Potatoes wilting?!?

I planted three types of potatoes in my SFG in late March. They came up very quickly, and have been growing like gangbusters ever since. I dug ~8" down to plant them, then filled and filled as they grew. Then I added a 4" box (all we had at the time), then a 6", then another 6". I think I may leave it there and see what we get (I think a few of the plants may have gotten over 10" above the mix before I filled the last time, anyway).

A couple of evenings ago, my husband discovered some holes in some of the leaves, and a big, fat caterpillar. It was dark, seemed dark green, and had stripes along the length of its body. He killed it.

Yesterday evening, I noticed one of the plants was wilted. I thought maybe it had managed to get dry, though I thought it unlikely. I watered especially thoroughly.

This morning, I noticed that not only is that plant wilted, there is another one that is wilted. What's happening to my potatoes? Is there anything I can do?

There is a disease called black leg that can affect potatoes. It's pretty easy to tell if your plants are affected as the stem (where it meets the ground) will be rotted and black.

Potatoes can also get blight just like tomatoes. Are the leaves spotted and yellow/brown?

If the plant is just wilting it could mean it's time to harvest. If you planted an early variety this is likely your answer. Sometime potatoes die back before they flower, but they still produce potatoes.

HARVEST?!? I thought potatoes took a long time! I just did bury them that second 6", too!

I'll go look at the leaves and the stems to see if I see any discoloration...

(I did notice what looked like a developing flower head on one of the reds yesterday.)

LOL

What can I say, sometimes mother nature has a mind of her own.

BTW, it could also be over-watering, but that usually isn't a problem with MM.

Okay, I went and looked. The stem is normal at ground level. The MM is damp, and I've been watering lightly every day, or a little heavier every other day if I miss one. I watered the potatoes heavily yesterday because of the wilting, thinking they had somehow dried out. I have not had any trouble with the MM retaining too much water, and I was very careful to follow the recipe to the T, though I did end up with fine vermiculite when I thought I had bought coarse.

Here's a picture of the largest wilted plant (if you click to see it full size, you should be able to read the text I put):



I have several smaller wilted plants, and I have 12 plants in all, 4/square. The plant shown is a Red Norland that has been in the ground about 5 weeks now. I have Russets and Purple Majesty, and they each sport a wilted plant or two as well.

Hmm. I'm still researching, but I found this description of bacterial wilt to fit the picture you posted. I'll let you know if I come up with something else.

http://www.oisat.org/pests/diseases/bacterial/bacterial_wilt.html

I hope this isn't it... But it looks like it might be.

Can someone else chime in here?

If it is Bacterial wilt you need to get those plants out ASAP and avoid planting potatoes in that area.

Oh, no! That's just awful... I'll be doing more research...

Some hope?

I just came in from looking at the potatoes. They are every bit as wilted as before, and probably more so.

But...

I began to carefully remove the MM from around one of the smaller wilted plants. About 2" down, I found a gash that went about 2/3 of the way (at least) through the stem. It had obviously been this way for a while, because the stem around the gash was mushy. There was a small insect that looked almost like a red mite marauding about the gash, trying to figure out where all his cozy cover had gone.

I proceeded to dig around the largest potato plant victim, but found nothing, though I went a good 6-8" down. I cannot say that my inspection was thorough, though, since I could not see the far side of the stem, and didn't uncover as much of that side for feeling. The stem was rigid, though, not floppy like the other.

I uncovered a couple more plants a couple of inches down, but found nothing. One of them was in the middle of a thick group of stems, though, and was difficult to see. The other was at the far side of the box.

Does the gash I found on the first one provide me with some hope for all the others? Is there a chance that this is not bacterial wilt?

I don't think it's a bug issue. The one with the gash could be black leg. It starts underground and works it way up.

Other than that, I really just can't say what it is. I wish I could help you with a definitive answer, but I can't. It definitely looks like Bacterial Wilt.

At this point, I'd contact my country extension agent and ask him or her what they thought. Send in some pictures.

I will say this, Bacterial Wilt is highly contagious. Make sure to wash your hands and sterilize your tools before working with any other plants in your garden especially if they are in the nightshade family.

I went to go dig up the potatoes, not wanting to take a chance with eggplants nearby and tomatoes not much farther, since the extension office won't be open until Monday. First, I conducted a little experiment, based on something I saw here: http://www.avrdc.org/LC/tomato/bactwilt.html

I took a glass measuring cup of water out, and snapped off the top of a healthy plant (I was digging them all up anyway). I put it in the water, held well above the bottom, and watched. Nothing visible came from the stem. So I snapped off the top of the large, wilted plant and stuck it in the water. I expected to see little streams of bacteria. But nothing... so... inconclusive.

