串珠藁本分布与危害的调查研究

Investigation on the Distribution and Harms of Ligusticum Moniliforme

实地访问、调查表明，串珠藁本（ＬｉｇｕｓｔｉｃｕｍｍｏｎｉｌｉｆｏｒｍｅＰｅｎｇＺＸｅｔＺｈａｎｇＢＹ，ｓｐ．ｎｏｖ．）广布于甘肃南部与青海东部海拔２２００ｍ以上的高寒阴湿区，随海拔的升高，其发生危害也越重。在各类杂草中串珠藁本占６１．０％～９８．０％．还发现前茬是蚕豆、油菜的小麦田发生较轻，前茬是小麦、青稞的蚕豆、油菜田发生则较重。田间试验表明，串珠蒿本密度与小麦产量呈显著负相关，当每公顷密度由０增至９００万株时，小麦每公顷减产由０增至８５２．０ｋｇ．

The investigation shows that Ligusticum moniliforme (Peng Z X et Zhang B Y Sp.Nov.) is widely distributed in the cold and high regions 2200 meters above the sea level in the south of Gansu and the east of Qinghai.The higher the altitude of the areas is,the serious the harm becomes. Ligusticum moniliforme takes 61.0～ 98.7% of the total field weeds.It is found that the wheat field with the last crop as broad bean or rape is less affected by ligusticum moniliforme than the broasd bean or rape field with the last crop as wheat or highland barley.There is a remarkable negetive correlation between the density of ligusticum moniliforme and the wheat yield.If the density is increased from 0 to 9 000 000 plants/hm 2,the decrement of wheat yield will be increased from 0 to 852.0 kg/hm 2.