Chicago wheat slid on Thursday as the market took a breather after the previous session's strong gains, although the decline was limited by concerns over U.S. yields and adverse weather in some of the key exporting countries.
Corn gained ground on worries about dryness in parts of the U.S. Midwest, while soybeans ticked higher.
Disappointing early spring wheat yields in Russia and continued dryness in Canadian spring areas could result in tighter global supplies, commodities research firm Hightower said in a report.
"In a switch from recent market movements, wheat may begin to lead corn higher rather than simply being a follower."
The most-active wheat contract on the Chicago Board of Trade (CBOT) Wv1 fell 1.2% to $6.66-3/4 a bushel, as of 0427 GMT. Soybeans Sv1 added a quarter of a cent to $13.55-1/4 a bushel and corn Cv1gained 0.4% at 4.95-1/2 a bushel.
Wheat jumped more than 5% on Wednesday after the U.S. Department of Agriculture (USDA) said just 37% of the winter crop was harvested as of Sunday, versus 52% last year. The agency also unexpectedly cut its spring wheat rating as rains failed to improve conditions.
The USDA rated 51% of U.S. corn in good-to-excellent condition, up a point from the prior week. Soybean conditions, however, fell by a point.
Ratings for both crops have been declining for several weeks due to an expanding Midwest drought.
A reduced chance of a "very strong" version of the El Niño weather phenomenon later this year should offer some relief to agricultural producers in Argentina, the Rosario Stock Exchange said on Wednesday.
Commodity funds were net buyers of CBOT wheat, corn, soybean and soyoil futures contracts on Wednesday, and net sellers of soymeal futures, traders said.