Effect Of Different Fungicides Against Phytophthora Infestans (Mont) De Bary Causing Late Blight Of Potato

The aim of this experiment is Evaluation of various fungicides and their effectiveness at different doses against Phytophthorainfestans, the causal pathogen of late blight disease of potato. For the study of design Descriptive statistics was used and each treatment was replicated thrice by using complete randomize design. The experiment was conducted in Department of Plant Pathology, CSA University of Agriculture &Technology, Kanpur, Uttar Pradesh, India in November 2016. In this we use “Food Poison Technique” (1) to find out the relative efficacy of various fungicides in inhibiting the growth of pathogen. A small piece of infected leaf from border of sporulating lesion along with some healthy green tissue was cut and Sterilized. These small pieces were then placed on Pimaricin, Ampicillin and Rifampicin media (PAR media) which was previously poured in sterilized Petri plates. As soon as the mycelia growth is noticedaround the bits, the pathogen was purified by hyphal tip culture method. Mycelial bits of 5 mm from the pure culture were placed on the tomato extract media which was incorporated with various fungicides at different doses. In this we use five different fungicides among these Acrobat inhibited the mycelial growth upto 99.2% over the control at 300 ppm concentration followed by 98.44% inhibition at 300 ppm concentration mancozeb at 3500 ppm concentration inhibited the radial growth upto75.48% followed by 71.15% inhibition at 3000 ppm concentration. By this we concluded that this method can be used for analysing the efficacy of various fungicides against different pathogens within a very short period of time.