No abstract

Leaf blight of potato and tomato caused by Alternaria solani is an important fungal disease that causes heavy loss to the growers. In case of suitable conditions the pathogen causes maximum damage to these vegetable crops and even the fruits of tomato are also attacked by the pathogen. In the present study the pathogens was isolated and pure culture was maintained on Potato Dextrose Agar medium. In vitro experiments were done to evaluate the fungitoxic effects of three different concentrations of 7 selected fungicides as well as leaf extracts of 7 different plants extracts separately. Among the fungicides, 100 inhibition was found when 2000 ppm of Difenconazole, Propinconazole and Benomyl was used. Diphenconazole and Propinconazole even at 1000 ppm, completely inhibited the mycelial growth of the pathogen in vitro. Lowest percentage of inhibition of mycelial growth was found in case of copper hydroxide. Even at 2000 ppm the percentage of inhibition was 68.72 only. Similarly, Thiophenate at 2000 ppm could inhibit the mycelial growth that was 78.85 only. Among the phytoextracts, leaf extract of Acasia nilotica at 30 inhibited 84.74 of mycelial growth, which was followed by the extract taken from the cloves of Allium sativa. At 30 the percentage of inhibition was 81.65. This was followed by the percentage of inhibition by leaf extract of Azadirachta indica, which were 78.54 at 30. Minimum inhibition at 30 of leaf extract of Phyllanthus niruri was 68.66. In the present work it was noted that mycelial growth was inhibited at all the concentrations of the seven fungicides and leaf extracts of all the plants with different percentages of inhibition.