CHICAGO (AP) _ Grain futures were lower Tuesday on the Chicago Board of Trade. Sept. corn fell by 1.25 cents at $5.12 a bushel. Sept. wheat was down 2 cents at $7.28 a bushel. Sept. oats was off 12.5 cents at $3.44 a bushel. Sept. soybeans lost 0.25 cent at $12.98 a bushel. Beef was...