388 ALFALFA 



branched roots than others. It is said that the variegated alfalfas 

 have a tendency to produce branched roots, and that this character 

 is correlated with winter hardiness. However, the character of the 

 soil so affects the type of root that no very accurate information has 

 been collected as to the root structure of the different forms and its 

 relation to hardiness. 



Development of Shoots. A strong alfalfa plant, under aver- 

 age conditions, will produce from twenty to fifty stems, although 

 individual plants have been known to produce as high as three hun- 

 dred. The top of the plant is known as the " crown," made up of a 

 series of short, heavy branches. Buds arise from any point on these 

 branches down to one or two inches below the surface of the soil. 

 Usually as soon as the first set of stems have reached full height, a 

 new crop of buds develops, ready to grow up at once if the old stems 

 are cut away. Under ordinary conditions, a new crop of stems will 

 be produced every forty days. The only condition that seems to 

 retard the development of new buds is extreme drought. In very 

 dry regions the first crop of stems may even blossom and mature 

 seed, the whole time taking eighty or a hundred days, with very little 

 tendency to develop new buds, unless rain comes or irrigation water 

 is turned on. 



In humid regions it is usually believed best to cut the hay when 

 the new buds are well started, or about two to three inches in length. 



Life Period of Alfalfa. In humid regions, from six to ten 

 years is considered the average life of an alfalfa meadow. It is 

 much longer lived in dry regions, and has been known to live at 

 least fifty years and produce good crops in semi-arid countries. In 

 the northern States the plants are very commonly killed through 

 winter injury. On heavy clay soils the plants are heaved out by 

 hard freezing. In other cases they seem to be killed by hard freez- 

 ing. In humid regions the old plants are usually sooner or later 

 attacked by some form of rot, and after a year or two succumb. 



Submerging is very injurious to alfalfa. A strong alfalfa field 

 will often be killed out by flooding not more than two or three days. 

 This is especially injurious on flat lands during the early spring 

 thaws. A thin layer of frozen water for only one or two days will 



