Date of this Version


Document Type



Peltier, George L. and Schroeder, F.R. (1932) The nature of resistance in alfalfa to wilt (Aplanobacter insidiosum L. Mc.) (Research Bulletin: Bulletin of the Agricultural Experiment Station of Nebraska No. 63)


ISSN 0097-1394


Alfalfa wilt was first discovered in 1924 in southern Wisconsin and northern Illinois. The causal organism, Aplanobacter insidiosum, was later described by McCulloch. Since that time wilt has been reported from most of the alfalfa-growing sections of the United States and in some states it has been responsible for a rapid decrease in the acreage of alfalfa. During the past three years a number of investigators have found that certain alfalfas are somewhat resistant to wilt, whereas others are very susceptible. At the Nebraska station the results to date indicate that all common and most variegated alfalfas are very susceptible to wilt. So far only certain alfalfas having their origin in Asia have been found to be relatively resistant. It is apparent that the solution of the alfalfa-wilt problem lies in the development of resistant sorts that are winter-hardy as well as productive, and it is for this reason that a thorough study of the nature of resistance in alfalfas is desirable. The object of this investigation was to determine, at first from anatomical and later from physiological and microchemical studies, why certain alfalfas are resistant, whereas others are susceptible to bacterial wilt.