Restoring of Growth Potential and Selection of Adaptative Cultivars of Mei Flowers in Nanshan Mountain,Chongqing

From the end of 1991 to the beginning of 1995,380 weak Mei flower trees had been researched;meanwhile,the introduction experiment of 55 Mei cultivars was carried out.Through a series of management measures,such as pest and disease control,pruning,soil improvement,watering and fertilizing,the growth potential of weak trees was restored.The continuous measurement shows that,the average height of the 300 weak trees reached to 2.31 m,increased by 1.02 m;crown width reached to 1.96 m,increased by 1.19 m;stem diameter reached to 2.1 cm,increased by 1.1 cm.The average values of the 50 cultivar trees:height up to 2.29 m with 0.64 m increase,crown width up to 1.73 m with 0.77 m increase,stem diameter up to 2.8 cm with 0.9 cm increase.22 elite cultivars adaptative to the local environment were finally selected.