CBOT September soyabeans rose as high as $17.80¾ per bushel, up 1 per cent on the day and beating a previous record reached on July 20.
The worst drought since the 1950s has lowered expectations for this year's US soyabean and corn crops, sending prices of agricultural commodities soaring. The government estimated that 38 per cent of soyabean fields were in poor to very-poor condition this week.
Analysts say that prices need to stay high to slow consumption. Soyabeans are usually crushed into meal fed to animals and into vegetable oil.
But the US Department of Agriculture on Thursday reported another strong week of soyabean exports, with 731,400 tonnes of sales booked for the coming crop year, including 230,000 tonnes to China, the biggest importer.
The agency predicts that the US will export an annual total of 30.2m tonnes of the oilseed in the crop year beginning September 1.
"We just haven't seen much evidence of the crop rationing we know needs to be done," said Richard Feltes, vice-president at broker RJ O'Brien.
Weather forecasts also pointed to worsening conditions for soyabeans, with temperatures set to rise above 32C in key growing states such as Iowa and Illinois and the remnants of hurricane Isaac expected to dump a lot of rain in Missouri late on Friday.
While some precipitation could relieve stressed bean plants, a torrent would harm them, Mr Feltes said.
"Putting four to six inches on the soyabean crop this close to maturity is not helpful," Mr Feltes said. "There's stuff going on both the supply and demand sides that have people riled up."
The US Drought Monitor, a government service, reported that 82 per cent of the Midwest region was in drought, slightly more than last week. While rains moistened some spots in the past week, "improvements were made, but it should be noted that many of the row crops will not benefit from these rains and pastures have had minimal improvement so far," the service said.
Other agricultural commodities also gained, with CBOT September soyameal up 0.8 per cent to $547.50 per short ton, CBOT September corn up 0.7 per cent to $8.16¼ per bushel and CBOT September wheat rising 0.7 per cent to $8.92 per bushel.
The USDA expects the US soyabean crop to be 12 per cent smaller than last year and says the average field will yield the least beans per acre since 2003. Brazil is forecast to surpass the US as the world's leading soyabean producer this year.
I fear we are seeing the start of the next mass extinction event. With humans as the top predator if food runs scarce every other living thing will become fair game.