36 CALIFORNIA AGRICULTURAL EXTENSION Service [Circ 42 
An irrigation after the crop is harvested, generally in September 
or October, will benefit the trees and put the soil in condition to 
favor the germination and growth of the cover crop. This irrigation 
also aids fruit bud development and is. therefore, important from the 
Fig. 9.—Winter irrigation bv means of the check or basin svstem. 
standpoint of the succeeding season’s crop. It is desirable to keep an 
available supply of moisture in the soil throughout the year, since 
with sufficient moisture root growth may continue during late fall 
and winter months even though the top is dormant.