AMERICAN 
JOURNAL OF BOTANY 
Vol, V June, 1918 No. 6 
BREEDING FOR DISEASE RESISTANCE IN PLANTS^ 
W. A. Orton 
Our common asparagus {Asparagus officinalis) was cultivated in 
America from the time it was introduced from Europe until 1896 
without any losses from disease worthy of record. The varieties in 
general use were then of American origin and had been developed for 
qualities other than disease resistance. 
Asparagus rust, a disease due to the parasitic fungus Puccinia 
asparagi, was discovered in New Jersey in 1896, and within six years 
had spread to the Pacific coast. This rust proved very destructive; 
asparagus fields were killed within a few years. Attempts to control 
it by spraying or other preventive and sanitary measures were un- 
profitable, and the outlook for asparagus culture was for a time very 
gloomy. 
It was observed that some varieties, such as Argenteuil and Pal- 
metto, were partially resistant. An organization was formed to de- 
velop a rust-resistant asparagus from numerous varieties of asparagus 
imported from foreign countries, and the breeding work was placed in 
charge of Mr. J. B. Norton. Among the imported varieties was one 
from England, named Reading Giant, which was more rust-resistant 
than any other. This was variable in type as well as in resistance, 
but selected individuals pollinated by selected male plants of this and 
other varieties have given rise to races of asparagus which are almost 
immune to rust and are at the same time of superior size, quality, and 
productiveness (i). 
The problem of asparagus rust control was thus solved within 
five years. It remained only to disseminate the new resistant varieties. 
^ Invitation paper read before a joint meeting of the Botanical Society of America 
and the American Phytopathological Society at Pittsburgh, December 31, 1917. 
[The Journal for May (5: 219-278) was issued June 21, 1918.] 
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