Late summer rains during the worst drought in 56 years arrived in time to buoy U.S. soybean production but were too late to salvage the stunted corn crop, analysts said on Tuesday.

Fourteen analysts polled by Reuters, on average, estimated a soybean yield of 35.85 bushels per acre, up from the U.S. Department of Agriculture's Sept. 12 forecast of 35.3 bushels - the first time analysts have raised their yield estimate this season.

In contrast, the analyst average for this year's corn yield was 121.014 bushels per acre, below USDA's September outlook for 122.8; the analyst outlook for production was 10.416 billion bushels, below USDA's current estimate for 10.727 billion.

Anecdotal accounts of better-than-expected soybean yields caused soybean futures at the Chicago Board of Trade to tumble by the daily trading limit of 70 cents on Monday, with follow-through selling adding to the losses on Tuesday.

"Soybean yields are tracking crop ratings perfectly so far, so it looks like the crop has added one bushel per acre since USDA did its September survey," said Bryce Knorr, senior editor for Farm Futures Magazine, referring to the magazine's estimate.

The summer of relentless heat and drought stunted the U.S. soybean crop but the later planted soybeans and double crop soy benefited from a turn to cooler and damper weather since that portion of the crop had not yet set pods.

"We went up on soybean yields because of late rains and actual harvest results. We're hearing better yields across the crop belt. The late rains really did help," said Don Roose, president of U.S. Commodities, Des Moines, Iowa. The USDA on Monday said a record high 10 percent of the U.S. soybean crop had been harvested as of Sunday.

USDA said corn harvest also was at a record 26 percent complete but field reports of corn yields are not as positive as for soybeans since corn plants bore the brunt of the sweltering summer.

The heat and drought were peaking at the same time the corn crop was pollinating in late June and early July, a combination that proved deadly to a large portion of this year's corn acreage.