b'ROUNDTABLEPotatoes whichhave been dug for a sugar sampling test. PHOTO: TECHMARK,INC.internal colour, and total defects. So those arein some of the areas that were talking about wellused to change sugar ratings?the pieces. Well break the fries down in zeros andhave over mature potatoes, where we have a longHR: When we put these potatoes into storage and ones, twos and threes and fours. These graphsgrowing season We can have a time where westarted warming them up, they werent looking show regional trends based on variety. The purplestill have real green vines, but weve got chemi- the best. Even the processor was to the point line would be the minimum, blue is the average,cally mature potatoes under those vines. of saying, We dont know if we have a place for and green the maximum. We track bin tempera- them and What are we going to do with them? ture throughout the storage season along with theSS: How does temperature affect sugarSo, it was a little discouraging. When you look at percent change in quality and sugar data sinceratings? the sucrose at basically 1.9 and glucose at .6. the previous sample. Visit https://spudsmart.com/ TF: If weve got a lot of sucrose, its going to take awe had mostly fours in there, they were ugly. And wp-content/uploads/2020/06/Sugar-test-sample. lot of respiration to get rid of that because it has toso, the question became is what do we do with pdf to view an example of a sugar report.go through invertase to get glucose in and out. Andthem? And part of the thing that helped us with invertase activity is regulated by respiration rate.was our pre-harvest sampling to say we know SS: How do sugar ratings change withSo, the higher the respiration rate, the higher thisthat we started in the ground with a relatively the maturity of plants? conversion, and the higher the supply of glucosemature potato, and this is all stress related. We TF: We might not hit what I would call tuberis. In the fall, when the outside temperature dropsstarted here on Nov. 26, taking samples and we adolescence to get sugars to the point where weand the soil temperature drops, that potato needstook 200 pounds of this particular bin and I put it need to be to actually store well at our standardto survive. Its goal is to reproduce. And so, if itin our shop and started just warming it up We practices. So, we need to watch out for what wegets to the point where its starting to get close towere trying to see if we can learn something by might call juvenile potatoes. Those are potatoesfreezing in that 28 F to 29 F range, the sugars startwarming it up over the next six weeks Is it still with sucrose ratings around 2.0. Those do occurto come forward. And even when you get below 40possible to bring them around? This is what we sometimes when we have a little later planting,F in the soil, we get elevated sugar concentrations.started with, and this is what we ended with. Be-or we have a cool summer where we dont reallyThe reason that sugar concentration elevates iscause we started in the field with a mature potato, get finished off. We then move into the adolescentto increase the amount of soluble solids in theI felt quite comfortable, I didnt think we could get phase. These are potatoes that can be condi- plant solutionsuch that will drop its freezingthem this good though. But they turned out very tioned, with sucrose ratings from about 1.75 totemperature, just like road salt or other things putwell. If you look now our sucrose down a .78, it cut about 1.25. These might require some precon- on the roads helps drop the freezing point of thedrastically down and our glucose a .131 But ditioning, some warmer temperatures early on,water so that we can melt the icesimilar caseyou also see we kept them over 60 F for most of depending on the utilization of the crop and whenwith a potato, its trying to survive, so it needsthat time during this experiment. we want to bring it to the factory.more soluble solids. For more information on sugar sampling visit Then there are chemically mature potatoesSpudSmart.com and watch our latest webinar where their sucrose ratings are below 1.25. NowSS: How can storage temperature beabout it. 36 SPUDSMART.COM SUMMER 2020'