The 2018 Freshpack potato variety trial results from northeast Michigan are available
A tablestock potato variety trial in Michigan’s Presque Isle County showcased 48 different varieties of russet, red, yellow, round white and novelty type tubers.
The Michigan Potato Industry Commission, Michigan State University potato specialist Chris Long and MSU Extension continued a tablestock potato variety trial in Presque Isle County in 2018. The trial was again hosted by Wilk Farms near Metz, Michigan, and showcased 48 different varieties of russet, red, yellow, round white and novelty type tubers. Varieties were planted in single, unreplicated rows 100 feet in length on May 23. The field was not fumigated, and tubers were planted 10 inches apart on 34-inch rows. Starter and side-dress fertilizer were applied by the grower at recommended rates according to soil analysis and best practices for the adjacent commercial field.
This year’s growing season featured above-average temperatures and below normal precipitation, resulting in drought designation for most of the growing season. Growing degree-day (GDD) accumulation for most of the growing season was one to two weeks ahead of average years, amounting to 3,150 GDD from planting to vine kill. Only 10 inches of rain fell on the trial field between planting and harvest, roughly 3 inches below the 10-year average for normal precipitation. While the plot was under irrigated, watering was discontinued due to the reservoir pond’s water supply depleting in August.
Vines were killed Sept. 22 and the plot was harvested Oct. 24. Harvest was delayed considerably due to persistent rains from the end of September through October. Common scab pressure was low across most varieties this year, but slightly worse than the previous year, with the trial average rating amounting to 0.9 out of 5. Other disease symptoms were minimal, and physiological disorders were also relatively limited, but alligator hide and misshapen tubers did appear to affect most yellow type tubers this year.
Of the russet varieties, Russet Norkotah was the top yielder, producing a total of 536 cwt. per acre, 518 cwt. of which graded as US No. 1 tubers. All russet varieties had no common scab. A08433-4VRRUS, CW08071-2RUS, Mountain Gem and AF5406-7RUS were other high yielding russets, all producing over 400 cwt. per acre of US No. 1 tubers. The only physiological defects of these varieties were a minor amount of vascular discoloration: 20 percent, 30 percent, 0 percent, 0 percent and 10 percent, respectively.
Of the red skin varieties, Cerata was once again the top yielding line. Approximately 521 cwt per acre of U.S. No. 1 tubers were harvested out of the total 577 cwt. yield produced by Cerata. The scab rating for this variety was only 0.5 and internal quality was excellent. Other top yielding red skin varieties were W8405-1R, Red Marker #2 and AF4831-2R. Each of these top yielding varieties produced over 400 cwt. per acre of U.S. #1 tubers. These varieties had a common scab rating of 0, 0 and 1.5, respectively.
Of the yellow skin varieties, Laperia was the top performer grossing 499 cwt. per acre, with 448 cwt. per acre making U.S. No. 1 grade. Soraya had a moderate scab rating of 2.0, and 10 percent of tubers checked showed vascular discoloration. Other top performing yellow skin varieties were Alegria, NY149, Wendy and Queen Anne. All of these verities produced between 300 and 400 cwt. per acre of U.S. No. 1 tubers. Defects were minimal across these varieties, only exhibiting slight vascular discoloration, and scab ratings of 1.5, 0, 1.0 and 0.5, respectively.
Lastly, of the round white types, MSY111-1 out-performed the other varieties, yielding 465 cwt. per acre of U.S. No. 1 tubers out of the total 508 cwt. per acre harvested. MSY111-1 had excellent raw tuber quality and a common scab rating of 1.5. Reba was the only other round white variety to yield over 400 cwt. per acre of U.S. No. 1 tubers, and had excellent raw tuber quality with a common scab rating of 0.
Complete variety trail results for russet lines can be viewed here: 2018 Potato Outreach Program On-Farm Variety Trials: Michigan Russet Variety Trials.
Ccomplete tablestock variety trial results can be viewed here: 2018 Potato Outreach Program On-Farm Variety Trials: Michigan Tablestock (Non-Russet) Variety Trials.
MSU Extension Presque Isle County thanks the Michigan Potato Industry Commission, Chris Long and Clifford Wilk for their ongoing work to provide northeast Michigan potato growers with variety information to help in future decision-making.