A discussion on hybridization

I recently read this article on the Haiti Rewired site, a forum for discussing development questions. There was a raging debate regarding the safety and usefulness of hybrid seeds, so I dropped some knowledge. You can read my explanation about hybrid seeds below:

Hi all, I'm new to Haiti Rewired. I don't think any agronomists have weighed in on this thread, so I thought I'd offer some background on hybridization, just so everyone's on the same page.

Illio pointed out that hybridization is a cross between two different varieties of a species, or even between two different species. This is biologically correct, and in that sense all people, as well as all crops we plant, are technically hybrids of their parents.

But in the agricultural context, “hybrid” has a more restricted meaning. Hybrid seed refers to the offspring of two purebred, inbred lines. The process is as follows: from a diverse population of plants (even many plant varieties, which may seem quite homogeneous in appearance, possess a lot of genetic diversity within the population), a breeder selects one plant that has certain traits he or she wants. The breeder then self-pollinates this plant, so that its offspring will only bear the genes of this single parent. But even these offspring will be quite diverse, so when the offspring seeds are planted and reach maturity, the breeder again picks only those plants that have the desired traits, and crosses each plant to itself again. This goes on for various generations, until the breeder is left with a pure line that has the desired traits and consistently produces essentially identical offspring. It is incest to the extreme! And as with incest, these inbred lines tend to have certain drawbacks in terms of strength and yield. So the breeder takes one inbred line, lets say one that germinates well in cold soil, and crosses it with another inbred line, maybe one with resistance to a certain disease. The offspring of this cross (this is what plant breeders refer to as the F1 generation) will be genetically identical to one another, a half-and-half mix of each parent line's alleles. And because they are hybrids and not inbred lines, these F1 offspring have a high yield and are very strong. The problem is that the seeds produced by these plants (the F2 generation) will not be similar to the hybrid plants; they will be a remixing of the traits of the grandparents, and many of them will possess the same weakness and flaws of the grandparents. So if you plant hybrid seed, you harvest its grain, sell it, and buy new seed, because saving grain to plant as seed doesn't give a good result.

I think this is the main issue in the case of the Monsanto donation. Normally Haitian farmers save seed from generation to generation, but if they were to use hybrid seed, they couldn't do this. Any farmer who used hybrid seed this year would be obligated to buy more seed next year. Aside from that, usually hybrid seeds are bred to respond well to ideal cropping conditions—good soil moisture, high fertility, total control of pests and weeds by chemical inputs. Hybrid seeds are great for farmers in Illinois, whose flat land and input-intensive agriculture allow them to provide the ideal environment for crops. But usually these seeds are not so attractive for subsistence farmers. There are even traits of hybrid seed that are inherently undesirable for the Haitian context! For instance, the genetic uniformity of hybrid seeds means that all the plants mature at the same time. This is great if you're harvesting hundreds of acres with a huge mechanical combine, and you can't check to see if one plant is mature while another isn't yet ready to harvest. But for a subsistence farmer with a small field of many different crops, it's often a plus if your corn crop doesn't all mature at the same time. That way you've got a mix of tender sweet corn and mature corn for shelling throughout the latter part of the growing season, and you don't have to harvest everything all at once.

Illio and Rick Davis commented that all the food on farms or at the grocery store is hybridized. That's actually not quite true, at least not in the agronomic sense I've detailed above. In the US for instance, almost all the corn and sorghum planted are hybrid seeds, but almost none of the soy, wheat, fruit, or livestock we consume are hybrids. That said, our livestock (particularly chickens and hogs) is extremely inbred, and so it has some things in common with hybrid seed, both in terms of advantages (high productivity and uniformity) as well as disadvantages (susceptibility to disease, need for lots of industrial inputs). In fact, in the 1980s some well-intentioned Iowa farmers donated elite inbred pigs to Haiti, and most farmers found them totally unsuited to the Haitian climate and farming conditions.

So I wouldn't classify Haitian farmers' rejection of Monsanto's donation as silliness or ingratitude. It's perhaps just that the donation isn't very useful. Ever since the tragic earthquake in Haiti, the concerned among us have been admonishing our relatives that the best gift is money or things that respond to a specific stated need. Despite their good intentions, we tell our Aunt Edna that no one wants her old shoes, or we tell our cousin Dave that his IBM 486 computer from 1994 probably isn't a great help. And if a container of old shoes and IBM 486 computers arrived to a Haitian village, people might even get pissed off and burn them, not out of ingratitude but out of frustration that they're not getting what they need!