Carnations are very susceptible to leaf spot disease, affecting growth. When the disease occurs, there will be a long strip of disease spots on the stems and leaves. When it is serious, the disease spots will circumcise the stems and cause the upper branches and leaves to die. If the disease is infected in the flowering stage, the flowers cannot open or show deformity.
When planting, disinfect and remove the diseased plant in time. Strengthen the management, keep the plant surface dry as much as possible, and plant in good ventilation, light transmission and drainage. The greenhouse should be well ventilated before dusk.
Leaf spot disease can occur year after year, so it is necessary to spray preventive bactericides once a week, such as mancozeb, zineb, promethine, chlorothalonil, etc., especially when it is in full bloom, with 75% chlorothalonil, 50% captan 500 fold solution or 1% Bordeaux solution.
The carnation is affected by grey mould disease. After being covered with grey mould on the flower bud, petal and stem and leaf, it appears brown water spot, which causes the petal to rot, the flower bud to fall off, the stem and leaf to die, the susceptible flower bud cannot open, the flower color of the infected flower to lose its luster. When the temperature is high and the humidity is high, the disease is serious, spreads rapidly and the damage is rampant. Therefore, it must be prevented and controlled to protect the stem, leaf, flower bud and petal. Promote flowering, prolong flowering period and improve ornamental value.
Timely prevention: spray 1000 times potassium permanganate solution on the leaf once a month, and spray all leaves, buds and petals evenly, so as to start dripping water. If there is a lot of rain, high temperature and high humidity, there will be a lot of grey mold on the stems, leaves and flower buds. Spray 1000 bisulklin twice or three times continuously on the leaves and once every 7-10 days to kill the pathogens and quickly restore the normal growth of the diseased parts, strengthen the stems, leaves, flower buds and petals, and promote flowering.