FLAX WILT: A STUDY OF THE NATURE AND INHER¬ 
ITANCE OF WILT RESISTANCE 
By W. H. Tisdale, 
Wisconsin Agricultural Experiment Station 
INTRODUCTION 
The main object of these investigations has been to study the nature 
and inheritance of wilt resistance. Bolley (4-xi) 1 has so thoroughly 
worked out the more practical phases of the problem that it has left a 
clear field for a study of this kind. It seems important, however, to 
give, by way of introduction, a few fundamental statements regarding 
the disease and the causal organism. 
. The flaxwilt problem has been of great importance in this country 
and is also a serious problem in some of the flax-growing countries of the 
East (5, 12 , 19, p. 211-217). In America the flax industry has been 
forced rapidly westward, owing to the loss from wilt. The disease is 
typical of the wilt diseases which are produced by various species of 
Fusarium. Plants at any age from germination to maturity may be 
attacked and killed by the parasite. The disease is manifested by a 
sudden wilting of young seedlings and a yellowing of the foliage of older 
plants, followed by a wilting which may involve the entire plant or only 
one side of it, thus causing a bending or twisting of fhe plant toward 
the wilted side. The disease is highly destructive to common flax 
(Linum usiiatissimum) when grown on thoroughly infected soil, and 
very often the entire crop is destroyed. 
SOURCE OR MATERIAL 
Flaxseed and “flax-sick soil” were kindly supplied for this work by 
Prof. H. L. Bolley, 2 of the North Dakota Agricultural Experiment 
Station. From plants grown from these seeds in the “sick soil” a 
species of Fusarium was isolated which agreed in cultural characteristics 
and pathogenicity with Fusarium Uni Bolley (4). There was a wider 
range of spore size than Bolley gave in his original description, but this 
could be accounted for by the difference in environmental conditions 
under which the spores were produced, as environment was found to 
1 Reference is made by number (italic) to “ Literature cited,” p. 604-605. 
2 The writer wishes to express his sincere appreciation to Prof. H. L. Bolley for his hearty cooperation 
in offering invaluable suggestions and in supplying material for the work. He is also indebted to Prof. 
L. R. Jones, of the Plant Pathology Department, and to Prof. L. J. Cole, of the Experimental Breeding 
Department, of the University of Wisconsin, for their aid in defining the problems at the outset and for 
their respective supervision and kindly criticisms of the pathological and breeding phases as they pro¬ 
gressed. 
Journal of Agricultural Research, 
Washington, D. C. 
lb 
(573) 
Vol. XI, No. 11 
Dec. 10,1917 
Key Wis.No—8 
