This year's corn crop is growing rapidly, leading to a drop in corn prices.

U.S. corn futures tumbled more than 2 percent on Monday to the lowest point in almost four years as largely ideal crop development weather around the Midwest reinforced expectations for a record-large harvest this autumn.

Soybeans slid more than 1 percent to five-month lows on good crop weather. Chicago Board of Trade wheat slumped more than 3 percent to the lowest since 2010, pressured by adequate global supplies.

Fund long liquidations dragged all corn contracts to fresh contract lows as trading resumed after the long U.S. Independence Day holiday weekend.

“Corn is lower as weather conditions continue to be superb over the vast preponderance of the growing area,” said Sterling Smith, analyst at Citigroup.

Plentiful soil moisture and warm weather throughout much of the Midwest posed little threat to the developing corn and soybean crops. Corn is entering its critical pollination stage of development this month.

“We will probably be looking at weather that will be ideal for pollination,” Smith said.

Weekly crop condition ratings were expected to hold steady with the U.S. corn crop in the best shape in 15 years and soybeans seen at their best in 20 years, analysts said on Monday.

CBOT July corn was down 2.8 percent, at $4.05-3/4 per bushel near midday, the lowest level for a spot contract since August 2010.

Actively traded December corn fell 2.8 percent, to $4.03-3/4 a bushel. CBOT July soybeans dropped 2 percent, to $13.60-1/2 a bushel, while new-crop November futures shed 1.1 percent, to $11.21-1/4 per bushel. Both were at levels not seen since February.

Wheat prices slumped despite worries about new-crop quality following adverse weather this spring. Global stocks are ample and most major producing countries are currently harvesting large crops.