Causes and Countermeasures of Leaf falling during the growing period of Ligustrum lucidum

Ligustrum lucidum is a kind of excellent color shrub. In some places, its leaves, especially the new leaves, appear spots one after another in the growing season, and then develop to dry up, the leaves fall off, the branches gradually dry up from top to bottom, and a small number of them die. According to the survey, most of the deaths occurred in the middle of the planting plots and grew well around them. The reasons are mainly caused by the following two aspects.

1. Caused by diseases

The reason for this is the spot disease of Ligustrum lucidum. Spot disease is caused by pathogenic fungi. At the initial stage of the disease, the leaves showed small brown spots, surrounded by purplish red halos, and black mildew could be seen on the spots. As the temperature rises, sometimes several disease spots are connected, and finally the leaves scorch and fall off.

Second, the harm of scale insects

The scale insect is smaller, about 2 mm, and crawls faster on the branches before it is fixed. Where the branches and leaves are too dense and the ventilation and light transmission conditions are poor, the insect pests are serious, which often cause fallen leaves, and even make the plants wither and die.

Prevention and cure measures

1. The planting area should be conducive to drainage and do not cause stagnant water. Planting should be reasonable and close planting, and with the growth of the plant to reasonably thinning branches, enhance the plant internal ventilation, light transmission conditions, reduce humidity.

two。 Reduce the source of disease infection. Remove the diseased and disabled bodies from the planting site and remove weeds at any time.

3. Strengthen the management of fertilizer and water. In the aspect of road greening, the soil is generally barren, coupled with less fertilization, it is easy to cause plant malnutrition, so fertilizer can be applied once in spring and compound fertilizer combined with rain in the rainy season. it is beneficial to improve the disease resistance and promote the early recovery of Ligustrum lucidum.

4. Trim the wound in time and treat the wound in time. Can be re-cut in winter, into the rainy season should be reduced pruning, in order to reduce the wound, reduce the chance of germs invading from the wound. Spray fungicides immediately after pruning. Over the years, practice has proved that the more frequent pruning in the rainy season, the more serious the disease.

5. Regular spray prevention and treatment. Starting in late June, the medicine is sprayed every 7 to 10 days until the end of the rainy season in September. In the early stage of the disease, internal inhalation fungicides can be used, such as carbendazim, methyl thiophanate, lixivium and so on. Protective fungicides can be used in the later stage, such as Bordeaux solution, mancozeb and so on. In order to prevent pathogens from developing resistance, agents can be used alternately. To control shell insects, imidacloprid can be used together with fungicides before the worm is fixed.