By Esty
Wiltshire,
United Kingdom 
Hello,
I have a courgette enigma: I have grown from seed two yellow ('soleil') plants and two green ('zuccini') plants. One green and one yellow are in a raised bed (A) with manure, the other yellow and green are in a new bed (B) (I previously had chickens there) with the same manure.
In bed A both yellow and green plants are doing very well, while in bed B the yellow one isn't doing well yet the green one is and they are side by side. This yellow one's leaves have turned yellow with a little green left in the veins and a little bit of mozaic effect with one young with yellow dots on and new leaves are affected as they unfold and grow as well as the old ones. It is, I will add, producing many tiny courgettes while the green one isn't yet.
I have looked at potential nutrient deficiencies inconclusively but just cannot understand why this yellow plant is suffering while the green one right next to it isn't. (None had this problem last year, by the way).
Any wisdom would be apreciated,
Miss Barbey
16 Jun, 2012
Answers
I cannot answer the question but on reading the title quickly my brain came up with the title courgette enema.....gave me a bit of a tingling sensation somewhere just thinking about it.
Sorry about that, i'll keep away now.
16 Jun, 2012
Similarly silly is my response.
The Courgette Enigma by Agatha Christie. Another challenge for Miss Marple.
16 Jun, 2012
Thanks guys, I'll give it some potash tomorrow and if I need a book to read...
16 Jun, 2012
I wondered about mosaic virus? And I read enema too at first!
16 Jun, 2012
I did wonder about the mosaic virus but it doesn't look like it from photos in books and on the net.
I did a soil test today and the results are that the nitrogen from the chickens must have leached out during the wet spring as that came up as very low. The potasium was non-existant but the phosphorus was medium/medium high. So I gave everything some potash and will add nitrogen asap.
Funny thing is that other than that one plant's colour they look very healthy despite the lack of nitrogen.
17 Jun, 2012
It is indeed an enigma and to be honest I haven't come across this but I'll hazard a guess;
You said you had chicken in there!
What is going through my mind is you may have a 'hot spot' under this particular plant.
What I mean by hot spot is; raw chicken dropping can be quite toxic to plants if the roots are physically in contact with them.
I am thinking that just by chance there is a dollop of raw chicken manure immediately under the affected plant and the roots have come in contact with it, causing your problem.
Now chicken droppings are generally high in nitrogen and phosphates but low in potash, so you could try a high potash feed, something like tomato feed, and see if this balances the fertilser content around the plant!
But as I said; its only a guess!...Tg
16 Jun, 2012