Diseases and Pests of Immortelle and Their Control

Scale insects

It harms leaves and buds, and in severe cases can cause sooty disease. Commonly used pesticides: 25% phosmet 800~1000 times diluted, omethoate 1200 times diluted, 50% marathon emulsion 1000 times diluted, 40% cypermethrin 1000 times diluted. Manual removal can be done using a toothpick.

aphid

Damages young leaves and flower buds.

Commonly used pesticides: 700~800 times diluted dichlorvos, 1000 times diluted 40% dimethoate emulsion.

Rot

This is mainly because the drainage and ventilation of the potting soil are poor, and it is continuously too moist, causing the rot of the otter.

Prevention and control: The potting soil must have good drainage. It needs to be placed in a ventilated room on rainy days and sprayed regularly with 500 times diluted 50% carbendazim wettable powder for sterilization. If local rot is found, immediately cut off the rotten part with a sterilized sharp knife, and do not apply water until the wound heals.

The key to treating rot is prevention. Avoid stagnant water and use 70% wettable powder of methyl thiophanate to treat rot. It not only has a strong bactericidal effect, but also has systemic properties, and can achieve both prevention and treatment. During treatment, the wound should be kept uncovered and dry. The faster the wound dries, the better. Do not rush to cover it with soil to avoid secondary infection. After the diseased plants recover, do not water them within half a month to prevent recurrence of the disease. After several months of care, make sure the wound has healed before covering it with dry sand. New roots will sprout soon thereafter.