What are the common symptoms of diseases and insect pests in Cymbidium?

Due to different locations and different diseases, the blight is divided into black rot, heart rot, stem rot, quenching and so on. Under the condition of high cultivation temperature, too much watering and poor ventilation, there is a large amount of water in the leaf tip for a long time. It's the easiest to cause the disease. The peak period of the disease is from June to August every year. It can be damaged from seedlings to flowering plants.

Soft rot usually affects the leaves, buds and bulbs of Cymbidium, which can occur from spring to autumn in a year, and is rarely found in winter, sometimes accompanied with blight, and its invasion is mainly through wounds or natural stomata. The disease spreads very quickly when it is hot and humid. At 100% relative humidity and temperature of 30 ℃, the adult invasion process was completed after 3 hours of artificial inoculation. The manifestation of the disease is similar to that of the epidemic disease, which makes it difficult to distinguish those who raise orchids. Gently touch, the juice will flow out, at the same time have the stench of fishy smell, drop the juice in the clear water cup, you can see the cloud-like turbid matter spread around.

Root rot is a fungal disease, which is easy to be infected in any growth period of Cymbidium plants, whether in seedling pots, medium seedlings, large seedlings and mature flowering plants. If uncontrolled, rot can develop to stems and lower leaves. In the process of infection development, a brown rot zone will be formed, which will cause seedling death around the base of the plant. The adult plant will gradually weaken when it is attacked. In general, rot is limited to the root, causing root death, but sometimes rot will expand to invade the pseudobulb, making the growth of plants infected with root rot decline, and the leaves and pseudobulbs are yellow, thin, twisted, shrunken and finally die.

Anthracnose damages the leaves, pseudobulbs, calyx and petals of Cymbidium. It belongs to the asexual generation of fungi and is generally weakly parasitic. Weak plants with underdeveloped roots caused by cold injury, pesticide injury, sun burn, excessive nitrogen fertilizer application, plant material too acid or planting too dense, poor ventilation and water imbalance are easy to suffer. When the pathogen infects the leaves or pseudobulbs of orchids, the first symptoms are brown or yellowish green long irregular stains, slightly sunken, clear edges, and when mature, concentric rings usually appear on the disease spots, and conidia are produced on the ring spots. There is a clear dividing line between the affected tissue and the healthy tissue. In the later stage, the lesion is slowly connected into a piece, the coverage area increases gradually, and the depression becomes necrotic and gangrenous spot.

Leaf blight is a kind of fungal disease, which occurs near the leaf tip of Cymbidium or at the front of the leaf, initially produces small black spots, the spots gradually expand and become irregular spots, the periphery of the spot is dark brown, the middle question is light gray, and there are small black spots. in severe cases, it can spread to the whole leaf surface, and finally die and fall off.

What to do with the growing insects of Cymbidium? control of diseases and insect pests / 4 insect pests and 4 diseases of Cymbidium

Cymbidium, an artificially cultivated orchid variety, has large flowers, up to 10 centimeters in diameter, bright colors and high ornamental value, and is kept at home by many people. However, in the process of cultivating Cymbidium, many people will encounter the invasion of diseases and insect pests, so what if Cymbidium grows worms? Here are 8 common diseases and insect pests of Cymbidium. Follow the editor to learn about them.

First, the long worm of Cymbidium should be sprayed with medicine

Raise Cymbidium indoors, because there are so many novices, they often encounter the symptoms of growing insects and getting sick. At this time, flower friends must be in a hurry. What about Cymbidium cymbidium? First of all, do not panic, to calmly identify pests, and then to solve, in this regard, the editor summarized 8 kinds of Cymbidium diseases and insect pests, and attached control methods, we continue to look at.

II. Disease and pest control of Cymbidium

1. Scale insects

The scale insects harmful to Cymbidium are cotton-blowing scale insects, cotton scale insects, black-spot scale insects and so on. They often parasitize on the leaves and use piercing mouthparts to penetrate into the stomata of the plants to absorb nutrients. Symptoms: the leaves of Cymbidium turn yellow, which can lead to death in severe cases.

Prevention and control methods: after a small amount of shell insects are found, they can be gently brushed off with a soft brush and then rinsed with water; when the disease is serious, 40% dimethoate or omethoate EC 1000 times or 50% trichlorfon 250 times solution can be sprayed continuously for 1-3 times, and the effect is better at 7-10 days interval each time.

2. Whitefly

Whitefly will come to Cymbidium when it is not properly maintained and poorly ventilated. The insect is smaller than scale insects and propagates very fast. once they are found, they will be very dense and will dry up the whole leaves of Cymbidium.

Control methods: after the whitefly is found, it is necessary to control it in time, and it can be sprayed with 2000 times liquid to control whitefly, once every 5-6 days, 2-3 times continuously.

3. Red spider

Mites are also one of the diseases and insect pests of Cymbidium, the most common of which is the red spider, which is small and not easy to be found, but does great damage to the plant. Symptoms of injury: red spiders absorb nutrients from leaves by mouthparts, causing imbalance of water metabolism and affecting the normal growth and development of plants.

Prevention and control methods: when you get sick, you can choose to spray evenly with 40% dicofol EC 1000 / 1500 times, and the control effect is good; red spiders generally breed in an environment with high temperature and low humidity, so in peacetime, we should pay attention to the regulation and control of temperature.

4. Cockroaches

If there are cockroaches in the kitchen and Cymbidium happens to be next to the kitchen, the cockroaches will harm the buds, spikes, buds, flowers and root tips of the plant. Symptoms: poor growth and incomplete spikes and flowers of Cymbidium, losing ornamental value.

