Simple Management of National Orchid (4)

The common diseases of Guolan are blight, anthrax, Sclerotinia sclerotiorum, root rot, wilt, soft rot, Bayas disease, rust and so on. Anthracnose is more common in this region, and Fusarium wilt (caused by Fusarium oxysporum) has also spread rapidly in recent years. Anthrax disease is commonly known as black spot disease or black spot disease, spring, summer and autumn are the onset period (winter can also occur), but summer and autumn are the most intense. When the disease occurs, black spots begin to appear in the upper part of the tender leaves, and in severe cases, the surface and bottom of the leaves can be covered with large and small black spots. Anthrax has a malignant attack: at this time the black spot appears black with yellow, with this as the center, there can be many black yellowish spots around, forming a circular disease ring. In the fierce sun, anthrax is easy to occur, thin cutin (generally known as powdery) orchid plants, but also easy to have black spots. On the other hand, Rain Water and the splash and flow of spray during watering have become contagious. I remember that when I first came to Chen Village to establish Feng's Orchid Garden many years ago, when I bought a lot of orchids at the same time, anthrax and epidemic disease (with water stains on the leaves) broke out at the same time. At that time, I used six kinds of drugs, such as Topurazine, Chlorothalonil, Haoshengling, and so on. It took me two months to cure the disease. For this disease, I now mainly use 500 times good creatures as foliar spray, once every half a month in summer and autumn, and the effect is good. At the same time of spraying, the seriously diseased leaves and acute attack leaves should be removed to reduce the focus. Fusarium wilt spread rapidly in this region in recent years, mainly occurred in the white ink strain of Magnolia, other orchids and new varieties, Xiashan orchid also gradually became infected and fell ill. In ordinary orchid gardens, it is common to die dozens of pots of this disease every year, and more than half of them die seriously. After the onset of the disease, the diseased leaves quickly yellowed and fell off, making it difficult to treat. According to research, the source of the disease is Fusarium, which is transmitted by water and invaded by stomata and wounds. Some people think that it is related to the acid content of soil, so they use potassium manganate, alkali grass, wood ash water and so on, but the effect is not obvious. However, Guolan likes to plant soil with slight acid. Therefore, once the disease is discovered, there is no way to recover, so there is only prevention. However, if the alkaline liquid is fully poured, it is bound to greatly reduce the acidity of the soil, which is not conducive to the growth of the national orchid, so it is impractical. It is a kind of disease prevention measure to abandon the diseased plant, replace the planting soil, and disinfect the wound and scissors of the orchid plant. In terms of medication, soaking healthy plants with 2000 times of 25% pokra emulsion for several hours, and using 25% pokra emulsion mixed with 2000 times of decaying powder once every 5 to 7 days, three times in a row, it is also said to have a control effect. In addition, "he Miao Brand-RC resurrection agent" can be used: foliar spraying 1200-1500 times, or irrigating the roots with water 3000-5000 times, all have good results. For this disease, I think Lanjie should attach great importance to it and develop a set of effective prevention and treatment methods as soon as possible. Extracted from "Orchid Treasure Book" Feng Gangyi of Macao