There are several factors to cause azalea for nutrient deficiency such as unbalance moisture, insufficient or over illumination and poor soil condition. Plant will be chlorosis if soil lacks of trace element such as Cu, Sulfur, Ferrous sulfate and manganese sulfate.
Symptoms and solutions
Nitrogen deficient plants show chlorosis, and the vein is light red. A common way to correct this condition is to apply 0.2%-0.5% urea.
Phosphate deficient azaleas show dark green on old leaves and the veins turn to amaranth. This condition can be corrected by topdressing 0.2%-0.5% MKP.
Symptoms of Fe deficiency start with yellowing new leaves and then the marginal areas turn to brown and get withered gradually. Topdressing and spraying 0.02%-0.05% ferrous sulfate solutions at the same time can correct this condition effectively.
Signs of copper deficient plant include chlorosis new leaves, and in severe case the new leaves will be withered. Topdressing 0.02%-0.05% copper sulfate is an effective way to remedy copper deficiency.
Manganese deficient plant show necrosis spots between the veins. The most effective way to remedy this condition is to spray 0.05%-1% manganese sulfate solutions to the deficient plant.
Therefore, applying trace element solutions such as manganese sulfate solutions can prevent azaleas from nutrient deficiency effectively.