20 CALIFORNIA FRUITS I HOW TO GROW THEM 



Average Summer Temperature at Various California Points 



Coast and Coast Eleva- Deg. 



Valleys Deg. F. Interior Valleys Deg. F. Foothills tion. F. 



Upper Lake 86 Redding 80 Auburn 1,363 75 



Napa 65 Oroville 79 Colfax 2,241 76 



Livermore 69 Marysville 78 Georgetown 2,500 85 



San Jose 67 Sacramento 72 Caliente 1,290 82 



Hollister 66 Merced 79 Fall Brook 700 68 



Santa Barbara ... 65 Fresno 79 Redlands 1,352 77 



Los Angeles .... 70 Tulare 78 



San Diego 68 Riverside 73 , 



These points are selected because the European varieties of the 

 grape reach perfection in their vicinity. The excess of heat above 

 that required, as is found at all the interior points mentioned in the table, 

 results in a very high sugar percentage in the grapes, and contributes 

 to the ripening of a second and third crop, as will be noted presently. 

 The superior length of the growing season in California, of course, 

 is an important agency toward the same end. 



DIRECT SUNLIGHT ALSO A REQUISITE 



Count de Gasparin was first to point out that not alone sufficient 

 heat, but abundance of continuous sunshine is a requisite of perfec- 

 tion in fruit growth and ripening, and on his authority may be based 

 a claim of exceptional value to the fruit grower in the months of 

 cloudless skies which are characteristic of the California summer. 



"The solar rays," says Gasparin, "do not only produce heat, but 

 brings us light, and the effects of the heat and light rays differ in a 

 very pronounced manner. Without light there is no fructification ; 

 it is not necessary that the want of light should be complete that 

 there should be a failure of fruits. In fact, diffused light alone does 

 not suffice for the greater number of plants; cultivated plants will 

 not ripen their seed without the direct rays of sun, and the longer 

 they are deprived of it the smaller the quantity which they will 

 mature."* 



Again referring to the grape, for in connection with the growth 

 of this fruit the most careful researches have been made, Humboldt 

 wrote : "If to give a potable wine the vine shuns the islands and 

 nearly all seacoasts, even those of the West, the cause is not only 

 in the moderate heat of summer upon the seashore, but it exists 

 more in the difference which there is between direct and diffused 

 light ; between a clear sky, and one veiled with clouds. "f 



*Cours d' Agriculture, t. II, p. 96. 

 fCosmos, t. I, p. 349. 



