521

1.   521 is composed of eighteen clones originating from several experimental lines of fall dormant types including the varieties 520 and ATRA that survived in an infestation of spotted alfalfa aphids in the seedling stage. More than 10,000 seedlings were in the original population. Surviving plants were established in a nursery near Five Points, California for evaluation of seed production and confirmation of spotted aphid resistance. Plants with high seed yields were selected for progeny row forage production evaluation at two locations in