Lesson #5: Manure vs. LECA, City vs. Farm, Heirloom vs. Hybrid

STUDY DESIGN

A small, triple variable, prospective, cohort study conducted at a large metropolitan hospital in Minneapolis, MN (n=3)

BACKGROUND:

Variable #1: LECA stands for Lightweight Expanded Clay Aggregate.  Manure is, for the purpose of this post, a liquid farm slurry of cow shit.

Variable #2: The city is St. Paul, and the farm is in Little Canada, MN. 

Variable #3a:  A hybrid is usually a car that combines a conventional internal combustion propulsion system with an electric propulsion system with names reminiscent of future planets, Greek characters, and energy nomenclature.  But, this time of year at our house, it refers to a tomato that has been commercially bred by crossing two distinct parents that are inbred for disease resistance, evening ripening, firm skins.  You find them at the grocery store because they have been bred for commercial purposes to be machine picked, to last on the shelf for 3 to 4 weeks and pretty much you get what amounts to a tennis ball; slightly different color and taste.  Taste suffers and the tomato’s durability and new facelift characteristics prevail. 

Variable #3b: So finally, what is an heirloom?  Grandma’s broche is one.  My brother’s underwear, another.  The wooden desk from Benjamin Franklin’s fish cleaning house yet another.  But, this time of year at our house, that term is used with respect to tomatoes.  An heirloom tomato is of a variety that has been passed down from generation to generation because of some cherished characteristic.  There are 4 classes of heirloom tomatoes.  They are:

1. Commercial Heirlooms: Open-pollinated varieties introduced before 1940, or tomato varieties more than 50 years in circulation.
2. Family Heirlooms: Seeds that have been passed down for several generations through a family.
3. Created Heirlooms: Crossing two known parents (either two heirlooms or an heirloom and a hybrid) and dehybridizing the resulting seeds for how ever many years/generations it takes to eliminate the undesirable characteristics and stabilize the desired characteristics, perhaps as many as 8 years or more.
4. Mystery Heirlooms: Varieties that are a product of natural cross-pollination of other heirloom varieties.

In recent years, the number of heirloom tomato varieties has plummeted proportional to the decrease in small family farms that supported heirloom lines of tomatoes. The unique heirloom varieties that had adapted to survive well for hundreds of years are being lost or replaced by newer hybrid tomatoes, genetically altered to be beautiful on the shelves of grocery stores.  As the number of heirloom varieties decreases, so does the genetic variability of this vegetable.  Every heirloom tomato type is genetically unique and inherent in this uniqueness is an evolved resistance to pests and diseases.  Local heirloom varieties have adapted to specific growing conditions and climates in places like Minnesota.  This narrowing of the genetic pool, and loss of adaptable characteristics has been called “genetic erosion.”

So with that background, the contest of opposites begins this week between a few friendly tomato growers at the hospital. 

METHODS

My little 40 sqft. backyard plot in the inner city of St. Paul, with a pH balanced 1/3 manure, 1/3 compost, and 1/3 dirt mixture will house my brandywine, boxcar willie, sungold, and black prince tomato plants.  My friend, Deb, will plant hers in 100% manure in the distant outskirts of the Twin Cities where the air is fresh and the deer roam free, and my boss, Terry, will plant his in LECA (“clay balls” as he calls them) next to his orchids in the basement, and grow the tomatoes hydroponically with exact (to the mmol) control of nutrients, UV light, and temperature. 

RESULTS

This contest will end late in September when we have the “taste off” in the office at work.  Perhaps Terry’s will taste like clay, Deb’s will taste nice and hearty organic, and mine will taste like exhaust from the neighbor’s 1982 diesel volvo rolling down the alley next to my tomato bed all summer (it’s the only spot in my yard that gets more than a couple hours of sun each day).  In the end, the genetics of the tomato will prevail over the conditions they grow in, and they will all make great additions to caprese salads, pasta sauce, and hamburgers all summer long.  While we enjoy our tomatoes, we will each do our part to keep a couple heirlooms going this summer maintaining some genetic variability in the days of tennis ball tomatoes. 

CONCLUSION

So is there a lesson in this Lesson #5 blog?  Not yet, but I expect it to be that you shouldn’t grow tomatoes in clay balls.  We’ll see when I get the Results section finished.