Topic: ANOTHER POTATO PROBLEM

[PREMTAL]

Hi All,
         This year I decided to grow a Dutch potato by the name of "Symfona" because it had a high resistance to disease.

The yield was not great but the majority of the potatoes were large red skinned and free from insect damage. :)

However on preparing them for the pot it was evident that each large potato had a 2mm brown spot right in the centre. :(

Can anyone enlighten me as to the cause, I should also add that this condition was not found in the few smaller potatoes of the harvest. ???

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[sandersj89]

I think this may be interla rust spot also know as internal fleck.

The brown spots are dead cells but have little effect on the eating quality unless there are lots of them.

I get it a little in Arran Victory, a late maturing variety.

More information here:

http://www.dpi.qld.gov.au/horticulture/17360.html

Jerry

[PREMTAL]

Hi sandersj89,
                       Having read your link this may well be the answer, the area in which the potatoes were grown is the only light textured soil on my plot

The soil dries out much quicker there and is therefore more susceptible to rapid moisture loss.

Thanks for the info. ;D

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[john_miller]

The positioning of the brown spot would indicate to me that this:
http://www.panhandle.unl.edu/potato/html/hollow_heart.htm
is more likely to be the cause as the internal browning that Jerry experiences tends to happen at the end of the tubers. Hollow heart is also more likely to occur on well drained soils too.

[PREMTAL]

Hi john- miller,
                       The star shaped cavity described in your link is exactly what I have found in the large tubers that I have so far prepared for eating.

This is my first season growing annual crops on my allotment, it is also the first time in  my many years of growing annual veg in my garden that I have  encountered this problem with potatoes.

I am grateful for your input, I will now test the soil to establish the nutrient values over the entire allotment area.

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[moonbells]

I had hollow heart last year in my Sarpo potatoes, as I didn't really prepare the ground very well, didn't add any manure and didn't water in the season. (Lotties suffer when you're organising weddings!)

This year I dug a trench and added about 5" manure in the bottom, planted the spuds straight into it and then covered it all over. Have a great crop, no hollow heart so far noted (though have only eaten one of the giant spuds) and this despite this summer being dryer than last.  Did water the spuds a bit but not very much.

moonbells

[Sarah-b]

Which variety did you do this year MB? - same as last year?

Our straw and manure system seemed to see off the scab - but still have a bit of slug trouble and fairly small harvest.
Think I will try desiree next year as our neighbour does very well with that and they seem to be slug resistant? - or maybe he is just lucky...

SB

[moonbells]

SB - yes, some more Sarpo, with Pink Fir Apple, Ratte, Burgundy Red,  Salad Blue other maincrops.  Royal Kidney, Estima, Red Duke, Kestrel. Next year I'm swapping Estima for Picasso. 

All individual tubers, so a couple of this, five of that etc.  All got planted in loads of manure and have a lot less scab this time round.  Very few problems at all really.

moonbells

[john_miller]

I am grateful for your input, I will now test the soil to establish the nutrient values over the entire allotment area.

If you have manured and fertilised your soil well then there should be sufficent nutrients to grow a healthy crop. I would emphasise the part in the web page about moisture stress, especially with your comment about your soil. Sufficent moisture during tuber initaition and swelling is critical. The information regarding K in the link was new to me as I have always been taught that a deficency of B is more commonly considered a promoter of hollow heart. Given that it too is necessary for cell formation and that it can a combination of low levels and low moisture (it is highly water soluble) that will lead to local deficencies and promote hollow heart.
I have seen a number of links here to U.S. web sites, particularly those of universites, for various pathogen and disorder diagnoses. They should always be viewed with a little scepticisim as they will reflect local conditions which may not translate into covering other areas. It may be that Nebraska has soil types that have low residual amounts of K, and/or high levels of B, so that hollow heart will have different causes than the U.K. As an example, one web site I saw, from the University of California at Davies, stated that potatoes grown locally don't have a photoperiodic response. It is only when you realise that they grow potatoes through the winter for early spring cropping, too hot and dry the rest of the year, does this make sense (they are growing the equivalent of the U.K.'s "earlies").

[PREMTAL]

Hi john_miller,
                       I try to be as organic as possible and therefore tend not to use manure unless it is from Aberdeen Angus stock which I am told is relatively free from growth hormones, steroids and the like.

My normal feed is a Comfrey and Nettle tea mix, this is the fertiliser of choice for the organic types at our allotments.

I have made a point of asking other plot holders if they have had the same problem, but so far have no one has encountered it.

You mention high levels of B as a possible causal factor, I am not familiar with this, our test kits only test for K, N and P. ???

I do however see where you are coming from with the California seasonal cultivation situation. ;)

Thanks again for your input John. :)

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[john_miller]

B levels have to be tested at a laboratory. It is needed at very small levels and simply applying some in the hope of reversing a problem generally associated with it's deficency is not recommended. Problems associated with B toxicity are very common because people follow this path.
I would again emphasise the part of my post about the water soubility of B as you specifically mention that this problem happened on the part of your plot with light, well drained soil. Inadequate moisture during tuber expansion will create this problem. It is very likely that added manure will supply the levels of B necessary for good plant growth as U.K. soils in general have adequate levels of B and which plants and animals can absorb into their tissues. Additionally, your comment about not finding the problem in the smaller potatoes would indicate that the in immediate area of the larger tubers there was not sufficent B to develop the greater number of cells in these tubers.
While this may complicate your rotation other crops where B deficency can be an issue include swedes (also resulting in hollow heart), cauliflower, cabbage ( resulting in hollow stems) and celery (split stems which wil turn brown).

