TY  - BOOK
AU  - Royle,D.J.
TI  - Infection periods in relation to the natural development of hop down y mildew (pseudoperonospora humuli) / 
PY  - 1970///
CY  - Ashford, Kent  : 
PB  - Wye College, University of London, 
KW  - Hops
KW  - Diseases and pests
KW  - England
N1  -  Includes bibliographical references : p. 290-291
ER  -