Prakrit Khamduangdao was looking for an alternative to agricultural chemicals to control pests in his vegetable farm.  However, he was not completely satisfied with various botanical pest control measures being promoted in northern Thailand.  He reports that even though certain natural insect repellents were beneficial, their effects were too limited.  Additionally, finding adequate amounts of necessary raw plant materials and processing them into sprays was laborious and time consuming.  When Mr. Prakrit first heard about wood vinegar in 2000 he was intrigued.  Compelled by the idea of a natural by-product of charcoal production that can control pests and diseases of crops, he bought his first bottle.   Having used the product, Mr. Prakrit was pleased with the ease of mixing and application.  Ultimately, after observing much fewer insect pests and fungal diseases on his crops, he became convinced of the effectiveness of wood vinegar. Not long afterwards, Mr. Prakrit became self-sufficient in producing both charcoal and wood vinegar with a 200-liter horizontal drum kiln.  He has beenan advocate of wood vinegar ever since. Wood vinegar (pryoligneous liquor) is rapidly gaining acceptance as an essential Asian natural farming input.  Reported agricultural use as a fertilizer and growth-promoting agent goes back to the 1930s, making the product a relatively new innovation.