22 STATE BOARD OF HORTICULTURE. 



were lemons. As the average net value of a carload of orangen 

 and lemons to the producer for the season of 1900-01 was al)OUt 

 •1!350, the total value of the shipments amounts to $8,715,000. 

 About as much more money was disbursed for cultivation, 

 packing, and freight, making a grand total for that season of 

 about $17,430,000. The above only represents the actual 

 amounts that were moved to markets. 



Especially Favorable and Dangerous Localities.— All 



along the belt of country from Tehama County to San Diego 

 there are especially protected or favored localities where the 

 orange and the lemon grow to perfection, and also localities 

 where it would be unsafe to attempt citrus fruit culture as a 

 commercial enterprise. This is caused by the local topography 

 of the country and does not depend much on the altitude. 

 Wherever cold currents of air from high altitudes flow to the 

 valley without interruption, it will not be safe to attempt citrus 

 culture at any elevation within the sweep of these currents. 

 On the other hand, wherever these descending currents are cut 

 off or turned aside by spurs of the mountains, leaving the 

 warm atmosphere of the days undisturbed during the nights, 

 there orange and lemon culture may be engaged in without 

 danger from frost. In other words, the eddies of air currents 

 must be selected and the main flow of these currents must be 

 avoided. 



Ever}' one who has traveled along these Sierra foothills 

 parallel with the valleys, particularly in the winter season and 

 at night, will recall his surprise at the sudden changes of the 

 temperature of the atmosphere within short distances. He 

 may also rememl>er to have noticed tender plants and shrubs 

 seared and frost l>itten, while just over a ridge or cone the same 

 plants and shrubs were in full leaf and growing luxuriantly. 

 Want of attention to these facts has caused many a disastrous 

 failure in the cultivation of citrus fruits in California. 



It may be here observed that these peculiar natural 

 phenomena are more striking and their lessons are more 

 imperative north than south of the Tehachapi pass — for the 

 reason that south of that point the coast range of mountains is 

 broken up into fragments, and the tempering influences of the 

 waters and breezes of the ocean are more direct and powerful 



