Wet weather has held back corn sowing in the US to its slowest since at least the 1980s, with planting grinding to a halt in some states, and the pace of seedings of other crops too at historically low levels.
US farmers sowed just 4% of their corn crop last week in what is typically one of the busiest weeks of the spring planting season, taking total seedings to 13% of expected acres, US Department of Agriculture data showed.
This was behind market expectations and the 40% typically sown by the beginning of May, with 66% in the ground last year, which had boasted excellent planting conditions – in marked contrast with the heavy rains, and cold, which have held up field work this year.
"The corn planting pace is the slowest since the data was compiled in the 1980s," Ker Chung Yang at Singapore-based broker Phillip Futures said, although other brokers have disputed this assertion.
In 1995, sowings had hit only 10% by the end of April.
Mr Ker also highlighted that Illinois, America's second-ranked corn producing state, Indiana and Ohio failed to show any progress.
Farmers in Ohio, the sixth biggest producing state in the US, the world's top corn growing country, have planted just 1% of their corn, compared with 61% a year ago.
State records show some slower progress, with Indiana farmers in 1961 not seeding any corn by the start of May, compared with 2% this year, and an average of 31%.
The pace of sowings is - generally - viewed as critical to the yield prospects of the crop, with mid-May viewed. As a rule of thumb, as a cut-off date after which potential falls.
"For much of the Corn Belt, optimal corn planting dates are believed to be in late April into very early May," University of Illinois agricultural economist Darrel Good said, with the fall in yields accelerating the longer sowings are delayed.
However, some bservers have questioned this logic, pointing to 2009 when sowings were late but the final yield set a record.
The Canadian Wheat Board last week said that "there is little compelling evidence that a crop that is planted somewhat late will have a corresponding reduction in yield".
Mr Good said that the 2009 result was down to "extremely favourable" summer weather, which could not be counted on this year.
"An examination of weather records reveals that the uniformly favourable conditions of 2009 have been rare."
The report came amid a window of drier weather in the western Corn Belt which is allowing some farmers to make significant progress.
In Iowa, Mike Mawdsley at broker Market 1 said that "locally the green flag was dropped over the weekend", with "significant progress" likely in the top corn-growing state this week.
The data also showed sowings significantly behind average in all other spring crops monitored, including sugar beet, where 15% of plantings had been completed as of Sunday, May 1 compared with an average of 61%.
Just 10% of spring wheat had been sown, compared with an average of 43% by now, and the slowest pace since at least the 1990s.
In 1997, growers had planted 12% of their crop by May 3, USDA data show.
The condition of US winter wheat also continued to decline, with the proportion rated in "good" or "excellent" condition falling by 1 point to 34%.
'Two weeks behind normal'
Separately, the Canadian Wheat Board revealed that in western Canada, the country's main agricultural district, farmers had sown less than 2% of spring crops, compared with an average of 10% by now.
"Seeding is at least two weeks behind normal, due to high moisture levels, snowpack and overland flooding," the board said.
"While the snow is expected to melt quickly, field drying will be hampered by below-normal temperatures."