118 BULLETIN 624, U. S. DEPARTMENT OF AGRICULTURE. 



small size. Since that time this prejudice has gradually disappeared 

 and thousands of buds from such wood have been used successfully 

 in both experimental and commercial propagations. 



If bud wood is desired at times when the fruits are unripe or when 

 the bud wood is not in condition for use, it should be cut when the 

 ripe fruits are available for inspection and stored in sterilized moss 

 until needed. 



The identification of a valuable strain is of vital commercial im- 

 portance to the entire orange industry. The segregation of the in- 

 ferior strains is of interest only from an experimental standpoint. 

 The propagation of valuable strains vail result not only in an in- 

 creased production, but what is equally important, in a uniform pro- 

 duction of crops of greater commercial value. 



TOP-WORKING UNDESIRABLE TREES. 



Healthy Valencia orange trees of inferior or undesirable strains 

 can be successfully top-worked, using the kind of bud wood de- 

 scribed in the preceding paragraphs. This bud wood can be used 

 either as grafts or, as is the usual practice, for budding directly into 

 some of the main limbs. 



The selection of trees to be top-worked should be made before their 

 fruits are picked. While trees of some inferior strains are easily 

 recognized from their habits of growth or foliage characteristics, it is 

 desirable wherever possible to base the selection of trees to be top- 

 worked on their performance records and fruit characteristics. The 

 selection of bud wood for top-working purposes should also be based 

 on individual-tree performance records associated with an intimate 

 knowledge of tree and fruit characteristics secured from careful 

 observations in the orchards. 



In top-working established trees, two or three of the main limbs 

 should be selected for the foundation of the new heads. Two buds 

 should be inserted in each of these limbs, from 12 to 24 inches above 

 the fork of the trunk. After the buds have united with the older 

 limbs, these limbs should be cut off about 6 inches above the point of 

 insertion of the buds, and the cut surfaces covered with grafting wax 

 or some pruning compound. The trunks and remaining portions of 

 the limbs should be heavily whitewashed or otherwise protected, in 

 order to prevent injuries from exposure. About a year later the 

 stubs of the original limbs should be cut back close to the young 

 buds, making the cuts oblique in order to facilitate their healing, and 

 the cut surfaces should be again waxed or painted. In every case 

 great care must be exercised in removing all sprouts from the trunk 

 and old limbs in order to develop the new heads entirely from the 

 inserted buds. 



