EFFECTS OF FREEZES ON CITRUS IN CALIFORNIA 31 1 



frozen oranges showed .3 of a gram of acid per fruit, in comparison 

 with an average of about 1 gram per fruit in unfrozen oranges. The 

 unfrozen lemons vary to a considerable degree in the amount of acids 

 present, ranging from 2 to 3 grams per fruit, while in the frozen fruit 

 it practically all disappears (see table 13). 



TABLE 13. Grams Acid Per Fruit. 



NAVEL ORANGES EUREKA LEMONS 



Stored lota (a) Different picks (b) Stored lots (a) Different picks (b) 



(a) Fruit picked on January 13th. 



(b) Successive new lots picked on date izrfven. 



Following any severe freeze growers are confronted with the prob- 

 lem of whether injured fruit should be harvested immediately and 

 used for by-products or whether the picking should be delayed until 

 the extent of the injury becomes apparent. The rapid decrease that 

 takes place in the amount of sugar and acid per fruit in both oranges 

 and lemons as shown by the above tables, indicates that frozen fruit, 

 if it is to be used for by-products should be picked and sold as soon 

 after the freeze as possible. 



GROWTH OF FROZEN FRUIT 



When fruit is badly frozen the question arises whether the tree 

 would be harmed should the fruit remain upon the branches until it 

 falls naturally. If the frozen fruit did not grow, but remained on 

 the tree in the same condition as when frozen, it would presumably 

 take little nourishment from the tree with the exception of the mois- 

 ture evaportaed from the rind. In order to determine this point, 

 several hundred Valencia oranges were marked and measured and 

 their growth was noted each month for four months. Groves for this 



IA*SON OF SUBTROPICAL HORTICULTURE 

 COLLEGE OF AGRICULTURE 

 BERKELEY. C 



