Topic: seed potatoes : does size matter?

[plotstoeat]

Do smaller seeds produce smaller crops?
Also; is it too early to plant spuds under glass?

All thoughts welcome

Thanks. Ken

[manicscousers]

Our seed spuds range from pullet eggs to bakers this year, don't know the answer to your question, sorry. Just started 2 bags of premiere potatoes in the poly, will fleece them if it gets too cold 

[goodlife]

In certain extend the size does matter.
Tiny seed potatoes usually tend to result lots of small spuds...or just one or two larger ones...it will take more effort for the potato plant to reach good size, when it is able to crop properly .
 Where as larger size 'seed' has more energy to 'feed' more robust plants to start with..the number of 'sprouts' left on that 'mother' potato will determine if you then end up fewer but BIG potatoes or number of good-normal size ones.

And no...it is not too early to plant spuds under glass...they will come up and grow when they are ready..the main thing is that once the foliage is up, it will need to be kept frost free.

[Ellen K]

Last year I planted a row of Charlottes in size order, the largest was 2 to 3 times the size of the smallest, 25 tubers in all (the contents of a bag from B&Q).

Whilst the largest broke the surface earlier that the smallest, there was no real difference in yield per plant compared to normal plant-to-plant variation.

This is just one experiment mind, and I do chuck a load of chicken pellets and Poundland potato fertiliser in the trench when planting.

But I don't think it makes as much difference as you think, compared to feeding and watering.

[plotstoeat]

Last year I planted a row of Charlottes in size order, the largest was 2 to 3 times the size of the smallest, 25 tubers in all (the contents of a bag from B&Q).

Whilst the largest broke the surface earlier that the smallest, there was no real difference in yield per plant compared to normal plant-to-plant variation.

This is just one experiment mind, and I do chuck a load of chicken pellets and Poundland potato fertiliser in the trench when planting.

But I don't think it makes as much difference as you think, compared to feeding and watering.

Thanks Ellen
I like your scientific approach , although, as you say, it's not conclusive. The high amount of fertilizer could be a big factor. Do you water them in dry spells?

[gavinjconway]

The growers know what they are doing so anything bought as proper seed spuds will grow a fine crop.. if not then you need to look at your methods.

[digmore]

I am with Gavin, seed pots are regulated.

If you have small seed pots, any variety, plant them at the end of the row and leave an extra inch or so before the next one. They will have better foliage and more pots underneath. Also place your potato fertilizer in the raised soil above the seed pots, it gives a longer period of feeding as it dissolves downward through the soil as it gets wet.
 
I find that any small pots I have left over from last year are only worth planting in 30L buckets or bags to give small (new) pots.

I started pots in Nov/Dec in old fashioned dustbins in the greenhouse (unheated), they are just showing the first shoots.

Digmore.

[nefertiti]

With enough fertilizer and water the difference is more likely in first earlies due to the shorter growing time.
For maincrop the size of the seed potato does not matter (from experience). When i have more space than potatoes and they have multiple "eyes" i cut them in pieces and they always grow the same as whole ones. My grandad always cut his. He would turn in his grave seeing people planting whole baking potatoes. 

[plotstoeat]

Thanks for all your comments folks. I have been growing spuds for many years but, as with many things, there are always new things to learn and other stuff you forget like cutting large ones in half (thanks Nefertiti)

[shifty581]

I have lots of large seed potatoes, is it O.K to cut them in half, if so do I cut them now as they are chitting or when I plant them.

[Floyds]

I have lots of large seed potatoes, is it O.K to cut them in half, if so do I cut them now as they are chitting or when I plant them.

I don't think it really matters. I've done both and there was no difference in crop growth. Whatever you do cut them lengthways so that there are roughly the same amount of eyes either side.

[antipodes]

This gives me hope! I have discovered that a small box of last year's potatoes have badly sprouted; some of them are very small spuds. I am tempted to chuck em in the ground and see what happens. Surprisingly despite a rainy year last year I got no blight. So they should be pretty healthy. It is so mild here I am thinking that I could probably start some spuds, if they start to come up I will just keep earthing the foliage if it turns frosty.

[gavinjconway]

antipodes I'd rather not plant those you have kept over as you could spread viruses... for the sake of a few quid for a bag of proper seed spuddies why take the chance of diseases..

[Tee Gee]

I have been reading this thread with interest and would like to offer a few basic observations;

Seed potatoes are not seeds they are tubers therefore vegetative, and we all know crops from seed do not as a general rule produce plants true to the parent,but vegetative cuttings do.

So with potatoes the ' eye' is the most important part of the tuber as this is where the haulm and root system emanates from (the seed potato rots away) so the more eyes there are the more haulms you will get meaning more potatoes but not necessarily heavy potatoes.

