For the second year in a row, California outranked traditional Midwest leaders, according to the Agriculture Department. The estimated value of California commodities exported in the fiscal year that ended last Sept. 30 was about $2.4 billion. It was a year that saw overall U.S. farm exports drop to $26.3 billion. In 1984-85, California was first with $2.7 billion out of a U.S. total of $31.2 billion. Illinois displaced Iowa for the No. 2 spot, reducing Iowa to third place last year.