Abstract:The studies revealed that
A.
solani were found responsible for causing early blight of tomato. The morphological characteristics of
Alternaria solani were studied. The mycelium width about 2.97 to 4.19 µm and the length of conidia was about 150 to 300 µm and 14 to 18 µm thickness. The conidia were having long and thick beak. The research studies revealed that all the ten culture media tested, encouraged better growth of
A.
solani. The different cultural media
viz., PDA, Oat Meal agar were most suitable media for
A.
solani and exhibited maximum radial mycelial growth i.e., 83.67 mm and 62.67 mm respectively.
In vitro assessment of chitosan against Alternaria solani on PDA showed most promising results. Chitosan @ 500 ppm inhibited highest mycelial growth whereas minimum mycelial growth inhibition was found at 50 ppm concentration. Increase in concentration of chitosan increases mycelial growth inhibition of test pathogen.