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Pomona College Journal of Economic Botany 



A little less than two years ago Mr. A. D. Shamel of the Bureau of Plant 

 Industry took up the work of gathering data which might lead to systematic bud 

 selection for citrus stock improvement. The report of his first year's work was 

 given at the State Fruit Grower's Convention held last March, and at that time 

 a committee was appointed to consider the question of pedigreeing citrus trees. 

 Mr. Shamel' 8 work has been confined to oranges and grapefruit in the vicinity of 

 Corona. A very full report of the first year's observations is given in his report 

 to the Bureau of Plant Industry, published as circular No. 77. 



About a year ago the Limoneira Company took up similar work on the Lisbon 

 lemons in their grove, and later on Eureka lemons in the thirty-five year old 

 orchard of Mr. X. W. Blanehard of Santa Paula. This work is being carried on 

 because the company is planning large plantings in the near future and wish the 

 best stock available from trees whose merits have been proven. Much of the data, 

 however, is of interest to every nurseryman and orehardist. 



In the first place the section of the orchard that has been consistently the 

 best bearer for a number of years was chosen for the observations, and from the 

 2,000 trees in it the best 200 were picked. These trees were chosen for their 

 apparent crop, the appearance of the fruit, the general form and foliage of the 

 tree, and the absence of thorns. Later the number was reduced from 200 to 100, 

 which were marked and numbered. 



The next step was a description of the trees. The photograph method used 

 by Mr. Shamel would undoubtedly have been better in many ways, but was not 

 undertaken here. The written description included the size, shape, form, foliage, 

 thorns and setting of fruit for each tree. With this preliminary work completed 

 we were ready for the data of individual yields, the permanent record of which is 

 kept in the form reproduced in the accompanying cut. 



During the year the average yield per tree for the special trees was 18.49 

 field (45 lb.) boxes. The average for the rest of the section (all misses and 

 extremely poor trees having been eliminated in the count) was 10.25 boxes, 

 showing a difference of over 150 pounds to the tree. To the casual observer the 

 trees in the section look very uniform, and yet this wide variation exists. If one- 

 half of this difference could be overcome by raising the standard of the poorer trees 

 the increase would be at least 100 packed boxes to every acre. Or on a percentage 

 basis, an increase of about 3%. 



To show that this work needs the accurate keeping of records, even the special 

 trees varied from 15.4 boxes to 10.1, although the trees were chosen by experienced 

 men who knew the groves. 



The data from this first year's work is, of course, very preliminary. After 

 these records have been kept for a number of years we will be able to tell whether 

 the apparent differences are repeated. We will know whether certain trees are 

 inherently summer bearers and others not. Then, too, we wish to determine 

 whether the characteristics that may be proven for the parent tree will be trans- 

 mitted to the offspring by budding, and in order to determine this the buds taken 

 from each individual tree will be used in a definite block of the nursery, and later 

 set in a definite part of the grove — records of which will be carefully kept. 



