Spraying Experiments in Nebraska 
51 
this time. .What is known as the cluster-bud stage, just as the 
flowers of the clusters are separating and showing "pink" but 
before the individual blossoms open, is the proper time for this 
application, according to results obtained. In dry seasons or in 
orchards where thoro spraying and orchard sanitation have been 
the rule, this application may be omitted without serious loss as 
shown by the results obtained in most of the orchards in 1914 
and in the Omaha orchard (table 30) in 1915. 
A second application at the petal-fall stage, and another two 
to three weeks later, are as a rule required to insure protection. 
During this time new surfaces of fruit and fohage are being rap- 
idly exposed and are liable to infection. Another spray in the 
latter part of July or the first part of August may be necessary to 
prevent late infection in wet seasons such as that of 1915. 
In order to secure the best results, it is necessary that the 
grower watch the weather conditions carefully and regulate his 
schedule accordingly. Thousands of bushels of apples have been 
lost in this State because the grower delayed spraying on account 
of rainy weather, fearing the spray would wash off. This is just 
the time when protection is needed to prevent infection. There 
is rarely a season in Nebraska when, because of wet weather, 
there is not sufficient time to spray, and if it is possible to work 
for only a part of a day at a time, spraying should proceed. 
Ordinarily the spray material will dry in 30 minutes of sunshine 
so that it will adhere well thru any ordinary hard washing rain. 
APPLE BLOTCH 
Spraying experiments were begun in 1913, primarily to de- 
termine efficient methods of control for codling moth, plum 
curculio, and apple scab, but it was soon discovered that apple 
blotch was more destructive in some parts of the state than apple 
scab. The disease was carefully observed during the season and 
notes taken on the efficiency of the sprays, intended for scab, in 
controlling blotch. This disease has only recently invaded 
Nebraska from the south and east and as yet is serious only in 
the southeastern portion of the State. It is widely distributed 
over the United States. The writer had abundant opportunity 
to observe its destructiveness in Kansas in 1910, '11, and '12, 
where in some sections it causes more damage than any other 
disease which attacks the apple. 
DESCRIPTION AND BEHAVIOR 
The fungus attacks fruit spurs, twigs, and rapidly growing 
shoots, producing characteristic cankers (Scott and Rorer, 1909). 
(1909) ^fcott, W. P. and Rorer, James B. Apple blotch a serious disease of southern orchards. 
U. S. D. A. Bui. No. 144. 
