US farm machinery maker John Deere is confident Thailand sales will enjoy healthy growth thanks to the small ratio of farm machinery use.The company wants to double its market share in Thailand by 2018. It did not provide current sales figures or market share.To increase sales, the Thai operation plans to add 10 more dealers to its 37 nationwide by next fiscal year starting nov 1,said Michael Gause,director of sales and marketing for John Deere Asia.