Common diseases of lilac and their prevention and control methods

Lilac spot disease

symptom

The spot disease mainly occurs on the leaves. Different degrees of the disease will have different degrees of manifestation. It is mainly divided into four types: star spots, dot spots, mottled spots, and scorch. Depending on the severity of the disease, the spots will change in sequence, and in severe cases, the entire plant will die.

Prevention and treatment methods

Pay attention to watering and keep the soil in the pot moist without water accumulation. When placed outdoors for maintenance, pay attention to sheltering from rain or draining water in time.

When the disease occurs, spray the pesticide in time for prevention and control. You can choose to dilute Bordeaux mixture for spraying. The concentration should be low and spray 3 to 5 times.

Lilac powdery mildew

symptom

Powdery mildew of lilac is very common. When the disease occurs, sporadic spots will appear on the leaves, which will then gradually expand and the leaves will be covered with white mold and hyphae. Finally, the white mold layer will turn into a sparse white network, and small black particles will gradually appear until the plant dies.

Prevention and treatment methods

Prune in time, remove fallen leaves, cut off diseased and insect-infested branches and weak branches, and prepare for wintering. During the growth period, prune the dense branches to facilitate ventilation and light transmission.

Spray the pesticide in time before the disease occurs. You can choose 50% of fenacet or benomyl. Spraying is the most effective and quickest solution.

Lilac Black Spot

symptom

Black spot disease mainly harms leaves, with circular or irregular spots appearing on the leaves, which are brown or dark brown and have ring patterns. Black mold will appear on both sides of the lesions, and the lesions will gradually expand, causing the entire leaf to be damaged.

Prevention and treatment methods

Clean up the dead leaves in time after they fall to reduce the source of infection.

Spray the pesticide in time. You can choose chlorothalonil powder and dilute it with water before spraying.

Lilac brown spot

symptom

It mainly harms the leaves of lilac and is the most important disease of lilac. In the early stage, circular spots will appear on the leaves, with brown fine lines on the edges and light brown in the middle. In the later stage, dark brown fluffy objects will appear on the board. When the disease is severe, the leaves will be covered with spots. The symptoms of brown spot and black spot are generally the same.

Prevention and treatment methods

To take preventive measures, after the lilac sprouts and grows new leaves in early spring, spray it with benomyl or carbendazim solution in time, once every 10 to 15 days, 2 to 3 times will be enough.