Observation and record of Prevention and Control of Diseases and insect pests in Orchid

After reading the orchid book and raising several pots of orchids, I found some phenomena that were not recorded or not quite consistent with the book knowledge in the process of orchid cultivation practice.

First, about the red spider

Many books and periodicals have emphasized the harmfulness of red spiders to orchids, but the author's observations in recent years have found that red spiders do not like to invade orchid plants, and only a small number of them migrate to the back of orchid leaves at the end of orchids during famine. Red spiders have miscellaneous food habits, the common hosts are African chrysanthemum, rose, egg flower, citrus, safflower grass, lantern grass and so on. The author visited several flower beds, due to poor management, rose, African chrysanthemum, blue peach and other red spiders lingering, adjacent national orchid, Phalaenopsis, crane top orchid did not find red spider harm. Raise orchids in their own balcony, the author also has a similar experience. At that time, there was a pot of egg flower, because it was so tall that it was inconvenient to inspect it. By the time it was found, almost all the leaves were covered with red spiders and insect silk. When I was surprised, I checked the orchid leaves and found only sporadic worms. The egg blossom well was removed and never reissued after it was wiped by hand. In the courtyard, it can be seen that there are many insect spots on the ground, but the orchid leaves have not been violated. These phenomena suggest: 1. Guolan is not an ideal host for red spiders. two。 The first measure to control red spiders is not to be mixed with their common strange plants, and to remove weeds on the ground.

Second, about thrips.

While the red spider seems to be inappropriately emphasized, on the contrary, thrips are often ignored (as a result, many orchid friends have no knowledge of thrips at all). In fact, thrips are far more harmful to orchids than red spiders, second only to shell insects.

The adult thrips are 1.0-1.5mm long, dark brown, black or ochre yellow, and can reproduce more than 10 generations a year. Flowering is harmful to flowers and flowers. The yellow-brown spots appeared in the injured flowers, which made the vegetarian flowers look colorful. Looking through the petals and bracts, we can see that the insect quickly climbed to the depths of the flower heart, and when the petals withered, twisted, tangled or unable to open, the fragrance was greatly reduced. The anthesis is harmful to the tender buds, and it is extremely difficult to find the insect body at this time. When the new buds spread their leaves, they will find dense light yellow patches of young leaves, which can easily be mistaken for Baylas disease. With the growth of young leaves, some of these patches become brownish yellow or black; in severe cases, the buds die young. Fortunately, it is not difficult to control thrips, and omethoate and agricultural insects are very effective. There is an orchid garden in Sanming area, where hundreds of thousands of mu of orchids are planted, which are damaged by thrips year after year. Its owner is at a loss, the orchid you of the surrounding area introduced seedlings from the orchid nursery, after planting, most of the new seedlings did not see similar signs, this phenomenon is somewhat puzzling, therefore, the author read some materials, just recognized the face of thrips.

Third, about the white silk disease

The occurrence of white silk disease is closely related to plant materials. Nowadays, soilless cultivation is popular, but some orchids still prefer soilless cultivation. I remember that when introducing organic gun materials, the book listed snake wood, pine needles, traditional Chinese medicine dregs, grain husks, sawdust, shavings, bark, bagasse, corn cobs and so on. These plants may be entrapped with bacteria and insects, which can be killed by strict disinfection, but it is not easy to do so in large areas. On the other hand, immature organic plants will release some volatile substances such as methanol, acetaldehyde and tetrachloroethane when they are wet, which can stimulate the germination of dormant Sclerotinia sclerotiorum, resulting in the outbreak of white silk disease. The faster the decay rate of the organic plant, the more significant the release effect. Especially the residue of traditional Chinese medicine, the composition is complex and difficult to grasp. The author has tried the residue of traditional Chinese medicine in the corner of orchids planted in the ground-- I remember that there are mainly Dendrobium (the stem of Dendrobium orchidaceae). During the hot and rainy season, these orchids soon died under the lewd power of white silk disease. It's still in my memory.

IV. On anthrax

The author has put more than ten pots of orchids on the north balcony and mixed with a pot of aloe. Later, these more than ten pots of orchids suffered from anthrax and did not heal, which lasted for more than half a year. After cutting again and again, I accidentally noticed that the leaves of aloe were also stained with black spots. I thought that this might be an important source of infection, so I abandoned aloe and expanded it again, cutting leaves and spraying medicine. Therefore, in order to control diseases and insect pests, we should first remove the nearby sources of infection. Should some varieties with very poor resistance be isolated and released separately?.

These phenomena observed since the cultivation of orchids are described as above, because of their one-sidedness and the particularity of the background of these phenomena, they must not be regarded as any experience; the deep theoretical nature of these phenomena needs to be analyzed, summarized and summarized by Lanyou experts.

Xu Qinzhong

Address: Yongchun County Hospital, Fujian

Postcode: 362600