COST OF PRODUCING APPLES IN YAKIMA VALLEY. 89 
THINNING. 
Thinning is an annual practice of all orchardists visited in the 
valley. (See fig. 7.) Usually it is begun during the month of June, 
shortly after what is known as the “June drop.”” The time required 
for this operation varies much, depending on the size of the crop, 
the variety, age, and size of tree, and the method adopted in thinning. 
The usual practice is to thin so that the fruit is well distributed 
over the tree. No set rule can be given, although the growers aim 
to leave only one apple in a place, partly for the reason that where 
two apples touch each other a favorite opportunity is offered for the 
codling-moth larva to work. The amount of thinning depends to a 
Fic. 7.—Thinning a 7-year-old Winesap tree in the Zillah district. Alfalfa is used as an intercrop and 
mulch crop here. Note the size of tree for its age. 
considerable extent upon the season. If the crop is light and the 
apples are borne in clusters, two apples sometimes are left in a place; 
but with a heavy crop and varieties which tend to small size, many 
make a practice of thinning to 6 or 8 inches. Needless to say, with 
a large crop the work of thinning will be doubled or even trebled. 
Many times it is necessary to do more than one thinning during the 
season, this being especially true of red varieties. Practically all 
thinning throughout the valley is done with thinning shears. The 
trees are of such size and age that most of the work may be done from 
the ground or from an 8- to 10-foot stepladder. 
The amount of thinning is governed not only by the size of the 
crop but by the amount of pruning thatis done. The cost of thinning 
operations in the valley is 18.38 per cent of the total gross labor cost 
