8 Nebraska Agricultural Exp. Station, Research Bui. 10 
It was very difficult to spray all of the trees exactly alike. 
To overcome this difficulty, one of the above mentioned men or 
the writer was present and directly supervised the weighing, 
mixing, and application of each spray for every plat. 
Perhaps one of the greatest troubles encountered was the 
adoption of a uniform system of taking data and making records. 
The many degrees of insect, fungous, and spray injuries make it 
very difficult for different men to make uniform records because of 
different degrees of importance they may attach to each. This 
was overcome to a great extent by the writer working with each 
man thruout as much of the season as possible. 
Especially during the season of 1915, russet appeared on the 
fruit of the check trees so that it was sometimes hard to distinguish 
between this and spray injury. Often where two unsprayed trees 
of the same variety stood side by side the fruit on one would be 
russeted and that on the other comparatively free. An attempt 
was made to overcome this by averaging the amount of russet on 
unsprayed trees, accepting this as a standard, and calling all 
over this amount, on the sprayed trees, spray injury. 
INSECTS AND DISEASES CONSIDERED 
The principal insects affecting apples in Nebraska are the 
codling moth {Carpocapsa pomonella) and the plum curculio {Con- 
otrachelus nenuphar). There are numerous other foliage and fruit 
eating insects of minor importance, but they are controlled inci- 
dentally by the sprays intended for the former. The principal dis- 
eases affecting apples are apple scab (Venturia inaequalis) and 
apple blotch (Phyllosticta solitaria). As in the case of insects, 
there are many diseases of minor importance affecting the fruit 
and foliage of the apple which are usually controlled by sprays 
intended for the two principal diseases. 
Occasionally serious outbreaks of cedar rust (Gymnosporangium 
macropus) occur in localities where large numbers of cedar trees 
are found near the orchards, but during the last three seasons 
practically no cedar rust has been noted. In wet seasons, sooty 
blotch (Leptothyrium pomi) often causes considerable damage. 
TERMINOLOGY AND EXPLANATION 
Bordeaux — The term ''Bordeaux" is used thruout this repon 
in place of Bordeaux mixture. 
Lime sulphur — The term lime sulphur is used in place o 
lime sulphur solution. 
In all tables Bordeaux is indicated by the letters Bx, lim* 
sulphur by LS, arsenate of lead by Pb. 
In indicating the formula when Bordeaux is used, 50 gallon 
1 
