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This is our first year growing potatoes (no potatoes or cultivated nightshades have been grown in this soil for at least 2 years before). Central NY zone 4b/5a. The potato plants started out healthy, green, and thriving, but have since stopped growing. The leaves are curling and turning brown. (And there's some flea beetle type damage which I expected and I don't think is the main problem.)

What could be wrong with our potatoes? What should we do about it?

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Update 2022-08-21 We harvested the potato patch yesterday. The plant tops were totally withered and brown. The potato harvest itself looks pretty healthy and blight-free, which is great! enter image description here

Kilobyte
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2 Answers2

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First of all, I think you should consider that at least some of the damages look likes the result of a period with drought.

If you are sure that is not the case, some of the deformations in the leaves suggests a fungus like potato blight (Phytophthora infestans)

If it is a fungus, then the potatoes is usually damaged too. Compare to the photo at this NSDU page, which also states

Positive identification of late blight can be made by microscopic examination of sporulating samples from infected leaves or tubers. Identification of nonsporulating samples and identification of late blight genotypes can be done by PCR. This service is available at NDSU.

Rapid tests are also available.

In case of blight the NSDU page has several advices for management. I will especially emphasize

  • Destroy all cull and volunteer potatoes.
  • Plant late blight-free seed tubers.
Gyrfalcon
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One of our two types of potato is completely done (and ready to harvest, made a decent crop) (same zone, a bit more East) already. It might just be that.

Depending on irrigation, it might also be water and/or heat stress related given the way this year has gone.

Our other variety (don't recall either one's name, at the moment) is starting die-off but not all dead yet.

Ecnerwal
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