J. V. Eyre, E. S. Salmon and L. K. Wormald 285 



production of coiiidiophores have a iinicli greater resistance to the 

 fungicidal action of ammonium polysulphide solutions. The following 

 tabulated results of three experiments in which three different solutions 

 were used may be given .here to illustrate this point. 



Ref. No. of 

 E.xperiment 



10/17 



55 



SI) 



Ammonium 



polysulphide 



solution, 



and its 



dilution 



II; 1:50 



IV: 1 : 100 



IV A; 1 : 100 



Mildew in the 



"powdery" conidial 



stage 



(I) on 8 leaves, at 

 5th to 8th node 

 from apex 



(1) on a leaves at 

 5th to 7th node 



(1) on 3 leaves at 

 5th node 



Mildew in the 

 early, non-pow- 

 dery stages 



Results 



(2) on 1 leaf at fifth (1) all killed 

 node, among ■ (2) unaffected 

 "powdery" | 



patches 



(2) on 1 leaf at 5th 

 node 



(2) on 3 leaves at 

 4th node 



(1) all killed 



(2) checked 



(1) all killed 



(2) somewhat 

 cheeked 



In several of the experiments it was noticeable that a consideraltde 

 variation occurred as regards the resistance shown to the solution even 

 when the mildew-patches were all in the powdery conidial stage. The 

 powdery patches on the young leaves resisted a concentration of the 

 solution which was lethal to those on the older leaves of the same plant. 

 Some of the more striking cases are tabulated below. 



Journ. of Agrie. Sci. ix 



I'J 



