Potato Blight

I got this email last week. There is a website that may be helpful, I have not looked it over yet. Does not sound good.

The discovery of active late blight (Phytophthora infestans) in some Michigan potatoes in southwestern Michigan has potato specialists worried. This is the same blight that started the Irish Potato Famine in the mid 1800s. Here are some resources describing the problem:

ANR Comm. news release: http://anrcom.msu.edu/press/060110/063010_lateblight.htm

The MSU Plant Diagnostic Lab says that the lab will do late blight tests for homeowners & growers for free because of the current issue (homeowners should bring in the correct types of samples). There is a pdf by Jan Byrne discussing potato/tomato late blight at http://www.pestid.msu.edu on the home page.

ed, look at the underside of your leaf and see if it looks like dull green velvet full of little tiny white spores. thats what late blight looks like. hard to tell from your video. there is a spotted leaf blight that potatos have thats not quite as bad. just steals foliage.

mitch

Highway,

It looks like early blight to us as well, but again hard to tell. There are so many diseases and environmental factors that are causing problems. We have a combo of early blight and ozone stress from the hot weather on our potatoes, copper is all that we use to slow it down. I would recommend asking your extension agent to have a look, if it is late blight they will be able to warn growers in your area of an outbreak. This is especially helpful info for those of us that rely on vegetables for our livelihood so that we can apply copper as a protectant as the fungus approaches.

Erika

@mitchmaine 19717 wrote:

just my opinion, but all the extension agent does is go from farm to farm distributing spores from other farms and spreading blight. if you have to know take him a plant. otherwise spray your copper and hope for the best.

We had a potato wreck a number of years back. Everything was fine, plants up a foot or two then started to turn yellow/brown from the top down. Thought it might be water related, so watered more. Eventually every plant looked like seaweed and they died. Spuds were alright (I guess) but the growing season ended for them in July – early. I never got a definitive answer but wondered if it was phytophora(sp) rot. It was fast and complete.

If you decide to take a plant to extension, make sure you bag it first.

Good luck. Farming/gardening can be a humbling profession.

absolutely, erica. it’s a community problem. however big your neighborhood gets. even state wide. just cause you have it doesn’t mean the end is near, right? disposal of cull potatos and vines until the spores are dead. dead dead.
theres no great shame getting it, cause anyone can get it, even with good practices. the mistake is not letting your neighbor know or dealing with the problem correctly.
some of the blight going around now was someone elses problem last summer.
thanks for bringing that up.
mitch

If you planted more than one variety of potato, you could take it as an opportunity:

http://www.growseed.org/potato-breeding.html

This article uses a more traditional method, there’s a bean project in Mexico though that selected the first generation _for_ susceptible plants, and after that for least susceptible plants. They wanted to get rid of the single-gene protection, and breed for multiple partial protection genes.

Coming in late to this conversation, but wanted to weigh in since we live so close to each other, Ed. I had what I believe was early blight last year. As soon as I decided what it was, I pulled all the above ground plant and bagged it, per the extension recommendations. Needless to say I was disappointed…initially. But my potato crop was affected only minimally. I dug up beautiful taters in late September…..just smaller than usual. We had potatoes till May. They held up in my pathetic excuse for a root cellar
Without any evidence of fungus.

Let me know what happens. I moved my taters far away from last years patch and am watching them carefully. I have a few beetles, but nothing devastating yet. Jennifer