甘■在汉中地区栽培面积25万余亩,主要分布在盆地边缘及丘陵地带。由于栽培时间较长,没有重视良种的繁育,因而种性退化,品质变劣,产量降低。如农林四号,藷块纤维增多,味淡,易染病害,藷块变小,产量降低。其它当地种如白皮洋、马尾苕、白皮土苕等种性退化更为严重。为了迅速选育新种,提高藷类单位面积产量,汉中农业试验站57年从华北 Gan ■ cultivated area of ​​250,000 acres in Hanzhong, mainly in the basin edge and hilly areas. Due to the long cultivation time, no emphasis on the breeding of the elite, which degenerated, the quality of inferior, lower yields. Such as agriculture and forestry on the 4th, tuber fiber increased, light taste, easy to dye diseases, potato smaller, lower production. Other native species, such as the white ocean, mawei, white soil 苕 other species degeneration is more serious. In order to quickly breed new species and improve potato yield per unit area, Hanzhong Agricultural Experimental Station 57 years from North China