EFFECTS OF FREEZES ON CITRUS IN CALIFORNIA 291 



Grafting or Budding Badly-Injured Trees. Where trees were 

 frozen down to the bud, one of three things was done : the trees were 

 uprooted and thrown away; or they were allowed to send out new 

 shoots, one of which was budded ; or they were cut off and grafted. 

 Grafting was successful in some places, and failed in others. The 

 two methods used were cleft-grafting and crown-grafting. Where the 

 tree was one or two inches in diameter, it was sawed off down to good 

 live wood, was split, and then two wedge-shaped scions were put in 

 by the cleft-graft method, one on each side, so that the cambium of 

 the scion came next to the cambium of the stock. Where the trees 

 were so large that they could not easily be split in this way, a stick 

 of bud-wood with one end cut diagonally was placed between the bark 

 and the wood, with the cut surface next to the wood. The failures 

 were caused mainly by the drying out of the scions before they had 

 united with the stocks, or by the dying back of the stock below the 

 place where the scion was inserted. Grafting, in general, proved 

 unsatisfactory. 



The most successful method pursued was to train up a vigorous 

 sprout from the stock which was budded in the summer as soon as it 

 had reached sufficient size. 



Irrigation to Aid Recovery of Frozen Fruit. It was thought by 

 some people that fruit which had been partly frozen would recover 

 if the conditions were favorable, and that frequent irrigation would 

 assist in this recovery. Irrigation was given a fair trial in several 

 cases with Valencias and navels, but the fruit was not benefited, 

 showing no improvement over adjacent groves which were not irri- 

 gated. In fact, no places were found where there was any recovery 

 of fruit after February 1 which was of any commercial importance. 

 Some frozen lemons were examined in which it looked as if new pulp 

 cells had formed next to the skin, but this was not general enough nor 

 extensive enougli to need consideration commercially. Instead of 

 any recovery taking place in frozen fruit, there was a steady deteriora- 

 tion the older it grew. 



Stimulating Growth in Frozen Trees by Fertilization. Many 

 growers following the 1913 freeze gave their trees extra applications 

 of nitrate of soda and other quick-acting fertilizers, thinking thereby 

 to stimulate more rapid growth and cause the flowers to set more 

 fruit. Little or no benefit was derived from such extra applications, 

 though no harm was done, as has sometimes followed in Florida. The 

 omitting of all fertilization, however, was very clearly a mistake, 

 unless the freezing had been so severe as to kill all or the greater 

 portion of the tops, or in cases where the grove had been highly ferti- 

 lized a short time preceding the freeze. 



