196 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. 



by the packers is also high, being $50 to $60 per ton at the packing 

 house in 1910. Another reason given is that the grapes grown in 

 the Imperial Valley have poor shipping and keeping qualities and that 

 only a small proportion get to the market in good condition. As a 

 matter of fact, some of the grapes grown in the valley have excep- 

 tionally good keeping and shipping qualities. The true main reason 

 for the failure to make grape growing pay seems to lie in the failure 

 to adopt suitable methods of growing and treating the vines and 

 grapes. The climatic and soil conditions are peculiar and different 

 from those of any other grape growing section of California, and 

 special methods are necessary to insure profitable returns. The full 

 profit of the industry will be realized only when the methods best 

 adapted to the conditions are generally known and followed. What 

 these best methods are, study, time and experience alone can determine. 



Every phase of the subject, from the preparation of the ground for 

 planting to the delivery of the grapes to the consumer, requires in- 

 vestigation. Already, indeed, a considerable amount of experimenta- 

 tion, intentional and otherwise, has been carried out. Grape growers 

 from widely differing viticultural sections have been planting and 

 cultivating vines in the valley for several years, all modifying their 

 practice more or less in accordance with the customs of their old 

 homes. A large number of vinifera varieties have been introduced 

 and tested. On many points, therefore, there is experimental data on 

 which to make comparisons and form conclusions. 



At present, the grapes are grown exclusively for early shipment as 

 table grapes or for local consumption. The principal shipping season 

 extends from about the middle of June to the end of July, varying 

 somewhat in different years. The great bulk of the grapes consists of 

 Sultanina (Thompson's Seedless), Malaga, and Muscat of Alexandria, 

 ripening in the order named. The shipments of Malaga far exceed 

 those of all other varieties combined. The season could undoubtedly 

 be lengthened by the use of varieties ripening before the Sultanina 

 and of very late varieties. The latter would come in competition with 

 varieties from other sections, but being very distinct in character they 

 would undoubtedly find a market. 



Preparation of the Soil. It is very important that the vines should 

 have strong root systems penetrating deeply into the soil. 



In many, probably in most, of the vineyards of the valley the vines 

 have shallow spreading roots confined to the top foot of soil. In 

 several cases examined, no roots as large as a pencil were found below 

 ten inches from the surface. Such vines may grow vigorously and 



