INSECTS & DISEASES IN SEEDLING STANDS

Insects can begin attacking alfalfa plants at or before emergence. Frequent scouting of new stands is essential to good insect control.  

Grasshoppers, armyworms, cutworms, and other general feeders infest stands in a few days. Timely application of insecticides is the most reliable method of control. It may be advisable to spray fence lines and field borders, if grasshopper infestations are heavy.  

During the fall, spotted alfalfa aphids, and occasionally pea aphids, build up on seedling alfalfa. Blue alfalfa aphids come into alfalfa fields in the fall and are present nearly every winter and spring.  

Using adapted resistant varieties and good cultural practices that encourage rapid growth provide the best controls for aphid infestations. Early detection is an important factor because it allows timely insecticide application before problems have gone too far.  

Diseases, such as damping off and root rots, are sometimes problems with alfalfa stand establishment. Fungicidal treatments, applied to seed or sprayed on seedlings, are effective for a short time and may make the difference between successful stand establishment and failure.  

Genetic resistance in conjunction with crop rotation, good land preparation practices, and good seedbed preparation are more long-lasting control measures. Root rots are most commonly found in soils that are wet for a prolonged period; therefore, providing drainage before sowing is an excellent disease prevention measure.