Diseases and pests of Osmanthus fragrans and their control methods

Diseases and control methods of Osmanthus fragrans

Black spot

A disease that is widely distributed throughout the world. When infected, Osmanthus fragrans will have spots on its leaves, about 1 cm in diameter. The leaves will gradually turn yellow and then fall off.

Severely damaged Osmanthus fragrans will gradually weaken in growth, bloom late and in small quantities, and is prone to death due to frost damage.

Countless spores are formed in the conidiophores and are spread by splashing raindrops, dew, watering, and gardeners working among wet plants.

Prevention and treatment methods

When planting from the beginning, choose high-quality varieties that are disease-free and resistant.

Remove fallen and dead leaves in time after autumn.

Pests of Osmanthus fragrans and their control methods

aphid

Aphids are the fastest reproducing insects, and can reproduce 10 to 30 generations a year. Female aphids can reproduce from birth and do not need males to reproduce.

Aphids use their mouth needles with sucking mouths to pierce the epidermis of plants and suck the juice from the tender leaves of the plants, causing the plants to grow slowly. The secretions of aphids also attract ants.

Prevention and treatment methods

If the number is small, kill them manually and spray them with 1500 times diluted 80% DDT emulsion in the initial stage.

Red Spider

Red spider mites prefer high temperature and dry environment. Therefore, under hot and dry climatic conditions, they reproduce rapidly and cause serious damage. The insects often gather on the back of leaves and spin silk webs to cause damage.

Individual red spider mites are very small, less than one millimeter, so they are not easy to be found. Once they are found causing damage, the damage to the Osmanthus fragrans is often quite serious.

Red spider mites attack plants by piercing their mouthparts into the leaves to suck juice, which destroys the chlorophyll and causes the leaves to turn grayish yellow or develop spots. Later, the leaves turn yellow and fall off. In severe cases, the entire plant will lose all its leaves.

Prevention and treatment methods

In the early stage of the disease, diseased leaves should be removed promptly after being discovered. If the plants are severely damaged, they need to be pulled out and burned.

When the disease is serious, use 7000 to 9000 times diluted 1.8% avermectin emulsifiable concentrate to spray evenly for prevention and control; or use 2500 to 3000 times diluted 15% cypermethrin emulsifiable concentrate to achieve good prevention and control effects.