Orchid white silk disease can be treated with food-grade alkali

Last year, one of my pots of Qiusu (autumn plain orchid) developed white silk disease. Because the pot was tilted at an angle, by the time I discovered it the mycelium had already spread all over the pot surface. The current-year growth, about 15 cm tall at the time, had completely rotted at the base and came up with a single pull; 100% of the parent pseudobulbs had lesions that had penetrated deep into the bulb flesh; over 90% of the grandparent pseudobulbs had lesions of varying degrees. Healthy dormant buds were hard to find.
　　
By convention, this pot of Qiusu together with its potting soil should have been completely destroyed. Iorchid plantswashed clean and, based on the severity of the disease, divided them into three groups. The first group consisted of a few old plants that had fortunately escaped infection; the second group had lesions of varying sizes on the cortical layer of the pseudobulbs; the third group was destined for disposal, with lesions that had penetrated deep into the bulb flesh. Inspired by the fact that lime can prevent and control white silk disease, I chose food-grade alkali, the additive used in making steamed buns, and for groups one and two, soaked the leaves in 1.5% alkaline water for one minute, then soaked the portion below the base for 20 minutes, then rinsed with tap water, dried in the shade for 12 hours, and potted them separately. While handling the third group, I found one parent plant whose pseudobulb was especially large, as thick as a thumb, with a pale brown lesion the size of a broad bean on the surface near the soil line. I used my fingernail to gouge out the rotten flesh until I had also removed some healthy flesh. By then only 2/3 of the pseudobulb remained, with two leaves and two broken roots left; I treated it by the same method and potted it separately. Seven to ten days after potting, groups one and two successively sent up new shoots; the current-year growth was rather weak, but by last spring it had grown into robust plants. The remnant plant of the third group, with only 2/3 of its bulb flesh left, unexpectedly also produced a new shoot, but the overwintering growth that reached about one cun in length also sent up a new plant, growing somewhat weakly, and now the shoot is over 20 cm tall.