I began removing the MM from the middle of the box. Once I had removed a couple of inches, a nearby wilted plant fell over. I looked, and it had a mushy stem. At this, I began to concentrate on removing the soil around the large wilted plant.

I found a leaf stem that had been severed by the same rot. I continued carefully excavating. More than a foot down, I finally found a couple of inches of the stem on this plant, too, rotted.

I think I'm looking at something besides bacterial wilt now. Is this black leg? The rot doesn't look black, though I haven't exactly washed the MM off of it, either.

Am I dealing with something that is perhaps less virulent than bacterial wilt? Less of a threat?

Miss M,

It sounds like we might be able to rule out bacterial wilt for the moment.

Let's look at the rot a bit more.

Take a look here at this article from OSU. There are 3 pictures of stem rot. Does your plant look like this? http://ohioline.osu.edu/hyg-fact/3000/3106.html

Also look here for stem rot: http://diseases.growingpotatos.org/stem-rot-potato-disease/ and here http://www.ipm.ucdavis.edu/PMG/r607101111.html

Are we getting close at all?

Dizzygardener, you have been so patient and helpful!

I carefully dug the largest affected plant out in its entirety (except the top, which I had broken off for my water experiment). I wanted to be able to look at the whole thing, and get a better, complete picture of what was happening.

Here is damage to a smaller plant, still in the hole:



Here is the damage to the large plant, still in the hole:





A picture of the plant after digging it up and rinsing it off:



Close-up of the rotted stem:



Close-up of the Red Norland seed:



A couple of pests, starting with a grub I found under the seed:



Some sort of winged ant (I found several of these in one scoop of MM, along with some little black ants) that was about 6" below the actual surface of the garden, or 22" below the surface of the potato box, right near the seed:



I don't think the pests have anything to do with the demise of the plants.

I'm leaning a little toward aerial blackleg a.k.a. aerial stem rot or bacterial stem rot. The damage does not appear to originate from the seed. The seed is firm, but has darker lesions or bumps all over it.

What do you think?

Firstly, what amazing pics. Now I don't mean to make light of your problem but to share that type of detail is great for ALL future potato growers. The fact that the plant is still trying to live through such trauma is impressive.

The seed potato appears diseased to begin with. Those spots seem un-natural and perhaps soft rot or black leg that has been suggested. The lesions on the seed potato look indicative of that hypothesis.

Dizzie, you have supplied some great links relating to this also. Its funny because I spent sometime on google looking for pics and I was just about to post the Ohio state ext service link but looked back through the thread and you had the same one posted so had to delete. Those 3 pics seem identical to what you have, right down to the seed potato lesions. It certainly looks like that. That would be my guess for sure.

I'm sorry Miss M but thanks for the uploaded pics. They really help.

Thank you, Staf, I appreciate it. Though naturally my primary reason for posting such large, detailed pictures was to aid any possible diagnosis, my secondary reason was to provide them as a resource for others. I figured while I hate to lose the plants, I may as well use it as an opportunity to add to the knowledge base.

An interesting note is the fact that in the first picture I posted yesterday (I think it was yesterday), the plant that I had labeled the "healthy neighbor" turned out to be the other half of the same plant (the stem on the right side of the whole-plant picture I took today). I thought that was pretty amazing, too, that it was still fighting to survive, with the disease rapidly progressing through the plant.

From what I've read so far, I need only remove the infected plants, and hope that the rest will survive. I believe the russets may have been the infected source, since I think I may lose them all, and they were the first ones I planted. The others may have been contaminated when I used the knife I had cut the russets with to cut a red and a purple . I know better, now!!!

We have had the PERFECT conditions here for this disease. While the MM isn't exactly wet, it is constantly, pretty thoroughly damp. Add to that the flirtation with 90* for the last couple of weeks (as well as the nearly daily 80s before that, back to mid-February), and it truly was a recipe for disaster. I don't know that I could have done anything differently to prevent this, once the potatoes were planted. I need to check the bag to see if it said that these were certified disease-free seeds. If not, it's a lesson learned to be sure and look for that notation. If so, then I know not to buy this brand again.

I will post back what the bag has to say. I also need to cut open that seed potato and see what it looks like inside.

I looked at my seed potato bags. The russets were from Dutch Valley Growers, a 5# bag. They had nothing on them about being disease-free. I looked on their website, looked at their promo brochure, still nothing about their seed potatoes being disease-free.

The Red Norland and Purple Majesty were from Van Zyverden, and they said nothing about being disease-free, either.

I got them all from Wal-Mart, but they are sold elsewhere. At the time I bought them, I didn't know about looking for disease-free seeds.

