Hot weather in July and August hurt the U.S. crop and may lower the amount of milled rice produced from every 100 tons of rough rice to 50 tons, from the usual 65 tons, Roberts said in an interview yesterday.

"We had a lot of rains at the wrong time," Joe Crane, who grows about 1,000 acres (405 hectares) of rice in Texas, said in an interview in Singapore today. "It caused a lot of blanks because of the pollination problems. We also had extremely high nighttime temperatures up in the central part of the U.S.," further lowering yields, he said.

Rough-rice for November delivery gained 0.4 percent to $13.05 per 100 pounds on the Chicago Board of Trade at 3:16 p.m. Singapore time, erasing an earlier loss of 0.4 percent.

"We've never had a year where we started out thinking we're going to have a record crop and then over the last three weeks, everything has changed because of field yields and milling yield problems," Roberts said. "The milling-yield problem has yet to figure into the USDA data."

Eoin Treacy's view The bulk of grain and bean commentary in the financial press has focused on wheat and subsequently corn and soybeans. This is the first article I've seen telling the same story as the price action which is that there is a problem with the supply of the commodity.

Despite some violent intraday volatility, rough rice has trended steadily higher over the last few months and a sustained move below $12 would be required to break the progression of higher reaction lows and question scope for further upside.