BULLETIN 231] WALNUT CULTURE IN CALIFORNIA. 229 



tendency of the freshly exposed tissue of the walnut to oxidize and 

 turn black. After this has once happened the tissue is sure to die and 

 no union takes place. A further uncertainty is connected with the 

 growth of the bud even after it has apparently formed a perfect union. 

 Quite frequently a good union seems to have taken place, the bark of 

 the bud remaining fresh and green, but after this the bud dies and 

 therefore no sprout is able to develop. In all walnut budding partic- 

 ular skill and dexterity is necessary in order that the fresh surfaces or 

 cambium of the bud and stock may be exposed as little as possible to 

 the air during the operation. The operator must work rapidly and at 

 the same time carefully, making a close fit in each case, tying each bud 

 so that the inner surface of the bark will come into close contact all 

 over the exposed surface of the cut in the stock, arid getting the buds 

 cut and into place just as quickly as possible without unnecessary expo- 

 sure to the air. The buds should not be taken off until the last possi- 

 ble moment so that only one bud can be cut at a time. In working with 

 a single-bladed knife, it is usually necessary to cut the bud first and 

 then lay it on the stock in order to make the cut on the latter of the 

 same size. By using a double-bladed knife this becomes unnecessary, 

 and the bark can be removed from the stock before the bud is entirely 

 removed. In case of any little delay after cutting the bud it is a good 

 idea for the operator to put the bud in his mouth until he is ready to 

 place it upon the stock, rather than to keep it exposed to the air. In 

 nursery budding on a large scale it may be found economical for the 

 men to work in pairs rather than for each man to do all the work. One 

 man, for instance, may make the cut on the stock, cut and place the 

 bud, while the other ties, waxes or otherwise assists to the best advan- 

 tage. There should not be the slightest delay, however, at any stage 

 of the operation. 



As a general proposition, there are but few advantages in nursery 

 budding over grafting for one who is particularly skilful in the latter 

 operation. Grafting can be done more rapidly, and is certain to pro- 

 duce good-sized trees the same year if they are well cared for. Bud- 

 ding, however, may be valuable at times, especially if practiced in con- 

 junction with grafting. In the case of propagating varieties where 

 grafting wood is scarce, the available supply goes considefably further 

 in budding than in grafting, since only one bud is used for each tree 

 and buds can be taken from sol't, pithy wood, or large wood which 

 would not make a scion. Another useful feature of budding is that it 

 may be practiced in spring and early summer upon trees which were 

 too small for grafting, or upon the sprouts coming from trees on which 

 grafts did not take. It also extends for several weeks the rather lim- 

 ited season during which grafting may be done. Another advantage 



