A New Idea in Plant Propagation -By Robert A. Sanborn, 



Missa- 

 chuietts 



REMARKABLE NEW ADAPTATION OF A VERY OLD PRINCIPLE OF PROPAGATION, WHICH SHORTENS THE "WAITING 

 PERIOD" OF THE HYBRIDIZER AND GREATLY INCREASES THE CHANCES OF LIFE IN CERTAIN KINDS OF SEEDLINGS 



THAT there are new applications of 

 old principles merely awaiting the 

 thought of some operator to develop, has 

 once again been illustrated in the "seedling- 

 inarch" method of plant propagation. 

 Now, inarching — or the bringing together 

 of two growing plants and uniting them 

 by a grafting process, while each one 

 still retains its own roots has long 

 been a garden practice with a few kinds 

 of plants — inarching the vinifera grapes 

 for instance, is common. But somehow 

 the method has always been applied to 

 two mature plants. Nobody seemed to 

 think of modifying the ordinary budding 

 process by giving the bud the advantage 

 of its own root system till union was com- 

 plete. But this is exactly what Mr. G. W. 

 Oliver of the Department of Agriculture did 

 lately and the results are before the world. 



To the amateur who found a great 

 obstacle in plant breeding in the length 

 of time necessary to mature the new plant 

 this new application of inarching a seed- 

 ling opens up great possibilities. For he 

 can be sure of seeing his results in a very 

 short time. 



The essentials of the operation are so 

 simple that they may be easily grasped and 

 successfully applied by any intelligent 

 boy. The seedling, for example, of a new 

 hybrid rose a few weeks after germination 

 may be taken from its pot, the top earth 

 removed, the root-ball wrapped in cocoanut 



fibre and sacking, a shallow cut about two 

 inches long made in the stem, joined and 

 tied to a similar cut made in a suitable stock 

 plant. Within a month the union will 

 be made and the little seedling is estab- 

 lished upon the older and more vigorous 

 root-system of the stock. Any hard- 

 wooded, dicotyledenous plant may be 

 inarched, and the union made with any 

 strong-growing plant of other species of 

 the same genus, or in some cases on species 

 of other genera of the same family. 



The method has been worked in the 

 Department to secure two principal ends. 

 One is the saving of time in the bringing 

 to flower and fruit rare or new plant 

 varieties; the other is to increase the 

 proportion of successes in propagating 

 certain species which do not respond well 

 to the ordinarily used methods of budding 

 and grafting. 



Expert budders are born, not made. 



Seedling of the finger lime, five weeks old. inarched 

 to a two-year-old lemon stock. The cloth is used to 

 keep the soil in place around roots of the seedling 



Inarched rose seedling two months after inarch- 

 ing (one and one-fourth times natural size). Note 

 the root of the seedling projecting below the union 



An expert ' in this work must study his 

 plants not only with all five senses but 

 he must possess a sixth sense that will 

 tell him the precise proper moment for 

 acting, and a tactual delicacy comparable 

 to that of the finest violin virtuoso. And 

 even so he will often fail. The inarcher 

 of plants cannot proceed without a knowl- 

 edge of plants and tools but all that is 

 required of knowledge and skill he can 

 learn in half an hour under competent 

 advice. 



The especial value of inarching as 

 compared with either budding or grafting 

 rests upon the advantage of having in 

 the one case both live root-systems during 

 the formation of a union. Instead of 

 depending anxiously on several subtle 

 factors, that cannot in a majority of cases 

 all be controlled, to secure a union where 

 a delicate bud or graft has been fitted to 

 the live tissues of the stock, the inarcher 

 can well afford to shrug his shoulders 



20 



Branch of mango with eleven shoots inarched to 

 seedlings. This branch is supported by a stout stake, 

 which takes the place of the elaborate benching for- 

 merly used for the support of plants in large pots 



and dismiss all doubt from his mind. He 

 is perfectly sure whether there is a union 

 or not that provided both root-systems 

 are protected and watered neither plant 

 will be lost, and in addition he has proved 

 that more than go per cent, of his attempts 

 have resulted in success. Take the case 

 of a strong-growing mango seedling stock 

 inarched to a branch of a mature mango 

 tree of some approved variety. Both 

 root-systems are working normally, the 

 sap is coursing to the leaf tips of both 

 plants. If the cuts are well joined, union 

 is inevitable and the cuts need not be as 

 delicately made as in either budding or 

 grafting because of the vital assistance 

 given by the normal action of the plants. 

 Mr. Oliver states that in his experiments 

 with inarching the mango which opened 

 up this new field to him, that he has ob- 

 tained ioo per cent, of successes. The 

 grafting of the mango is so uncertain that 

 2 per cent, of successes is considered a 

 reasonable expectation. Mr. Oliver has 

 succeeded equally well with the mangos- 

 teen, roses, litchis, citrus fruits, chestnuts, 

 walnuts, oaks and many others. 



The introducer of foreign plant varieties 

 and the hybridizer of native plants will 

 most appreciate this new development. 

 The introduction of a new species or a 

 hybrid to the plant world is seriously 

 handicapped by the length of time re- 

 quired to test the flowering or fruiting 



