20 CALIFORNIA FRUITS: HOW TO GROW THEM 



Average Summer Temperature at Various California Points 



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 in 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 growing 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 bring us light, and the effects of the heat and light rays differ 

 in a very pronounced manner. Without light there is no fructifica- 

 tion ; 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 

 doesn ot 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 



The advantage of California over Eastern and Southern fruit 

 regions in the abundance of clear sunshine is shown in the table 

 below. Cloudiness is rated from to 10, three observations daily, 

 and the figures in the table are the averages from these daily ob- 

 servations, for a series of years, compiled from the records of the 

 U. S. Weather Bureau. 



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

 tCosmos. t. I, p. 349. 



