PARMA, Idaho — Specialized testing of seed potatoes has advanced to the point that it allows farmers to deal with potential problems before they even plant their crop.
For example, seed-piece evaluations, which detect diseases in potatoes, help soil scientist John Taberna inform customers about the quality of their seed potatoes.
His operation, Western Laboratories, is in Parma, Idaho.
“In 15 years, we’ve advanced with the detection limits,” he said. “We can now detect subspecies of a bacteria or a virus.”
Seed-piece evaluations can be used to detect Potato Virus Y and Mop Top Virus. PVY can reduce yields by one-third or more, Taberna said. Mop Top can reduce production and quality, and persist in the soil for years.
“On potato tubers, we can detect PVY at much lower levels than before,” he said. “Before, it was either positive or negative.” Amounts of the virus, and its strain, can be determined now through DNA.
University and commercial laboratories have worked to advance detection limits and precision to the extent that the tests can more effectively help growers make decisions on buying and treating seed, planting strategies, water management and other activities, Taberna said.
A test showing a degree of Mop Top may prompt a potato grower to focus planting in a soil type less conducive to its vector, Powdery Scab.
Farmers are finding that the testing pays off.
“Our potato seed testing is up 30% to 40% from the long-term average, and we expect it to get much higher,” he said.
Western and customers from as far away as North Dakota and Texas are dealing with a freeze-curtailed 2019 crop of seed potatoes, particularly in Montana and Manitoba and other parts of Canada, Taberna said.
It appears most of the Idaho seed crop was harvested before hard freezes in early October, he said.
Seed potatoes typically are grown in higher, colder regions less prone to disease pressure. Early-generation seeds are the least disease-prone.
Many growers, unable to buy from their usual supplier, are testing their own commercial potatoes for suitability to replant, Taberna said.
“The seed-piece test tells them if their seed has a chance of finishing without reduction of yields by diseases,” he said.
Western also plans to get more involved with hops, a southwestern Idaho crop that has seen large acreage increases in recent years.
“We will be testing the alpha and beta acid content to enable the grower to harvest at peak quality,” Taberna said.
The test also will show soil and plant fertility information important to achieving optimum acids — which influence flavor — and yields. Expected to be available by April, it will be an alternative to tests based on harvest date and cone volume.
“The cost of farming is going to go up, and this testing gives the grower the tools he needs to make decisions on quality, not quantity — because he is paid on quality,” he said.
Western is now building facilities for cloning disease-free transplants of hops and, eventually, hemp.
Taberna said the business aims to become a certified hemp-testing facility to complement state laboratories. It does not have any hemp in its building, as the crop is still illegal in Idaho; its hemp plants are in neighboring Oregon.
“It’s necessary to be ready for the demand when it happens,” he said.