Studies on black spot of rose caused by Diplocarpon rosae wolf

Among different fungicides tested Carbendazim (0.1%), Thiophanate methyl (0.1%), Propiconazole (0.05%), Chlorothalonil (0.1%) and Myclobutanil (0.05%), completely inhibited the growth of the test fungus. Under field conditions, the treatment comprising of Potash application + Thiophanate methyl spray was most effective in managing black spot disease of rose. Among nine varieties tested under natural conditions five rose varieties viz., Superstar, Juley, Biambero, Madam President and Peter Franken Felt were moderately resistant while Folklore and Feriporch were susceptible to black spot. The varieties Sophia Lorens and Paradise were highly susceptible to black spot. The lowest disease incidence (15.46%) was recorded in Superstar where as the highest disease incidence (81.33%) was observed in Sophia Lorens.