It is best to disinfect the plant before putting it on the pot.

At the end of 2002, Lan You and I went to an orchid-producing area in Hubei Province. Among more than 3000 orchids, dozens of them were selected and planted back (round flower buds, characteristic leaf shape and all with fragrance). Because it is winter, the space of the winter orchid shed is limited (the environment is semi-underground, plastic film, straw curtain at night, open during the day; open a slit on one side of the film for ventilation), plus busy work, in order to save trouble, simply find two plastic pots for selling cakes to fake seed first and wait for winter. Plant material is, a small amount of peat soil, weathered rock, decomposed pine needles and used seed mushroom fine sawdust.

Two months later, several orchids appeared dehydration phenomenon, check the orchid root without abnormal phenomenon (at that time the highest temperature in the shed during the day about 10℃, humidity 60%-70%). I thought it was caused by extrusion or freezing injury of orchid leaves on the way to shipment, so I didn't pay attention to it. I simply soaked it in clean water or potassium permanganate fresh water, and the orchid leaves immediately returned to their original state. I moved these several orchids to indoor maintenance. At that time, there was warm air in the room, the temperature was between 20℃ and 22 ℃, and the humidity was lower by 25%-30%. The leaves that were originally thought to have recovered appeared dehydrated one after another three or four days. Gradually, the tip of the leaves appeared light brown. Finally the whole leaf becomes pale black and recedes, leaving only a bare pseudobulb. Fortunately, there were only a few trees, so he didn't care too much.

Until the middle of March 2003, when the weather gradually warmed up, it was suddenly found that all the leaves of other spring orchids that had just come down the mountain were more or less dehydrated and withered (the weather was cold, and it was inconvenient to enter and exit the shed, so check once a week or two). The buds that had been vernalized could not bloom halfway or withered after a few days of flowering. All of these phenomena indicate that there may be problems with the roots (including some flower buds with rot), resulting in lack of nutrient supply, and of course the air humidity is too low. Sure enough, turning over the basin found that most of the langen had rotted away.(Orchid root turns gray black, full of water, broken by hand), white hyphae around the root, all the half-grown seedlings in the whole grass turn light brown from the base and rot, most of the parent seedlings next to the tender seedlings are infected and dehydrated, and most of their pseudobulbs turn light brown. Older seedlings are less affected. Only one or two old seedlings with incomplete leaves are left in one of the original 4-5 seedlings, and all the first and second seedlings are withdrawn. The losses can be imagined.

This should be the white silk disease said in the book, let me encounter it, but I personally feel that the book said and I have a time of onset, the book said June-August for the peak period, and I am in March shed temperature is not high, only a dozen degrees.

Again, these infected orchids, all with methyl thiophane and mancozeb for disinfection treatment, plant materials are also used a thousand times methyl thiophane and mancozeb all poured again. At this time, I felt the "terrible" of white silk disease. It was a kind of stubborn and annoying bacteria. If there was a pot of yellow spring orchid brought back at the same time, after disinfection, it was specially planted with orchid stone alone, and the above symptoms also appeared. However, this pot of orchid was thirty or forty centimeters away from those diseased orchids. It was very likely that the hands estimated to have bacteria or the cross infection was not noticed in shallow water. Other orchids placed nearby did not have any problems. After more than ten days of observation, the effect was not ideal, so I decided to try again with peat ash water (mixed with a certain proportion of water burned with wood), now observed more than a month later, that is, in early May, the pots were turned over to see that there were individual grass leaves with yellowing phenomenon and no buds, some bare false bulbs had already made small buds, and some false bulbs were all necrotic.

Orchid cultivation for more than two years, I am willing to try to use a variety of methods to plant orchid, such as using high-foot plastic pots or purple sand pots with orchid stone, fairy soil, snake wood (unused do not need disinfection, has been used the best disinfection), such as using earthen pots with humus soil, as well as separate use of moss, fairy and so on, feel that roots and seedlings can also be, but also not disinfected also did not appear too big problems, this time the problem is precisely in the used fine sawdust.

In retrospect, I was afraid of trouble and tried to save trouble (it can be said that the disinfection work was not taken seriously at that time), which caused some complicated procedures that are more troublesome now, and may not achieve good results. Now every contact with the disease orchid, pay attention to the use of all the equipment after disinfection again to contact other pots orchid, for fear of problems, a bit of "once bitten by a snake, ten years afraid of well rope" feeling, more like the current epidemic "SARS" need to pay attention to everywhere. I hope you Lan friends to my example as a warning, so that your orchids grow vigorously, this is my original intention to write this article. In this special period, I hope every Lanyou will treat it with a normal mentality and spend the SARS period safely and smoothly.

14 May 2003

Beijing Ouyang Yanming

Unit: Fusuijing Urban Management Team, Xicheng District, Beijing City

Postal Code: 100035

Address: No.25 Xiaocheng Lane, Xicheng District, Beijing City

Tel: 66183040

(The pot was turned over again before the publication, and the results showed that except for a few false bulbs, all the others had sprouted (not unearthed), and more than two buds, some had four or five buds, some were old seedlings or false bulbs in normal conjoined conditions, and several of them had sprouted in my place.)