Diversity is key to minituber grower’s success

Valley Tissue Culture in Halstad, Minn., sets itself apart from other seed growers by the number of varieties it produces.
Valley Tissue cultures and grows between 60 and 75 potato varieties in its laboratory and greenhouse, said Sandi Aarestad, president and owner of the seed culturing business. The company has been growing minitubers since 1984 and has been selling seed potatoes for about 20 years. About 85 percent of the minitubers are under contract by customers before they’re produced, which helps Aarestad know what varieties to grow.

Growers have been generous and helpful in telling me what to produce,” she said.

The company produces about 20,000 pounds of seed potatoes annually. It typically takes about 300 pounds of minitubers to plant one acre of nuclear or first-generation seed.

All of the cultures are developed in the laboratory on-site. The sample is serologically tested and then cloned from the one tissue plant. That eliminates the differences that could occur between two potatoes from the same line, Aarestad said.

The company uses the same technology and procedures that it developed in the late 1980s. Aarestad said the business hasn’t changed over the years, although she’s implemented some changes to increase productivity.

“The techniques have been tweaked to maximize productivity of the labor, greenhouse space and growing a high-quality seed product. I feel this system works for me and my customers. Until something comes along that is proven to be better, I probably will keep doing the same old, same old thing.”

Valley Tissue Culture doesn’t grow minitubers during the winter season. That benefits customers because they won’t have any dormancy problems, Aarestad said.

“Mintubers tend to be a little bit more dormant,” she said. “They need a nine-month period.”

With so many varieties grown in the lab in the company’s greenhouse, Aarestad said she has to be extremely careful to keep things organized.

“I am very organized and a perfectionist, so it’s natural to have challenges like this. If anything did happen, such as a mixture, it would be very hard to see it until it hits the field production, because of the vigor and density of the plants in the greenhouse.”

The greenhouses use screens on intake and exhaust vents to prevent insects from getting in, and the greenhouses are monitored daily for breaches. Employees also are continually cleaning.

“There’s a lot of vigor in the plant, so it’s hard to catch things,” she said. “That’s why we serologically test.”

If a seed grower makes a mistake, it can negatively affect not only the company but growers and their customers.

“If I screw up, it not only hurts me, it hurts the industry as well,” Aarestad said.

The facility is inspected regularly by the Minnesota Department of Agriculture. At least once every two weeks, from mid-May through the end of September, a state inspector visits the minituber operations. Each lot in the growing season is inspected and documented.

Customers can request the size of their minitubers, which range from 2 grams to 30 grams. But when she grows a variety specifically for one customer, Aarestad said the client takes the whole lot and doesn’t get a choice of size.

Customers are mostly scattered throughout the United States. Aarestad said the trend in selection is to use more protected varieties than in previous years.

“But every customer has their own sales niche, so that is why I pre-contract sales,” she said.

Aarestad takes special consideration when shipping the minitubers to customers. Customers usually receive their seed potatoes two to three weeks prior to planting, so shipping and storage after arrival are important. She ships 50-pound boxes through regular ground freight, but uses air freight if ground will take more than four days. Shipments only go out on Mondays or Tuesdays, to avoid the risk of minitubers arriving on a weekend and sitting in an unfavorable location. If there is a possibility of frost, the minitubers won’t be shipped.

After a customer receives the minitubers, they may sit for up to three weeks, so Aarestad tries to educate customers on proper storage techniques. She recommends putting the seed potatoes in a low-traffic area. The minitubers should not be stored with other potatoes and not put in a location where workers have to keep moving them.

Aarestad has eight to 10 employees during the initial cutting phase, which usually starts in November and is in full swing by January, when the employees will be cutting every day. During the summer, the staff grows to 10 to 12 employees. The work can be tedious and sometimes moves slowly, as little as 100 feet some days.

“It’s all handwork,” Aarestad said. “Nothing is mechanical.”

Aarestad has four children: Christina, Danielle, Alexandra and Charles. The three girls are in college, and Charles is a high school senior. They’ve all worked in the lab or the greenhouse. Aarestad said she and her husband wanted their kids to get an education, but thought it would be great if they came to work for the company.

“But it’s their decision,” she said. “They need to have the passion for the business to keep it going in a forward direction. If passion is lacking, then it’s just a job.”

The biggest issue Aarestad is dealing with is the rising cost of materials. Last season looked to be an especially good year for Valley Tissue Culture, but the dramatic increase in petroleum prices set the company back.

“Everything I have here is made of plastic and is disposable,” Aarestad said.

Prices for materials had double-digit increases, but Aarestad said she wasn’t willing to increase her prices quite so much. Potato growers were already seeing price increases for some of their other supplies, but potato prices weren’t increasing at the same rate.

“It’s hard to increase your price by 40 percent,” she said. “One thing is for sure, the price of minitubers will have to go up.”
But industry groups, researchers, universities and certification and government agencies work together to help seed growers and potato farmers.

“That is one of the more enjoyable parts of the business,” Aarestad said. “It’s the people you meet and work with; it’s a way of life for everyone involved.”