138 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. 



way through the vines, as shown in Fig. 26, B, it is possible to make a 

 smaller scion unite on both sides. For still larger vines, those over 

 % inch in diameter, the best graft is the ordinary cleft, shown in 



Fig. 26, 0, CC. 



Tying and Waxing. No wax or clay should be used on the graft. 

 Anything which completely excludes the air prevents the knitting of 

 the tissues. A little clay, cloth, or a leaf may be placed over the split 

 in the stock when the cleft graft is used, simply to keep out the soil. 

 Otherwise there is nothing more suitable or more favorable to the 

 formation of a good union that can be put around the graft than loose, 

 moist soil. If the soil is clayey, stiff or lumpy it is necessary to surround 

 the union with loose soil or sand brought from outside the vineyard. 



It will usually be necessary to tie the grafts. A well-made cleft 

 graft often holds the scion with sufficient force to prevent its displace- 

 ment and no tying is necessary. Wherever there is any danger of the 

 graft moving, however, it should be tied. There is nothing better for 

 this purpose than ordinary raffia. The raffia should not be bluestoned, 

 as it will last long enough without and will be sure to rot in a few 

 weeks and the trouble of cutting it will be avoided. Cotton string or 

 anything which will keep the graft in place for a few weeks may also 

 be used. 



As soon as the graft is made and tied, a stake should be driven and 

 the union covered with a little earth. The hilling up of the graft may 

 be left for a few hours, except in very hot, dry weather. Finally, the 

 whole graft should be covered with a broad hill of loose soil 2 inches 

 above the top of the scion. 



Season for Field Grafting. Field grafting should not be commenced 

 as a rule, except in the hottest and driest localities, before the middle 

 of March. Before that there is too much danger that heavy rains may 

 keep the soil soaked for several weeks a condition very unfavorable 

 to the formation of good unions. In any case the grafting should not 

 be done while the soil is wet. Grafting may continue as long as the 

 cuttings can be kept dormant. It is difficult to graft successfully, 

 however, when the bark of the stock becomes loose, as it does soon after 

 the middle of April in most localities. 



Treatment the First Year. Field grafts require practically the same 

 treatment as bench grafts in the nursery, except that there is little or 

 no danger of their drying out, if they are properly mounded up. There 

 is usually sufficient sap in the stock to keep them moist. 



They should be disturbed as little as possible for two or three months 

 after grafting. Some time in July it is necessary to remove the suckers 



