Harmful symptoms and preventive measures of orchid brown rust

Orchid is one of the traditional famous flowers in China, which has been cultivated for more than a thousand years. It has high ornamental value and is loved by the majority of flower friends. However, brown rust will occur in the specific planting process, which will greatly affect the growth and development of orchids. In serious cases, it will also lead to orchid plant death. So today the editor will talk about the harmful symptoms and preventive measures of orchid brown rust.

I. causes and symptoms

The pathogen of orchid brown rust is summer spore rust (fungus). Because of different orchid varieties, the symptoms will be different. One is that it will infect the front of the orchid leaf, there are many yellowish-brown powdery spores on the orchid leaf surface, leaving stripes on the leaf surface, while the back of the leaf generally has no other symptoms, which will lead to leaf drying and death in severe cases. The other is to harm the orchid leaf back, the orchid leaf back will appear reddish brown dots, in the later stage of the damage will converge into a strip of large spots, the above dense rust spores.

Second, the law of the disease.

In the process of orchid culture, low temperature, many wounds on orchid leaves and keeping moisture for a long time, and orchid plants are too wet, these are the important reasons for the incidence of orchid brown rust. Brown rust usually occurs in early spring. Symptoms of brown rust can be seen in mid-February and rust spores can be seen in April.

Although brown rust will only cause orchid plant growth decline, but will not lead to orchid death, and if after the disease, do not take corresponding control measures, brown rust will quickly spread to other orchid plants, thus making the orchid lose its ornamental value.

III. Preventive measures

1. Thoroughly cut off the disabled body

Check the diseased leaves on the orchid plant pot by pot and leaf by leaf. If diseased leaves are found, they should be completely cut off and cut 2 cm to the health department. After pruning, burn or bury these diseased leaves centrally, which can reduce the source of the disease.

2. Prevention by drug application

Spray 70% mancozeb wettable powder 500 times every half a month, twice in a row. Spray evenly, especially on the back of the leaf, the basin and the surrounding environment.

3. Treatment of diseased plant

77% copper hydroxide wettable powder or 75% chlorothalonil wettable powder, etc., were diluted into a 500-fold solution and sprayed every 7 days to prevent brown rust.