108 BULLETIN" 697^ U. S. DEPAETMENT OE AGRICULTURE. 



Trees of the Bell, Rough, and Unproductive strains are all undesir- 

 able from the commercial standpoint, and should be eliminated in 

 bearing orchards and avoided for propagation, except perhaps for 

 purely experimental purposes. Fortunately, there are but few trees 

 of these strains in most of the established California orchards of the 

 Marsh variety, so that their elimination is a comparatively simple 

 and inexpensive matter. 



It is probable that by means of individual-tree records in bearing 

 orchards covering two years most of the trees of inferior strains can 

 be located, so that they can be top-worked with select buds of the 

 Marsh strain. 



PfR cf/\/r or A PAC/(CD BOX pfff TPrs -^^^^-^ p£p cf/vr or A PAC/(rD box prp rprr \ 



65.2 //2 28.6 warn 



96 /S.5 Hi I 



80 ns mm \ 



64 2S.0 mmk I 



j4a 2S.0 mm 



32 28./^^ 



24 58.4m^^^ 



4.2S PACxro Boxrs j ^ ^^^'^p^/^y^/^ ^^^^ \ '-se PACKro Boxrs \ 



M6 PACKrP Boxes Off ( TNB MOST DrS/ffABir S/Z£S \ 0.68 PACXBD BOXBS OP \ 



s.44Pr^rA/r or mr crop 1 80.64, and 48 1 34.1 prp cjtnt or mr crop \ 



340.0 PACxrp BOxrs [ PffODUCT/oNo^^mrAcprBAs/s j ,^^^ ^^^^^^ ^^^^j ! 



illJi7?nn \ ACTUAL VAl Of PfP ACPB \ ^ ,^^ ,^ i 



# OJJ. uu j p£-i,\,ff^^p ^j- Tfir PACX/NG ffousr J •*^-^°^- '^ j 



P20927HP ' 



Fig. 14. — Average number of fruits of the various commercial sizes produced annually during the 6-year i 

 period, 1910 to 1915, inclusive, by the five highest and the five lowest yielding trees of Marsh grapefruit ' 

 in the investigational performance-record plat B in a grove planted in the fall of 1903. This production | 

 is expressed as percentages of a packed box calculated from the number of fruits of the different sizes j 

 contained in a box. The percentage of most desirable sizes is also stated, and the production on the ! 

 acre basis is shown and its value calculated from the actual returns received for the fruit from this grove ! 



during the 6-year period. 



1 



THE UNINTENTIONAL PROPAGATION OF UNDESIRABLE STRAINS. \ 



The trees of undesirable strains in established orchards have been ; 

 propagated unintentionally through a lack of careful selection of] 

 bud wood. Heretofore, aU trees of the variety have been co.n- 1 

 sidered to be equally good for propagation, and little or no selection j 

 of trees or bud wood has been practiced. \ 



As an illustration of this condition, the experience of the senior | 

 writer in 1910, in the first grapefruit orchard selected for individual- i 

 tree performance-record work, may be cited. In this orchard, asj 

 soon as the owner f omid that the seedy fruits were mainly borne by { 



