Among them is Choe San Bok, now active at the Moranbong District Greengrocery Wholesale Store in Pyongyang.

Choe has devoted all her energy and wisdom to mushroom cultivation for decades since she succeeded in developing the technique of cultivation based on activated sludge spores.

She gave 800-odd lectures on the mushroom cultivation techniques to tens of thousands of people, playing a key role in the introduction of new techniques into various units across the country. She has also produced many spores every year, which are enough to grow large amounts of mushroom.

Recently, a new rotation production technique was introduced to cultivation units of industrial establishments, co-op farms and others. This is one of the techniques developed by Choe for mushroom cultivation.

Her practicable mushroom cultivation techniques, popular among different units of the country, include ones related to designing and building of cultivation base, controlling of the rate of substrate and ensuring fermentation temperature for substrate.