Irrigation 173 



Oregon commercial apple crop is grown under a system of 

 intensive irrigation. 



The Hood River Valley of Oregon, while not an arid 

 region, employs irrigation in many of its orchards. The 

 Rogue River or the Medford district in Oregon was form- 

 erly a non-irrigated section but continued drought com- 

 pelled the practice of irrigation when possible. The only 

 important non-irrigated apple regions in the West are the 

 Watsonville and Sebastopol sections of California located 

 within a few miles of the coast. 



The irrigated fruit regions differ in many ways from the 

 apple sections of the Central West and East. Some of 

 their most outstanding characteristics are : 



1. Compactness. All irrigated fruit districts are very 

 intensive and compact. They are generally confined 

 within a certain limited and well defined area. The typ- 

 ical farms are small and the orchards average only about 

 ten to twenty acres. Often the orchard of one grower 

 borders directly on that of his neighbor, so that the plant- 

 ings in an irrigated valley appear as one large orchard 

 with but few breaks of land not in trees. 



2. Productivity. Orchards in irrigated sections free 

 from frequent frost-injury bear larger annual crops, partly 

 because the water supply is largely under control. 



3. Rapid tree growth. Trees in irrigated districts grow 

 very rapidly and attain maturity early. Often trees at 

 ten years of age are practically in full bearing and in many 

 cases even at seven or eight years of age they bear very 

 heavily. Trees in the Wenatchee Valley attain maturity 

 in about one-half the time required for the same varieties 

 in the East. 



4. Trees are set close together. The trees in the irri- 



