Y. J. F. SHAW 119 



The depredations of some stiay cattle were responsible for tlie pancity 

 of mustard in the manured plot. 



Tobacco. The tobacco crop grew well at first but " tokra " appeared early 

 in December and continued to come up in ever increasing numbers causing 

 large cracks to appear all round the tobacco plants. Whether from the loss of 

 moisture through these cracks or from the actual parasitic effect of the 

 "tokra," the tobacco had a wilted appearance, this condition was most 

 noticeable in the afternoon. In February the whole field was full of " tokra," 

 a certain amount of 0. indica being mingled with 0. cernua (Piate II, fig. 4 ; 

 Plate III, figs. Sand 6). On the 20th February the crop had a veiy pooi 

 appearance and was cut. The following figures give the actual amounts of 

 the two species of Orohanche in comparison with the tobacco : — 



Number of Number of Number of 



tobacco plants 0. cernua 0. indirn 



Manured (S) . . 287 16,574 1,999 



Unmanured(P) .. 288 9,976 1,700 



These figures are most emphatically against the claim that sodium nitrate 

 may be used as a preventive against ''tokra." In comparison with the figures 

 for the mustard plots, those for the tobacco show the extent to which the 

 species which is the chief parasite of one crop can infect the other crop. 



(5) BiRowLiE— Season 1916-17. 



The same field was placed under mustard and tobacco as in the previous 

 season (Text-figure 6). 



Mustard. Sodium nitrate (20 lb.) was scattered upon the southern 

 mustard plot (M) about two week.s after sowing. The crop grew bacilv and, 

 as at Pusa, "tokra" was later in appearing and less in amount than in the 

 previous season. The crop was cut on February 18tb. 



Weight of Number of ])lants Numlier of 



mustard of mustard O. indica 



Mds. Srs. 

 Manured (M) .. 3 6 3,445 687 



Unmanured (0) ..2 28 2,846 1,404 



There was no 0. cernua in the mustard. These figures show that in 1910-17 

 the total amount of 0. indica in both plots was very much less than in the 

 previous season ; this fact has already been noticed in the case of the Pusa 

 experiment. No explanation can be given as to why the season 1910-17 

 appears to have been less favourable to 0. indica. 



