李怀玉教授冷寒带苹果研究获重大突破──苹果种植区域北移２００公里从省有关方面获悉：由沈阳农业大学教授李怀玉主持培育的抗寒优质大苹果，已顺利通过鉴定，并于不久前命名为宁丰、宁酥。它的育成，不仅使我省栽培大苹果的区域由南（海城地区）向北延伸了２００多公里... Professor Li Huaiyu Cold and Burn Apple Research Breakthrough - Apple Planting Area Moves 200 Kilometers to the North from Relevant Information from the Province: The cold-resistant and high-quality big apple cultivated by Professor Li Huaiyu, a professor at Shenyang Agricultural University, has passed the appraisal and was recently named Ning Feng, Ning crisp. Its bred, not only make our province grow big apples in the area from south (Haicheng area) extends north more than 200 kilometers ...