Danger Points 61 



is often necessary to heat the pots, and even at best it is 

 a slow and nasty job. 



The style of oil burning pot that is most needed is on^ 

 that is inexpensive, in which the burning oil can be kept 

 at the same distance from the top of the container all of 

 the time, and which will make the maximum amount of 

 heat with a given quantity, and also one that will require 

 the minimum amount of labor in filling, cleaning and 

 storing. 



In heating an orchard it is important that the operator 

 know what to do and how to do it, so that for persons 

 who have never operated orchard heaters it is advisable 

 by all means that several of the heaters be set out in the 

 orchard, or an open place some time in advance of the 

 time they are liable to be needed, and filled up with the 

 fuel to be used and then lighted. Watch the way the fuel 

 burns, and time the pots to see how long they will con- 

 tinue to throw off the greatest amount of heat they are 

 capable of producing. It will take but little time and be 

 very little expense to make such a test, while it will more 

 than likely serve a good turn to the orchardist when the 

 danger time comes in the spring. 



Danger Points 



It is commonly believed that the danger point for fruit 

 buds is 32 degrees F., or the point at which frost forms 

 and water freezes. This, however, is not correct, as the, 

 danger point to different kinds of fruits is variable, both 

 with the kind of fruit and stage of development of the 

 flowers. It will also vary with the conditions of the soil 

 as to whether it is wet or dry or warm or cold. The 

 Missouri Agricultural Experiment Station has found that 

 dormant peach buds can stand a temperature of 8 or 9 

 degrees below zero with no injury. When the buds are 

 appreciably swollen, zero weather is the danger point. 

 When the buds are showing pink they can stand 15 de- 

 grees above zero. When the buds are almost open, 25 

 degrees is the danger point. When they are newly opened 