[PREMTAL]

Hi john_miller,
                       My thanks for your in depth reply on the question of "B" I have it mind that my rotation for annual crops could be extended to 4 years.

My plot is primarily dedicated to growing medicinal herbs and fruit.

The herbs usually require a 3 to 4 year life cycle to absorb nutrient before they are considered worthy of medicinal value.

I  have also been trenching and adding over ripe bananas and organic chicken manure in the area concerned, the bananas I scrounge from the local  supermarket.

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[john_miller]

The herbs usually require a 3 to 4 year life cycle to absorb nutrient before they are considered worthy of medicinal value.

Can you provide a reference for this? As I understood it, the older plants are the greater the levels of carbon, a non nutrient, is present in the tissue, as a percentage of dry matter. An acquaintance of mine grows Echinaea for a local medicinal herb company and he harvests 22 months after sowing. I realise economics may have an influence upon this harvest but I have always assumed there were other factors involved that made this time period optimal.

[PREMTAL]

Hi john_miller,
                       Herbs like Ginseng, Astragalus and Chinese Liquorice are among many medicinal herbs which require a long period of cultivation.

In the case of Ginseng it is not considered to be of any use medicinally until it has the minimum 6 years of growth.

I also grow Echinacea, which will be harvested next season for the 3rd year roots.

I tried growing Ashwagandha as an annual, this is an Ayurvedic perennial herb which has similar medicinal properties to Ginseng. I was easy to cultivate but the harvested roots had no medicinal value worth the effort of their cultivation.

The rule would appear to be that if mother nature gives a medicinal plant a long life span she has a good reason for doing so.

In such cases it is usually the root of the plant which contains the medicinal virtues, and these virtues take years to accumulate.

I hope this goes some way to answering the question of life cycle before harvest John.

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[PREMTAL]

Hi john_miller,
                       Saw this item in one of our local papers last week, six 110 year old ginseng roots sold for the astonishing price of $119,400 in South Korea. ;)

http://hosted.ap.org/dynamic/stories/S/SKOREA_PRICEY_GINSENG?

[john_miller]

After reading your previous reply I realised I wasn't thinking widely enough. My practical experience of herbs is mostly restricted to culinary types and have seen 'mature' examples of them from California that were mostly wood with a few leaves attached. That is what I originally thought you were referring too. You did prompt memories of an export conference I attended many years ago where the featured speaker was a Vermont grower who was exporting North American ginseng to China and was looking for other growers to join him as he couldn't keep up with demand. He specifically mentioned harvesting his crop after it was in the ground for six years. 
$119,000? I could live on that for a while.

[PREMTAL]

Hi john_miller,
                       The Chinese favour American ginseng for its calming effect on the nervous system, I give this to my mother who is 86 and suffers from senile dementia as it has for her a beneficial on the clarity of her mind.

People seem to believe that panax(Korean) ginseng is a cure all but this is not the case.

Anyone who is of a nervous disposition or hypertensive should steer clear of panax ginseng as it can exacerbate their existing symptoms.

Similarly liquorice should be taken in very small amounts on a regular basis as large amounts can upset to fluid balance of the body if taken often in large amounts.

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[john_miller]

Hi john_miller,
                       The Chinese favour American ginseng for its calming effect on the nervous system, I give this to my mother who is 86 and suffers from senile dementia as it has for her a beneficial on the clarity of her mind.

I thought I remembered the grower making that comment. It was also the reason that he was looking for other growers to join him. This was happening as the "thaw" in relations between China and the U.S. was happening and the market potential, as he saw it, was so great that he knew he couldn't singlehandedly fill it.

Similarly liquorice should be taken in very small amounts on a regular basis as large amounts can upset to fluid balance of the body if taken often in large amounts.
                                                     PREMTAL

I'll carry on getting my liquorice flavour fixes from fennel in that case!

[PREMTAL]

Hi john_miller,
                       Ginseng could be cultivated in the UK as our climate is well suited, the problem is we haves slugs in abundance. >:(

I would go as far as to say that, if slugs had a market value we allotment people would be financially independent. ;D

Getting back to reality, I have given much thought to the differing medicinal values that this herb provides.

This herb in Korea can be found in the strangest of locations, halfway up a rocky outcrop or a forest floor.

It seems to mirror the conditions of its locality and the available nutrients, survival despite the adverse conditions on a physical level.

This is why it is so highly regarded and why large sums of money are spent on such roots.

Having said that cultivated Korean Ginseng still retains some of the physical medicinal virtues due to the soil that it is grown in.

American Ginseng however is cultivated in soil which has a nutrient value quite different to that of Korea, this Ginseng does not require to fight for survival.

If you think of the two differing soil conditions, coupled with the need or otherwise to survive, this might well be why the medicinal values also differ.

There is also a Japanese cultivar, but I am not at this time acquainted with the medicinal virtues it affords.


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