720 THE MONTHLY BULLETIN. 



Placement of Heaters in Orchard. 



One heater for each tree is the number ordinarily used. They are 

 commonly placed in the center of the rectangle formed by four trees. 



When to Light. 



Firing should begin before the temperature has reached the danger 

 point, the object being to keep it at a certain point rather than to let 

 it drop below and then try to raise it again. For example, it is much 

 easier to maintain a temperature of 32° when the outside temperature 

 is 25° than it is to raise it to 32° after it has dropped down to 25°. 

 While fruit buds or blossoms may stand this temperature for a short 

 time, it is never safe to let it get so cold. 



Keep Firing Well After Sunrise. 



Many a crop of fruit has been lost because fuel played out. or because 

 men became tired or careless and let fires go down at daybreak. The 

 coldest period is very often about sunrise and the heaviest firing is 

 necessary at this time. 



Use Only Tested Thermometers. 



To depend upon a twenty-five cent thermometer in the orchard- 

 heating business, when thousands of dollars are at stake, is inexcusable 

 foolishness, and yet such has often been done. Nothing but reliable, 

 tested thermometers should be used in this important work. Several 

 should be used and placed in different parts of the orchard, as there may 

 be quite a temperature variation in a short distance. Electric alarms 

 may be used, but it is more satisfactory in actual practice to have reliable 

 men to watch the thermometers and record temperatures every few 

 minutes during the time of expected freeze. 



Success Means Hard Work. 



Our present knowledge of frost fighting with orchard heaters is not 

 such that it can be recommended under all conditions. With the tem- 

 peratures that we usually have during the period of spring and winter 

 freezes in California, it is safe to say that the man who is willing to 

 observe all the details and who is not afraid of the hardest kind of work 

 will succeed. Not every man who has orchard heaters does, neither 

 does every man who sprays make a success of that operation. Orchard 

 heating, if it is done at all, should be done rightly, or else all labor and 

 expense may be thrown away. No one who is looking only for the easy 

 jobs should have anything to do with this work. 



REPORT OF DOCTOR G. HAROLD POWELL, MANAGER OF THE 

 CALIFORNIA FRUIT GROWERS' EXCHANGE. 



By A. J. Cook, State Commissioner of Horticulture. 



This report is full of encouragement. It shows the value of this great 

 co-operative association, demonstrates completely success in what was 

 at first thought to be a most serious calamity, and must give to all citrus 

 growers renewed courage. 



The estimated crop at the beginning of the year, September, 1912, 



