Potato Blight

[Mackay]

My potatoes got blight this year and I suspect it was from overhead watering daily

We are due for our first heavy frost this weekend. Should I cut the greens down? Let the frost have them?

I have learned that potatoes grow in size considerably after the first frost and the greens are killed.

will they still grow if I just cut the greens off?

Will the soil be contaminated for next year?

I understand that the potatoes will still be usable but should not be used for seed next year.

Opinions?

 

[Mackay]

Doesnt anyone know about potato blight and how to prevent or manage it?

 

[digitS']

I find myself reading about a disease that I have never seen, Mackay. Except for a few years back, I think that most home gardeners had no experience with late blight and I'm not sure how many saw it in 2009 or just suspected that it was what was causing problems for their tomatoes and potatoes. There are quite a few fungal diseases that attack these crops each year. Some are fairly serious, others are not.

Here is some information from the University of Massachusetts on recognizing the different diseases: (click). And, here is what they say about late blight specifically: (click).

Thirty years must have passed without me planting potatoes and I have never seen a serious fungus problem in the spud patch. The common varieties were awfully cheap in the supermarkets and it has only been the last 7 or 8 years that I've taken up growing them again. But, it is the tomatoes that have the disease problems.

I have blamed early blight for a foliar disease that has shown up in my tomatoes now and then. There has never been a lot of problems. Here is some information about early blight in potatoes and tomatoes from a plant pathologist at theUniversity of Minnesota: (click).

I have read that late blight has been reported in some provinces of eastern Canada. Additionally, Pennsylvania State University directs us to this site for US reports: (click). As you can see, except for the case in Florida, the reports are all in the upper Midwest and Northeast. The heavy rains in September were blamed for conditions that led to these occurrences.

Late blight must be a very serious disease and every effort should be made to dispose of the infected crop and prevent its recurrence. Growers can preempt blight by using fungicides on their crops. Decisions to do so is partly based on weather conditions that favor the fungus outbreak. That's about all I can say and hope the information on those webpages is of help.

Steve
edited to straighten out the links, i hope

 

[lesa]

Tomato and potato are tough ones. I spent the winter researching them- and you will find a million reasons and explanations. Certainly, it would be best to rotate crops and not plant tomatoes or potatoes in that spot. That being said, I have seen the experts say, that blight will not winter over in winter conditions like mine (zone 4). As Steve says, clean up is essential- don't dispose of anything in your compost pile. Conditions were ripe for blight this year. So many areas suffering record rainfall. I think you are right to avoid overhead watering, as well. The good thing about late blight is that it really doesn't hurt your harvest too much. Glad you were able to get a good crop.
When potato plants die back they do look pretty nasty, dead in fact. Are you sure you had blight and not just the normal die back??

 

[gettinaclue]

I was watching a series on youtube Victorian Farm, Edwardian Farm - something like that. Three people got together and lived like they lived back in those times and they got blight in the potato field (this was in Englad I believe). The "cure" was to cut the top 2/3 of the greens and burn them.

The top 2/3 because they caught it early (if I remember correctly) and the bottom 1/3 was to keep them alive and prevent them rotting in the ground. I remember very well that the potatoes didn't grow after they cut the greens.

I've tried to find this episode and I can't find it for the life of me. I'll post it if I find it.

Sorry I can't give more first hand advice - I have had no experience with it.

 

[Mackay]

Thanks everyone. More to chew on and Ill go through this reading this week. I was certainly hoping for an easier answer... like oh dont worry about it. It will go away

I do think it is late blight. everything looked so well till just a month ago. One type of potato we planted didn't get it at all and they are lined up right next to a whole dead row. Wish I had labeled better which potato I put where. Thats a lesson.

Guess Ill plan a new plot for potatoes next year just in case the hard freeze does not stop it. Im zone 3 to 4. Potatos are an essential survival crop and I must assure that they do well.