FRUIT-GROWING AND PRESERVING. 55 



propagation. All these plum stocks have been classified and 

 selected, and the first considerable trial plantation was planted 

 out about two years ago. 



While the main interest in the work at East Mailing, from 

 the point of view of practical results, has naturally centred 

 round the enquiry into root -stocks, other fundamental problems 

 affecting fruit-growing are not being neglected. Such questions 

 as root influence with regard to effect upon disease, the functions 

 of different types of roots, comparison of budded with grafted 

 trees, effect of depth and method of planting and treatment of 

 soil on roots, methods of vegetative propagation, and so on, 

 are being studied simultaneously or in connection with the 

 stock classification work. Further, important work in connection 

 with the breeding and trial of new varieties of hops, with special 

 reference to aroma, resin content, fruitfulness, extension of 

 season and resistance to disease,* has been in progress since 

 1917 under the direction of the Advisory Mycologist attached to 

 Wye College, and some promising new varieties have been 

 secured. Under an arrangement made with the Imperial College 

 of Science, a physiologist is attached to the station, and his 

 researches are at present largely concentrated on finding out 

 exactly how it is that the root -stock has so much influence on 

 the tree, with a view to establishing guiding principles for the 

 best possible selection of stocks. 



The Root. 

 During the progress of research in fruit culture it has become 

 increasingly evident that the well-being of a tree is influenced 

 primarily by the behaviour of its root -system. If it is to lead 

 a healthy existence and produce profitable crops, its roots must 

 be able to function satisfactorily and be kept throughout life 

 under the best conditions. Relatively little is known on the 

 subject of root -action, and the Long Ashton Institute has 

 therefore set itself to find out the conditions that promote healthy 

 root-growth. Since fruit trees invariably have to be trans- 

 planted from the nursery quarters where they are raised into 

 their permanent position in the orchard or fruit plantation, 

 the enquiry was begun by an examination of root behaviour 

 following transplantation, combined with which was a series 

 of experiments to test the effect of various methods of root 

 treatment at the time of planting. The re-establishment of the 

 root -system after planting is, of course, a critical factor in the 

 life history of the tree, and it may well be that the future fate 



* See also page 82. 



