F. J. F. SHAW 115 



of this plot was distinctly gneener and larger than hi the remainhjg portion. 

 Thi? difference was not observed in the western tobacco plot (A), which had 

 been manured in tlie two previous seasons. 



The tobacco was cut and the "tokras" counted on 2i!d March with the 

 following results : — 



Eastern plot (B). 



Manured 



Un manured 



Manured 

 Un manured 



It was interesting to observe that in the eastern plot (B), in both manured 

 fiid unmaiuired areas, the "tokra" was most plentiful in the eastern half, in 

 which it had been the more abundant in the previous season. In the westerji 

 plot it was most abundant in the northern portion of the plot which had been 

 infected with seed of 0. cernua in the previous April. The amount of 0. indica 

 in both plots was considerably less than in the previous season — ^a fact which 

 will be found to apply to all the experiments in 1916-17. The amount of 

 0. cernua, however, in each plot was very greatly increased. Thus last year 

 plot (A) had only 185 0. cernua but this year it had 4,709. The significance of 

 these resuhs in relation to the application of the nitrate will be considered, in 

 conjunction with the results of other experiments, later. 



(6) Mustard. The two plots (C and D) were sown with mustard on October 

 11th and 20 lb. of sodium nitrate was scattered on the western plot (C) on 

 October 30th, when the young plants were up. The crop grew well but in 

 both plots the "tokra" seemed to be later and less than in the previous 

 season. The ciop was cut on February 3rd and the figures were: — 



Weiglit of Number of mustard Number of 



mustard plants O. indica 



Manured (C) .. 10-| mds. 3,753 1,402 



Unmanured (D) . . 7J „ 4,109 732 



These figures show that the amount of 0. indica in both plots was verv 

 much less in 1916-17 than in the previous season. No reason can be given for 

 this. Comparijig the two plots with one auother in each season it is seen 



