Alfalfa 
7 
seed, the plants being screened. The seed was saved for future work. 
Irrigation was withheld to induce better seed production. The dry 
condition seemed to increase the frost injuries the following winter 
for a still greater loss of plants occurred in the same plats where the 
winter-killing first began. The northern strains were still free from 
any injury, while the plats from the Arabian and African seed were 
practically all dead The loss of plants by winter-killing has con- 
Plate No. 4.—Another portion of the 1907 alfalfa nursery, taken April 
25, 1911, showing the portion of the nursery seeded with the Turkestan and 
other heavy stooling crown types, where no loss from winter-killing has 
occurred in four winters. 
tinued to occur to some extent in the non-hardy plats for the past four 
winters. 
Plate No. 3 is a view of a portion of the nursery, taken April 25, 
1911, showing the effects of four winters. The loss of plants in several 
of the non-hardy plats is noticeable. Plate No- 4 is a view of another 
portion of the same nursery taken at the same time, showing the hardy 
northern strains where no loss from winter-killing has occurred. 
During the past four years careful examination has been made of 
many hundred plants, to determine the cause of the loss of plants in one 
plat and not in another. Several seedings have been made and plow¬ 
ed up, in order to study the relative difference, if any, between the 
crowns where winter-killing occurred and where it did not. 
