Disease and Pest Control of Rhododendron yunjinensis

Leaf swell

This disease does cause the leaves to "swell up" and is most likely to occur at the end of spring and the beginning of summer. It is very easy to occur if the temperature is low or the humidity is too high. Especially from March to May, when the average temperature may reach 15-20℃ and the relative humidity is relatively high, it is easy to happen when it rains continuously. If it grows at a higher altitude, the probability of occurrence is even greater. It is necessary to take preventive measures before the disease occurs. You can spray Bordeaux liquid when the shoots emerge. Once diseased leaves are found, they should be removed and destroyed immediately, and then the non-diseased plants should be sprayed with pesticides 2-3 times within a month.

Leaf spot

This disease will initially cause only small spots to grow on the leaf surface, but if not properly prevented and controlled, the small spots will gradually expand. In severe cases, they may spread to the entire leaf and the entire leaf will fall off, so it is important to prevent it as early as possible and treat it in a timely manner after discovery. If you encounter diseased leaves, you must remove them and destroy them, because this type of pathogen can overwinter on the residue. If you don't destroy it, it will attack the plant again the following year.

Once this situation occurs, in addition to destroying the diseased plants, you must also use drugs to control the disease. Spray the medicine once every 10 days, and 7-8 sprayings will be enough.

Currency sickness

If the leaves have been damaged, a white or red layer will appear on the surface of the leaves, mainly because the sites bitten by other insects have become infected by bacteria. Similarly, after removing the diseased leaves, you should also spray the medicine, or put furadan in the pot to prevent and control the occurrence of this disease.