B. P. I.— 0(4. 



A STUDY OF THE IMPROVEMENT OF CITRUS 

 FRUITS THROUGH HUD SELECTION.' 



INTRODUCTION. 



In April, 1009, under instructions of the Chief of the Bureau of 

 Plant Industry, the writer visited a large luimber of orange, lemon, 

 and pomelo groves in southern California, accompanied by Mr. 

 G. Harold Powell, at that time in charge of fruit transportation and 

 storage investigations of the Bureau. 



In all of the groves it was easily apparent that great differences 

 existed in the quantity and size of the fruit, in the proportion of 

 irregular and abnormal fruits, and in the habit of growth and leaf 

 characters of the trees among neighboring trees of the same variety, 

 in the same grove, and under uniform conditions. 



One of the largest and most successful citrus growers in California, 

 at Riverside, when questioned as to the cause of these striking difler- 

 ences, suggested that it might be due to variation in the buds from 

 which the trees were propagated. He stated further that he believed 

 that 60 per cent of the trees in his orange groves produced his crops 

 and that the remaining 4:0 per cent were light producers or barren 

 and practically worthless. 



Little or no selection of buds from select trees has thus far been 

 practiced in the propagation of citrus trees. In most instances the 

 propagator secures buds from successful growers of a given variety, 

 taking the buds without regard to the past or present crops of fruit 

 borne by individual trees. In some cases the buds for propagation 

 are cut from nursery stock, where no selection of buds based on crop 

 performance is possible. "Where selection of buds has been practiced, 

 almost invariably the propagator has selected the lai-gest and most 

 vigorous trees without regard to the crop of fruit borne by them. 



Owing to the fact that the introduction into California of the com- 

 mercially successful varieties of citrus fruits is of comparatively 



' Thi.s circular has been prepared with a view to supplying information regarding the methods of 

 work used in investigating the variation in the yield of citrus fruits in California. It is not intended 

 here to present definite results of this work. Many investigators and fruit growers in different parts 

 of the United States are interested in this type of investigation, and it is believed that a descrijition 

 of the Bureau work at this time will aid mjiterially in assisting those who desire to pursue similar 

 lines. — W.M. A. Tavlor, Acting Chic/ of Bureau. 



[Cir. 77] 3 



