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1 - To determine the effect of 5 fungicides (benomyl,tricyclazole, Mancozeb,Edifenphos, and Carbendazim)on control of rice blast disease,the experiments was run on a susceptible rice cultivare, Musa-tarum in a Split plot design in one (at tillering stage)& 2 times spraying (at tillering stage and heading) with 4 replications. The experiment was performed in rice research station of Amol during the summer of 1986. Fungicides were sprayed at a concentration of
0.2%.
Among the fungicides tested,tricyclazole significantly reduced neck blast incidence than the others. The blast in 2 times applications were less than the once.
2 - In another experiment,tricyclazole was sprayed on the plants of half plots of 6 planting dates at near tillering stage. The severity of the leaf blast (number of the spots on the leaves X)reduced as the growth increased (ages of the plants Y). The neck blast in the fourth date of planting were less than the others. The effect of spraying on the disease and interaction (Sprayingx date of planting) were not significantly difference,Log y=4.288-0.04X ,
R=-0.917.