152 THE DATE PALM. 



Rain and atmospheric humidity, effects on date palm, discussion ............ 52-58 



at Moorzook, Fezzan, Sahara, destruction of date ....... . ........... _. . 118 



in Death Valley, lack ................................................ 123 



injury to flowers and fruit of date palm ................... ............ 54 



notes on amount at various date-growing points ...................... 57 



Rainfall, sufficiency, for dates in parts of California and Arizona (see also Rain ) 49 

 Rainy days and rainless months in date regions, records . ................... 56 



Reproduction of date palm in natural state ................................. 15 



Rhars date, good qualities ........ ....................................... 32, 33 



notes ................................................. 30, 41, 50, 132 



Rohlfs, Gerhard, remark regarding dates in Morocco ......... . .............. 39 



Ripening of dates, artificial, method ....................................... 135 



benefit of hot dry wind ................................. 71 



hastening by use of warm water in irrigation ............. 67 



heat requirement ....................................... 65-70 



Deglet Noor date, remarks ................................. 67, 68, 69 



Rirh River. See Oued Rirh. 



Rolland, M. , estimate of water supply for date _____ ......................... 45 



Roots of date palm, characteristics ......................................... 19 



depth in alkali soil .................................... 112 



moisture in earth, necessity ............................ 46 



need of aeration . ...................................... 50 



offshoots starting after planting ........................ 21 



trimming in transplanting ............................. 20 



fan palm in alkali, remarks ..................................... 112, 119 



Rose, M. le commandant, estimate of water supply for date .................. 45 



Sacramento and San Joaquin valleys, date culture, probable success ......... 123 



Sahara, comparison of water supply with Colorado River ................... 105 



dates and date palms .......................................... 39, 40, 41 



importance of date growing .............................. ......... 17 



investigation of alkali-resisting power of date palm .................. 73-99 



protection of fig and olive by date palms ........................... 44 



ratio of male date palms, note ..................................... 23 



season of flowering of date ........................................ 27 



Souf country, growing of Deglet Noor dates ........................ 35 



sunken date gardens, description ..................... 69 



study of alkali resistance of date palm ........................... 115-120 



temperature curves in date region. . ................................ 63-64 



temperatures, mean and mean maximum ........................... 66-68 



Saharan alfalfa, use on alkaline soils in date orchard ........................ 23 



varieties of date palms, introduction into United States ............. 41-43 



Salt River Valley, Ariz., alkali in relation to date culture (see also Arizona) . . 99-101 

 climatic conditions for date .................... 53, 55, 57 



date culture, probable success ..................... 127 



irrigation water, temperature and -composition ---- i 49, 99 



seedling dates ........................... ....... 32, 128 



Saltbush, Australian, resistance to alkali ........................... I ..... 115, 121 



Saltoii Basin, Cal. , alkali as compared with Algeria ........................ 93, 113 



character ...................................... '. . 101 



conditions in relation to date culture ........ ---- 101-114 



amount of water needed for irrigation of date, note ....... 46 



artesian wells .......................................... Ill 



chemical composition of alkali ................ , ....... 112-1 13 



climate, remarks ............................... - ....... 112 



culture of Deglet Noor dates .............. 33, 65, 67, 69, 110, 136 



crop growing by Indians in early days ...... . . ........... 103 



danger, possible, to date from cold ...................... 72 



date culture advantages, summary ....................... 141 



probable success . .......... ..'. 5, 12, 33, 67, 122, 136 



growing areas .................. - .................. 110 



dates to be secured ..................................... 



distribution of alkali, by depths ....................... 117-118 



drainage for date growing, remarks ..................... 51-52 



experimental garden at Mecca .......................... 110 



fan-palm oases ......................................... HI 



fertility of soil ...................... r .................. 114 



