Physiological parameters influences mycelium growth and sporangium production of phytophthora infestans

Optimum growth and sporangia production by Phytophthora infestans occurred on Rye Agar Media followed by on Oatmeal agar, whereas Tomato agar, Carrot agar and Onion agar showed less linear growth and sporulation after 7 days per inoculation. P. infestans was incubated at various temperature ranged from 10°C to 35°C. Maximum growth was recorded at 25°C but production of sporangia was high at ±18°C. Growth and sporangium formation is more sensitive to high temperature as compared to low temperature. Optimum pH for growth was recorded at 6, while growth decreases as the pH fluctuated from optimum range. Sporangia were produced maximum at both pH 6 and 7. It is apparent from the present investigation that mycelium growth and sporangia production of P. infestans were directly influenced by physiological factors.