Black spot in potatoes

[IB4Fun]

Hello, I am very new here and to growing a garden. I have planted 3 different types of potatoes. I have Russet, Yukon Gold and red potatoes. I checked under one plant today and found that it had potatoes under it so I took only from that plant and brought the potatoes in. I had enough to do a little something with them for dinner. Upon cutting them though I found that the inside of some of my potatoes had black spots inside them. I have looked online but I can not find anything that tells me what causes this and how I can prevent it from happening. The outside of the potato looks very good and healthy and the plants look good and healthy as well. We have had some warm days but we have had rain off and on pretty good for the garden. So I am confused as to why this is happening.

Any help would be appreciated.

Thanks,

IB

 

[thistlebloom]

Hi IB! Welcome to TEG
That's a good question you raised, and one I've wondered about myself. I did a quick google and I found this info:
http://www.kitchensavvy.com/journal/2006/04/black_spots_on_.html
Hope that helps you out, I found it informative.

 

[IB4Fun]

I went and looked at that site ThistleBloom but it was not what was going on with mine as this black spot was dead center of the potato when I was cutting it up. I have seen this in store bought potatoes but I thought it was due to the plastic bags that they were in. These have never been in a bag. That is why I am a bit confused.

 

[thistlebloom]

Hmmm... well does this sound like anything you're experiencing?



16. Blackheart, nonpathogenic

This injury occurs as the result of low oxygen levels in the interior of the tuber and is relatively easy to diagnose. The center of affected tubers is black to blue black, in an irregular pattern, and the border of the discolored area is usually very distinct. Darkened areas of the tuber are usually fairly firm, in contrast to those of tubers affected by Pythium leak, which are spongy. Affected tissues do not smell, and shrinking of the tissue may result in the formation of a cavity in the center of the tuber. Blackheart develops when tubers are held in a lowoxygen environment or when gas diffusion through the tubers is slowed because of extremely cold (32 F) or warm (96104 F) temperatures. This condition can also develop in the field when soils are flooded or in poorly aerated storages. Because seedpiece size is effectively reduced by the death of affected tissues, plant stand and vigor are likely to be reduced.

 

[IB4Fun]

It may be, the black part did not stink though the ground was not flooded by any means. The only thing in that would be the low oxygen, but how do you put oxygen into the ground?

 

[digitS']

Hollow heart is an irregular growth problem with the tuber. The most common cause is inconsistent soil moisture, the spud scientists tell us.

Hollow heart starts out as a darkened spot in the center of the tuber. Does this look the problem:

Steve

 

[IB4Fun]

Digit yes that is what it looks like! So how can I resolve this so that I do not have this in my potatoes? Do you know?

Thanks,

IB

 

[digitS']

Well, I don't remember having this problem, IB. I have seen it in store-bought potatoes. The type of soil you have in your garden could be contributing. For a very long time, I've gardened in very porous soil. (I once experienced a season of killing plants in clay . . :/)

Despite my location, I am not a potato expert. (It is hundreds of miles to an Idaho potato field and nearly as far to one in Washington from here .) I used to grow potatoes and then stopped for quite a few decades - getting back into it about 5 or 6 years ago . . . happily!

Now, if this was a cucumber . . . . . . no wait. I think any situation that interrupts growth can be a problem and should be avoided. Of course, you can't often avoid weather problems. And, that just may be the situation your potatoes faced (so to speak).

If you can control the soil moisture a little better in your garden - do that. Mulching may be a good answer and since I cover my potatoes with compost after the plants make a good start, that compost may be the reason they haven't had hollow heart.

Steve

 

[IB4Fun]

Okay I have a question then, as I said I am a beginning gardener. When I read about how to grow potatoes I think I miss understood something. I thought (and have been told) that in order to grow potatoes you should pull the dirt up over the lower leaves of the plant to produce more potatoes. In pulling up the soil over the lower branches of the potato plant could that have caused this problem? The Soil we have holds moisture pretty good, could that also be the cause?

Thanks,

IB

 

[digitS']

I wouldn't think so, IB ~ Altho' we could be looking at the oxygen in the soil issue Thistle' is talking about if the tubers are kind of smothered.

I'm not a great fan of what I would think of as over-doing the mulch on potatoes. They are plants and need their leaves for growth and production of tubers. What is going into the tubers are far and away starches and a result of photosynthesis not nutrients out of the soil.

Still, hilling is important and shouldn't be detrimental unless the plant is always struggling to get up into the fresh air and sunlight.

In general, where are you IB that you are already harvesting potatoes?

Steve