6 



BULLETIN 617, U. S. DEPARTMENT OF AGRICULTURE. 



tures are recorded, this saltbush grows luxuriantly. Along the 

 coast, where high temperatures are seldom recorded, it does equally 

 well. The minimum temperature recorded at any place in California 

 or Arizona where it is known to be growing at the present time is 

 10° F., at Tucson, Ariz. 



The mean annual precipitation at places in California where the 

 Australian saltbush is growing well without irrigation ranges from 9 to 

 19 inches. This saltbush thrives about San Diego, where the mean 

 annual precipitation is about 9 inches. Here, however, fogs make 

 the conditions favorable, and plants no doubt do well with much less 

 precipitation than would be the case inland. At Santa Barbara, 

 where the mean annual precipitation is 1 G.G inches, this saltbush grows 

 luxuriantly, but it does not occur in as great abundance as about San 

 Diego and Los Angeles. At Santa Cruz, where the mean annual 

 precipitation is 27 inches, and about San Francisco Bay, where the 

 mean annual precipitation is 22.5 inches, it is not found. Whether or 

 not this is due to the heavier precipitation is not certain. It may be 

 partly due to generally cooler weather, as the mean annual temperature 

 at these places is lower than at points farther south where this salt- 

 bush does well. The mean annual temperature in regions where it 

 is more abundant is about 60°. However, at Salinas, where it is 

 growing quite vigorously, the mean annual temperature is about 56° 

 F., which is the same as at San Francisco and 2 degrees lower than at 

 Santa Cruz. 



Table I. — Climatological record for various places in the saltbush area of Arizona and 



California. 



[Data from Bulletins Q and L, Weather Bureau, U.S. Department of Agriculture.] 



State and place of observation. 



California: 



San Diego 



Los Angeles 



Santa Barbara . . . 



San Luis Obispo. 



Santa Cruz 



San Francisco 



Hollister 



San Jose 



Salinas 



Soledad 



Kings City 



Redlands 



Riverside 



Fresno 



Tulare 



Bakersfield 



Mojave 



Arizona: 



Yuma 



Phoenix 



Tucson 



Temperature (° F.). 



Mean 

 annual. 



61 



62 

 (10 

 59 

 58 

 56 

 59 

 58 

 56 



"58"' 

 64 



62.9 

 63 



"66"" 

 65.5 



72.0 

 70.0 

 68.0 



Maxi- 

 mum. 



101 

 109 

 100 

 106 

 108 

 100 

 105 

 101 

 95 



114 

 113 



114 



114 



118 

 116 

 112 



Mini- 

 mum. 



Mean 

 annual 

 precipi- 

 tation. 



Inches. 

 9.4 

 15.6 

 lfi. 6 

 19.2 

 27.0 

 22.5 

 12.3 

 14.8 

 14.12 

 8.97 

 10.8 

 14.7 

 10.01 

 9.2 

 7.65 

 4.8 

 4.79 



2.7 

 6.8 

 9.8 



