The main diseases of Magnolia are anthrax, chlorosis and leaf burn.
Anthrax mainly damages the leaves of Magnolia. It is mainly manifested in irregular spots from the tip of the leaf or round spots on the surface of the leaf. In the early stage of anthrax, there were small black granules on the surface of the leaves of Magnolia. The lesion is water stained, brown, with dark brown ridge line on the edge, which is very different from the healthy part.
The pathogen of anthrax will invade the leaf tissue in spring and cause the disease. In summer, the high temperature period is the peak period of anthrax. The main cause of the disease is that the plant water and fertilizer management is not in place, and the growing environment is not well ventilated.
The control method of anthrax is to strengthen the water and fertilizer management of Magnolia, improve the disease resistance ability of Magnolia; at the end of autumn, the leaves will be removed and burned intensively. In the case of anthrax, seventy percent of anthrax and 500 times the liquid can be sprayed. Or spray the Magnolia Magnolia with seventy-five percent times of 800 times of chlorothalonil wettable granules. Or every 10 days, continuous spraying 3 to 4 times can effectively control the disease.
Chlorosis is also one of the diseases that affect the growth of Magnolia. The symptoms of chlorosis are as follows: firstly, the chlorophyll of Magnolia decreases gradually, the whole leaf turns yellow, then turns white, the growth of plant declines gradually, and finally dies.
Etiolation is a physiological disease. The main causes of etiolation are soil viscosity, pH value exceeding the standard, and insufficient iron supply. To prevent yellowing disease, we can use 0.2% ferrous sulfate solution to irrigate the roots of Magnolia, and also spray the leaves with 0.1% ferrous sulfate solution.
Magnolia's pests mainly include coir moth, moth, spider, longicorn, etc., and also underground pests, such as grubs.
80% of dichlorvos emulsion 800 times can be used to control the pest. Or you can use 50% fenitrothion EC 800 times to control the pest. Kill red spider with 5% nisolone 2000 times solution. To kill the moth, you can also use 50% fenitrothion cream 800 times. Kill the longicorn with 500 times green Willy solution. If you want to kill grubs, you can use 50% of the zinc thiophosphate emulsion 1000 times liquid to root.