Usually there is an optimum weight you will get per root, which is usually relevant to the nutrients in the given root area.

That is more tubers quite often results in smaller tubers unless you add more nutrient.

So some gardeners take steps to reduce the haulm growth by rubbing off  a few chits from a seed potato or cut it in half.

They want to reduce the amount off roots,and subsequently the number of tubers per haulm.

This means the haulm can sustain the tubers better.

Which in my opinion is the main reason we all get different results.

That is; we plant seed tubers with varying amounts of 'eyes' in soil with varying amounts of available nutrients.

To put another slant on the 'eye' issue if you pare off the eye and grow it in a culture disc ( macro propagation) you will produce a seedling which will produce a normal crop of potatoes.

Then there is the exhibitor who grow in bags within a controlled environment that hopefully produce spotless tubers of a regular size.

So in my opinion it is simply a case of what lengths you want to go to when growing your crop.

In terms of disease caused by saved tubers I have reservations about this.

I am of the opinion that if the crop was not diseased prior to saving then they should be OK as most potatoes are affected by soil borne or wind borne diseases on the plot.

......and that concludes my thoughts on the subject!

[Ellen K]

I've seen people rub chits off - it's a waste of time, they just grow back once you've planted.

And I'd support buying new seed potatoes every year as they are tested for diseases and certified disease free, and they are not that expensive.  For me, one of my goals is to try to keep down the disease load on my plot, not increase it by replanting.

If you want big potatoes, you need to grow a variety which produces big potatoes, duh!  And feed / water well.  And space em out!  I see a lot of spuds planted very close together.

[Ellen K]

I think sometimes we believe things that "have stood the test of time" etc but we forget that the world has changed.  We are stuck in a timewarp - I know I'm that way.

For instance, I'd like to drive round in an Audi car and won't consider a Skoda, because Skodas are rubbish, right?  Well, that might have been true in the 1970s but in this century they are made to a much higher standard by the same company.

Similarly, we could get away with gardening practices which won't work now.  A lot of diseases are pest-born and back in the day, we had the likes of DDT and lindane to keep pests down.  Not so now so housekeeping is more important than its ever been.


......... and that concludes my thoughts on the subject 

[goodlife]

Code: [Select]

In terms of disease caused by saved tubers I have reservations about this.

I am of the opinion that if the crop was not diseased prior to saving then they should be OK as most potatoes are affected by soil borne or wind borne diseases on the plot.

My thoughts too....
I save most of my seed potatoes each year..but it all comes down to selection.
 I'm not that convinced about commercial seed potatoes being that 'superior'. If they have been grown to produce 'virus free' stock...does that really cover each and every spud and how can they promise that? Lot of potatoes commercially are handled with commercial machinery...so you do get odd damaged ones in a bulk bags..that could be handling damage but could also be source of other 'problems'?
The mother plants that I choose my seed potatoes from, haven't shown any problems during their growth....they are blemish free through out their storage...cleaned from 'old soil'  etc etc ....and I can say all the years I've been growing potatoes..my potatoes have had very little health problems.
It is a bit of extra work to produce one's own 'seeds'...but I don't find it too much hassle. I start seed potato 'crop' early in buckets of compost in GH...and once the weather outside is more and less frost free the buckets go outside for a while..tops cut/removed as soon as the spuds are ready and let to 'mature' and develop good skins..and if the weather is on wet side..it is easy to put lids on the buckets to keep the compost 'dry' And letting the compost go to 'dry side' towards the end mean that one can store the spuds until autumn in buckets and not having to find place where to keep them during (hot) summer months.
Starting early indoors mean that there is hardly any aphids about..later on the buckets go near my bird feeders> aphids will have struggle to survive from 100's of birds... ...not that I see many aphids anywhere on my plots

[GREGME]

Just a quick opinion that if i have a choice of size I go for similar sized seed pots usually just larger than a hens egg.
It may not make much difference but at that size you know they will always rot down before harvest ( hate finding the old gooey one when I pull) Also since tubers form higher than the seed potato you won't need to plant individual large ones deeper or earth those up more. Small tubers can do well but I find they can shrivel up during chitting and don't look as healthy.

[telboy]

After many years, I don't now grow many maincrop spuds but do grow a good row of earlies to avoid disease.
My grype is, why the 'sheds' bring the stock in January and hold it in a heated warehouse where the 'chits' grow to ridiculous lengths.
I float in at a sensible late January and see a pile of sh*t?
I try to explain the reasons to the 'Manager' the good way to store stock but it's like trying to educate someone why they should not buy a Purgeot.

[gavinjconway]

Nothing wrong with a Peugeot..... Ive probably had 10 of them...