Management of powdery mildew in polyhouse tomato with organic inputs

Tomato, one of the important crops under protected cultivation is affected by various fungal and bacterial pathogens, of which powdery mildew is one of the serious problems of tomato crop. Although various chemicals have been recommended for spray against powdery mildew but due to their hazardous effects their use in organic farming is not allowed. Other environment friendly alternative methods based on the natural source of sulfur are required. In literature, the role of milk, asafoetida and plants rich in sulfur like onion, garlic and brassica crops have been well documented. Therefore, nine organic inputs/treatments viz., T₁-cow milk (1%), T₂-cow milk (10%), T₃- cow milk (10%) +asafoetida (1%), T₄-sulfur (1%), T₅- cow milk (10%) +sulfur (1%), T₆-garlic and onion extract(10%), T₇-fermented leaves of Brassica oleracea var. acephala(Kale) in cow urine (10%), T₈-sulfur water from Manikarn Hot Springs and T₉-contol were evaluated against this disease in three genotypes of tomato viz., Hawaii, Palam Pride and 12-1 under polyhouse conditions in the Department of Organic Agriculture, CSKHPKV, Palampur during April to July, 2011. The sprays were repeated at weekly interval. None of the treatment could fully control the disease. However, among these, T₄ provided minimum disease severity in all the three varieties with disease severity ranged between 5 to 8% followed by T3 (10 to 15%) and T2 (15 to 25%) in comparison to control. Rest of the treatments were intermediate in disease management.