Irrigation 183 



Correct timing of the first irrigation is exceedingly 

 important and will depend somewhat on the amount of 

 winter rains. It is thought that early irrigation tends 

 materially to reduce the June drop. If the trees are kept 

 growing vigorously, they will not usually suffer excessive 

 drop. The spraying operations must be considered in rela- 

 tion to the time of irrigation in order that the soil may be 

 sufficiently dry to permit the hauling of the spray outfit. 

 It is desirable that the water supply be continuous rather 

 than intermittent in order that the grower may definitely 

 plan his work and not be kept waiting for water at critical 

 times. 



The number of irrigations varies but will average from 

 four to five in a season, being made at intervals of twenty 

 to thirty days. A light sandy soil which is not retentive 

 of moisture must be irrigated every two or three weeks. 



There is a noticeable tendency in late irrigations to 

 swell the size of the fruit. This practice detracts from its 

 keeping qualities and flavor. Excessively large apples 

 tend to go down in storage. Heavy late irrigations, fur- 

 thermore, increase loss from scald and bitter-pit. It is 

 best to irrigate heavily up until about August fifteenth 

 and then gradually taper off. Ordinarily no irrigation 

 should be made after September fifth. 



METHODS OF IRRIGATION 



Originally water was supplied to the western apple 

 orchards through earthen ditches. With the increasing 

 scarcity of water, there has been a pronounced tendency 

 towards lining the main canals in order to make them 

 water-tight and to install underground piping to distribute 

 water to the highest point in the orchard or along the high- 



