chlorothalonil

noun

chlo·​ro·​thal·​o·​nil ˌklȯr-ə-ˈtha-lə-ˌnil 

: an organochlorine fungicide C₈Cl₄N₂ that protects against a wide range of fungal diseases and is used especially on agricultural crops (such as peanuts and tomatoes)

And, although chlorothalonil is an excellent home garden fungicide, and oil sprays are highly effective against mites and other soft-bodied insects, the two are not compatible and cannot be combined or used within several days of each other.

—H. S. Stevens, Dallas Morning News, 28 May 1999

… one of the most widely used fungicides on crops in the United States, chlorothalonil, raises mortality rates among frog tadpoles at low concentrations.

—Susan Milius, Science News, 11 Sept. 2010

Word History

First Known Use

1973, in the meaning defined above

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