Thursday, November 5, 2009

Heirloom "Rebuttal" (part 2)

The following is a continued discussion spurred on by the article cited in the post immediately below this one. Article in quotes and italic. My responses follow in standard type and in red-brown.


"Weak and Wimpy
The selection of these traits has taken a toll on the heirloom's hardiness: They are often plagued by fungal infections that cause the fruit to crack, split and otherwise rot quickly. Wild plants must continuously evolve to fend off natural pathogens, points out Roger Chetelat of the Tomato Genetics Resource Center at the University of California, Davis. But in their quest for size, shape and flavor, humans have inadvertently eliminated defensive genes. As a result, most possess only a single disease-resistance gene."

Ah, but here's part of what rubs me so wrong with this article and its tone and premise. I'll try to make this concise.
  • Attacking heirlooms exclusively is a mistake. Most current hybridized tomatoes have to work with the same 'limited' set of genes. Also, these have also had the same misfortune of having been selected by humans who are just now learning about other genes in a related 'primitive' ancestor plant.
  • It would be inaccurate to assume that all open-pollinated seed sources were selected only for size, shape and flavor. Only if you look at history from a modern lens might you think this. In my book, seed would be selected for reliability and production if I needed these plants to produce and be part of the resource that fed my family all winter long.
  • If a variety is maintained from season to season in a region by families/farmers and they continue to select for the healthiest plants, would it not stand to reason that there is at least some allowance for evolution to fend off pathogens?
  • I will not argue that many heirlooms do have problems with splitting and cracking. But, I will argue against the claim that hybrids do not do so. At this point, the argument against heirloom/open-pollinated cultivars is one-dimensional here - we are forgetting other factors...

"Perhaps that's the price to pay for a good, flavorful fruit? Hardly, Chetelat says, because the heirlooms' taste may have less to do with its genes than with the productivity of the plant and the growing environment. Any plant that sets only two fruits, as heirlooms typically do, is bound to produce juicier, sweeter and more flavorful fruit than varieties that set 100, as commercial types do. Plus, heirlooms are sold ripened on the vine, a surefire way to get tastier results than allowing them to mature on the shelf."

And here are some of those other factors, disguised somewhat as an indictment against heirlooms.

  • Taste tests on our part have shown that people can tell a difference between different types of heirloom tomatoes grown in the same environment). Was it a scientifically solid study? No. But, good enough to start the argument.
  • Does the growing environment impact flavor? Yes. Now we are beginning to get somewhere. There is a diverse set of circumstances that go into growing food.
  • Does the production level of a plant impact taste? Maybe. There is a study that has shown that limiting the number of fruit on a plant seems to increase the nutritional value per fruit. Or, more accurately, that by trying to maximize production on one plant, the nutritional value per fruit is lower.
  • Ripened on the vine vs on the shelf. Well, there you have it. Sounds like an argument for small, diverse farms and local foods to me - rather than one against heirlooms.
  • Do heirlooms typically set two fruit per plant? This deserves a bit more response:

First, fruit SET is not the same as fruit PRODUCTION. And, production is not the same as SALABLE PRODUCT. A fruit is said to set once it is successfully pollinated and the fruit begins to grow. This does NOT imply that the fruit will reach maturity. Fruit that reach maturity do not necessarily receive the grade by the producer to be salable. Many are determined to be CULLS and can then be selected for use as feed for animals, compost or sold as 'juicing' specials. Salable produce is often graded, with the highest grades going to the fruit that typically looks the best and has the most uniform characteristics - something a retail operation typically prefers.

That said, the article might be more correct in saying that there ARE heirloom varieties that may only give you two top grade salable tomatoes per plant. This is especially true if you do not irrigate to keep moisture consistent. For example, Tasty Evergreen is notorious for splitting due to variability in available water. Even worse is the fact that they are thin-skinned and often split in transport. On the other hand, Roman Candle fruits rarely have a problem and plants average 70-100 unblemished, top rating yellow romas.

But, even that is an unfair comparison. A large, green tomato versus a smaller yellow roma being compared by count is silly. But, so is assuming that all heirlooms produce at low levels. Think of it this way. We plant about 450 plants per season (now all heirloom). If they produced only 2 per plant, we would have only 900 to give to our CSA and/or sell. To make this easier, we'll assume each fruit is one-half pound in size to account for different varieties. That gives us 450# of tomatoes if we accept the assumption given here.

So, explain why my back is sore after lifting in the neighborhood of 3500 pounds of tomatoes, not counting snack and cherry types? And this is with some varieties doing poorly (by our definition) this year.

Is this 100 per plant? No. Does this count culls? No. Could we have done better if we had the labor/outlet for more? Yes. Was this an average year? No, it was low given a cooler season.

But, consider the 100 per plant number cited in the article. This is not likely to be a good average for all types of tomato used in commerical production for the same reasons I argue about the lumping of all heirlooms together.

If you want to make a case, you need to use facts with some integrity, otherwise the argument becomes suspect even if it has merit.

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