Study on methods for controlling aphis in commercial lucerne production.
In Jiuquan, Gansu, China, the lucerne was infested by Aphis craccivora, A. fabae, A. gossypii, Schizaphis graminum, Sitobion avenae, and etc. For their control, the following methods were tested. Their infestation was classified into 1-5 grades. When it was at 3-5 grades in fields with lucerne plants lower than 70 cm, chemicals were applied. Lucerne was not harvested in 15 days after chemical was applied. The main chemicals were 40% omethoate EC, 40% monocrotophos EC and etc. After those methods were adopted, aphid infestation was more than 85% controlled.