germination, which had critical inhibition at 10.0, 100.0 ppm. At the second, was procymidon with effect for all isolates, and pyrimethanil had inhibition only two isolates, but carbendazim had not clear effect on spore germination.
Microscopic studies showed that no differences of shape between isolates which had got (length of conidophore, spores Sclerotia, the shape of colonies and their colors). Electrophoresis showed that there were different isolates, so there were five strains.
In field, the mixture (cyprodinil + fludioxonil) was the most efficient, followed by mixture (carbendazim + diethofenocarb).There were differences in the results of the mixtures between in vivo and in vitro.