840 VI. General Discussion 



causing the Brown Rot of fruit, and investigation of these physiological 

 differences is of the most direct practical importance to growers. 



The history of the American Gooseberry Mildew is very interesting 

 from our point of view, for little was done to educate opinion until 

 legislation came into force. The year 1907 was memorable in that the 

 Diseases of Insects and Pests Act then came into force and the working 

 of this Act and the inspection by the Ministry Officials has been of great 

 educational value. 



There are certain other steps to which I may refer. At a fruit growers' 

 conference at Wye a fine-spray American nozzle was exhibited and at 

 first one was blamed for introducing "foreign stuff." This pattern was 

 however not patented in this country and commercial makers im- 

 mediately recognised its value and manufactured copies which are now 

 used widely. There is very much yet to be done in the improving of such 

 mechanical objects and their operation. 



I should also like to see travelling scholarships given by the Board so 

 that students could see the best practice in disease control in other 

 countries and bring back first hand knowledge. 



Great steps have recently been made regarding the standardisation 

 of fungicides. In 1909 a standard lime sulphur wash was first demon- 

 strated at Wye and since that time has had wide recognition. The value 

 of standardisation is obvious and commercial manufacturers are now 

 themselves demanding that the washes sold should be of guaranteed 

 specific gravity. 



I agree with Professor Blackman that the physiological point of 

 view is essential in our subject, but equally imperative is field experience 

 not only of the crops but of the growers. A grower with a diseased 

 plantation may not ask how he shall treat the disease but what will be 

 the effect of pigs on the land. One must not only have a knowledge of 

 fungi but a wide experience of the potentialities of the host plants. 



F. T. Brooks {Botany School, Cambridge). 



Plant physiology is all important and I should like to spend the next 

 five years in this study and then return to plant pathology. Equally 

 important is field work, for this is widely different from laboratory 

 knowledge. Only in the field can one obtain any true idea of the epidemic 

 spread of disease, of the relative susceptibility of varieties to disease 

 and the fact that environmental conditions often play a more important 

 part than the actual pathogen. A tropical pathologist of acumen sug- 

 gested that a necessary preliminary to mycological work was the digging 



