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CHICAGO, May 22 (Reuters) - Chicago Board of Trade corn and soybean futures rose on Monday morning, supported by concerns that rain will delay field work in key growing areas and may damage some recently seeded crops, traders said.
"Grain futures are trying to start the week higher across the board following a soggy weekend across most of the Midwest," Farm Futures senior analyst Bryce Knorr said in a note to clients.
Corn futures hit their highest in three weeks.
Wheat futures also rose, with concerns about excessive moisture in the central U.S. Plains threatening crop yields in that area ahead of harvest.
Persistent weakness of the dollar, which touched a six-month low against a basket of currencies, also underpinned U.S. futures, although large U.S. and global grain inventories continued to cap prices.
At 10:42 a.m. CDT (1542 GMT), CBOT July corn futures were up 4-1/2 cents at $3.77. Corn reached its highest since May 2. Soybean futures for July delivery were 5-1/2 cents higher at $9.58-1/2 a bushel.
"Bad weather is continuing to delay U.S. planting of corn and soybeans," said Kaname Gokon from Tokyo brokerage Okato Shoji. "There is lot of rain and cold weather in the Midwest."
Traders will get an indication of crop conditions, as well how much has been planted, after the market close on Monday, when the U.S. Department of Agriculture issues its weekly crop progress report.
Corn in some areas of the Midwest will need reseeding because of flooding and poor crop emergence, and may have missed the optimal planting window, while late soybean planting was being slowed by showers.
Rainfall has also caused concern about winter wheat in the run-up to harvesting.
Forecasts called for unfavorably wet weather in the central Plains hard red wheat zone in the next two weeks, but more limited rain prospects in the southern Plains could help harvesting, the Commodity Weather Group said in a daily note.
CBOT July soft red winter wheat, which rose to its highest since May 5, was up 6-1/2 cents at $4.41-3/4 a bushel. (Additional reporting by Naveen Thukral in Singapore and Gus Trompiz in Paris; Editing by David Evans and Steve Orlofsky)