8 CONTENTS. 



Page, 



Resistance of the date palm to alkali 72 



Investigation of the alkali-resisting power of the date palm in the Sahara. 73 



Alkali conditions in relation to date culture at Biskra, Algeria 76 



Alkali conditions in relation to date culture at Fougala, Algeria 78 



Alkali conditions in elation to date culture at Chegga, Algeria 84 



Alkali conditions in relation to date culture at M'rai'er, Algeria 88 



Alkali conditions in relation to date culture at Ourlana, Algeria 89 



Previous and subsequent analyses of alkaline soils from the Sahara. . . 97 

 Drainage water from alkaline soils used to irrigate date palms in the 



Sahara 98 



Alkali conditions in relation to date culture in the Salt Eiver Valley, 



Arizona 99 



Alkali conditions in relation to date culture in the Sal ton Basin, California. 101 



Geography and geology of the Salton Basin 101 



Water supply of the Salton Basin 104 



Soil conditions in the Salton Basin 106 



Alkali conditions at Palm Canyon in the foothills bordering the Salton 



Basin Ill 



Chemical composition of the alkali of the Salton Basin 112 



Fertility of the soils of the Salton Basin 114 



Subsidiary cultures to follow in connection with date plantations on alka- 

 line soils 115 



Limits of alkali resistance of the date palm 115 



Resistance of the date palm to chlorids 118 



Resistance of the date palm to sulphates 119 



Resistance of the date palm to carbonates ( black alkali) 119 



Regions in the United States where date culture can succeed 122 



California 122 



Salton Basin or Colorado Desert 122 



Death Valley 122 



Colorado River Valley 123 



Plateau region 123 



Interior valley region 123 



Coast region of southern California 125 



Nevada 4 125 



Arizona 126 



Salt River Valley 127 



Colorado River Valley 129 



New Mexico 133 



Texas 134 



No danger from Mexican competition in date culture 134 



Profits of date culture 136 



Extent of the market 138 



Importance of life history investigations in demonstrating the feasibility of 



date culture 139 



Summary 141 



Description of plates " 142 



Index.. 145 



