MANAGEMENT OF POWDERY MILDEW DISEASE OF BOTTLE GOURD (Lagenaria siceraria) USING POTASSIUM AND SULPHUR CONTAINING MODERN PHYTO-CHEMICALS

Abstract

ABSTRACT Powdery mildew of bottle gourd is one of the important disease responsible for lower yield of bottle gourd in many countries. Management of powdery mildew disease is required to maintain the quality and quantity of the fruit. Different management approaches have been led to control the disease. In this experiment, we evaluated silica and salicylic acid-based fungicide, Peak Performance Nutrient (PPN), Potassium silicate, Phosphorus silicate and sulphur-based fungicide (McSulphur 80 WP) against control. The experiment was conducted from November 2019 to May 2020. BARI Lau-4 variety was selected for the present experiment. In the present POinvestigation the highest reduction of disease incidence (36.89%) was recorded by the application of potassium silicate (T₂). The nearest reduction of disease incidence was found in Peak Performance Nutrient (T₅) (24.18%) followed by Silica (T₁) (20.49%) and Phosphorus silicate (T₃) (20.08%). At 107 days after transplanting, the PDI (Percent Disease Index) values were observed and it was found that the maximum PDI was calculated from the control (64.17%). At 107 DAT, potassium silicate (T₂) showed the highest performance (60.52%) in reduction of disease severity. The second highest reduction of disease severity was recorded in case of Peak Performance Nutrient (T₅) (38.06%) followed by Silica (T₁) (31.82%), Phosphorus silicate (T₃) (30.74%), McSulphur 80 WP (T₆) (21.04%) and Salicylic acid (T₄) (3.90%). The maximum number of fruit (10.00) was recorded from application of potassium silicate (T₂) followed by McSulphur 80 WP (T₆) (9.67) and Silica (T₁) (8.33). In case of weight, the maximum average weight of bottle gourd fruit (2.52 kg) was recorded from application of potassium silicate (T₂) followed by McSulphur 80 WP (T₆) (1.99), Phosphorus silicate (T₃) (1.87 kg) and Peak Performance Nutrient (T₅) (1.85). Potassium silicate (K₂SiO₃) was found effective against powdery mildew disease of bottle gourd. It also gave the best result in giving large sized and heaviest fruits. Potassium silicate may be used as an alternative of ‘sulphur containing fungicide’.