REPORTS from the US Department of Agriculture (USDA) over the June / July period have a history of springing some surprises and the body's June Acreage Report, issued Saturday morning Australian time certainly did not disappoint.
In the lead-up to the report, corn values had soared to multi-year highs on the back of concerns about the US crop due to an excessively wet planting period, but much of these gains has been given back this week in a savage correction.
Many analysts suggested there had been significant acres of corn abandoned due to the wet, with farmers swinging into soybeans, which can be planted later.
However, in its acreage report the USDA found nothing of the sort, with total corn acres virtually unchanged from its March estimate.
This saw Chicago Board of Trade (CBOT) corn futures drop limit down, the September contract falling the maximum US25 cents a bushel to US425c/bu.
In spite of the market reaction there has been some cynicism about the report in some quarters, with many analysts pointing to the fact that farmers completed the survey earlier in the month before further rain delayed planting again.
Even the USDA appears to be unsure as to the accuracy of the report, calling for a resurvey in 14 key states regarding planting intentions to see whether the flooding did end up changing the crop composition.
US wheat futures followed corn down, falling by as much as US20c/bu, with the September contract currently at US522c/bu.
There were some massive discrepancies in the report compared to market expectations.
Brad Knight, managing director of Bendigo-based grain brokerage business GeoCommodities, said the market and USDA forecasts were millions of acres apart.
"With the USDA figure of 91.7m acres, it is 5 million acres above what the trade was thinking so there is no wonder there was such a big shift in the market.
"In a way it backs up what some people were saying, that maybe the market had over-reacted in terms of the extent of the damage caused by the wet, although it is interesting there was no change at all in terms of planting intentions.
"It is only early in the year for corn, so we'll find out more, the next thing people will want to find out is whether the late, wet start is going to have a significant impact on overall yields."
Private yield estimates out of the US currently range a whopping 20 bushels an acre, a historically high variation for this time of the year.
Nick Carracher, Lachstock Commodities chief executive, said the market was extremely sensitive to information from the USDA.
"There is so much money traded with algorithms these days and that is why you see such big movements so quickly."
He said debate would continue regarding the US corn crop, but added that the crop was in a weak spot.
"All the anecdotal evidence we have got from states such as Illinois is that the wet is a huge problem.
"Whether it has led to total crop abandonment or not is up for debate but yield potential is likely to drop.
"Pollination is critical in corn and this excessive moisture pushes crop development back so it is going to be an uphill battle for the corn crop."
Mr Carracher said planting was difficult to get a handle on.
"The economics have swung around in line with pricing, at one stage it was skewed in favour of growers taking their prevent planting insurance payments, but then when the market lifted it swayed back in favour of putting a crop in the ground."
Phin Ziebell, agribusiness economist with NAB, said the USDA number saw the market readjust.
"Everybody had been so doom and gloom in relation to corn and we see the USDA numbers and they are not so pessimistic and the market has reacted accordingly," Mr Ziebell said.
"The question is whether prices were overdone in the lead-up to the USDA report, if not, then there is still scope for further upside in the Australian market."
Mr Ziebell said the east coast domestic market was still the major focus for Australian prices, in spite of ASX wheat futures falling sharply on Monday after the USDA report came out.
"There is still going to be a lot of grain needed to service those livestock industries in northern NSW and southern Queensland, so Australian prices will be relatively detached from the world market.
Mr Knight agreed the domestic market would be important, but added there would still be Australian grain exports.
"Even in these really bad years Australia still has an exportable surplus of grain, so what is happening with international prices is still important, especially in Western Australia and perhaps even in Victoria and South Australia, where the season is currently looking reasonable."
Mr Ziebell said conditions were currently good in southern and western Australia, but added he had some concerns, given how dry the start to the year had been in both regions.