The Technology Game

Colorado's Martinez Farms operates on-site tissue lab

By Matt McCallum, Publisher

Segundo Diaz never planned to be growing seed potatoes in the San Luis Valley of Colorado. The Peruvian native came to the US. in the early 1980's to get his master's degree at Utah State University and worked with an agricultural engineering company in the potato fields during the summers. As fate would have it, he fell in love with the daughter of a potato farmer and hasn't left since. In 1984, Segundo Diaz married Margie Martinez, the daughter of Feliberto and Catalina Martinez, who owned Martinez Farms in Alamosa, Colo. Feliberto's son, Freddy, was killed in a tragic car accident in 1986 at the age of 36. Unsure of the future of the farm, Feliberto asked Segundo if he'd like to come into the operation. "I was raised on a farm, so I knew how to get my hands dirty," Segundo said. "The difference was that I thought high-tech farming was difficult. We worked together for a few years and the more I learned, the more I liked it'" Segundo and Margie now run the operation. Feliberto is retired, but still helps out when necessary. As for all that technology, Segundo now embraces it and is one of the most advanced seed growers in the San Luis Valley with his own tissue culture lab. "With the slim margins of today, we must use all the technology available as tools to help us on the profit side," he said.

Tissue culture

Segundo and Margie Diaz stand in their tissue culture lab.

The Diazes have been making their own tissue culture plants for four years. They have two greenhouses that total close to 10,000 square feet. The newest one is 6,340 square feet and can hold 55,000 plants. A boom system is used to irrigate and apply fungicides. An automated control system keeps the house at a constant 85'F during the day and 40'F at night. The older greenhouse is 3,500 square feet. "The greenhouse and lab enable us to manage things better, so we can produce plantlets when we want," said Margie, who runs the greenhouse operation. The mother plants for the cutting come from Colorado State University's (CSU) clone bank to ensure they are free of disease and genetically true. Cuttings from the disease-free mother plants are made in a sterilized lab, put in growing dishes and placed in the growing room for 20 days at 72'F. Cuttings are made until enough plants have been started to fill that year's need. The plants are then put in the greenhouse and grown into mini tubers. They are then harvested and stored in a cooler at 36'F and 95% humidity until they are planted in the spring. In the Colorado certification pro- gram the Gi lots are required to be from tissue culture and have 0% diseases and viruses.

In the Field

Wheat cover crops are planted on the edges of potato fields to trap aphids

The climate in the San Luis Valley generally makes it a great place to grow seed potatoes. Hard winters and lots of snow kill off the aphids and volunteers help break the cycle of disease. To make sure his seed crop stays dis- ease free, Segundo scouts his fields every week. Pesticides and fungicides are ap- plied using chemigation or by airplane. Chemicals are rotated to avoid resistance. Roguing is another key to disease-free seed, Segundo said. "Ifs one of the basic tools we have," he said. "I can see the fruits of good roguing in fields because diseases don't ever have a chance to get established Segundo does a lot of the roguing himself to get an idea of how each lot is doing. "I don't want a problem to get out of hand," he said. To keep aphid pressure low, Segundo is experimenting with wheat cover crops on the edges of fields to trap the insects. "The cover crops are a lusher green than the potatoes, so they like it and by the time they make it to the potatoes their mouths are clean, so they don't transmit much virus," he said. "They infect the wheat and not the potatoes'' All of the fields are also inspected three times during the growing season by the Potato Certification Service. inspections are done around July 1, July 20 and right before vine kill. Each block is checked for viruses and other diseases. Segundo has served on the association board for six years and was chairman in 1990 and 1991. All of the fields and generations are treated separately so no cross contamination will occur. There are three storages and seed is segregated with Gl and G2 in one, G3 and G4 in another and any higher generations in another. All pilers and conveyors are washed and sanitized with hot steam before moving to every new field to ensure no disease is spread during handling.


Martinez Farms grows seed potatoes, malting barley for Coors and wheat on 2,400 acres. They own about 1,300 acres and rent the rest from Margie's family. They have 15 circles (130 acres each) with 95% in Alamosa County and the rest in Rio Grande County. Total certified seed production in 1999 was 1,047 acres. Main varieties are Russet Nugget and Russet Norkotah, which are mainly sold to growers in the southwest. Other varieties being planted are Centennial, Chipeta, Alpha and some numbered varieties. Segundo is also eyeing the export market. He has grown Atlantic, a round white chipping potato, in the past and sold them mainly in the southwest U.S. There are now some export opportunities to South America and other countries. Chieftain, a round red fresh variety, has a good opportunity to be exported to Uruguay because 60% of that countries potatoes are Chieftain. The National Potato Promotion Board (NPPB) has been trying to open up the export market along with Richard Zink, CSU potato specialist, who is a technical advisor to the NPPBs seed task force. Zink led delegates from the Uruguay Ministry of Agriculture on a tour of the U.S. seed potato industry in June. Stops featured seed growing regions in Maine, Wisconsin and Colorado. Segundo gave the delegation a tour of his farm's lab and greenhouse facilities, all narrated in Spanish by members of his bilingual family. "It is very important that we export more because we need new markets for our seed," Segundo said.

Adapted from "Spudman" magazine, Feb. 2000, pp.12-15.

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