Diseases and Pests of Cycas and Their Control

Diseases and Pests of Cycas and Their Control

Spot disease

It often occurs in hot and rainy weather. The infected cycad leaves initially show small light brown spots, which then gradually spread and expand into nearly circular or irregular shapes. The centers of the spots appear dark brown to grayish white, causing the leaves to die and break. The prevention and treatment methods are as follows:

1. For the selection of culture soil, slightly acidic sandy soil is suitable;

2. Water the plants frequently in summer and remove diseased and old leaves in time.

3. In the early stage of the disease, you can spray Bordeaux mixture, or 600 times solution of 75% thiophanate-methyl wettable agent, or 1000 times solution of potassium permanganate, once every 10 days or so.

anthrax

The disease initially manifests itself as small yellow or red spots on the leaves, which then gradually expand and become brown or reddish brown. In severe cases, the entire leaf or even the entire branch will die.

The prevention and treatment methods are as follows:

1. Strengthen management, apply fertilizers reasonably, ensure good ventilation, and prune diseased and insect-infested branches and leaves in time in autumn and winter.

2. When new leaves sprout, spray them immediately with 150 times diluted 27% high lipid film.

3. During the outbreak period, spray 500-800 times diluted Anthrax Fumei, spray once every other week, and spray 2-3 times continuously.

Stem rot

Cycad stem rot is characterized by rapid disease development and spread. If it is not discovered or controlled in time, it will cause widespread disease and cause heavy losses. The prevention and treatment methods are as follows:

1. Soil disinfection must be done when planting cycads;

2. Strengthen management at ordinary times and pay attention to ditch digging and drainage. Before the plum rain, you can water the soil with 100 times diluted disease-killing agent for prevention.

3. For diseased plants, the diseased part should be removed in time at the early stage of the disease, and the wound should be cleaned with 0.2% potassium permanganate solution. After drying, apply chlorothalonil or carbendazim powder to the wound for prevention and control.

Scale insects

If the cycads are placed on the balcony for maintenance and the ventilation and light conditions are poor, the leaves will be easily damaged by scale insects. The prevention and treatment methods are as follows:

1. You can mix white wine with water in a ratio of 1:2, and water the surface soil of the pot thoroughly. Water it once every 15 days or so. You will see the effect after four consecutive times.

2. For the damaged cycad leaves, you can use alcohol or soak a cotton ball in rice vinegar and gently wipe them repeatedly to effectively kill the adults and larvae.