ALFALFA. 153 



this variety to be superior in hardiness and in productive 

 capacity to the common.^ 



Variegated Alfalfa. — This is said to be a cross between 

 common alfalfa and yellow lucerne, a forage crop which is 

 closely related to alfalfa. The flowers vary in color from 

 yellow to greenish purple. This variety is said to be more 

 hardy than ordinary alfalfa and adapted to poorer soils. Where 

 either the common or the Grimm can be grown they are pre- 

 ferred to the variegated, which is characterized by decumbent 

 growth, greater consequent tendency to lodge and lower feeding 

 value. This variety has not been tested in the Massachusetts 

 Experiment Station. 



Obstacles to Success. 



Diseases. — Relatively few diseases have proved trouble- 

 some in Massachusetts. The only important one is leaf spot, 

 which is most injurious on newly sown areas. The spots, 

 which usually appear first on the lower leaves of the plant, 

 are yellow to dark reddish brown in color. Sometimes the 

 lower leaves only are affected, in which case not much damage 

 will be done, but in cases of bad infection, and under favorable 

 weather conditions (hot, humid air and frequent showers), the 

 trouble may spread rapidly; all the leaves turn yellow and 

 gradually fall. In such cases the disease if unchecked greatly 

 enfeebles the plants, and weeds, grasses or clovers tend to 

 displace the alfalfa. No preventive treatment is known, but 

 the disease can usually be checked and healthy growth re- 

 established by cutting, and whether the alfalfa be young or 

 old it should be promptly cut if the disease appears to be serious 

 and rapidly spreading toward the upper leaves. If the field 

 is newly sown and the crop only a few inches high the cutting 

 should not be too close, and what is cut may be allowed to 

 lie where it falls. If the new growth is not healthy the field 

 should be recut. In the case of an established field the forage 

 may be either made into hay or fed green. 



Dodder. — This is a parasite characterized by abundant 

 development of thread-like reddish-yellow stems, attached to 



1 See page 156. 



