I think my raspberries may have manganese deficiency

[watervole]

http://www.hbci.com/~wenonah/min-def/plate308.jpg

A lot of the leaves look like that, with yellow between the veins. They're growing in the least fertile corner of the garden (the one that originally had the most builder's rubble in it) and it's never had as much compost dug into it as the rest. Does clay contain much manganese? It may be that organic matter makes minerals more available. My soil science was a very long time ago - does anyone know much about it?

Comments

[linda-joyce.livejournal.com]

From the little I remember from my soil science days, what clay contains depends on what is in your sub soil. But what ever it contains it holds onto mainly because it gets waterlogged easily and plant roots don't work well in waterlogged soil. From my wide perusal of gardening programs putting more organic matter into clay soils can only be a good thing. well rotted farmyard manure seems to be tops.

[reapermum.livejournal.com]

Just checked Raymond Bush, "Soft fruit growing", Penguin, 1951.

The builder's rubble could be over liming the soil, causing an iron deficiency. His answer was more organic material in the soil.

[watervole.livejournal.com]

Iron deficiency yellows the leaves, but does not leave the green veins - at least not according to the picture I found on the web.

I wonder if lime affects manganese too?

[reapermum.livejournal.com]

I wonder if lime affects manganese too

I don't know, but all the gardening books I have and trust agree that lime is bad for soft fruit.

Manganese or Magnesium?

[johnrw.livejournal.com]

It could also be magnesium deficiency, yellowing in the pattern shown it more probably that than Manganese (Which if it is manganese you could easily treat by using an organic mulch with added seaweed) As for magnesium deficiency try adding a dessert spoon of epson salts to a large watering can of water.

As you say the soil is clay and builders rubble - now that's an incompatible mix if there was one, a heavy clay will tend to lock nutrients away in the clay matrix, (and be slightly acidic) and builders rubble will tend to be somewhat alkaline from either the lime mortar (if very old) or the cement mortar) I'd think you've got and interesting experiment in applied reclamation there!

Another point, are you suffering from low rainfall? A water shortage has the secondary effect of locking the nutrients tighter into the clay matrix.

aspodeline would probably have better ideas, as she's done gardens professionally. However she's offline for the next week, which doesn't help you now.

Re: Manganese or Magnesium?

[watervole.livejournal.com]

I've just given the Epsom salts a try. Let's see how they work out.