Author Topic: Viruses in Certified Seed Potatoes  (Read 209 times)

bill

  • Administrator
  • Full Member
  • *****
  • Posts: 114
  • Karma: 19
  • USA, WA Coast
    • View Profile
    • Cultivariable
Viruses in Certified Seed Potatoes
« on: 2020-02-17, 01:15:09 PM »
Certified seed potatoes are the most disease free option available to potato growers (other than TPS), but they are not disease free.  There are tolerances for various diseases.  For some, the tolerance is zero (most bacterial diseases), but for viruses, there is generally an allowance.  So, you can get any of the common potato viruses from certified seed.  The most common virus that I see in certified seed is Potato Virus S (PVS).  Most programs don't have an upper limit for PVS infection.  PVS is generally considered to be a virus of minor importance, but is has a number of undesirable effects, particularly if you are saving your own tubers year on year.  PVS, in my experience, makes potatoes much less likely to hold flowers.  It also amplifies the symptoms of other viruses and can reduce resistance to late blight.

The picture shows test results for the variety 'German Butterball,' received from a major certified seed supplier this year.  As far as I could tell, the whole lot was infected with PVS.


William S.

  • Full Member
  • *****
  • Posts: 624
  • Karma: 41
    • View Profile
Re: Viruses in Certified Seed Potatoes
« Reply #1 on: 2020-02-17, 02:04:59 PM »
So around here seed potatoes start as tissue culture clones, than grow out in big potato fields, are tested, any positive testing plants are destroyed, then the big trucks full of seed potatoes roll out in the early spring headed for production fields in Idaho. It's a premium crop and closely guarded. However, it's not perfect, in that those big fields are surely breeding grounds for any viruses not considered to be important like what Bill just mentioned.
Western Montana garden, glacial lake Missoula sediment lacustrian silty clay mollisoil sometimes with added sand in places. Zone 6A with 100 to 130 frost free days

Ferdzy

  • Full Member
  • *****
  • Posts: 178
  • Karma: 12
    • View Profile
Re: Viruses in Certified Seed Potatoes
« Reply #2 on: 2020-02-17, 02:07:19 PM »
Interesting you mention German Butterball in particular; it has produced more seedballs for me than anything else by orders of magnitude.
« Last Edit: 2020-02-17, 03:51:47 PM by Ferdzy »

bill

  • Administrator
  • Full Member
  • *****
  • Posts: 114
  • Karma: 19
  • USA, WA Coast
    • View Profile
    • Cultivariable
Re: Viruses in Certified Seed Potatoes
« Reply #3 on: 2020-02-17, 03:37:55 PM »
That makes sense.  GB is one of the few widely available varieties that is male fertile.  I plan to cross yellow flesh diploids to it, but that will now have to wait a year.