Potato blight? Autumn potatoes

[HansMollman]

Hello I was wondering if someone could help me, do I have potato blight in my autmun potatoes? See attached images. We have had an unusually warm September.

[Gary350]

It does not look like any blight I have seen in my area TN. The 2 spots on the leaves looks like mold or mildew. I think blight is a type of mold or mildew. Maybe blight looks different in your geographical location. Potatoes are a 3½ to 4 month crop, how old are your plants? When plants are past 3 months old leaves start to die that is common, leaves often turn yellow or brown. Potato plants have an amazing ability to grow new plants if the entire plant is cut away with no harm to the plant or the new potato crop. Some potato growers cut their plants off a month after they blossom this causes plants to put all its energy into growing new potatoes and not growing leaves. It should not hurt anything to cut away leaves of your infected potato plant.

What is that I see in the pictures? Are you growing in a raised bed? What are you using for soil? Potatoes are sensitive to soil ph they like 5.5 to 6 ph best. Buy a 99¢ pack of ph paper to test your own soil. If your soil is 7 or 8 ph pour vinegar on your soil. Mix 1 gallon of vinegar with 4 gallons of water then water your plants. Wait 2 days then test soil with ph paper again.

[HansMollman]

Thanks for responding. They have been planted for about 1 month. We grow them in manure always have and normally do well. We build them up wirh manure when the tubers grow. I have cut the stems right back to the tuber hopefully they will regrow. I haven't done a ph test yet but wiol do.

[applestar]

I just came across this Japanese video and remembered this thread— key phrase being “autumn potatoes”

In the video, the presenter gardens in Tokyo area which has climate equivalent to Washington DC area. And he said “autumn potatoes” are planted August to September and harvested November to December from 90 day (early maturing) varieties. He mentioned typical seed potatoes available at “local home centers” — and two of them were Japanese, but third one he mentioned was “Andes Red” which I have seen in gardening websites and catalogs (but Afaik, seed potatoes are only shipped in Spring here…..)

He said, prior to planting, it’s critical to eradicate beetle grubs from the soil as well as deeply cultivating to suppress pest nematodes, and recommends 2 week solarization (organic fertilizers, inoculate with thermophillic -heat loving- beneficial microbes) to control solanacea diseases.

Tips for making soil for growing autumn potatoes learned from Japanese f...

https://youtu.be/PTHXU-Rfd78