96 



Flag Smut of W'Jieat. 



The ordinary marketable chaff was also chosen, on which spores of the 

 smut had been found, and a small handful was added to the soil of a pot, 

 and the clean grain grown amongst it. Care was taken that there was no 

 grains among the chaif which might possibly be affected independently, 

 and in 40 days it was found that about 12 per cent, of the plants had become 

 infected. 



Finally, manure was added to the soil from horses which had been fed 

 on diseased hay, and a small percentage of the plants was affected. 



The following Table gives details of the experiments :— 

 Pot Experiments with Flag Smut, 1906-7. 



Method of lulection. 



13.11.08 



22.11.06 



27.11.08 

 29.11.06 



30.11.06 

 6.12.06 



100 



i Seed just germinated, then 

 I dusted with spores and 



sown 

 50 Seed dusted, with spores 



of 1908 crop 



50 



50 



3.1.07 50 



9.1.07 50 



50 



26.2.07 50 



Seed dusted with spores 

 of 1905 crop 



Chaff sample badly smut- 

 ted placed in soil and 

 grain sown 



Smutted straw of 1908 

 crop put in pot, 

 22.11.08; grain sown, 

 30.11.03 



Diseased hay fed to horse, 

 maniu-e put in pot and 

 grain sown 



Diseassd straw of 1906 

 crop put in pot, 

 22.11.08 ; grain sown, 

 9.1.07 



Diseased straw of 1906 

 crop kept in laboratory 

 till date of sowing and 

 then added to pot 



Same as 5, manure in pot 

 since 6.12.06; sown, 

 9.1.07 



Same as 5, but manure 

 left in box, only added 

 to pot when seed sown 



Straw from 1906 crop kept 

 on soil till date of sow- 

 ing and then mixed with 

 soil in pot 



35 



19 



18 



Plants died very 

 rapidly, some pro- 

 bably diseased 



All dead, 31.1.07 ; 

 probably more than 

 six diseased 



All dead, 10.3.07 



Plants began to die 

 rapidly about end 

 of March 



All died very rapidly 



Control plots in every case free from disease. 



These experiments prove conclusively that not only does infection occur 

 in the seedling stage, or at least before the young plant has reached the 

 surface, and when the spores adhere to the grain, but also when the spores 

 are distributed through the soil on stubble or in the manure from horses fed 

 on diseased hay. The failure of the different treatments, such as formalin, 

 bluestone, and hot water, to prevent the occurrence of the smut, when the 

 seed thus disinfected was sown in the soil containing the spores, also proves 



