Department of Plant Pathology, Punjab Agricultural University, Ludhiana-141004
National Symposium on “Plant Pathology in the Changing Global Scenario” held at National Bureau of Plant Genetic Resources, New Delhi on February 27–28, 2009
In an attempt to find a suitable alternative to the otherwise perilous chemical control strategy of disease management, seven different resistance inducer salts were evaluated for their efficacy to elicit resistance in cauliflower (Brassica oleracea L. var. botrytis subvar cauliflora) against downy mildew (DM) disease caused by Peronospora parasitica. To achieve this, a dose response analysis was conducted and concentrations of seven chemical salts viz., NH4H2PO4, KH2PO4, K2HPO4, KOH, H3PO3, K2SO4 and SA at 0.5, 1.0, 2.0 and 4.0 ml/l were tested on one month old seedlings using the spray method. In a glass house experiment, the protection achieved was in the order K2HPO4 > K2SO4 > KH2PO4 > NH4H2PO4 > Salicylic Acid > H3PO3 >KOH. Studies revealed that the protection was maximum up to three days of treatment but diluted with time, till 15 days. The minimum lesion size (2.54 mm) was recorded in the case of K2HPO4 as compared to control (12.17 p.s.i.). These salt solutions, at the dose tested were not phytotoxic to cauliflower foliage.
