Chicago wheat gained more ground on Monday to hit its highest since early January, as an escalating war between Russia and Ukraine threatened to curb supplies from the Black Sea region.
Soybeans jumped to a seven-month high on worries about dryness in Argentina and excessive rains in Brazil.
"Increased concerns about the Black Sea region and the impact on exports and production from the region due to escalating tensions between Russia and Ukraine late last week helped to support the market," Hightower said in a report.
"The market has become accustomed to aggressive exports from the Black Sea region, so if the situation changes in the future, exportable surplus could tighten."
Chicago Board of Trade
The most-active Chicago Board of Trade (CBOT) wheat contract Wv1 was up 0.1% at $7.87 a bushel, as of 0451 GMT, after climbing earlier in the session to $7.91 a bushel, its highest since the early days of the year.
Soybeans Sv1 rose 0.3% to $15.46-1/2 a bushel, having earlier jumped to $15.53 a bushel - the highest since June, while corn Cv1 gave up 0.3% to 6.78-3/4 a bushel.
Russian missiles hit power facilities on Friday across Ukraine, where President Volodymyr Zelenskiy returned from a tour of Western capitals and Ukrainian officials said a long-awaited Russian offensive was underway in the east.
The escalation is putting at risk the U.N.-backed grain deal which allows grain shipments from Russia and Ukraine.
Ukraine's agriculture ministry has proposed increasing the minimal tonnage of ships which carry grain and vegetable oil from the country via a grain corridor, aiming to boost exports despite opposition from Russia.
Russia's ambassador to the United Nations said Moscow had not been able to export any grain as part of the Black Sea grain deal.
Corn and soybean traders are monitoring forecasts projecting rains in Argentina in the coming days, though showers may miss some drought-stricken crop belts.
Expectations of a record soybean crop in Brazil have tempered worries over Argentine losses, but heavy rains there threatened to delay the harvest and push seeding of the country's safrinha corn crop beyond the ideal time frame.
Commodity funds were net buyers of CBOT soybean, corn, wheat, soy oil and soymeal futures contracts on Friday, traders said.
News by Reuters, edited by Donna Ahern, Checkout. For more supply chain stories, click here. Click subscribe to sign up for the Checkout print edition.