Will the US corn yield this year really be 148.1 bushels per acre, as US farm officials forecast on Monday?
The debate, which has raged for weeks, about whether crop will end up in the low 150s, or even somewhere near 140 bushels per acre misses the bigger point.
And that is why the yield should be lower than last year's 152.8 bushels per acre, which was in turn below the record 164.7 bushels per acre farmers managed in 2009.
One drop in year-on-year yield can easily be dismissed as misfortune. With two successive ones, it is not so easy. A back-to-back has happened only once in corn, in 1973 and 1974, in the last 50 years.
And the worrying factor this time is happened during a so-called revolution in seed technology – genetic modification or biotechnology - which had painted a far brighter picture.
It would be highly unfair, on such evidence, to dismiss biotech. The seed industry can, perfectly reasonably, say that yields would have been even worse if it were not for genetic engineering.
There are plenty of trial results supporting the efficacy of the technology, in crops from corn to potatoes.
But it is the biggest trial of all, the US harvest, that counts.
And it is certainly embarrassing for GM for successive yield declines to happen on its watch - 88% of US corn planted this year was from biotech seed.
Furthermore, the sagging national yield is not the only setback which has put biotech under the microscope.
Research from Iowa State University has shown that western corn rootworms in some Iowa fields have evolved resistance to Monsanto corn genetically modified to be resistant to the pest.
Monsanto has dismissed this as an issue "in a handful of situations - around 100 farmers a year".
But the so-called superweeds found to have developed resistance to Roundup, after seeds resistant to the weedkiller became so convenient that farmers stopped using other weedkillers, look a bigger problem, reported to have spread to millions of acres in more than 20 states.
Sure, farmers have some questions to answer.
Many abandoned traditional farming best practice, such as crop rotation, in the belief that GM was the answer to all agronomic problems. That looks a big cause of biotech's setbacks.
Furthermore, the biotech industry may yet to discovered its killer ap. If the last couple of years are anything to go by, characteristics giving greater tolerance of weather extremes might provide a big uplift to yields.
But it would not be unreasonable for a US farmer to examine closely whether the premium for biotech seed is worth it. (Especially when the likes of Bunge are refusing to handle a Syngenta variety.)
Nor for Europe to continue lagging on its acceptance of the technology when, whatever the truth on risks, the rewards appear less than extraordinary.
Nor, for that matter, for buyers to worry that the structural squeeze on corn supplies may be more intractable than they had feared.
By Mike Verdin