ORCHARD HEATING 29 



Near the top of the tables, the word "apples" is written and 

 underneath it is drawn a line about one-fourth as long as the 

 table is wide. Underneath the left end of the line will bo found 

 the average date that the apples begin to bloom in this particular 

 county and underneath the right end of the line will be found the 

 average date the petals have fallen and the fruit is setting. The 

 same explanation hold for the other kinds of fruit listed. 



Where a figure in the table is underscored once, it means 

 that in our judgment a peach orchard in that county should have 

 been heated on that night. If a figure is underscored tfoice, an 

 apple orchard should have been heated. The basis of our selec- 

 tion of these dates and of our estimation from these of the total 

 number of times that heating should have been done to prevent 

 loss from frost is this : It has been our experience that the buds 

 in their early stages can stand one or two freezes of 25o F. to 27 'o 

 F. and there will still be enough buds left to give a satisfactory 

 crop, but when a third frost occurs the heaters should be lighted. 

 A cautious orchardist would heat considerably oftener than we 

 have indicated because on some of the nights o'f, early spring 

 where we counted on not heating, it being the first freeze and of 

 26 deg. F. only, he may have heated because of expecting a lower 

 temperature. It has been the experience of most of the workers 

 in the field that it is much easier to hold the temperature just 

 above the critical point than it is to raise it to that point after 

 it has cooled ; hence as a matter of safety and to be conservative 

 they have uniformly advocated lighting the fires early. The 

 figures therefore represent our judgment as to the least number 

 of times that the heaters should have been lighted. 



It has been found by this station that none of the fruit is in- 

 jured by a temperature of 20 deg. F., for which reason only 

 temperatures lower than this were placed in the tables. 



DOES ORCHARD HEATING PAY IN UTAH? 



A study of the temperature tables Nos. IV to XIII shows that 

 on an average in the five most important horticultural counties 

 in the state, heating is necessary at least three times a year to 

 save the peach crop. We found by gathering data from the 

 farmers in these counties ourselves as well as from the data col- 

 lected by County Agricultural Agents that farmers lose on an 

 average of ten years over twenty per cent of their crops and that 

 the average normal yield is 400 bushels of peaches to the acre 

 This means then that they lose on an average 80 bushels of 

 peaches a year. The average price received by the farmers after 



