8 
Colorado Experiment Station 
there is a rapidly growing interest in them among the fruit 
growers.” , , 
The first disease to attract attention in Colorado was the twig 
blight of pear and apple. In 1888, Cassidy (Cassidy, James, “Ap¬ 
ple Twig Blight,” 1st Annual Report Colo. Agr. Exp. Station, pp. 
64-70, 1888) i-eported this disease near Fort Collins, as appearing 
in the latter part of June and continuing until late in August. He 
considered this trouble on the apple to be identical with fire blight 
of pear and a similar trouble on Lombardy and other species of cot¬ 
tonwood. Blight of pear and apple has become increasingly serious 
throughout Colorado. In 1891, Crandall (Crandall, Chas., “A Pre¬ 
liminary Report on the Fruit Interests of the State.” Bull. No. 17, 
Colo. Agri. Exp. Sta., 1891) comments that the “bacterial disease 
variously known as ‘pear blight,’ ‘apple tree blight’ and ‘twig 
blight’ is prevalent and in some sections has done great damage.” 
In 1898, (Crandall, C. S., “Blight and Other Plant Diseases,” Bull. 
41, Colo. Exp. Station, 1898) Crandall indicates that the disease 
had brought numerous inquiries to him. We judge from this that 
it had become more widespread. Paddock (Paddock, W., 22nd 
Annual Report State Board of Agriculture, 1900) reports a body 
blight of apple and pear known in some localities as “crater blight.” 
This is now considered to be due to the organism causing fire 
blight. In 1903, Paddock (Paddock, W., Bull. 84, Colo. Exp. Sta., 
1903) showed that apricot blight was the same as pear blight. It 
seems well established now that the bacterial organism, Bacillus 
amylovorus, may cause a blight on pear, apple, quince, apricot and 
plum, known by such common names as pear blight, fire blight, 
twig blight, apple blight, blossom blight and body blight. From the 
foregoing brief historical sketch of pear blight in Colorado, we see 
that since its appearance in 1888, it has become more widely spread 
in the state and its attacks have increased in severity. 
The history of potato' diseases in Colorado is as instructive as 
that of pear blight. The first mention of potato troubles in Colo¬ 
rado is found in a publication by Paddock and Rolfs, (Paddock, W., 
and Rolfs, F. M., “Potato Failures,” Bull. 64, Pi*ess Bull. No. 8, 
Colo. Exp. Sta., 1901) in 1901, in which they call attention to po¬ 
tato failures in various sections, due probably to Rhizoctonia. They 
indicate that this disease has “undoubtedly been present in our pota¬ 
to fields for a long time.” They say that little blight (Fusarium) 
is in evidence. In 1Q02, Rolfs (Rolfs, F. M., “Potato Failures,” 
Bull. 70, Colo. Exp. Sta., 1902) published a preliminary report on 
Rhizoctonia, describing the occurrence and effects of the disease on 
the potato, the nature of the fungus, and giving the results of in¬ 
oculation and preventive experiments. This is our first valuable 
