Inside Report (5)

Hey, comrade! There's fungus in my wheat!

Moscow has stopped buying US wheat after noting what a Soviet official termed ''fungus and impurities'' in a sample batch from this year's crop. The Soviets, trying to cope with their fourth disappointing domestic harvest in a row, have continued to buy US corn. The Americans acknowledge the presence of a small percentage of wheat affected by fungus in this year's crop from two US states, but US sources add that the great majority of the wheat is fine.

News reports in the past 10 days speak of a large Soviet purchase of Canadian wheat and a smaller deal with the French.