In "At Home: A Short History of Private Life" Bill Bryson wrote:
Maize can't reproducey itself without human help.
I can't believe this. What if a corncob falls on the ground? Why shouldn't a few kernels of maize fall out and grow?
I think Bill is not an expert on this. Can anyone answer this?
Domestic corn or maize needs humans to be successful
From gardeningchannel.com "Corn vs. Maize, What’s the Difference?"
What’s the difference between corn and maize? Not much! Corn and maize are both terms that reference the same cereal grain. Corn is primarily used in the North American english vernacular, whereas maize is used in the British english vernacular.
According to the backgarden.org article "Is Corn Man-Made?"
Believe it or not, corn does not exist naturally in the wild and can only continue to thrive and evolve with the help of human hands.
In order for corn seed to grow the husks must be removed and the seed separated from the husk.
Later in the article
The modern species of corn cannot reproduce by themselves. Kernels are very firmly coated by husks and cannot be dispersed without our help.
The article concludes
Although corn was made by man through selectively breeding teosinte plants for thousands of years, it has become an essential crop for many generations.
Corn lost its ability to propagate itself when it mutated the husked ear, which trapped its seeds (kernels) so they couldn’t couldn’t disperse.
If you see a soybean field with volunteer corn growing here and there you might think "See, corn can grow by itself"
But, what happened is that the farmer planted corn the previous year. During the harvest process the combine harvested the corn cobs and separated the corn from the cob and sometimes some good seed gets thrown out of the back of the combine. These seeds will get mixed into the soil when tilled and grow the next year along with the soybeans.
From farms.com "Volunteer Corn"
Volunteer Corn is left over from past crops. Sometimes they appear because not all the seeds from the previous crop were completely harvested, many of their seeds can fall on the ground during harvest or they can be spread by farm equipment. If the seeds are able to survive the winter months, it has the potential to germinate and grow in the next year’s crop.
Can an ear of corn grow?
Sort of.
From "Sprout a Corn Cob"
Notice that this corn cob has no husk.
The plants on this cob will fight for resources with each other and the plants will be stunted. If this ear of corn with sprouts were left outside to manage on it's own the plants would eventually die out.
DOMESTIC maize does indeed require human interference to germinate, but wild maize (the original subspecies of Zea mays from which all domestic varieties were hybridized) does not. From this paper about a program to add the ability to grow in nitrogen-poor soils to modern maize strains:
...phylogenetic analysis traces all modern maize (Zea mays mays) to a single domestication event that occurred in southern Mexico 9,000 years ago from its wild ancestor Z. mays ssp. parviglumis (Parviglumis teosinte) with a minor contribution from Z. mays ssp. mexicana (Matsuoka et al., 2002). Parviglumis teosinte shows tolerance to low nitrogen stress (Gaudin et al., 2011; Han et al., 2015), and as a wild plant evolved in the absence of human nitrogen inputs, unlike its cultivated progenitors. Parviglumis can still be found thriving in nutrient poor soil in the Balsas River valley of Mexico.
Note that Parviglumis is known more commomly as teosinte.
There is also an ancient landrace called Mixteco that is still in existence, but I think it, too, needs human help to reproduce.
Of course, teosinte does NOT look like domestic varieties at all; that's what 7,000 to 10,000 years of evolution will get you!
