Field and In vitro Study of Pronos and Dormulin against Downy Mildew and Powdery Mildew Diseases of Grape

Abstract

Downy mildew and powdery mildew are destructive diseases of grapes which require application of fungicides. Fungicides are expensive and cause ecological contamination and resistance. Pronos and Dormulin are 'Multi nutrient fertilizers' which were evaluated against the diseases. The field experiments were conducted against powdery mildew (Sangli, Maharashtra) and downy mildew (Theni, Tamil Nadu) in grapes. In vitro experiment against downy mildew conducted at ICAR-National Research Centre for Grapes laboratory. In vitro study comprised of 12 treatments. In the case of downy mildew, a field experiment was set with 7 treatments. The foliar application of Dormulin flowering @ 5 g/L of water, and Pronos @ 1.5 g/L of water recorded the lowest percent disease index on leaves, and they were at par with Dormulin (vegetative) followed by 3 sprays of Dormulin (flowering) @ 5 g/L ofwater. In the case of powdery mildew, experiment was set with 10 treatments. On leaves, Pronos (curative) and Pronos (Prophylactic) @ 1.5 g/L of water and Dormulin 1 flowering (curative) @ 5 g/L of water showed the lowest percent disease index on leaves than the untreated control. Therefore, Dormulin flowering @ 5 g/L and Pronos @ 1.5 g/L for downy mildew and Pronos (curative) and Pronos (Prophylactic) @ 1.5 g/L water and Dormulin 1 flowering (curative) @ 5 g/L for powdery mildew were claimed to be effective for controlling diseases. In vitro study showed that Dimethomorph at 1g/L of water was found to be superior over all the treatments with high disease suppression followed by Pronos @1.5gm/L, Dormulin-V1- Flowering grade, and Dormulin-V2- Flowering grade @ 10g/L with slight sporulation. Marketable yield was significantly higher with Pronos (curative) which was on par with Dormulin application as compared to control and fungicide treatment. Use of mineral nutrients in an appropriate proportion is one of the new approaches for plant disease management.