The US Agriculture Department will release its monthly supply and demand report at 11:00 a.m. CDT (1600 GMT).
WHEAT - Down 5 to 8 cents per bushel
* Wheat futures under pressure from USDA report released on Monday afternoon that showed 60 percent of the US winter wheat crop was in good to excellent condition, up from 56 percent a week earlier and above the high end of a range of analysts' expectations.
* Benchmark Chicago Board of Trade May soft red winter wheat futures contract dropped below its 30-day moving average during overnight trading. The contract ended overnight trading just above its session low.
* CBOT May wheat last traded down 7 cents at $4.58-1/4 per bushel. K.C. May hard red winter wheat was down 6-1/4 cents at $4.25-1/4 a bushel and MGEX May spring wheat was down 1 cent at $5.23 a bushel.
CORN - Down 1 to 3 cents per bushel
* Corn futures hit lowest since April 1 during overnight trading session. Weakness in wheat weighs on the corn market.
* Declines in corn kept in check by cold and wet soil conditions, forecasts for more rain that could delay spring plantings.
* CBOT May corn last traded down 1-1/2 cents at $3.58-1/2 per bushel.
SOYBEANS - Steady to up 2 cents per bushel
* Muted moves expected ahead of USDA report. Market underpinned by optimism about potential trade deal with China, although traders say details needed before market can rally.
* CBOT May soybean futures ended overnight trading just off its session high. The contract hit resistance at its 20-day moving average.
* CBOT May soybeans last traded up 1-1/4 cents at $9.00 a bushel.