สำนักราชบัณฑิตยสภา

The Journal of the Royal Institute of Thailand Volume III - 2011 161 Kuakoon Piyachomkwan, Morakot Tanticharoen soil types where other crops cannot be cultivated economically. These features led to rapid expansion of cassava planting throughout the country, especially in the Northeastern and Eastern part of Thailand. Currently, a total area of 1.1 million hectares is devoted for cassava planting by a large number of farmers, generating greater than 25 million tons of roots annually (Figure 1). Interestingly, the root productivity of cassava plants in Thailand has been significantly improved almost by 50% (from 15.63 in 2001 to 22.93 tons/ha in 2007), attributable to the employment of improved varieties and good cultivation practices, operating under the collaboration of many government agencies (Department of Agriculture, Ministry of Agriculture and Cooperatives; National Science and Technology Development Agency, Ministry of Science and Technology; Kasetsart University) and the private sector, led by the Thai Tapioca Development Institute (TTDI). Up to now, cassava root productivity in Thailand is the highest amongst the world-leading root producers including Nigeria, Brazil and Indonesia (root production = 44.5, 26.7 and 21.6 million tons, respectively with the world production of 232.5 million tons; root productivity = 11.80, 14.14 and 18.09 tons/hectare, respectively with the world average of 12.45 tons/hectare). With improved root productivity in association with higher root prices, farmerûs income per one rai (6.25 rai = 1 hectare) has increased by 300% from 1,700 Baht in 2001 to 6,900 Baht in 2010. Due to its excellent agronomic traits, improvement in root productivity and increased prices, cassava is now recognized as a cash crop that can generate more revenue for Thai farmers. Figure 1. Cassava planting area, root production, root productivity and prices in Thailand for the period 2001-2010. 160-170_mac9 5/3/12, 11:43 PM 161