24 BULLETIN 813, U. S. DEPARTMEISTT OF AGRICULTURE. 



The performance-record studies reported in this bulletin have been 

 carried on during a period when the propagation of lemon trees 

 has been particularly active. The lemon industry has expanded 

 rapidly during this time, and the information gained in the course of 

 these investigations has been utilized generally in the propagation of 

 the trees for the large new plantings. A very large number of buds 

 from the superior trees of the Eureka strain in the performance-record 

 plats have been furnished to propagators. These buds from the 

 individual parent trees have been kept separate, so that each progeny 

 can be traced at any time from the orchard planting to the parent 

 trees. Not only have a great number of buds been taken from the 

 best performance-record trees for propagation commercially, but 

 buds from some of the poorest trees have also been propagated at the 

 same time, in order to compare under orchard conditions the behavior 

 of the progenies of the most desirable with those from the undesirable 

 parent trees. The active interest shown by lemon growers in these 

 studies has given the work an additional interest. 



The early fruiting of the young trees propagated from the select 

 trees in the performance-record plats permits comparatively quick 

 opportunities for measuring the results of bud selection. The uni- 

 formly heavy and superior production of the progenies from the 

 desirable parent trees and the light production of inferior fruits of the 

 progenies from the undesirable parent trees have demonstrated 

 conclusively the importance of bud selection in lemon propagation. 

 The information gained from these investigational individual- tree 

 performance-record data, the demonstrations of the important 

 results of bud selection, and the related observations made during 

 the course of these studies have been the basis upon which have been 

 developed the present improved methods of practice in California 

 in keeping individual-tree records, in the selection of undesirable 

 trees in established orchards for top-working or removal, and in the 

 choice of superior trees as sources of bud wood for propagation. 



It is desirable to emphasize the fact that the conclusions presented 

 here have not all been derived from a study of the performance-record 

 data alone. Some phases of tree and fruit characteristics can not 

 be recorded in figures or reproduced by illustrations. These inde- 

 finable characteristics are of importance and usually are perceived 

 only by those who have a natural aptitude for this kind of work. 

 The intimate tree knowledge essential for this work is gained only by 

 almost daily and continuous contact with the trees and fruits. The 

 instinct enabling the observer to distinguish one strain of tree or 

 fruit from another and to select the best from among many indi- 

 viduals is almost, if not equally, as important as the actual tree 

 records themselves. 



