CHICAGO: Chicago corn futures surged nearly 4% on Tuesday after the US Department of Agriculture reported that American farmers planted 92 million acres of corn this spring, a figure that fell below a range of analyst expectations.

Soyabean futures rose after the USDA put US plantings at 83.8 million acres, up a bit from its March forecast but below most analyst expectations.

Chicago Board of Trade September corn was up 12-3/4 cents at $3.41-1/2 a bushel, its biggest jump since May 28, 2019, after reaching $3.45-3/4 a bushel.

CBOT August soyabeans added 17-1/4 cents to $8.78-3/4 per bushel, while CBOT September wheat was up 5-1/4 cents at $4.91-3/4 a bushel.

The USDA's corn planting figure was about 5 million acres below its March 31 forecast of 97 million acres, the biggest March-to-June drop since 1983.

"Corn acres were well below expectations. Producers moved into spring with a bearish market and lots of uncertainty," said Brian Basting, analyst with Advance Trading. "We really did not see much of a transition of those acres over to soyabeans, which were only up 300,000 from March. It's a bit of a mystery."

US June 1 corn stocks were larger than anticipated, with 5.224 billion bushels in storage, topping a range of trade expectations. Soyabean stocks at 1.392 billion bushels were in line with expectations but down 400 million bushels from a year ago.

"The stocks report was actually a little bit negative, but nobody cared because the plantings report was so dramatically positive," said Jack Scoville of Price Futures Group.

The smaller-than-expected plantings figures for both corn and soyabeans offset pressure from favorable weather that has bolstered crop production expectations heading into July.

After Monday's close, the USDA rated 73% of US corn in good-to-excellent condition, up from 72% last week, while 71% of US soyabeans are in a good-to-excellent state, against 70% last week.