Grafted Tomato Plants

Last March Cindy grafted some of her tomato seedlings onto tomato root stock (see:  Dr. Cindy and Dr. Kay Operate), to give the tomato plants a better chance to fend off Fusarium Wilt and other fungus and bacterial diseases that attack tomato plants.

Last year's experiment with one Box Car Willie tomato plant was a success, so of course this year Cindy decided to try several different varieties of tomato: Box Car Willie, Stupice and Sioux and several different root stocks.  The Sioux plant and one of the Box Car Willies didn't survive for long, and Cindy hasn't pulled out the Stupice plants yet, but the other two grafted Box Cars and the control did very well.  All three were planted in the same bed and all three produced tomatoes, although we didn't keep track of which plant produced the most fruit this year.

Since the tomatoes are now at the end of their productive season, Cindy tore the Box Car Willie plants out yesterday, so we were able to compare the root systems of all three of those plants.

A Tale of Three Box Cars

From left to right in this picture, the control plant is on the left, the middle plant was grafted onto RST-04-106 rootstock from Tomato Growers Supply Company, and the plant on the right was grafted onto Estamino F-1 rootstock from Natural Gardening Company.

The main stem and subsidiary stems on the Estamino rootstock plant were larger than those on the RST-04-106 and about twice the size of the stems on the control plant.

Estamino and Control Plant Roots 

Estamino plant roots on the left and control plant roots on the right.

I have a feeling that next year there will be more grafting.

One More Thing

One thing that did surprise us about the Box Car Willie experiment, where Cindy grafted a tomato plant onto disease-resistant tomato root stock was that the grafted Box Car Willie produced much larger tomatoes than the ungrafted plant right beside it.

A Tale of Two Box Cars

This picture shows tomatoes from both plants: the tomato from the ungrafted plant is on the left and the grafted one on the right.  The ungrafted one was about three quarters of a pound and the grafted one weighed 1 and three quarters pounds.  

That's a lot of tomato.  

Last Tomato Standing

Grafted Box Car Willie

By this time it should come as no surprise that the last tomato plant standing is the Box Car Willie plant that was grafted onto disease-resistant root stock.

That plant has shown signs of stress in the form of yellowing leaves, but managed to fight off the powdery mildew and bacterial wilt that claimed all of the other tomato plants this season.

Other San Diego gardeners have reported that this was a terrible year for tomatoes all the way around; we enjoyed a mild winter, but apparently it never got cold enough to kill off all the bacteria and bugs that love our veggies as much as we do.

We are pleased that this plant was so successful, since it shows that it is possible to combat these diseases.  Cindy is hoping to have several other Master Gardeners graft their tomatoes next year so that we can develop more information about what works and what doesn't work so well.

Boxcar Willie Experiment Update

Cindy's experiment with grafting a Boxcar Willie tomato plant onto some disease-resistant tomato root stock is still proceeding, and we're now able to see some significant differences between the grafted Boxcar Willie and the ungrafted plant.  (For a description of the experiment, see http://plantagarden-itllgrowonyou.blogspot.com/2014/04/box-car-willie-tomato-experiment.html).

Two Boxcar Willie Plants, Grafted on the Left, Ungrafted on Right--July 1, 2014

Both plants are showing signs of serious stress; this has been a crappy year for tomatoes all the way around, not just for us but for most of the other vegetable gardeners Cindy knows, but the grafted plant is the clear winner of this experiment.

Both Boxcars on July 20, 2014

These two pictures show the progress of the disease on the ungrafted Boxcar Willie plant on the right; in three weeks the ungrafted plant has wilted considerably, while the grafted plant on the left is still putting out flowers and producing tomatoes.

Fortunately, we have had big, juicy tomatoes from both plants, but it's clear the ungrafted plant is now done.

Boxcar  Willie Tomatoes

Box Car Willie Tomato Experiment

Last year one of the tomato plants we grew was a Box Car Willie, an indeterminate variety that was expected to produce a heavy crop of 6 to 10 ounce tomatoes.  We got 12.5 pounds of tomatoes from Box Car Willie, but the plant unfortunately developed Fusarium Wilt and had to be taken out.  Fusarium Wilt is caused by a fungus that invades the plants through the roots and eventually kills the plant.

Box Car Willie plants--Control on Left, Graft on Right

So this year Cindy decided to run an experiment by trying to graft a Box Car Willie plant onto some resistant tomato root stock in the hope that the root stock would make the plant better able to fend off the pathogens that cause Fusarium Wilt.  Both the root stock and the tomato plants were started from seed.

Once the plants were about a quarter inch in diameter, she used grafting tape to splice the two plants together and planted the grafted plant in potting soil.  The plan was to raise it in a carefully controlled environment and then plant it and an ungrafted Box Car Willie plant side by side in the same bed.

The plan went awry when we had to leave for a week shortly after the plants were grafted, and we had no idea whether the graft would take while we were gone.  But the grafted plant survived and actually looked pretty healthy when we returned.

In fact, the grafted plant, on the right in these pictures, is now taller and healthier looking than the ungrafted control Box Car Willie plant on the left.

Four Days Later

So far they are both growing very well, putting on several inches of new growth just in the four days that elapsed between these two pictures.

My only reservation about this experiment is that if both these plants survive, we're going to be up to our kneecaps in Box Car Willie tomatoes, in addition to all the tomatoes from all the other varieties of tomato she's planted.

We'll keep you posted about the experiment as it progresses.

Box Car Willie

Box Car Willie

One of the varieties of tomato plants Cindy put in this year was the Box Car Willie tomato plant, which she chose mainly on account of its interesting name.  Who wouldn't love Box Car Willie?

The plant was described in the catalogue as an "indeterminate", meaning that it would keep producing tomatoes throughout the season, and was expected to produce "a very heavy crop of good sized, smooth red tomatoes with delicious flavor, ranging from 6 to 10 ounces."

The plant did indeed produce a good crop of delicious tomatoes, but unfortunately very early began to show signs of Verticillium Wilt or Fusarium Wilt, fungi that cause the leaves to turn yellow, then brown and eventually kill the plant.  Unfortunately, the fungus survives as microsclerotia in the soil and will reoccur in any plant that is susceptible to it.  

Signs of Wilt

So now Cindy will probably have to solarize the soil in that raised bed this winter to kill off the fungus before she can plant any more tomatoes in that bed.  One advantage of using the raised bed system is that each bed is a self-contained unit and the fungus should not spread to any of the other beds.

Too bad about Box Car Willie, but we did get some delicious tomatoes from it.

But We Got Some Tomatoes!