Research progress on the chemical control of weeds in alfalfa fields in China

Alfalfa (Medicago sativa), known as the “queen of all forage crops” is one of the most widely distributed leguminous plant species in the world. Weeds are the most important factor restricting the yield and quality improvement of alfalfa, with chemical herbicides being the main method applied to control their growth in alfalfa fields. Hence, to provide a reference for the high-efficiency control of weeds and scientific application of herbicides in alfalfa fields, we searched the CNKI database for domestic research studies conducted on “alfalfa” and “herbicides” in the recent 20 years and summarized the data from the papers that reported on chemical herbicides for controlling weeds in alfalfa fields. Our results showed that trifluralin and butralin were the preferred soil sealing herbicides, whereas benazolin-ethyl, imazethapyr, and cloransulam-methyl were the preferred agents for treating stems and leaves. The safest and most efficient herbicide combinations were bentazone + haloxyfop-P-methyl and benazolin-ethyl + haloxyfop-P-methyl. In the future, based on the actual productivity of alfalfa fields, researchers should strengthen study on the application of herbicides at different growth stages and pay attention to the issue of herbicide damage, so as to better serve the development of China’s alfalfa industry.