Hybrid seed is often selected for providing resistance to specific diseases and pests. With tomatoes, you'll notice all, or some, of the letters V, F, and N. These letters tell the buyer that the tomato is resistant to, respectively, verticillium wilt, fusarium wilt, and nematodes. Some heirlooms have resistance to these same factors, but often not all three in one plant. The difficulty with heirlooms is with their lack of genetic similarity. If your plants are attacked by a disease which the hybrid isn't "programmed" (or, selected) for, then the plants may be sitting ducks. Perhaps the whole field, or a great portion of it, will succumb to the disease. The dogmatic opponents of hybrids often mention this lack of genetic diversity as the Achilles' heel of hybrid seed. But, in all their testaments to the evils of hybrid seed, the heirloom proponents can only dredge up a handful of scary agricultural examples. More notable to the home gardener, the Achilles' heel argument only works well with the agricultural scale. Five hundred acres of one type of wheat is a far cry from the dozen or two types of vegetables, and the several or more varieties of many of the types, found in the average home garden. If all the tomato plants die, you'll be depressed—but, you won't be lacking in things to eat.
While the following story doesn't represent hard science, it will illustrate the difficulties generated when dogma on either side becomes fixed like a case of mental lockjaw.
The setting is the rural acreage a nonprofit organization we'll call the Institute. Located in the coastal belt of Northern California, these well-tended organic gardens—with an incredible organic matter content of 12%—lay at the western edge of a reasonable tomato climate. Still, every three- to four-years, a late summer blight stimulated by intruding all day fogs will wipe out 80% of the plants or a late spring frost will damage or kill a number of plants. (Flavor is another problem altogether. If the warmth of an unfoggy summer graces the garden and Indian summer lingers into October, then you'll have good chance at something approaching the archetypical Midwestern smile-on-your-lips tomato flavor.)
The Institute attracts the young, the enthusiastic and the righteous to a variety of gardening and landscaping programs. All who arrive come already indoctrinated in the Church of the Organic Way. A few have gardened before. Many already have it in for anything corporate, industrial, or chemical. This is a fertile breeding ground for the dogma of heirlooms.
The young interns got swept away with the growing tide of interest in preserving genetic vegetable diversity and started growing rare and unusual heirloom varieties. (They often turned a superior nose to heirloom flowers—as they only grew food, for sustenance.) They grew 25 to 40 varieties of heirloom tomatoes a season to sample the flavor and save seed. Somehow, they decided to have a contest for disease hardiness between hybrid and heirloom, open-pollinated varieties. They may have been shamed into it by the pestering of the remnants of the pro-hybrid gardeners. Or, the Church of Heirlooms may have decided to prove its superiority to the rest of the heretics. Whatever. The proselytizers of open-pollination made a big stink about the showdown. Many an evening meal ended up with various predictions of the triumphant heirlooms. They reveled in how the final report would show that their study had proven heirlooms victorious. I was living there at the time and found the horticultural piety amusing one day, and tedious on other days.
Summer passed. Evening conversation turned to other events or topics. And the first frosts blackened what remained of the tomato plants. Finally, I pulled aside one of the clergy from the Church of Heirlooms. "Where's the report," I asked. "What were the results?" In a hushed tone, he said "the hybrids were more disease resistant, so we didn't do a report." So much for the integrity of this flock of the Church of Heirlooms. The results failed to confirm their expectations, so nobody will find out. (These are the same people who degraded Nixon for the shabby and criminal way in which he suppressed information and kept secrets.!)
Let me know what you think.
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