A NEW METHOD OF GRAFTING 



Modification of the Morris Proximal Slot-Graft Successful With 



Plants Not Heretofore Grafted — Method of Value 



To Plant Breeders 



T. Ralph Robinson 

 Bureau of Plant ludustry, Washington, D. C. 



THE experimenter with woody 

 plants is confronted with the 

 problem of propagating the su- 

 perior varieties that he produces. Any 

 improvements of existing methods of 

 budding or grafting should therefore 

 be of direct interest and importance to 

 plant geneticists, as well as to plant 

 lovers and horiculturists, both ama- 

 teur and professional. 



A method that has a number of ad- 

 vantages over those generally used has 

 been developed recently. It would ap- 

 pear to have a wide application, and it 

 is hoped that the brief description 

 which follows may lead to further ex- 

 perimentation and improvements. 



Dr. Robert T. ^Morris, in his book on 

 "Nut Growing," describes a method he 

 has used with considerable success in 

 grafting nut-bearing trees. He calls it 

 the "proximal slot-graft." Besides the 

 technique involved in the method of 

 inserting the graft, a vital part of the 

 process is the use of melted paraffin as 

 a covering instead of the usual grafting 

 wax. Dr. Morris also lays considera- 

 ble emphasis on some ingenious meth- 

 ods of wrapping, when working with 

 nut trees. 



The Morris method in its main fea- 

 tures has been tried out during the past 

 year in Florida on subtrophical fruit 

 trees, chiefly citrus, avocados, and 

 mangos. Mr. James W. Barney, of 

 Palma Sola, Florida, was the first to 

 demonstrate the success of grafting 

 with the' aid of paraffin, using the slot- 

 graft method. He modified Dr. Morris' 

 procedure, however, and simplified the 

 technique very materially by doing 

 away with all wrappings, substituting 



for them a fine brad driven through 

 the graft into the wood of the tree. 

 Besides insuring a close contact not 

 easily disturbed, it permits the paraffin 

 covering to be applied in the most 

 thorough and effective manner — a 

 somewhat more difficult operation when 

 a complicated wrapping is used. 



At the April (1923) meeting of the 

 Florida State Horticultural Society, at 

 Orlando, Mr. Barney gave an account 

 of his preliminary experiments. Since 

 then others have been using this meth- 

 od with similar results. The writer has 

 been in touch with Mr. Barney's work 

 and has had sufficient experience in the 

 use of the method to feel sure it can 

 be used to advantage in working over 

 many kinds of fruit trees. Mr. Barney 

 has even succeded in grafting guavas, 

 which is usually regarded ag' impossible. 



The accompanying photographs are 

 designed to show only the main steps 

 in the process of inserting the "proxi- 

 mal slot-graft," some of the more ob- 

 vious operations not being shown. 



First, a cut is made with a chisel or 

 gouge downward and penetrating slight- 

 ly through the bark into the wood 

 of the stock. A transverse cut is 

 then made at the base of the first cut, 

 providing a shallow niche, with a slight 

 shelf at the bottom (Figure 7). The 

 exposed surface is immediately painted 

 over with melted paraffin, just warm 

 enough to stay in a liquid condition. 

 The paraffin brush should first be tried 

 on the hand ; if it proves hot enough 

 to burn, it should be cooled ofif before 

 using. The graft should then be pre- 

 pared by tapering to a wedge shape, 

 one side of the wedge longer than the 



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