Understanding and prevention of toxicosis of four seasons orchid

The most puzzling thing in the heart of Lan you, who cultivated the old variety of Orchid, is why toxin disease is always difficult to prevent, because the old variety has been propagated for too long and has no resistance to the disease. Or is it that the virus has lurked in the body and has not yet appeared? The author once had a painful experience, that is, he spent NT $240000 to buy a thousand seedlings of Tianxiang for cultivation eight years ago. As a result, all the new seedlings of the first generation grew toxin disease, and they were unwilling to give up, and then bought a thousand seedlings elsewhere to remedy the disease. As a result, the first generation of new seedlings still had 30% toxin disease. Every time they changed pots and screened each time, 50% of them were eliminated every year. At present, more than 100,000 seedlings have been found in blossom this year. A small number of pedicels are not tall. After careful observation, it is found that there are a few defects in the leaves, which seem to be not a disease. it turns out that a small number of them have been infected with toxin disease, but the symptoms are not obvious and have not been eliminated, which are caused by insect transmission during flowering or hand infection when dividing plants. As these old varieties have been spread for a long time, there are more opportunities of infection than new varieties, and the control measures are not thorough enough, so the toxin disease can not be eradicated.

According to expert research, the virus can only be parasitized in the living cells of organisms, the parasitic cells provide energy and substances, and inoculated in the living cells can reproduce. Once the plant becomes a virus parasite, it is transported to all parts of the plant along with the vascular ducts and sieve tubes. The virus can lose its virus in the high temperature of 65 ℃ ~ 70 ℃ for 10 minutes and dry for 10 days. Highly infectious and resistant to dryness, cold and general chemicals. Although the virus is tiny, it is still a huge molecule. It cannot enter the plant through the stomata in the leaves when flying with the wind, nor can it enter the body from the root with the absorption of water. Only with other help can it be successfully invaded by the wound.

The mode of transmission of the virus is transmitted by previous generations or wounds, and the preventive measures are as follows:

1. When ramet or pruning roots and leaves, the knife and scissors should be boiled and sterilized before and after use.

2. when changing pots, try not to wash healthy plants and never overlap them after washing, so as to prevent the virus from invading the wound by water droplets.

3. Pay attention to insect transmission, especially thrips, which not only eat stamens, but also suck buds, and spread very quickly, killing insects every two weeks during flowering and at least once a month in new buds.

4. the planted medium had better be discarded, and the planting basin must be washed and insolated before it can be reused.

5. Pesticides should never be treated by soaking, because chemical pesticides can not kill the virus, but can spread to each other through potions.

6. Plants should not be placed too close, avoid friction with each other, maintain good ventilation, pesticides, fertilizers, sunshine should not be excessive, reduce plant weakness or injury and infection.

7. When diseased plants are found, they should be isolated and destroyed immediately. (Liu Qingyong)