Alternaria alternata isolated from the infected fruit of Lagenaria, (bottle gourd) was used as the test pathogen to determine the
impact of selected contact and systemic fungicides on its mycelial growth in vitro. The contract fungicides used were Blitox-50, Thiram,
Captan 50 WP, while the systemic fungicides were chlorothalonil, carbendazim 50% (Bavistin) and Mancozeb. Maximum inhibition of
mycelial growth of the aforesaid phytopathogenic fungus was observed in culture which was treated with 0.25% of Mancozeb, followed
by carbendazim 50 WV. Similarly, Captan 50 WP gave better response in comparison to the Thiram and Blitox-50 at the similar
concentrations. It was further observed that Blitox-50 was the least effective among the contact fungicides used here. It was further
observed that sporulation of the fungus was equally affected by the same fungicides which were effective on mycelial growth. Here also
the efficacy of Mancozeb was better than that of the other fungicides while the impact of Blitox-50 was the lowest.