Disease control of Cymbidium

Improper cultivation and management of Cymbidium often lead to the invasion of bacteria and the occurrence of diseases. If it is light, it will affect its ornamental value, and if it is serious, the plant will die, resulting in undue loss.

1. Fusarium wilt. The occurrence site is the tip of the tender leaves, the symptoms develop from top to bottom, and in severe cases, the whole leaves turn yellow and wilt. The disease is mainly caused by excessive fertilization or too much watering.

Prevention and control methods: when the amount of fertilizer is too large, change the basin more soil, put a layer of fine sand under the root, the basin soil should be loose and rotten leaf soil, and the pH should be neutral. The amount of water should be controlled and should not be watered too much. When watering too much, the water should be controlled immediately, the yellow leaves should be removed, and the plant can still return to normal growth.

2. Leaf spot. There are two types of leaf spot symptoms, one is the occurrence of small yellow spots on the leaves, the disease spots are enlarged, the diameter of the disease spots can reach 3-5 mm, round, the disease spots spread, and the leaves are withered and yellow; the other is that the disease spots on the leaves are large and irregular, yellowish brown to grayish brown, slightly wheeled, and black spots appear on the back of the disease spots in the later stage. All these are due to poor ventilation and parasitism of shell insects, resulting in the weakening of plant growth.

Prevention and treatment: smear the disease spot with 0.5% potassium permanganate solution, or spray with 50% carbendazim 1000 times solution. If the disease is serious, the injured leaves should be removed and the wound should be dried with aseptic skimmed cotton.

3. Bacterial rot: the occurrence of the disease is caused by the invasion of bacteria caused by mechanical damage or the harm of shell insects, mainly the leaf sheath leaf center. The disease spot showed a water stain, then turned brown, and some of the disease was overflowed by bacterial pus.

Prevention and treatment: remove the rotten part, dry the wound with skimmed cotton, and then smear it with 0.02% streptomycin.

(Gao Shangshi, Shenyang Landscape Research Institute)