Growing Magazine - March, 2014

COLUMNS

Seed Research: Artisan Tomatoes

Independent breeder launches line at Johnny's
By Rebekah L. Fraser


The Artisan tomato lineup includes Blush, Purple Bumble Bee, Lucky Tiger, Green Tiger, Pink Tiger, Sunrise Bumble Bee and Pink Bumble Bee.
Photo courtesy of Johnny's Selected Seeds.

Solanum lycopersicum, the tomato, is the fourth most popular fresh-market vegetable in the U.S. Fresh-market tomatoes are grown in every state in the nation; however, the majority of the crop is grown in California and Florida. Consequently, many tomato varieties are bred to perform in warm climates and fail to thrive in other areas.

California and Florida growers typically ship their crops great distances, and this has influenced tomato breeding. "I think it's fair to say that more breeding work goes into disease resistance, shippability and color, rather than flavor and texture," says Andrew Mefferd, senior trial technician at Johnny's Selected Seeds.

When an independent breeder from California approached Johnny's Selected Seeds with a new line of tomatoes in 2008, the company's trial technicians saw varieties that had the chance to thrive throughout the U.S., from Alaska to Florida. The company was eager to release the line; however, Fred Hempel, plant breeder and founder of Artisan Seeds, promised Mefferd that if Johnny's Selected Seeds could be patient, he would deliver even better versions of the Artisan tomato line in a few years.

Over the next several years, Mefferd trialed more than 20 cultivars of Hempel's tomatoes at Johnny's Selected Seeds' 40-acre farm in Albion, Maine. Mefferd took copious notes on all aspects of the plant and fruit and offered feedback to the breeder. In November 2013, Johnny's Selected Seeds released seven cultivars of Artisan's striped tomatoes. Two of those varieties, Lucky Tiger and Sunrise Bumble Bee, are exclusive to Johnny's Selected Seeds.

"You don't just start making random crosses. You have an idea of where you want to go, what you want to produce," says Mefferd. "The Artisans we have today are what Fred had in mind years ago. He really made it happen."

"One of the goals for us early on when we started breeding was to create tomatoes that are recognizable and have exceptional flavor," Hempel explains, noting that the Artisan tomato line's calling card is stripes.

Striped tomatoes are popular at farmers' markets and gourmet grocery stores. However, despite their looks, the tomatoes often disappoint foodies seeking strong flavor. Hempel believes that's because many striped tomatoes have been selected for looks rather than flavor.

Until now, there hasn't been much competition in the striped tomato market. Heirloom tomatoes often boast both great flavor and looks, but poor yields make these varieties unsuitable for mid to large-scale commercial farming.

Artisanal performance

During the past decade, Hempel has prereleased his Artisan striped cherry tomatoes to select farmers. He's received mostly positive reports. The cultivars are vigorous and productive, with exceptional flavor. They're suitable for commercial farming as well as greenhouse growing.

In greenhouse settings, Blush, an elongated yellow bicolored tomato with stripes, is as productive or more productive than other greenhouse tomatoes.

Purple Bumble Bee, a round cherry tomato that's purple with metallic green striping, also performs very well and has some disease resistance.

The other five varieties (Lucky Tiger, Green Tiger, Pink Tiger, Sunrise Bumble Bee and Pink Bumble Bee) released recently by Johnny's Selected Seeds performed well in the company's field trials in Maine, Minnesota, Pennsylvania, California, Oregon and throughout the South. Hempel is waiting to learn more about their performance as the cultivars are put to the test in commercial settings.

Mefferd reports that Artisan tomatoes are very soft when completely ripe, which could make shipping a problem. However, in his field trials, Mefferd found that as long as the tomatoes are harvested when close to full color, the tomatoes will ripen during shipping and develop their full flavor. "The important thing about these tomatoes is they are widely adaptable," he says.

Disease resistance

Hempel did not breed Artisan tomatoes for disease resistance. However, by virtue of his breeding methods, the entire line is hardy and resistant to a variety of pests, diseases and fungi.

Hempel conducts the breeding work on his certified organic farm in California's Bay Area. Refusing to use even the sprays approved for organic growing on the tomatoes, Hempel instead allowed a certain amount of disease to remain in his fields.

"Just by the nature of the way you grow, you're going to have to select for things that are relatively robust without a lot of inputs," Hempel says. "In the end, we've been happy with reports about how well our plants do for people."

Much of the initial breeding occurred in the foggier portions of the Bay Area, where late blight was a problem. Hempel believes that by selecting plants that were relatively unaffected, he was breeding for disease resistance without focusing on which genes were creating that resistance. His collaborating growers throughout the U.S. reported that the Artisan varieties showed some resistance to blight. In some cases, the Artisan cultivars were the last tomato plants standing during blight outbreaks.

Methods

Tomatoes are self-pollinating. In tomato flowers, the male structures mature a little later than the female parts. Classical breeding involves removing the male part of the flower when the female part is fertile in one parent plant, then removing the male structures from the other parent plant just before they reach maturity. At that time, the female structures are ready to receive pollen. Lightly tapping the male structures of one parent on the female structures of the emasculated flower of the other parent completes the process.

The lineage of the Artisan tomato line includes heirloom tomatoes and other open-pollinated varieties that have been in production for a few decades. Black Cherry, an heirloom cherry tomato, and Northern Lights, a bicolored beefsteak tomato, contributed to all the Artisan varieties. Speckled Roman provided Artisan tomatoes with their stripes.

A former biotech industry plant biologist, Hempel and his family began working with tomatoes as a hobby in 2001. It wasn't until 2006 that he started farming as a way to test and support the breeding. "It's one thing to breed in isolation from the people you want to serve, but I feel like our breeding has gotten a whole lot better since we started farming," Hempel explains.

Farming gives him insight into the qualities and traits that work - or don't work - in a crop. Now, Hempel breeds three generations each year. He typically grows year-round, using greenhouses for the fall-winter and winter-spring generations.

The future of Artisan Seeds

"This is the beginning of what we want to do," Hempel says. Artisan Seeds will trial 12 new varieties with Johnny's Selected Seeds this summer. The next generation of Artisan products will be more tailored to commercial growers, as Hempel is focusing more attention on disease resistance and suitability for greenhouse growing.

Look for one or two new varieties of Artisan Seeds next year, and several more in 2016.

The author is a freelance writer based in Massachusetts and a monthly contributor to Growing.