Spraying Experiments in Nebraska 7 
were of uniform vigor and variety, and which were of such size 
and shape and planted in such a way that they would lend them- 
selves to platting for experimental work. 
NEBRASKA 
Fig. 1 — Map showing location of experimental orchards 
In order that the results might be thoroly reliable, and to over- 
come individual variation, a large number of trees were included 
in each plat, the number being in each case what could be con- 
veniently sprayed with one load, except in cases where barrel 
sprayers were used, when two or more barrels of spray were used 
on the same plat. After the fruit was set, from four to twelve 
trees were selected, as nearly uniform in all respects as possible, 
from which to examine the fruit. 
Trees were left unsprayed in each plat as a ' 'check" ^ whenever 
possible. It was necessary to select the ''check" trees before 
the fruit set and before the selection of the "count"^ sprayed 
trees, but enough were left in practically all cases so that those 
which were not comparable could be discarded. 
However, in spite of the utmost care, difficulties presented 
themselves from time to time. One of the greatest difficulties 
lay in the individual variation of trees. Another difficulty was 
the very noticeable variation in amount of disease infection and 
insect infestation in various parts of the same orchard. To 
counteract these variations, "checks" and "count" trees were 
selected as near together as possible in various places thruout the 
plats. 
i"Checks" are the trees which were not sprayed. 
-"Count" trees are those which were selected for special observation, the fruit being exam- 
ined and counted for records. 
