Areolate mildew, caused by the fungus Ramularia gossypii (Speg.) Cif., is the most important foliar disease on cotton. There are a few products available to the growers to manage this disease among them the fungicides tryazol and strobilurine. This study aimed to evaluate the effect of foliar application of potassium silicate, 'calda Viçosa' e protector fungicides (Mancozeb and Clorothalonyl) to control areolate mildew on cotton. The potassium silicate was not efficient to control the disease with severity of 15.38%, canopy quality at 166 days after plant emergence of 38.19%, yield of 2041.65 kg ha-1 and area under areolate mildew progress curve of 644, 598 and 172 at the lower, medium and higher canoy, respectively, with these all values being similar to the check treatment (no fungicide applied). The treatment with 'Calda Viçosa' gave the best disease control and did not differ from the treatments with Pyraclostrobin or Tebuconazole in terms of yield, but showed an increase of 88% in yield compared to the check treatment. The fungicides Mancozeb and Clorothalonyl mixed with 'Calda Viçosa' or with Tebuconazole were efficient to control the disease, especially the mixture of Mancozeb with Tebuconazole.
plant nutrition; silicon; Ramularia gossypii
