[ryetek]

As the title says does anyone know what wrong with our cucumber plant?

This is a leaf from low down on the plant:


The newer leaves have a distinct yellow edge:


As you can see we have had some fruit from the plant and it's still producing:


As usual thank you in advance.

[mumofstig]

Mosaic virus makes the growth twisted/distorted as well - your newer leaves look ok.

Check you haven't got any aphids or tiny red spider mites, other than that I'd just say it was old leaves going over.

[ryetek]

Thanks for the quick reply MoS. I have checked for aphids and spider mites and don't see any. I have seen some tiny black flies on them and squashed them but that was not recently.

I'm hoping it is just the older leaves going over but here is a little more information just in case:

Two or three of the lower fruits have dried up and gone brown so I've cut them off. Some of the fruits higher up the plant are starting to form well.

Is it possible that it's a nutrient deficiency or over-watering as I have a tendancy to over water?

Also I'm feeding them once per week with tomatoe feed. Is this OK?

Thanks again.

[New shoot]

The first picture shows a leaf with interveinal chlorosis, which could mean nutrient deficiency.  On most plants is it either iron or magnesium.  Magnesium shows on older leaves first.  I wasn't sure so looked it up and found this, if it helps.  Magnesium deficiency is easily cured with epsom salts 

http://agropedia.iitk.ac.in/content/deficiency-symptoms-nutrients-and-their-remedies-cucumber

Tomato feed once a week shouldn't be causing any problems and overwatering usually presents as completely yellow leaves 

[ryetek]

Thanks New shoot. We have some Epsom salts so I will give this a try.