Ivy leaf spot

Symptoms and pathological changes: in the early stage of the disease, there were small round dark spots on the leaf surface with oily halo. After the expansion, it is black. Some become polygonal, sometimes there are brown deposits around the spot, and occasionally ulcer spots occur on the petiole. The infected leaves do not fall off.

The disease overwinters in the diseased tissue, warm and humid conditions, bacteria overflow from the diseased tissue, spread by wind, rain or insects, causing primary infection and re-infection, poor ventilation and poor light transmission, the disease is more likely to occur.

Prevention and control methods: 1. Select the disease-free mother plant for reproduction. Thoroughly remove the diseased leaves and reduce the source of the disease. 2. Strengthen management and enhance plant disease resistance: reasonable close planting, scientific fertilization, and take effective measures to make plant growth strong and enhance disease resistance. 3. Chemical control: in the early stage of the disease, 3000 times of streptomycin sulfate or 12% green EC and 20% Longke suspension were sprayed. When the rate of diseased leaves reaches 10% to 15%, the medicament can choose 50% carbendazim wettable agent 1500 times, or 50% methyl thiophanate wettable powder 2000 times, or 80% Dysen zinc wettable powder 400 times, the control effect is better.

Ivy anthracnose

Anthrax

Common diseases. Mainly harmful leaves, the leaves are grayish white when the damage is serious, and it is easy to occur when the autumn rain continues.

Prevention and treatment: put it in a ventilated and transparent place, and it is forbidden to water the leaves. After the onset of the disease, spray 50% carbendazim wettable powder 500 times, once every 7 days, even 3-4 times to prevent and cure. Other methods can be seen in the section on pest control of Chamaecarpa angustifolia.

Leaf spot disease

Common diseases. It is easy to cause withered and yellow leaves, which is mostly caused by poor ventilation and muggy environment.

Prevention and treatment: the diseased leaves were removed at the initial stage of the disease and burned centrally. Spray 1% Bordeaux solution at the same time, once every 7 days, for 4-5 times.

Shell worm

Shell worm

Common pests. The damaged plants grow poorly and can pollute soot disease, causing leaves to turn yellow. early defoliation.

Prevention and treatment: manual scraping. When the occurrence area is large, you can also spray 40% omethoate cream 800 times solution. For other methods, see the cycad pest control section.

Epidemic disease

The main results were as follows: (1) symptom characteristics: the whole leaf or most of the leaves turned brown and rotted or the base of the stem vine and tender node showed dark green water stains, became soft and constricted, then turned brown to brown-black, and the branches and leaves above the diseased part withered. Some directly form rotten tops or dead heads; sometimes the stem base of cuttings also occurs and produces stem rot. When the cuttings carry bacteria or the soil carries bacteria, and the soil and air humidity is high, the disease is easy to occur and expand rapidly.

(2) Prevention and control methods

① found that the diseased plants were pulled out in time, and watering was controlled properly.

When planting ②, we should pay attention to select cuttings from plants that are free from diseases and insect pests and insert them in the substrate that has been sterilized or has not occurred epidemic disease. Planting should not be too dense, pay attention to ventilation and light.

③ drains in time during the rainy season to prevent moisture retention.

In the early stage of ④, spray or irrigate 25% metalaxyl wettable powder 800x or 58% metalaxyl. Manganese zinc wettable powder 600 times liquid, 64% poison alum wettable powder 600 times liquid, 72% Kelu 600 times liquid.

Grey mold disease

The main results are as follows: (1) symptom characteristics: watery brown or black spots are produced at the edge of the leaves, which can occupy most or the whole leaves in severe cases, and gray mold layer in damp cases.

(2) Control methods: cultivate with disease-free new soil, control watering, and don't apply too much nitrogen fertilizer. Remove the diseased leaves in time and burn them. When you get sick, spray 75% chlorothalonil 500 times. Once every 10 days for 2 or 3 consecutive times.

Purple oyster scale

The main results are as follows: (1) the characteristics of damage: sucking branch and leaf sap with nymph and female adult. In severe cases, it is covered with leaves and branches, resulting in plant drying, yellowing and death.

(2) Prevention and control methods: in winter, combined with plastic surgery, cutting off insect branches and leaves, and concentrated burning. During the nymph incubation period, 1000 times of 50% phoxim or 1500 times of rapid culling were sprayed.

Sunburn disease

Symptoms: upper leaves or new leaves become light gray, gradually withered and fallen leaves.

Etiology: physiological disease. In summer, the ivy, which has been in the shade for a long time, is easily burned by the scorching sun when it is suddenly put on a sunny day.

Control method: the cultivation environment is easy to be semi-shaded, and the sunshine is about 50%, 70%. Avoid strong direct sunlight.

Prevention and control of common diseases and insect pests of Ivy

1. Common diseases of anthrax. Mainly harmful leaves, the leaves are grayish white when the damage is serious, and it is easy to occur when the autumn rain continues.

Prevention and treatment: put it in a ventilated and transparent place, and it is forbidden to water the leaves. After the onset of the disease, spray 50% carbendazim wettable powder 500 times, once every 7 days, even 3-4 times to prevent and cure. Other methods can be seen in the section on pest control of Chamaecarpa angustifolia.

2. Common diseases of leaf spot. It is easy to cause withered and yellow leaves, which is mostly caused by poor ventilation and muggy environment.

Prevention and treatment: the diseased leaves were removed at the initial stage of the disease and burned centrally. Spray 1% Bordeaux solution at the same time, once every 7 days, for 4-5 times.

3. Common pests of scale insects. The damaged plants grow poorly and can pollute soot disease, causing leaves to turn yellow. early defoliation.

Prevention and treatment: manual scraping. When the occurrence area is large, you can also spray 40% omethoate cream 800 times solution. For other methods, see the cycad pest control section.