On a personal tomato note...

I said that I wasn't going to buy any seeds for my garden this year. I don't know where I'll be living, I don't know if I'll have time to maintain the garden up in Marblemount, and I'll have field trials to manage. I'm famously frugal among friends and family, but seeds are my financial Achilles' heel. I couldn't help myself...

Back in December, a grower brought this tomato to my attention as 'something you gotta try'. It's the Azoychka! The name is like an old Russian man sneezing,"Ah-Ah-Azoychka!". It is indeed a Russian heirloom was brought to the United States by Kent Whealy, one of the founders of the Seed Savers Exchange, from a collecting trip in Russia. The taste is supposed to be unlike any other tomato.

Now I just need to find my Azoychkas and me a sunny place to call home for the coming season.

Cherokee Purple

We will be growing ‘Cherokee Purple’ tomato, a large purple heirloom variety, as the scion (theupper portion of the grafted plant with desired fruit) in our 2010 tomato field trial.

Bound by time and labor constraints, I had to choose only one tomato variety. It only made sense to grow a tomato variety that is popular among locals growers, so I made some phone calls to organic farmers in the Puget Sound area. Cherokee Purple, an heirloom that is “fairly stingy on yield” (Source: Territorial Seeds), won the popularity contest. There has been considerable interest in grafting heirlooms which are generally have low disease tolerance and have been selected for fruit quality rather than vigor hybrid. One of the benefits of grafting is increased productivity due to a more well-developed root system. Cary Rivard, a graduate student at North Carolina State University, has done a lot of work looking at the effect of grafting heirloom tomatoes.

I think that I, as well as many of my fellow tomato lovers out there, find myself drawn to the nostalgia surrounding heirloom tomatoes. All vegetables are the result of human selection, and therefore products of our culture. Centuries of culinary preferences have dictated the form, flavor, and function of the vegetables in our diet. Most of the cultivars available today are the result of plant breeding, a scientific process carried out at land grant universities and private seed companies, and many of the most widely available tomato cultivars focus on year-round availability, red color, and uniform fruit size.

The official definition of “heirloom” is very loose, being any open-pollinated variety that has been maintained for 50-100 years. 150 years ago in western civilization and more recently in much of the world, there were no vegetables but “heirloom vegetables”, no seeds but “heirloom seeds” saved by the grower at the end of each harvest. Many seed companies and growers now view heirlooms as vegetables that come in odd shapes and unusual colors, providing unique and high-value alternatives to the standard spherical red tomato. “Cherokee Purple” falls in the latter category, having a dark brownish-purple tinge when ripe.

I think of heirloom vegetables as the social life of plant breeding. These vegetables contain generations of vegetable growers in their speckles and lumps. They exist because of conversations between neighbors, letter correspondences between friends and family, contact between European settlers and Native Americans, and Native Americans agricultural practices deeply rooted in American soil. And most importantly, heirloom vegetables carry centuries of vegetable growers reflecting on their harvest with hopes for the next year’s harvest. It is this hope carried forth over generations that captures the imagination of many of today’s vegetable gardeners and consumers.

I digress. Back to our tomato of the hour.

The Story of the Cherokee Purple Tomato.

According to numerous sources, the Cherokee Purple tomato was given to a well-known heirloom tomato collector, Craig LeHoullier, by J.D.

Green. J.D. Green was from Tennessee and said that the tomato was over 100 years old and had been grown by Cherokee Indians in the area. Amazingly, below is a scanned copy of the original letter from J.D. Green as posted on Mr. LeHoullier's website.

Mr. LeHoullier, who maintains a collection of over 1000 heirloom tomato varieties, named the tomato variety “Cherokee Purple” and introduced it to the Seed Savers Exchange in 1991. It has since become a popular heirloom variety prized for its flavor and interesting purple hue.

Sowing seeds and lyophilizing willow bark.

Yesterday, I spent an hour in the greenhouse seeding four flats of seeds. I'm getting some starts ready for a project for Environmental Biophysics (details forthcoming - once I actually draft up the project proposal) and also to get some more material for grafting practice.

Seeds sown:

• 66 'Cherokee Purple' tomato seeds (Source: Territorial Seeds)
• 72 'Pumpkin-On-A-Stick' (Solanum aethiopicum) seeds (Source: Abundant Life Seeds)
• 144 Mung Bean

"Mung Bean?!"

