(Updates with closing prices)
CHICAGO, June 1 (Reuters) - Chicago Board of Trade soft red winter wheat futures and K.C. hard red winter futures dropped to two-week lows on Thursday as forecasts for dry conditions in key growing areas raised the prospect of a quick start to harvest for both crops.
"We have got a little bit drier forecast," said Brian Hoops, an analyst with Midwest Marketing Solutions. "We are anticipating that harvest pressure."
But the dryness lent support to MGEX spring wheat futures, which firmed to a 4-1/2-month high on concerns about crop development in the northern U.S. Plains.
Corn and soybean futures fell amid expectations that recently seeded fields will begin to dry out in the coming days, fostering crop emergence and allowing some growers to replant parts of fields that were flooded.
"I think the trade is ready to engage the idea that the seed is going to get in the ground," said Bill Gentry, a broker at Risk Management Commodities.
CBOT July soft red winter wheat futures ended down 1/4 cent at $4.29 a bushel. The contract hit a session low of $4.21-1/4, its weakest since May 18. K.C. hard red winter wheat for July delivery settled 1 cent lower at $4.30-3/4 a bushel. It bottomed out at $4.24-1/4, also the lowest since May 18.
Traders noted bargain buying when the winter wheat contracts hit session lows.
MGEX July spring wheat futures closed up 6-3/4 cents at $5.78-3/4 a bushel. The front-month MGEX contract peaked at $5.79-1/2, its highest since Jan. 19.
The weekly U.S. Drought Monitor update issued on Thursday showed drought/dry conditions expanding remarkably in North Dakota.
It rated 99.9 percent of the state "abnormally dry," up from 43.6 percent a week earlier. Additionally, 24 percent of the state is in "moderate drought," up from 6 percent a week earlier.
CBOT July corn futures were 1-1/2 cents lower at $3.70-1/2 a bushel, and CBOT July soybeans were down 3-3/4 cents at $9.12-1/4 a bushel.
Declines in soybeans were limited by worries about a labor-related slowdown in South American export shipments.
Argentina's government replaced striking sanitary inspection workers in the main agricultural port of Rosario, allowing shipments to resume albeit with delays after the job action halted exports from there on Wednesday. (Additional reporting by Julie Ingwersen in Chicago; Editing by W Simon and Leslie Adler)