Control methods: find cockroaches, directly drive away, or use gram cockroach medicine to spray cockroach infested places; in addition, keep Cymbidium plants away from the home kitchen, and often clean the kitchen.

5. Epidemic disease

One of the diseases and insect pests of Cymbidium, it is easy to suffer from this disease when the temperature is high and the watering is too much. Symptoms: at the initial stage, the diseased leaves appear water-immersed spots, and then quickly expand into black-brown rot, resulting in fallen leaves, and sometimes there is a white thin mildew layer on the damaged surface of the leaves.

Prevention and treatment methods: when the disease occurs, the water should be strictly controlled and the diseased leaves and plants should be removed in time; at the same time, 25% metalaxyl powder 600 times solution and 40% metalaxyl copper wettable powder 700 times solution can be sprayed on the diseased plants.

6. Soft rot

The disease usually affects the leaves, buds and corms of Cymbidium, and the symptoms are similar to those of the blight, which makes it difficult to distinguish new orchids. The method of distinction: the decaying tissue of the disease has no juice or less juice, and there is no fishy smell, while the decaying tissue of soft rot has juice and has the stench of fishy smell.

Prevention and control methods: soft rot can only be prevented, once the disease occurs, we can only abandon the plant; in the prevention and control, we can spray 40% of Gangdening 400 times liquid, once every 7-10 days, 3 to 4 times in a row can be effective.

7. Anthrax

One of the common diseases of Cymbidium, which mainly harms the leaves. Symptoms: in the initial stage, the diseased leaves appear a number of yellowish, dark brown or light gray areas, there are many black spots, serious can be infected to the stems and branches.

Prevention and treatment: cut off the diseased leaves and burn them centrally to reduce the source of the disease; in severe cases, spray 1000 times of carbendazim or 1000 times of methyl topiramate for antiseptic, which can be effective after 2-3 times.

8. Root rot

If your cymbidium has discolored leaves, scorched leaves, or slow growth of new buds, you may be suffering from root rot. Symptoms: squeeze the ring or long ring brown spot on Cymbidium, and you will spill water.

Prevention and treatment: if the disease is difficult to cure by simple spraying, the method of watering the root must be adopted to be effective: the root rot of Cymbidium can be completely cured only by watering the root with 600-fold solution of dioxone or 600-fold solution of trimethoprim.

With regard to the prevention and control of diseases and insect pests of Cymbidium, this is the end of the editor's introduction. I believe that if you encounter Cymbidium or get sick again, you should know how to do it! Generally speaking, Cymbidium is easily disturbed by diseases and insect pests, so we must follow the cultivation methods of Cymbidium, as long as this is the only way, insects will not come to the door. Finally, I wish everyone's Cymbidium can produce beautiful flowers!

Leaf spot of Cymbidium grandiflora and prevention of Botrytis cinerea

The main diseases of Cymbidium include leaf spot and gray mold. The specific control methods are as follows. The main pests are aphids, red spiders and shell insects. Fenitrothion and omethoate EC can be used to control aphids and trichlorfenol or dichlorvos 1000-1000 times to control red spiders once every 15 days.

Diseases and insect pests of Cymbidium 1. Symptoms of leaf spot of Cymbidium

It occurs near the leaf tip of Cymbidium or at the front of the leaf, producing small black spots, which expand and become irregular disease spots. The periphery of the lesion is dark brown, the middle is light gray, and there are small black spots. In severe cases, it can spread to the whole leaf and finally die and fall off.

Occurrence regularity

The pathogen overwintered on diseased leaves or remnants with mycelium and conidia. In the following year, conidia gushed out from the orifice of the conidia, spread by wind and rain, invaded from the wound or stomata, and carried out primary infection and re-infection. The temperature is 25-27 ℃, and it is easy to get sick after rain. The plaque is sometimes perforated.

Prevention and cure method

A, careful maintenance, pay attention to improve the maintenance conditions of orchids, so that it is ventilated and transparent.

B, cut off the disease spot in time, remove it or burn it.

C, spraying 27% copper noble suspension or 12% green copper EC 600x solution, 30% copper oxychloride suspension 600x solution, 50% Chlorothalonil wettable powder 500x solution, 53.8% can kill 2000 dry suspension 1000 times solution. Once every 10-15 days, prevention and treatment for 2-3 times.

2. Symptoms of Botrytis cinerea

Mainly damage floral organs, and sometimes damage leaves and stems. After the petals or calyx were infected, a small translucent watery spot appeared in 24 hours, and then the spot turned brown, sometimes there was a circle of white or light pink around the spot, the number of spots on each flower was different, and the petals were dark brown and rotten. When the humidity is high, furry growth grows from rotting flowers, that is, the conidiophores and conidia of pathogens.

Occurrence regularity

The pathogen overwintered in 5~20cm soil with sclerotia. In the following spring, a large number of hyphae and conidia were produced on the sclerotia when the temperature was 7: 18 ℃ and the relative humidity was more than 88%. Conidia spread by means of air currents, water droplets or dew, and horticultural practices. The strain is a weak parasite, and the optimum temperature for development is 20-23 ℃. The temperature is 20 ℃ and the relative humidity is more than 90%, which is suitable for the epidemic of bacteria.

Prevention and cure method

A. the flower shed that is going to plant Cymbidium is routinely disinfected to remove the pathogen. The new Cymbidium was sprayed with 25% Pumike EC 800 times solution; the cultivation substrate and flowerpots and soil fertilizer blocks were sterilized with 25% Plumac 400 times solution, and then used after drying.

B. isolated cultivation of diseased plants with Botrytis cinerea.