:U0 VI. General Discussion 



skill required is largely that of the handling of men and money. For 

 example many treatments have been suggested for the Coffee Leaf 

 Disease but none which are not too expensive to apply. It is cheaper 

 to let the plant and the disease die out, but this course only serves to 

 spread the disease by providing centres of infection. On the other hand 

 the speaker and Mr E. E. Green had discovered remedial treatment for 

 cocoa canker which being simple and economically sound is extensively 

 applied. 



J. R. Ramsbottom {Natural History Museum). 



The problems of the growing plant and its relation to the environ- 

 ment are questions for the horticulturist and agriculturist. In plant 

 pathology the mycologist must know the fungus and regard the disease 

 as the result of the interaction of the host fungus complex and the 

 environmental conditions. Economic mycology however is inclusive 

 of more than plant disease. There is for example the relation of fungus 

 to host in such plants as the Ericaceae or Orchideae and the problems 

 centering around the mycorrhizal relation are of very great economic 

 importance. There is also the further problem of the fungi present in 

 the soil and the part they play therein. 



Questions of plant disease are undoubtedly largely physiological in 

 nature but even a competent physiologist trained in laboratory technique 

 may meet snags in his' application of such knowledge to field problems. 



Finance must always play a prominent part in plant pathology, for 

 uneconomic remedies are of no use however successful they may be 

 under trial conditions. Finally the plant pathologist must be able to 

 identify the common fungi he meets with and this requires a certain 

 amount of systematic study. 



Miss E. M. Wakefield {Royal Botanic Gardens, Kew). 



The plant pathologist cannot be a competent systematist but he 

 must have sufficient acquaintance with systematic work not only to 

 identify the pathogenic organisms but to recognise new species, and to 

 describe them accurately so that others may recognise them from his 

 diagnoses. Mistakes in identification have been only too frequent and 

 much confusion has resulted. 



Dr H. WoRMALD {Agricultural College, Wye). 



This conference has shown the great necessity for increasing the 

 number of workers in plant pathology so that our problems may be 

 investigated here. At present we are compelled to rely largely on Ameri- 



