[lucylike]

I have started yellow and green courgettes and pattison squash seeds
at the end of April and transplanted the plants about three weeks ago.
All plants were treated in the same way but the leaves of the yellow
courgette plants start to turn yellow. All other plants are fine.

Has anyone seen that type of colouring of courgette leaves before?
Is it some sort of virus or just a deficiency?

I would be happy about some advice.
Thanks

[Mitsy]

Have you checked for greenfly? 

[lucylike]

No, not yet. Would they be sitting on the plant?

I had a look underneath the leave but I couldn't see any knobs
or eggs or things like that.

[Mitsy]

Under leaves and I found babies hiding in the new shoots on the stems 

I lost my pumpkins and some cucumbers cos of them 

[lucylike]

Ok, I'll have a look when I pop around the allotment next time.

Does it mean it could be this mosaic virus?

[Elcie]

The leaves on my yellow courgettes are the same and they are healthily producing courgettes.  I assumed they were yellow because of the variety.

[lucylike]

Good point, I hadn't thought about that. I assumed that the leaves would be green regardless. In general the plants do look healthy.

I'll check for greenfly anyway, just to make sure.

[theakston_uk]

A couple of leaves on my courgette were turning yellow, had a look underneathe them last night and saw some grrenfly lurking so I quickly got shut of them.

[Sadgit]

well well well.. I never though about greenfly on courgettes.. I always have some leaves that go yellow and die but thought it was normal, as the number of fruit is always fairly high.. gonna check my pumpkins at the weekend as they are looking dreadfully yellow....

[fuzziefly]

Hi, I Grew yellow courgettes last year (Variety Parador F1- I think? )  and had similar things with the leaves. Mine grew fine and cropped prolificly. I dont think that because the fruit is yellow that the leaves will show signs as well.  I think it is a deficiency of something.

[lucylike]

I just checked my courgettes but couldn't see any green fly. There were some black flies on the tomatoes next to them though!?!  Would the green fly just sit there or lay eggs?

I think I'll probably sit and watch. As long as there are no misshapes I think it might be ok.

[MoreWhisky]

My parador leaves are yellow.

[richyrich7]

Nitrogen or magnesium deficiency would be my guess, give them a good feed with tomato food and a dose of epsom salts about a teaspoon full in  a gallon of water should do the trick. 

[realfood]

At least one variety of yellow courgette has yellow leaves. Nothing to worry about.