SEEDS SOILS TRANSPLANTING 51 



regard to hoeing, watering, and fertilizing. As a 

 matter of fact, this process may be continued profit- 

 ably throughout the entire life of a tree if one is 

 raising nuts with the idea of supplying a market. 

 The time for grafting seedling trees is a matter of 

 choice, but varies widely according to circum- 

 stances. Stocks of most nut trees may be grafted 

 at any time after the first year, but preference is 

 commonly given to three-year stocks by nurserymen 

 who graft saplings in the nursery row. Topworking 

 older trees which are established in their permanent 

 sites may be done to advantage until trees are twenty 

 or thirty years old. After that the difficulties of 

 grafting increase very rapidly. 



The matter of labeling trees and of keeping crop 

 records for purposes of reference is important. 

 Labels have a most astonishing way of getting lost. 

 In my own work the best labeling method consists 

 in lettering a strip of metal which goes with the 

 Roover machine and then fastening this label with 

 copper wire to a galvanized iron rod set in the 

 ground near the tree. The galvanized rod is clipped 

 from large wire with a pair of strong cutters. It is 

 very durable, as may be attested by hired men who 

 mow before they look. The entire label device is 

 imperishable and cannot be lost unless actually car- 

 ried away. 



2. PLANT PHYSIOLOGY 



In connection with the problems of propagation 

 perhaps we may review briefly the essentials of plant 



