578 



Journal of Agric\iUure, Victoria. |10 Oct., 1916. 



Double-worked Stocks. 



A double-worked blight-proof stock consists of two portions of the 

 blight-resistant variety intended for use. A piece of root is employed 

 as a " starter " on which is grafted a scion, or portion of yearling wood, 

 which produces the shoot on which the desired variety may be either 

 budded or grafted. 



Double-worked Northern Spy root grafts are the stocks recommended, 

 and they are mostly fav- 

 oured by' the fruit- 

 growei's in this State. 



FTata 16 shows method 

 of making this stock. 

 Fig. 1 (A) is a piece 

 of Northern Spy root 

 2| inches long, cut 

 with grafting knife and 

 tongued (a). Fig. 1 (B) 

 is a portion of yearling 

 wood of the same variety 

 4 inches lon^ cut and 

 tongued (/>). Therootand 

 scion are then placed to- 

 gether and the tongues 

 put into each other to 

 make a firm graft, and 

 tied with a piece of 

 soft string. Fig. 2 shows 

 the grafting operation 

 completed. The root 



graft is planted during , 

 early spring, and the 

 bud, Fig. 2 {a), is al- 

 lowed to project above 

 the soil level (h). The 

 sap commences to move 

 in the starter (e) (d), 

 that is, the piece of root 

 on which the scion is 

 grafted. Fibrous roots 

 are thrown out, and a 

 cambium connexion is 

 soon formed with the 

 scion (a) (d). Fibrous 

 roots are also thrown out 

 at the nodes (c) to {d), and from these the tree's future root system is 

 mainly formed. 



This characteristic of the Northern Spy scion to establish a root 

 system for itself independent altogether of the root-stock on which it is 

 grafted, often gives rise to the erroneous idea of a diseased condition, 

 being mistaken for crown gall or liairy root. 



Plate 17, Fig. 1, shows development of the root graft during the 

 first growing period after it was planted,. the original graft being {d) to 



Plate 16.— Root Grafts. 



