Re-discussion on the Prevention and Control of Orchid Disease [Bailas]

In the second issue of "Chinese Orchid" in 1992, I mentioned that the orchid disease "Bailas" is a physiological disease, that is, the deficiency of nutrients caused by poor nutritional conditions in the soil. Can you explain the following argument of Mr. Zhang in Taiwan?

Mr. Zhang from Taiwan believes that the new species picked by the mountains are beautiful and strong, and there are no defects, but they can still be infected with toxicosis due to improper environment and management (lack of ventilation and lack of water). It shows that Lanhui is more or less latent toxic disease. Or due to external factors, from negative to positive reaction, resulting in infection of the whole plant. The author believes that it is possible!

First of all, Mr. Zhang said: "the environment is poorly ventilated, the air is too dry, and orchids are susceptible to diseases."

S'. Plant nutrition has such a record: "although soil moisture has a good effect on nutrient transformation, too much water is easy to cause the loss of effective nutrients and poor ventilation, affecting the absorption of nutrients by crops." If the soil moisture is too low, the available nutrients will decrease. " Thus it can be seen that the two are interconnected. Can be summed up as follows: the air is too dry, soil moisture is too little, prone to nutritional deficiencies.

Secondly, Mr. Zhang put forward: "picking new species in the mountains is beautiful and strong, and there are no defects." You can still be infected with toxicosis due to improper environment and management (lack of ventilation and lack of water). It shows that Lanxu is more or less latent toxicosis.

The author believes that the problem can not be concluded in this way.

Due to the change of environment and soil (that is, plant materials, the same below), and the change from natural running water (rich in nutrition) to artificial water supply (monotonous and lack of nutrition), the source of nutrients of orchids will inevitably change. Therefore, it is not surprising that orchids are malnourished.

In addition, no matter any plant, after a certain period of physical growth, it will be disturbed by various factors (for example, the soil is dry and wet frequently, which is easy to cause the fixation of potassium, which greatly reduces the concentration of potassium in the soil solution, which leads to potassium deficiency, while rice reduces the absorption of nitrogen when it is deficient in potassium; when it is deficient in nitrogen, it relatively reduces the absorption of phosphorus and potassium. In the case of phosphorus deficiency, the absorption of nitrogen and potassium is reduced), and the absorption of nutrients is not balanced, resulting in some or more nutrient deficiencies.

Third, in order to find an effective way to prevent and cure the orchid disease "Byras", many experts, scholars and enthusiasts of orchids have made a lot of useful discussions.

Chen Huizhao, director of Chencun Lanyuan Garden in Shunde County, Guangdong Province, used plant ash (that is, the ash left after the burning of plant remains) to control the disease, and achieved certain results (after investigation: the composition of plant ash is extremely complex, containing various ash elements in crops, such as potassium, calcium, phosphorus, magnesium, sulfur, iron, silicon, etc., of which potassium and calcium is the most, followed by phosphorus, which is often used as a source of potassium from the point of view of fertilizer. However, for crop nutrition, it is not only the role of potassium, but also phosphorus and other elements), but it is difficult to consolidate and progress.

In this regard, the author believes that it may be due to the change of pH (plant ash is strongly alkaline), so that the orchid can not absorb all kinds of nutrients reasonably.

Li Junzhan, director of Chencun Flower Research Institute in Shunde County, Guangdong Province, has studied the disease for more than a decade, and now it has come to the conclusion that there is a lack of trace elements (that is, nutrient deficiency).

Mr. Zhang Fengrong, a Taiwanese scholar, also admitted that there was no cure for the disease, but he did not mention the use of nutrition.

Elements (that is, trace elements or trace fertilizers) treat diseases.

The author believes that the beneficial discussion of the above three can be integrated into one. (Zhu Yongyu)