Well, what can I say. I got side-tracked. I am raising the mung beans for a willow cofactor experiment that my plant propagation professor and I are playing around with.

I am currently a teaching assistant for Plant Propagation (HORT 251). We have been doing a series of experiments on auxin-induced rooting. Auxin is a plant hormone that induces rooting in plants. The hormone is produced in the terminal and axillary buds of a plant. Auxin moves from the shoots to the roots but not from the roots to the shoots (transfer occurs in one direction). However, auxin is not solely responsible for root induction. Rooting also requires cofactors, other chemical compounds, for auxin-induced rooting to occur.

It is commonly known that willow species (Salix sp.) root extremely easily. You can plant them vertical, horizontal, upside-down; you can weave them into sculptures or bundle them into

willow-cutting burritos, and, given moisture, they will root. One common gardening trick is to soak willow twigs in water and then use the resulting willow-infusion to water your plants, thereby increasing root development and overall plant vigor.

It is important to note that willow's rooting is not necessarily due to elevated auxin production in willows but rather in the willow cofactors. Willows contain high amounts of salicylic acid, the main ingredient in aspirin. Adding aspirin to flower water is reputed to make flowers stay fresh longer. Therefore, it could be that salicylic acid may be the rooting cofactor.

Most rooting hormone products such as Hormex consist of synthetic auxin (usually IBA or 1 H-indole-3-butyric acid) mixed with talc or other inert ingredients. The cut end of the stem is then dipped into the auxin to increase rootings (some auxin will be produced in the buds).

Dr. Kumar and I wanted to look at whether a compound could be made from willowbark and talc that would similarly induce rooting in cuttings. So, I went out and harvested some young willow branches from a large tree on campus.

We then soaked these willow branches until the buds began to swell, as we thought bud development would likely coincide with increased synthesis of auxin and cofactors. Once the buds had begun to swell, the bark was peeled from the branches and submersed in liquid nitrogen. Liquid nitrogen is -196C (-321F) and quickly freezes plant material causing plant cell walls to rupture. The bark was then put then put in a lyophilizer for 24 hours. Lyophilization removes moisture from the material by exposing the material to very low temperatures in a high vacuum.

The freeze-dried willow bark can then be ground into a powder using a coffee grinder.

Once the mung beans are big enough, we will use them to test the effect of willow-bark at different concentrations on rooting. And we will see where we can go from there.

Results from the "To Soak or Not To Soak" Eggplant Experiment

After 2 weeks, I had a 68% germination rate for the unsoaked eggplant seeds and a 92% germination rate for the soaked eggplants. Based on this small trial, I am inclined to believe that soaking the seeds for 24 hours improves germination. I will be seeding more eggplant this afternoon, so I began soaking my seeds last night.

The eggplants have become infested with thrips. The greenhouse folks have been treating them (see yellow sticky paper in photo below) but they say its a constant battle unless you want to resort to continual pesticide application.

The eggplants are up!

In just 8 days, a little sooner than expected, the eggplants are up.

Soaked Seeds: 32/48

Unsoaked Seeds: 28/48

There really is no significant difference between soaked or unsoaked seeds. I will have to keep track over the next week or so for the final tally.

I finally got a misting nozzle, but the corner of the soaked seed tray may have lower germination as the soil and seed got blasted by the high water pressure.

I will be raising these seedlings to practice grafting on and perhaps for my biophysics project (more details on that in the future).

Bottom Heat

Well, I learned an important lesson today: bottom heat makes soil dry out much quicker.

In the midst of juggling my hectic schedule of TAing, taking classes, and working on my thesis project, I figured that I could wait two days to check on the plants. How wrong I was! The soil was very dry.

Which comes to my second problem to solve: watering wands and breakers. The breaker provided was verging on pressure-washing force. At my request, the greenhouse manager set out a few more breakers and a watering can, all of which apply so much force that soil gets displaced from the cells. I've had to pick out a few seeds that have washed into neighboring cells and replant them in their original cell. This is not good. I'm going to try my best with the watering can, although it is hardly optimum.

And I will start checking on the plants everyday. Hopefully the seeds are forgiving of this week's "dry spell".