Effect on Zoospores and Mycelium Growth of P. infestans

Fluopicolide induced dramatic symptoms on P. infestans zoospores. They stopped swimming within a minute after being treated at concentration as low as 

1 xg mL . Then the zoospores swelled and burst in a few minutes (Fig. 19.2). Fluopicolide strongly inhibited in vitro the mycelium growth of P. infestans. A 80% growth inhibition was observed at a concentration as low as 0.1 pg mL over 4 to 7 days. Distinctive symptoms were also observed on treated mycelium (Fig. 19.3). There was evidence of leakage of cellular content after the staining of treated hyphae with Blue Trypan. This showed that fluopicolide also induced mycelium lysis, preferentially observed at the apex of the hyphae. 

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