Is this one of the blights? (Potato)


#1

Potato plants. This variety is “Yukon Gem” and its too early for natural dieback. Is this late blight or early blight?

I dig around and the spuds are usable, but still pretty small, so I don’t think it’s natural dieback.


#2

Yellow halos, and what look like concentric rings in the lesions. Very familiar! I believe it’s early blight (alternaria).


#3

Some look far worse.


#4

Advanced early blight infection can cause plant collapse—and I still think it’s probably EB. But whatever the pathogen, I’d remove and dispose of vines before digging in order to reduce chances of tubers being infected and rotting in storage.


#5

Should I dig the tubers, or just cut off the vines, burn them, and then let the tubers cure for a couple weeks in the ground?


#6

I’m certainly no potato expert, but if it were me, I’d go ahead and dig them when time allows; if the vines have collapsed, they’re not going to grow any more, and the longer they stay in the ground, the greater the chance of pathogens or pests getting at them. If they’re immature, they may not keep as long, but if you cure them well—in a cool, dry, dark place----for a couple of weeks, they might last for a month or two in good storage. I’d also go ahead and eat any puny ones; “new potatoes” are awfully good roasted!


#7

I spray my tomatoes with alternating chlorothalonil and Mancozeb to control blight and septoria. I’ll hit the potatoes with it next year, too.