Yellow marks on kale

[alipally]

I have blue vates curled kale, red russian and nero di tosca, all growing really well but now they are all getting yellow sorts of bubbles on them.  I have been trying to cut the affected leaves straight away, but if I leave them they get a sort of white powder in the 'bubbles'.  I assume it is some sort of desease, does anyone have any suggestions please as I don't want it to spread any more. 

Thanks
Ali

[alipally]

[allaboutliverpool]

If there is white powder it is possibly mildew which attacks less than healthy plants.
It can be because of overcrowding, over-watering (wet weather) but also underwatering, presumably because that weakens the plant and makes it susceptible.


http://www.allaboutliverpool.com/allaboutallotments1_homepage

[Rosyred]

I got the yellow bubbles too. I took off all the leaves with it on and gave them a spray used for insects.