EFFECTS OF FREEZES ON CITRUS IN CALIFORNIA 295 



Several factors contributed to make the crop of 1913-14 appear 

 larger than it really was in comparison with preceding crops. The 

 crop of 1911-12 was reduced by the loss of considerable fruit through 

 the Christmas freeze of 1911. The crop of 1912-13 was largely 

 destroyed by the great freeze. There had, therefore, been two years 

 without a normal crop. Meanwhile, very extensive areas of young 

 plantings had reached bearing age, and served to greatly increase the 

 crop of 1913-14. There were many acres of old, bearing trees and 

 trees of all ages, where the crop w r as very greatly reduced by the 

 freeze. The average yields per acre, therefore, were much smaller 

 than in many preceding years, although the total crop was fairly large. 



The lemon trees w r ere much more severely injured, the fruit- 

 bearing wood being destroyed in many sections. The crop of the year 

 following the freeze, 1913-14, was thus comparatively small, as will 

 be seen by an examination of table 4, giving the yields for the last 

 nine years. 



Planting Frosted Nursery Trees. During the summer following 

 the freeze, some cases were reported of loss due to the planting of 

 nursery trees that were more or less injured by the freeze in January 

 but that had recovered sufficiently to be sold for planting several 

 months later. 



The reason for this is probably due to the fact that the injured 

 tree, in order to produce a new top, or a new top and portion of the 

 trunk, must draw upon its reserve food material stored in roots and 

 trunk for this new tissue, and that the trees had not had sufficient time 

 before the second shock of transplanting to replenish this reduced 

 reserve food, which is necessary in order that the plant may recuperate 

 when set in the orchard. 



Thawing and Recovery of Frozen Fruit. It has long been known 

 that if frozen tissue is suddenly heated or thawed rapidly, it is severely 

 injured, but if gradually thawed, it often escapes injury. There 

 seems but little doubt that, had the freeze of 1918 been followed 

 immediately by warm sunny weather, instead of the continued cool, 

 cloudy weather accompanied by light showers, that devastation would 

 have been far more serious. It ma}' be stated, however, that no cases 

 of the commercial recovery of fruit was found. Individual fruits have 

 been found in most varieties that have shown a development of new 

 pulp cells, but this is not general enough to be of commercial impor- 

 tance. Instead of recovering, frozen fruit steadily deteriorates. 



The Sale of Frozen Fruit. A large proportion of the crop of 

 citrus fruits was badly frozen, but in many cases only a portion of 

 the fruit was seriously injured. Frozen fruit is known to remain 



