In a short but very interesting report to the Nut Congress of Grenoble in October, 1936 by Mr. Léon Treyves, and very kindly sent on to us, the author says, "This procedure, devised by my family around 1880, consists of grafting on one year old roots, branches from selected, vigorous trees, either by cleft or English grafts, whichever gives best fit of scion (which is generally smaller than root) and stock. Graft is then tied with raffia and waxed to avoid all contact with air and placed in a moderately heated frame. After a month of this treatment the graft has taken. Then it is gradually accustomed to open air and the frame is removed. In the fall or the following spring the graft may be planted in its permanent location or in nursery row.
This system presents numerous advantages:
1. Rapidity, since the plants can be grafted after one year, instead of three or four.
2. Economy of time and expense, since considerable numbers of grafts can be made rapidly and in limited space.
3. More rapid development of growth and fruiting. Saplings of 1 to 2 meters planted in winter of '28-'29 measured in October '36 25-27 cm. in circumference at one meter from ground. Trees two and three years old, still in nursery, are bearing one to two normally developed fruits.
The author indicates that he uses nigra for stocks, "since that is the only one that has proved its adaptation to grafting and its resistance to the "pus disease"."
At the time he gave his paper in '36 Mr. Treyves announced that he was continuing his grafting experiments on J. Sieboldiana, cordiformis and torreyi. [J. torreyi = J. major—J. C. McDaniel.]
Mr. Treyves, whom we cannot thank too much for his favor, was kind enough to set forth the preliminary techniques of his method of root-grafting. We give a resume of them here.
1. Preparation. Plant nuts well-spaced in rows in good soil, convenient to irrigation, if needed. Clean nuts of good quality, previously stratified, should be planted in winter. Plants are lifted before the following spring and heeled in. For scions wood of 7-8 cm. is cut from young, healthy and vigorous trees and passed to the grafter at the same time as the roots, which have been previously lifted, washed and cut off at the crown or a little below. Scion, bevelled, is set either in English or cleft graft, tied with raffia or with a numbered wool strip, waxed and potted in rich but light soil, moderately firmed around roots. Pots are then set in some homogeneous material (waste tan-bark or sawdust) and left in a moderately heated bed.
2. Care. Watering. Temperature of beds should be kept constant around grafts and they should be watered every other day. Of course, grass and mold should be prevented.