Staff Writer
Seed potatoes tested this winter showed a higher than usual percentage of virus in the portion of the 2007 crop intended to plant next year’s crop, according to a report given at the annual Maine Potato Conference in Caribou last week. The tests, conducted in Florida, give an indication of how well the seed potato will perform when planted the following year. The level of virus does not affect the industry’s fresh market or its use as a processed potato. Growers who want to have their seed labeled as certified seed have their produce tested to determine the level of disease within the tuber. Within the Maine Department of Agriculture, Food and Rural Resources, the Division of Plant Industry certifies seed potatoes to control the level of regulated pests in the state’s potato industry.
“The results aren’t as good this year,” said Robert Batteese, Jr., director of the Division of Plant Industry during the Thursday session of the conference. “It’s not good news, but it’s not unusual.”
The tests are conducted on a Maine state-owned farm in Florida. The potatoes tested represent 10,808 acres that were harvested in Maine during the 2007 season, down from the previous year, according to Batteese.
The overall result is that almost 2 percent of the seed tested was rejected and can’t be categorized as either foundation seed or certified seed.
The complete results are scheduled to be published in a few weeks and distributed to industry members.
Last year, only two commercial varieties were found to have problems, while this year there were nine varieties that were affected.
Certification is a three-step process, which begins during the summer growing season. The second step is planting samples on the Homestead Farm in Florida. Those passing the Florida test are further inspected during the shipping season, usually the following spring, to ensure they meet grade standards. According to state agriculture officials, only the lots that have met all three tests can be tagged as certified seed.
The Florida tests determine the amount of mosaic or leaf roll viruses found in the tuber. Those from 0 to .55 percent are labeled as foundation, while those from .55 to 5 percent are certified.
After that level, seed potatoes could not yield as well as those with a lower level of virus and lots found with more than 5 percent are rejected for either category, industry officia said.
