Sung had already visited Lishan in 1957 and had had over ten years of experience planting fruit trees. He declared that if you counted on growing temperate zone fruit trees in a tropical zone such as Thailand, then what you depended on was not so much astute agricultural skill and technology, as the ability to exploit the temperature differences in the mountainous areas.
民國四十六年上梨山、已有十多年種果樹經驗的宋慶雲表示，在泰國那種熱帶地方種溫帶果樹，並非仰賴什麼高明的農業技巧，而是利用高山的溫差。