Orchid rot disease enters a critical period for prevention and control

At present, we are in a season of high humidity and high moisture, which is exactly a period of high incidence of flower diseases.OrchidsRot disease mostly occurs in the humid, rainy summer and autumn seasons. Common types include black rot,soft rotand other diseases. Black rot: caused by fungi of the genus Phytophthora. It mostly occurs on leaves, roots and growing points. At first, semi-transparent spots appear on the diseased part, then the spots expand and the tissue turns black and rots.soft rotdisease: caused by bacteria of the genera Erwinia and Pseudomonas. In the early stage of the disease, tiny brown water-soaked spots appear on the leaves, then expand into gray, moist patches. With a slight touch or press, the epidermis will rupture, and bacterial ooze with a foul odor will flow out. Control methods: first, keep the plants well ventilated and reduce humidity. In the early stage of the disease, spray the leaf surface or apply to the diseased spots with 50% captan 500-fold solution, 50% tuijunte 1000-fold solution, or garlic water (crush garlic, soak it in water, and take the filtrate).Orchidsroot rotOrchidsalthough they like moisture, their fleshy root system is afraid of waterlogging. Excessive moisture or water accumulation from rain can easily cause root rot and easily induce black spot disease. Therefore,growing orchidsthe potting soil should not usually be too wet. In winter, orchids are in a dormant or slow-growth stage, so the potting soil should be on the dry side; spring and early summer are important periods for orchid root growth and leaf development, so the potting soil should be on the moist side; but long-term excessive moisture can also easily cause root rot, causing leaves to turn yellow and even die. During the plum rain or heavy rain season, potted orchids must be protected from rain, because with prolonged rain and excessive moisture, black spots are most likely to appear on new leaves, and the flower buds often show a "rotten sheath" phenomenon. This affects flowering and ornamental value. However, if the potting soil is too dry, it can easily cause the pseudobulbs to shrivel or other tissues to be affected in their metabolism due to water loss, which can also lead to weak tissues, poor plant growth, and even death. But in autumn, it is appropriate to keep things moderately moist, because autumn drought will have an adverse effect on leaf growth and flowering the following year. Therefore,orchid growersshould understand the key principle of "not wet in winter, not dry in autumn." The above shows that orchids have different requirements for water (including humidity) at different times, so the amount of water given to orchids should be strictly controlled. Improper fertilization of orchids, such as applying too much or too concentrated fertilizer, or pouring liquid fertilizer into the leaf sheaths or splashing it onto the leaves, can also easily cause root rot. Therefore, when fertilizing, apply it along the edge of the pot. Liu Guoxin