Apply Zorial pre-emergence in fall or early winter and incorporate it with irrigation or precipitation. Foxtail barley is exceptionally difficult to control in alfalfa. It also must be incorporated with irrigation or dependable precipitation. It is updated annually. The best methods to control them are disease resistant varieties, crop rotation and timely harvest.
Most new varieties have some foliar disease resistance.
Periodic field surveys will reveal the presence and severity of foliar diseases. If excessive leaf drop occurs in the lower canopy, harvest the alfalfa as soon as possible to minimize further loss and reduce disease pressure. Root and crown diseases are of significant economic importance in Colorado because they can reduce plant vigor and lower winter survival rates. Over time, this decreases crop yields and shortens stand life. Once the plant has contracted a disease, there is no cure.