White stripy things on trunk are killing my plant

Question

Something is killing my plant. The leaves are loosing their colour. On the branches, there is a white, stripy discharge that's slowly taking over the entire plant. Can someone identify this and tell me what I can do to heal my plant?

Some photo's (for scale: the branch is about a finger thick):

Answer 1

Edit: After a tip from Bamboo and a close up picture this looks like a scale insect. Most likely this is oyster shell scale

Control can be done in a number of ways which I list below:

• take a soft scrub brush soaked in 5 ml of soap to 1 litre of water and scrub them off the affected areas. Repeat three times at 7 to 10 day intervals.
• or prune the affected areas off the shrub. Dip your cutting instrument in alcohol afterwards and wipe off.
• or during the winter apply a dormant oil spray to the entire tree or shrub.
• my least favorite control method may not be available to you depending on pesticide control regulations where you live. A systemic insecticide applied as a soil drench to the root of the tree will help control scale. Applications may have to be repeated yearly. Specific products that are available depend on where you live. I find the products are smelly, require protective gear, are environmentally unfriendly and can stress an already weakened plant.

Edit: Stormy is correct that the white areas on the leaves look like powdery mildew, an airborne fungus. There are a number of control methods.

• prune the tree or shrub to promote more air circulation.
• spray with Neem oil or any number of home made recipes such as water and baking soda, dechlorinated water and milk or hydrogen peroxide. None of these home made recipes have worked for me but you may have more success. Repeated sprayings are necessary to continue control.