J U L Y / A U G U S T 2 0 1 9 18 POTATO GROWER maintained in that breeding program but in the interim period, the clones were planted for several consecutive years in trial fields amassing a consider- able disease load. In order to evaluate these clones we must first develop dis- ease free seed using anti-viral tissue cul- ture. We eliminated 19 clones which did not fit within recognized market classes, had previously been rated mar- ginal in other trials, or were genetic duplicates of one another. Of the remaining 42 clones, 17 were success- fully cleared of virus. These are being grown for seed increase in Grand Rapids, Minnesota They include: 7 rus- sets, 6 reds, 2 chips, 1 yellow, and 1 purple. Becker, Minnesota The SPRF has moved to a new location several miles from the previous loca- tion. The move to a new research site has been complicated by the need to start planting in a new location before the infrastructure has been completed. We planted in early May and there is irrigation but there are no buildings for equipment storage on the site. Similarly, although we acquired an optical grader from Exeter Engineering we will be unable to use it this year without on location buildings. Despite these limitations, we have two trials at SPRF this year. First, we are growing the 17 varieties from anti-viral tissue culture described above. We will measure yield and quality traits on these varieties and assess their suitabil- ity for entry into national and regional trials. Second, we are growing three late-stage red, fresh market cultivars from our program and four check vari- eties at five levels of added nitrogen. This will allow us both to evaluate these varieties in the sand plains envi- ronment and provide nitrogen recom- mendations should they prove suitable for release. Diploid Breeding Parallel to the traditional breeding approaches described above, a second major focus of our lab is diploid breed- ing. Diploid potatoes have half the DNA content of tetraploid potatoes and are more tractable for breeding. In the long term, diploid potatoes will allow us to dramatically increase the speed of cultivar development using an inbred-hybrid system, similar to the one used for corn. We are in the initial stages of developing diploid germplasm and breeding systems, as part of a community wide effort involving potato breeders and industry partners across the country and throughout the world. Last summer we col- lected flowers from grower production fields for pollinations with a wild potato rel- ative which naturally generates diploid potatoes. We are grate- ful to: Jeff Edling, Nate Hayes, Paul Gray, Peter Ewing, and Black Gold Farms for flower dona- tions. After 17,000 pollinations we have 40 diploids. These diploids will be crossed to self-compat- ible material in growth chambers on the Saint Paul campus this summer, as the first step toward the development of inbred lines. We will also continue flower collection and pollination to create diploids this summer. Last year we focused exclu- sively on red and yellow fresh market potatoes. This summer we aim to expand our focus to russets for process- ing. We appreciate the industry and grower support we’ve received in our first two years as well as backing from our department and college. We look for- ward to continued collaborations which will allow us to serve and con- tribute to the potato industry in Minnesota and the larger region. NDSU Nematologist Dr. Guiping Yan A field experiment was conducted in For Sale Used Spudnik model 910 sizer/dirt eliminator. 48" infeed 60" star table. 220 single phase. less than 30,000 CWT on rebuilt star table $15,000 FOB Greeley, CO. Phone 970-539-1776