Most talk on potato blight focuses on late blight (Phytophthora infestans) since potatoes are usually grown in regions with cooler summers.
However in places with warmer summers early blight is a much bigger issue, causing premature defoliation and a minor tuber rot (hard, sunken black spots). Late blight is often absent from these areas.
Since early blight lives in my area and has hit my potatoes the last two years, I figured I’d put together a list of my observations.
In general water stress makes potatoes (and tomatoes) more susceptible to early blight. Potatoes are very sensitive to soil moisture changes compared to most plants. They show this sensitivity by deformities in the tubers - second growth & alligator skin especially. But they also become more susceptible to early blight. Mulching my potato plantings seems to help dramatically with water stress & has almost completely eliminated deformities in the crop. It may also be helping the potatoes fend off early blight.
Like any disease there are likely different strains of early blight, so your results may be different than mine. I’m mainly grouping resistance by the incidence of tuber rot, since it’s easier to track + almost all varieties get some damage on the leaves as they get closer to senescence.
Resistant (very few, if any tubers hit)
Blackberry (more resistant to foliar damage, no tuber rot. Possibly the most resistant I’ve grown )
Desiree
Lehigh
Red Norland
Red Gold
Superior
Reba
Masquerade
Chieftain
Sarpo Mira
Red Thumb
French Fingerling
Pinto
Baltic Rose
Yummy Gold: This is a potato that came out of a grocery store bag labeled ‘gold potatoes’. It has deep purple lightsprouts and a darker gold flesh. I have never seen tuber rot on this variety, whatever it is.
Intermediate (enough strikes for me to remember, but less than ~25% of the crop)
Elba (under 10%)
Katahdin
German Butterball
Soraya (more resistant to foliar damage, produces so much that the yield of clean tubers is equal to other good producing varieties anyway)
Upstate Abundance
Susceptible (more than 25% tubers hit)
Eva (a shame, because it produces extremely well and has an incredible crunch as an oven fry)
Have you tried any of the Sarpo varieties? Wood Prairie Farm has 3 of them this year. I’m curious because when I grew Sarpo Mira a couple of years ago, it was not hit by early blight.
Unfortunately this year’s yield cratered. I used the tubers I had saved from the last year and got less than what I started with. Not sure if it didn’t like the tighter spacing or is having a negative reaction to a virus. They were exposed to PLRV last year but that year’s crop didn’t seem affected.
Virus builds up in potatoes very rapidly. Usually 2 or 3 years is all you can save and re-plant. You might give some more of the Sarpo series a try this year.
wood prarie is about 1.5 hrs drive south of me. i need to go check out their farm next summer. they have no less than 7 farm stands in thier town along rt.1. there. im suppised they dont sell thier potatoes in one of them to promote thier varieties more.
Viruses in potatoes are a fact of life. The most likely place to get them is from commercial potatoes. I tried growing some commercial yellow potatoes a few years ago and found out very fast that they were infected. That is one reason I did not grow potatoes last year. It allowed the virus to die out in my garden. Any potato bred for early blight or late blight resistance is unlikely to have much resistance to potato virus Y for example.
i had suprisingly good luck growing potatoes in 4 30gal containers i had next to my deck on the south side of my house last summer. i filled the containers about halfway when i planted then topped them off once the plants got about 6in. higher than the rim of the container. i then mulched the last few inches with green chicken bedding. i also gave them a good dressing of organic fertilizer when i filled the container and before i mulched. they grew very well with no disease issues. i harvested by dumping the containers in my pull behind cart. easy on the back and easy to dump the dirt afterwards.
Well yeah. Thats why I don’t care if I save my own seed potatoes year after year with leafroll virus being in the environment. The tolerant varieties will remain and the intolerant ones won’t. In a handful of potatoes out of a few thousand I see net necrosis.
For me the only time I could say a virus came with a potato was a mosaic infected potato in some certified seed. I just ate the tubers and the problem never showed up again.
I’ve never had success growing potatoes in containers, they’ve always dampened off. My neighbor has had success.
I first started with raised beds, but after a bad drought a couple years back I’ve switched to in-ground. My scale has dramatically increased since then, so now I don’t have the ability to irrigate all I want to grow anyway.
our summers are alot cooler here and i add some perlite and earthworm castings to my soil. i find the castings help alot with dampening off . i tried growing in raised beds but the voles found them and chewed all the tubers. my rocky clay isnt a option for root crops.