Marigold (Tagets erecta) is one of the most important major floriculture crop in India. The leaf blight of marigold is caused by Alternaria tagetica is becoming a common disease on marigold Alternaria blight appeared in mild to severe form in many regions of Maharashtra and sometimes resulting in complete failure of the crop especially during rainy season. The fungal pathogen are greatly influenced by environmental factor therefore the present work undertaken to study the effect of temperature and pH on growth of Alternaria tagetica. The effect of temperature and pH were determined by colony diameter method by using different media like potato dextrose agar and oat meal agar medium. It is clearly evident from the result that all the temperature pH tested showed variation in the diameter of colony. The temperature 25oC encouraged better growth of Alternaria tagetica as compared to 15oC and 35oC. The result also revealed that pH 6 and 7 encouraged better growth of Alternaria tagetica it is concluded from the result that temperature 25oC and pH 6 is optimum temperature and pH for the growth Alternaria tagetica.

The present study is aimed at examining the effect of pesticides viz, fungicides, insecticides, herbicides and antibiotics on Pseudomonas fluorescens to see its tolerance level against these pesticides. Herbicides were found most adaptive to Pseudomonas fluorescens as compared to fungicides, insecticides and antibiotics. Tolerance level was found high in Pseudomonas fluorescens against Spinosad @ 0.04 % (9.02 × 10 8 cfu/ml) and Imidacloprid @ 0.02 % (5.82 × 10 8 cfu/ml). P.fluorescens was found less sensitive to Thiram @ 0.2 % (2.15 × 10 8 cfu/ml), Benomyl @ 0.3 % (1.63 × 10 8 cfu/ml) and Carbendazim @ 0.1 % (1.38 × 10 8 cfu/ml). However, it tolerated the toxicity of Pendamethalin up to 0.4 % concentration. Although bacterium was adaptive to herbicides, it was found highly sensitive to antibiotics Streptomycin alone and also in combination with Tetracycline @ 0.01 % concentration.

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Marigold (Tagets erecta) is one of the most important major floriculture crop in India. The leaf blight of marigold is caused by Alternaria tagetica is becoming a common disease on marigold Alternaria blight appeared in mild to severe form in many regions of Maharashtra and sometimes resulting in complete failure of the crop especially during rainy season. The fungal pathogen are greatly influenced by environmental factor therefore the present work undertaken to study the effect of temperature and pH on growth of Alternaria tagetica. The effect of temperature and pH were determined by colony diameter method by using different media like potato dextrose agar and oat meal agar medium. It is clearly evident from the result that all the temperature pH tested showed variation in the diameter of colony. The temperature 25oC encouraged better growth of Alternaria tagetica as compared to 15oC and 35oC. The result also revealed that pH 6 and 7 encouraged better growth of Alternaria tagetica it is concluded from the result that temperature 25oC and pH 6 is optimum temperature and pH for the growth Alternaria tagetica.