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Efficiency of fungicides in wheat blast control

Wheat blast, caused by the fungus Pyricularia grisea, constitutes one of the major obstacles to the expansion of wheat production in Central Brazil. The aim of this study was to evaluate the efficiency of fungicides in the control of wheat blast. Three fungicides with different active ingredients and combined with four wheat genotypes were used. Two applications of the commercial product were performed in stages 45 and 65 of the scale of Zadoks et al. Artificial inoculation with P. grisea spores was done in stages 58-60 of the above-mentioned scale. The area under the disease progress curve (AUDPC), the severity on flag leaves (SEVFL) and the severity on spikes (SEVEsp) were determined, and grain yield (GY) was quantified. At the end of the experiment, different analyzed parameters were subjected to Pearson's correlation analysis. The fungicides epoxiconazole+pyraclostrobin and tebuconazole+trifloxystrobin provided the lowest AUDPC for the genotypes VI 03061, VI 07505 and BRS 254. There was no difference for SEVFL among genotypes in the presence of fungicides. The genotypes VI 98053 and VI 07505 showed the lowest SEVFL in the absence of fungicide. Tebuconazole+trifloxystrobin provided higher GY and lower SEVEsp. The disease severity on the ears was greater than on flag leaves. Control of wheat blast by means of fungicide application was effective for flag leaves but not for ears.

Triticum aestivum; Pyricularia grisea; chemical control


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