Volume IX SEPTEMBER, 1919 Part III 



SILVER-LEAF DISEASE, III ' al 



(INCLUDING OBSERVATIONS UPON THE INJECTION ' ''^''' 



OF TREES WITH ANTISEPTICS). 



By F. T. BROOKS, M.A. 

 [Senior Demonstrator of Botany, Cambridge Universitij), 



AND M. A. BAILEY, M.A. 



(John. I nties Horticultural Innlitution, Merlon, Surrei/.) 



CONTENTS. 



PAGE 



1. Introduction .......... 189 



2. Further observations upon the occurrence and incidence of silvcr- 



Icaf I'Jl 



3. Inoculation experiments: 



(a) With phim trees ........ 197 



(6) With apple trees 205 



((•) With other plants 200 



4. Attempts to induce silvering of foliage other than by inoculation 



with Stereum piirpureum ........ 207 



"). Further observations on the manner of infection in fruit plan- 

 tations ........... 208 



6. Experiments on the curative treatment of silver-leaf disease . 210 



7. Treatment in fruit plantations 214 



I. INTRODUCTION. 



The present paper contains the results of investigations on wilvei-leaf 

 disease which are a continuation of those previously described by one 

 of us (1,2) in earlier numbers of this periodical. 



Some time ago it was thought desirable to duplicate as far as possible 

 in different localities the experiments conducted on this disease. Hence 

 most of the experiments described in this paper have been carried out 

 both at Cambridge and at the John Innes Horticultural Institution, 

 Merton. 



As before, the experimental work at Cambridge has been done on 

 the University Farm by permission of the School of Agriculture, and in 

 the Botanic Garden by courtesy of Mr R. I. Lynch. The trees used at 

 Cambridge were mostly provided by a grant from the Development 

 Fund to which reference was made in earlier papers of this series. 



Journ. of Agric, 8ci. IX 13 



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