Blueberry leafs problem

[doko359]

Hi,
Can someone tell me what are these red dot on the leafs, is it dangerous and how to treat them?

 

[Chuck]

It looks as though your plant has chlorosis, either a lack of nitrogen and/or iron. It is caused by your soil being too alkaline or a lack of nutrients. The red looks like rust an airborne fungal disease. Apply fertilizer and/or chelated iron to the soil and spray the plant with a fungicide.