Erysiphe Polygoni. G. 0. Searlc. 



289 



ment discarded, usually through death of leaf; == No infection ; 

 ? = Subinfection; :- = Medium infection, rather more than 

 subinfection ; + .= Full infection. 



Table VI. 



Conidia from sources shown. 



Date 

 Jan. 20 



Jan. 26 



Source of 

 conidia 



B. Sprout ? 



Marrow-stemmed 

 Kale ? 



A5 



Marrow-stemmed 

 Kale ? 



B. Sprout ? 



Thousand Head 

 Kale ? 



Feb. 26 B. Sprout? 



Host used 

 M. S. Kale 



Thouseind 



Head Kale 

 B. Sprout 

 B. Sprout 



Thousand 



Head Kale 

 M. S. Kale 



Swede 



M. S. Kale 



Turnip 



Rape 



M. S. Kale 

 Turnip 

 B. Sprout 



B. Sprout 



M. S. Kale 

 Thousand 

 Head Kale 



B. Sprout 



M. 2. Kale 



No. of 

 inoculations 



,, ,, Thousand 



Head Kale 

 Marrow-stemmed B. Sprout 

 Kale ? 



M. S. Kale 



,, ,, Thousand 



Head Kale 

 Swede -t- Rape 



:-4 



+ 4 



+ 4 

 + 4 



'■ 4 



+ 4 



+ 4 

 ?4 

 + 4 

 :-2 

 -1-2 

 :-4 



Result 



Distinct discolour- 

 ation 



Very slight dis- 

 colouration 



4-2 



Slight discolour- 

 ation 

 Leaf died 

 Leaf died e^y 



Distinct discolour- 

 ation 



? 4 \'ery slight 



'■ 4 



Fair amount my- 

 celium. Few 

 conidia. Some 

 discolouration 



Fair amount my- 

 celium. Few co- 

 nidia. Distinct 

 discolouration 



-2 No discolouration 



Turnip 



:-2 



? 2 

 + 4 



+ 3 



Few conidia. 



Some discolour- 

 ation 



Some discolour- 

 ation 



Large quantity 

 mycelium. Few 

 conidia 



One leaf died 



4—2 



