CHICAGO, May 17 (Xinhua) -- Chicago Board of Trade (CBOT) agricultural futures closed mixed on Tuesday, with corn dropping and wheat and soybean rising.

       The most active corn contract for July delivery fell 8.75 cents, or 1.08 percent, to settle at 8.0075 U.S. dollars per bushel. July wheat soared 30 cents, or 2.4 percent, to settle at 12.775 dollars per bushel. July soybean rose 21.5 cents, or 1.3 percent, to settle at 16.78 dollars per bushel.

       Wheat surged to newer highs on global weather threats while corn struggled amid improved Midwest planting weather and lack of new export news.

       Chicago-based research company AgResource strongly doubts an intermediate top will be scored unless favorable Midwest summer weather can be confirmed in the next 30-45 days.

       Weather continues to threaten Northern Hemisphere wheat production. There is not much precipitation offered to the U.S. Southern and Western Plains into the opening days of June. Nor is there any sign that abnormal heat will abate for any lasting period.

       Firm Brazilian corn prices along with surging global rapeseed and wheat markets indicate there are few alternatives to U.S. corn and soybean supplies available for importers in the long run.

       It will be much wetter in the eastern half of the United States beginning late next week, as forecast features a fairly potent tropical storm working into the eastern Gulf on May 27-28. Otherwise, meaningful rainfall into May 22 will be confined to a narrow swath encompassing Missouri, southern Illinois, Indiana and Ohio.