BUD VARTATIOlSr IN THE EUREKA LEMON. 7 



PLAN OF THE INVESTIGATIONS. 



These investigations have been carriefl on by means of individual- 

 tree performance records. The term "performance record" is here 

 used to mean a systematic record for a period of several years of the 

 yield and behavior of individual trees. This record includes accu- 

 rate notes of the number, the commercial equality, and the variability 

 and other characteristics of the fruits produced by the individual 

 trees. It is usually accompanied by descriptive notes and photo- 

 graphs, or drawings, showing the characteristics of the habit of 

 growth, the leaves and flowers, and the position or arrangement of 

 the fruits on the trees. Individual-tree performance records for at 

 least two consecutive and normal seasons on lemon trees which have 

 reached full bearing age are considered necessary in order to deter- 

 mine the value of the trees for commercial fruit production. Similar 

 records for at least four years are advisable, in order to furnish an 

 adecjuate basis for the selection of superior trees as sources of bud 

 wood for propagation. 



The performance records presented in this bulletin have been made 

 from full-bearing trees located in successful commercial orchards 

 where the conditions have been particularly favorable for compar- 

 ative individual-tree studies. It has been possible to compile these 

 records only through the hearty cooperation of the owners of the 

 orchards selected for study. The picking of the fruits has usually 

 been done by members of the regular picking crew. The assorting, 

 .weighing, and counting have been done by the writers in the orchards 

 immediately after the fruits have been picked. The crops of fruit, 

 after the records have been finished, have been turned in with the 

 crop from the orchard as a whole, except such specimens as have 

 been needed for further study. Owing to the additional handling 

 necessary for the classification of the fruits, particular care has been 

 used in order to avoid as far as possible all mechanical injuries, which 

 frequently lead to decay and consequent loss to the growers. 



The conditions considered in the location of the individual-tree 

 performance-record plats were as follows: (1) The production of 

 successful and profitable crops of fruit; (2) location on virgin land, 

 in order to avoid any influence of previous cultural treatments; (3) 

 protection from cold, strong winds, or other climatic causes of tree 

 and fruit injuries; (4) the absence of radical pruning, rebudding, 

 top-working, or other similar tree treatments; (5) freedom from or 

 the effective control of diseases and insect pests; (6) uniform irriga- 

 tion and cultural practices during the entire history of the orchard; 

 (7) reliable information concerning the history of the buds used in 

 the propagation of the trees and the kind of stocks; (8) the prospect 

 of settled ownership for a period of years; and (9) the absence of 

 apparent local environmental factors influencing tree behavior, in 



