PROBLEMS AND PROGRESS IN PLANT PATHOLOGY 
109 
cultivation and crop rotation in relation to sanitation, together with 
the destruction of diseased plant tissues and the checking of the 
carriers of disease germs, deserve more critical attention than they 
have received from plant pathologists as well as plant cultivators. 
While America has for some time been the most advanced nation 
in controlling diseases by spraying, she has been one of the slowest to 
undertake plant disease exclusion. The plant quarantine act secured 
last year by the combined efforts of phytopathologists and entomolo- 
gists marks, therefore, a most important forward step. The recent 
hearings relative to the potato disease quarantine, under this act, 
have served not only to emphasize its importance, both commercially 
and educationally, but also to point out important new duties for 
plant pathologists. In order wisely to administer such quarantine 
measures there must be international cooperation among phyto- 
pathologists in determining the occurrence and seriousness of plant 
diseases. But while we are thus beginning to guard our borders 
against potato wart and other dangerous foreign diseases, what are we 
doing within our own territory? For example, we know that there is 
an alfalfa disease (Urophlyctis alfalfae) similar to the black wart of 
potato in its nature and destructive possibilities, as yet apparently 
limited in its distribution to a few western alfalfa-growing sections. 
No official steps have as yet been taken, so far as I know, to make 
exact determinations of its present distribution or to guard against its 
being carried to other places on seed. This would seem to be a 
national rather than a state function and the national plant disease 
survey already referred to would seem to be the logical first step. 
In this connection the plan outlined by Orton for official inspection 
and certification as to health of seed potatoes is highly significant.^^ 
I believe it must commend itself for adoption with various other crops 
as well. There is no other place more important for guarding the 
health of crops than at the source of seed. 
And finally, there is the question of disease resistance and im- 
munity. Of course, the idea is not new; observations upon the 
relative liability of varieties to disease come to us from early times. 
But the clearer conception of the possibilities in this respect of plant 
^5 O'Gara, P. J. Urophlyctis alfalfae, a fungus disease of alfalfa. Science, N. S. 
36: 487. 1912. 
Presented in a paper before the Annual Meeting Wisconsin Potato Growers' 
Association, Nov. 20, 1913. To be printed in the Proceedings of this Association, 
which may be had from J. G. Milward, Sec'y., Madison, Wis. 
