Stem rot of orchid

Summer anticorrosion

Distribution and harm of orchids: Latin name: Cymbidium, English name: boat orchids, alias: bluegrass (different varieties have different aliases), orchid flower language: indifferent, elegant. There are many varieties of orchids. According to incomplete statistics, there are more than 40,000 varieties of orchids in the world, among which the more famous ones are Chunlan, Cymbidium, Phalaenopsis and so on. Orchid stem rot, also known as orchid Fusarium wilt, is one of the most troublesome diseases in orchid species. It will cause the stem of the orchid to rot, shrink and die.

The symptoms usually first harm the mature orchid leaf sheath and the tissue near the base of the leaf, from the inside to the outside, and in severe cases cause the deep rot of the pseudobulb, and then cause the wilting of the leaf. The lesion and cross-section can sometimes be seen as dark brownish red. This kind of plant material, and will not control the water on the following stem rot!

The initial pathogenesis of the pathogen is generally caused by long-term high temperature, high heat and high humidity, and only a few are introduced through orchid communication. 1. The plant material is airtight. 2. The plant material is not rotten. 3. The plant material is not clean. 4. Orchid plants use less large pots, so that the plant material is more airtight and it is easy to stem rot. Pay attention to ventilation. Water properly. Make sure you don't do it or water it. If you water it, you water it thoroughly.

The occurrence pattern of orchid stem rot is consistent with the rapid growth period of orchids, that is to say, the faster the orchid grows, the faster the orchid stem rot will break out. this is related to the best temperature for orchid growth and the best temperature for orchid stem rot outbreak (the best temperature for orchid growth is 28ml 30 degrees Celsius, and the best temperature for orchid stem rot outbreak is 28ml 30 degrees Celsius). Sometimes solitary seedlings, sometimes spring and summer, sometimes autumn and winter (but rarely in winter), and most of the disease begins with big grass, strong grass and new grass, and a few start with old grass and small grass.

Prevention and control methods (1) Orchid, orchid pot and plant materials must be disinfected before potting, plant materials should be relatively thick, orchid grass should be planted shallowly as far as possible, the environment of planting and cultivation must be ventilated, the basin surface should not be too wet for a long time, and organic fertilizer should be used as much as possible. with little or no use of inorganic fertilizers and chemical fertilizers, stem rot can be avoided or less. (2) choose 70% Stem Fuling EC, which is widely imported. Usage: 1 ml of the drug is mixed with 600 grams of water, that is, 600 times the liquid (the dosage can be determined according to the number of orchids) 7 ml once every 10 days, spray 4 times in a row, and then prevent it once in 20 days according to the situation. However, it must be used in the following two cases: first, in the period of high temperature from April to October, on the second day after each soaking (watering), the drug is used for prevention, because the temperature and humidity on the orchid plant is suitable at this time, which is conducive to the reproduction of germs. the disease is most likely to occur; second, when buying high-grade orchids, they should be isolated for a period of time, and the drug should also be sprayed for sterilization to reduce the spread of diseases and insect pests due to the fluidity of orchids.

Bingyu2008 stem rot summary 1, stem rot lies in prevention rather than treatment, once the Reed head infection is currently no medicine can be saved. In the past, when I read the post, some friends said that plant ash could be cured, but I also tried, but I could properly control the spread of the disease, because the germicidal ingredients of plant ash inside the Reed head could not get in, so the grass treated with plant ash, including other so-called internal inhalation specific drugs, seems to have been cured on the surface, and it will definitely relapse the next year.

Second, it is necessary to observe frequently in peacetime management.

1. Observe the basin soil. During the normal watering cycle of the growing season grass, the potted soil dries very slowly, or other grasses can be watered. The soil of this potted grass is still relatively wet, so you should pay special attention to it. It is very likely that the grass has been infected with germs, and the germs have inhibited the growth of the grass. As can be seen in the above photos, the old roots of the grass are very strong, but they all have no crystal head, and the water absorption capacity is greatly weakened, so the potted soil dries slowly.

2. Observe the leaves. In general, before and after the Qingming Festival, the growth rate of orchids begins to accelerate. if they are planted in the open or semi-open air, after one or two spring rains, the leaves will obviously have an amount of oil, and the grass will look particularly energetic. If a pot of grass still looks listless at this time, there are only two cases, one may be mismanaged in winter and the roots are rotten. Another situation is the infection of germs, most of which are caused by infections. Turn the basin decisively when necessary, even if there is no infection, turning the basin in early spring will not hinder the growth. After turning the basin, you must cool and dry the root and then put it on the basin to prevent the infection of germs at this time.

3. Look at the growth rate of new seedlings. Generally speaking, after the new seedlings are unearthed, if the grass is healthy and the water and fertilizer are properly managed, they will grow very fast, and obvious signs of growth can be seen every two or three days. If there are a lot of new buds in this pot of grass, and there are no signs of growth for a long time after the bud tips are unearthed, you should pay special attention to it. It is necessary to poke away the soil around the new buds to see if the new buds are still normal, or if the fingers gently touch the new buds, the new buds infected with germs are like moldy wooden stakes at the base, which are not as firm as the new ones. Here is a special note: when observing new buds, we should accumulate more experience, because in the early stage of new buds taking root and spreading leaves, there will be a stagnant period of growth. We must not mistake this period for infection and pour the pot at will. When plucking the soil, you should be very careful. Remove the soil around the buds like excavating cultural relics, and do not hurt the new buds.

Fourth, early detection, early seedling division.

Stem rot is the number one killer of orchids, he is a stumbling block to the way forward for novices, is the main enemy of general orchid friends, and is an unexpected opponent of veterans. But as long as it is found early, in fact, stem rot can be saved to a certain extent, not treatment. The premise is that the grass is strong, there are many seedlings, and it can be found in time. It is found that immediately turn the basin, divide the seedlings, start one by one from the infected seedlings, until the wound does not change color (the discoloration of the Reed head incision is the most direct and easiest way to judge whether or not to be infected with germs). During the insurance period, this one that does not change color will also be ordered to plant, so the chance of keeping the roots on the other side of the grass is still very high. In general, if the grass is torn down in this way, even if there are still seedlings, it will go back to before liberation. (the theoretical basis for this is that one of the two grasses planted in the same pot gets sick, while the other can grow normally, indicating that the germs spread inside the Reed head. If it is a noble variety, if a lu head has a slight infection, you can cut it along the infected place with a sharp knife until you finish cutting the infected part of the Reed head. If there are still about 2 / 3 of the Lu head in, and there are bud points on the other side, or new buds, it is best to have a root, disinfect the wound and dry it, seal it, and cover it with an old man, there is still a certain chance of being able to preserve the seed.

I have personally tested all the above methods. At least the grass treated with this method last year has grown healthily up to now. It will take time to see whether it can survive this period of time.