Abstract
Interviews with longan growers were carried out in Sarapee and Chaiprakarn in Chiang Mai province, northern Thailand, in order to determine whether or not the application of potassium chlorate (KClO3) to longan trees improved flowering intensity and yield in commercial orchards. KClO3 application increased the ratio of inflorescences to total number of shoots and fruit yield in the central part of Chiang Mai province (Sarapee) . However, fruit size and thickness of the exocarp were decreased, resulting in a lower fruit price. Sales were not increased by the use of KClO3. In northern Chiang Mai (Chaiprakarn), KClO3 application shortened the time until harvest when applied in December, enabling the off season production of fruits. Therefore, KClO3 application increased the price and sales of longan fruits. These results suggest that the effect of KClO3 application on the profitability of longan cultivation is dependent on climatic conditions.
