First, the part of orchid leaves connecting bulbs is generally called leaf base or leaf sheath. If the leaf sheath is black, it means that the stem rot caused by bacterial infection must be paid great attention to. The leaf base and bulb can be sprayed and irrigated immediately with 2000 times solution of agricultural chloramphenicol and streptomycin or 500 times solution of carbofuran. Or choose 70 Ganfuling EC, a widely used medicine. Treatment method: use this medicine 600 times (the dosage can be determined according to the number of orchids) for 7- 10 days, spray for 4 times, and then spray 1 time according to the situation; During the period from April to 10 high temperature, the drug was used for prevention.
Second, if the roots are black, it is mostly caused by the high moisture content and poor air permeability of plant materials. This situation is mostly caused by improper management. Flower friends can investigate from various reasons, such as water responsibility, fertilizer damage, improper use of water (pH, polluted water), improper proportion of plant materials and so on.
Extended data:
Orchid planting can be divided into garden planting and large-scale field planting. Orchids are negative plants, which will be damaged by too strong light and need shading in summer.
Orchid flowerpot: Orchid flowerpot is the living room of orchids, which has a great influence on their growth. In the past, traditional orchids were planted in large pottery pots, and high-grade orchids were basically planted in small trumpet pots. There are two kinds of small pots, ceramic pots and plastic pots, each with its own advantages and disadvantages. What kind of pot to use depends on everyone's habits and cultivated varieties. But it is best to use the same potted plants in a greenhouse, which are different in size, neat and easy to manage.
Plant materials: In the past, the plant materials (base materials) for orchid cultivation mostly used pond sludge, and excellent plants were replaced by plant materials such as pond cornerstone, pumice, weathered fossils, water-absorbing stones and clay materials. Most wild orchids are planted with soft materials such as sawdust, chaff, dregs, cinder, sea sand and peanut shells. , with foam as the bottom. Mix and use more. Using these plants has its own advantages and disadvantages. What kind of plant material is better depends on everyone's habits, varieties cultivated and pots used (pots and plants cooperate with each other).
To plant orchids well, we must master the management of watering, fertilization and pest control. Among them, the principle of fertilization should generally be sunny, and the principle of fertilization should be sparse, diligent and not applied during hibernation. It is suggested to participate in orchid cultivation practice, read more books, visit more, ask more questions, ask questions if you don't understand, and constantly explore and sum up experiences and lessons in practice to continuously improve the technical level of orchid cultivation.