HAIKOU, June 29 (Xinhua) -- South China's Hainan Province has decided to invest ten million yuan (1.3 million U.S. dollars) in the next three years to boost its flower industry, government sources said.     The tropical island province will use the money for scientific research on flower cultivation technologies, said Lin Fanglue, vice governor of Hainan.     The province's flower-growing area increased from some 200 hectares in 2000 to more than 3,700 hectares last year, and the sales revenue rose to 400 million yuan from 70 million yuan, according to Lin.     The exports of flowers, mostly to Japan, reached five million U.S. dollars last year.     "The tropical climate has provided favorable conditions for the development of the flower industry in the province," said Lin.     Hainan has planned its total output of the flower industry would reach 1.5 billion yuan in 2010.