I cut open the seed potato of the plant I dug up, and one of the new potatoes:



As you can see, the seed potato, while otherwise quite crisp, had a mushy spot on it about the size of a half dollar. I didn't even realize it until I cut the potato, and I happened to cut it there. The spot is like jelly... or even almost liquid. There is no dark ring or anything else, so I can only figure that the demise of the seed potato itself had only just begun. The new potato was almost perfect, with only a slight hint of a shadow suggesting something might be starting to go wrong.

I will be digging up the remainder of the affected plants, and hopefully it will end there.

I am sorry for the demise of your potatoes! BUT, you take some fine specimen photos, well done and thanks for sharing!!!! Do you think you will try more potatoes this season in another spot, some where?

Also, good job Dizzy on the diagnosis.

Miss M, I too am sorry that you are going through all this, but I'm glad we were able to come to a resolution. I am also quite impressed with your photos! This will mmake a fine resource. I'm just glad I was able to help a little with the diagnosis. Please do keep us up to date on the progress of you other potatoes. Here's hoping you don't have this problem with those.

Firstly, thank you for this discussion. My potatoes were going thru this, two out of 5 plants and your photos and links helped me determine a possible problem. My question is what to do with the soil and mulch that I have around the potatoes? Can I reuse this soil on a different vegetable?

Hi,

I just had to pipe in and say that I really appreciate these posts. Miss M, your photos are awesome!! I just noticed that you even have arrows and words to direct viewer's attention to a specific spot. Wow! Thanks.

Oh, and I would also like to know what can be done with the left over soil after a situation like this.

I appreciate your willingness to share this discussion and show pictures. I learned a lot and will be checking my potatoes for any symptoms.

Just an FYI.... This thread is over two years old and most of the folk who posted here do not frequent the Forum much these days. Please go ahead and do some research and get back to the rest of us with any information you find. Also, please post links to any information of value.
Thanks!

PS: A good source for information is you local Coop Extension Service Agriculture agent.

camprn wrote:Just an FYI.... This thread is over two years old and most of the folk who posted here do not frequent the Forum much these days. Please go ahead and do some research and get back to the rest of us with any information you find. Also, please post links to any information of value.
Thanks!

PS: A good source for information is you local Coop Extension Service Agriculture agent.

Hi camprn,

I truly did not notice that this was a revived thread. Thanks for pointing that out to us. I feel a bit silly that I didn't see that.

I did do some research about use of soil after plants are infected with black leg. I found some information from the American Phytopathological Society (APS) ... say that five times fast ...

Solke H. De Boer wrote quite a bit about this topic. His/her article is quite long, but at the same time very comprehensive in its treatment of this subject. The website link is:

http://www.apsnet.org/edcenter/intropp/lessons/prokaryotes/Pages/Blacklegpotato.aspx

I don't want you all to have to read the entire article, so to summarize, De Boer wrote:

"The blackleg bacterium survives poorly in soil. Although other members of the pectolyic erwinia survive in surface water and in the soil environment, all evidence suggests that the blackleg bacterium does not survive very well outside of association with host plant tissue."

I actually had a blast researching this topic. I waited WAY to long to plant potatoes. It is far past the window in time to do anything with them, so next season for me.

Happy gardening!

I didn't notice the date either, lol! Thank you for the research Windmere, it will be something that will come in handy for others!

Hi, y'all!

It's been a year since I visited the forum, and two years since I started this thread. I'm glad that it's been a help to others!

I actually never replanted potatoes, but not because I didn't want to. The following January (2012), I went to clean out my thoroughly weedy SFG to prepare to plant. We discovered pretty much the whole thing had turned into a giant fire ant bed. I freaked, treated with Amdro, and then started this thread: https://squarefoot.forumotion.com/t9902-help-i-ve-been-stupid .

Anyway, the garden never got planted. A couple of weeks later, my uncle (with whom we were living) started dating rather seriously, and we realized in rather short order that we needed to move. So the garden went to the weeds, and we searched quickly for a place to move. Long story short, we bought 2 acres in the middle of nowhere, and moved last fall. And... my uncle got married two months later.

So we're planting for the first time in two years! And my standing-water SFG lies fallow. Ah, well...

I did not have the resources to fund enough Mel's Mix, so I have a row garden for now. I just needed to get some plants and seeds in. We'll see what happens later. At least I could do the regular SFG here, instead of building Noah's Ark.

As far as what you can do with the Mel's Mix that has been in contact with infected potatoes, I was solarizing mine. You put it into a heavy black plastic bag or two, and spread it flat on the driveway or somewhere VERY SUNNY that does not stay cool in the sun. The black plastic will soak in the sun, and the Mel's Mix will basically cook and sterilize. I don't remember how long it takes... a week or two, maybe? I never got back to mine, as things got a bit crazy!

I'm so glad I came on today! I came because a friend is growing a garden in the desert, and I wanted to find the pond bed threads I remembered.

back, Miss M
I'm new since you were here last, but I will follow with interest your resurrection to SFGing.