Why does Gastrodia elata rot completely after maturing?

Li Zongguo, a farmer from Jinluan Mountain Village, Jiahe Town, Yunxi County, wrote in to ask: I started learning to grow Gastrodia elata last year. Based on the relevant information, I planted fifty or sixty sq m indoors, and last year's harvest was good. This year I began to expand the planting, still following last year's methods. By September this year, I started digging, and sold at the market for only three days. Afterward I went to dig again, and found that all the Gastrodia elata had completely rotted. What is going on?

Zhang Qiudong of the Pest and Disease Control Section, Provincial Plant Protection Station, answers: The cause is mostly harm from unfavorable environmental factors such as high temperature, high humidity and poor aeration that are not conducive to the growth of Gastrodia elata, causing the tuber skin to become yellow and withered, the central tissue to rot, and the interior to turn into a thin slurry, ultimately dying as an empty shell that rots and stinks.

Control methods: First, strictly select Gastrodia elata seeds. It is best to use zero-generation or first-generation hybrid improved varieties of Gastrodia elata bred through sexual hybridization. If the seed tubers are found to be not plump, have indistinct growth points, or have rotten spots (even a tiny spot), they should all be discarded and not used. Second, pay attention to indoor cleanliness and hygiene, maintain good environmental sanitation, and ventilate frequently.

Attention should also be paid to pest control. Common pests include mole crickets, white grubs and white ants. Control methods: First, manual capture and killing. Once raised areas are found in the surface soil or sand of the cultivation site, the soil or sand can be dug open for manual capture and killing. Second, light trapping and killing. Taking advantage of the fact that most insects are phototactic, black light lamps can be set up at the Gastrodia elata cultivation site to trap and kill adults. Third, chemical bait trapping and killing. Mieyiling or Fanghailing powder can be scattered at fixed points in the cultivation site.