ＨＹ-４由红河州农科所供种 ,于２００１年引入蒙自县进行区域性品比试验 ,亩产７０３．３ｋｇ,２００２年续试 ,亩产达５２７．５ｋｇ,同年小面积生产试验 ,亩产达６２０．２ｋｇ。通过连续两年试验 ,表现抗病性强 ,丰产性好。其丰产性与我县的常规水稻当家品种滇屯５０２相当 HY-4 was supplied by Honghe Prefecture Agricultural Science Institute. It was introduced into Mengzi County in 2001 for regional product ratio test, with a yield of 703.3kg per mu. In 2002, the trial was continued with a yield of 527.5kg per mu. In the same year, Per-mu yield of 620.2kg. Through two consecutive years of experiments, the performance of disease resistance, high yield good. Its high yield is comparable to the conventional rice variety Diantun 502 in our county