[Lottiegob]

Can anyone suggest what is causing this condition to the rhubarb leaves. It only seemed to appear since we had a little rain this week?   Also how to fix it.

http://i751.photobucket.com/albums/xx159/lottiegob/Rhubarb1.jpg

[mumofstig]

Are you sure there are no tiny insects on the back of the leaves?

[Paul Plots]

How many of the leaves have this yellow "blotch"?

Is it just those at the top of the plant and does the rest of the plant seem to be suffering?

[viettaclark]

Acid rain!!!

[Lottiegob]

Thanks guys.  Seems all the leaves are affected on this plant, not sure about any insects will look later.  - Acid rain - never thought of that!  Other rhubarbs around which have smaller leaves are not affected. 

[Paul Plots]

It might be a nutrient deficiency.... perhaps due to being weakened by some nasty little critters...  

This might help: Rhubarb leaf problems!

It seems more likely to have been causd by a fungal infection