Effect of seed treatment with organic acids on the control of common bunt (Tilletia tritici and T. laevis) in wheat.

Common bunt caused by Tilletia tritici and T. laevis is an important disease, causes considerable losses in wheat yield on a world wild. The disease reduces yields, complicates harvesting and lowers the quality of the grain. It occurs more frequently and causes greater damage on winter wheat than on spring wheat. Grain standards designate wheat that has an unmistakable odor of smut or that contains smut balls, portions of balls, or spores of smut in excess of a quantity equal to 14 balls of average size in 250 g of wheat as "light smutty". Samples containing an excess of 30 balls, or their equivalent, in 250 g of wheat are graded as "smutty". Grain in these grades brings lower prices. Using commercial acetic acid and lactic acid, the pathogen was successfully controlled, but the treatment negatively affected seed germination and seedling vitality. Using dilutions of acetic acid and lactic acid, significant control of the pathogen also was achieved with acetic acid without causing phytotoxicity. Dilutions of lactic acid also gave good control, but showed some phytotoxicity. Using 30-50 ml/kg of vinegar, which is a natural source of acetic acid, proved to be one of the most effective alternatives for control of common bunt on wheat. The treatment had no negative effects on seed germination nor on seedling vitality.