Alfalfa Agronomic Topics
Choose from the list of alfalfa-specific topics by clicking on the name below. To visit other helpful sites for agronomic information Click Here.
- Evaluating Alfalfa Stands
- Product Selection – Fall Dormancy and Winterhardiness
- Getting a Good Start for Your Alfalfa Crop. Growing alfalfa (Medicago sativa ssp. sativa) is a multi year investment. Select a variety proven to be adapted to your area and that can maintain high production in the 3rd and 4th year. Now is a good time to start planning for spring seeding of alfalfa.
Genuity® Roundup Ready® Alfalfa
- Managing Genuity® Roundup Ready® Alfalfa
- Stewardship Requirements for Genuity® Roundup Ready® Alfalfa
Alfalfa weevil damage is often noted in alfalfa fields in early summer. Larvae, up to 5/16 inch long when mature, feed on leaf tissue and tend to concentrate on buds and newly emerging leaves. Early feeding injury of immature larvae appears as pinholes in leaves. As larvae mature, they remove leaf tissue between leaf veins giving the leaf a skeleton appearance. Fields with high weevil populations may take on a silver appearance as the green tissue between veins of leaves is removed. Larvae feeding (3 to 4 weeks) normally takes place from late May to mid June.
Alfalfa weevil larvae are light green colored, 3/8 to 5/16 inch long when mature; have a black head, and white line down the center of the back. They blend in very well with plant tissue so may be difficult to locate. They resemble clover weevils in appearance except clover weevils are much larger and have a tan head.
The economic threshold for alfalfa weevil larvae following first cutting is eight or more larvae per square foot.
(Photos Courtesy of the University of Illinois)