Stinking Smut Experiments. 165 



STINKING SMUT EXPERIMENTS. 



By D. McAljmie. 

 The Plan Adopted. 



Experiments were again carried out in the prevention of Stinking- 

 Smut, and the three substances which had given most successful 

 results in the ])ast were tried, viz.^ bluestone, formalin and corrosive 

 sublimate. 



In a previous experiment, 1,000 grains of the same variety of 

 wheat were taken for each treatment, bnt in this instance a bulk 

 sample was treated, and an ordinary farm drill was used to sow single 

 strips for each plot the full width of the drill and one chain in length, 

 so that the conditions closely approached those in existence on an 

 ordinary farm. The test, however, was naturally much more severe 

 than it would be in ordinary practice, for the farmer does not generally 

 sow seed which is visibly affected with smut, while here the grains 

 were all so coated with smut spores that they looked quite black. 



The badly smutted grain chosen for the purpose was daraped and 

 then the seed wheat, Queen's Jubilee, was thoroughly mixed with this, 

 so that every grain received its coating of smut-spores. Though 

 special care was taken to break the smut-balls, some doubtless 

 escaped, and this would account for the presence of h small amount of 

 smut in the crops, the seed of which had been treated. The smut- 

 balls are unacted upon by the substances used, and they would 

 afterwards be crushed in the drill when the seed was sown and thus 

 serve to reinfect the seed. 



Methods of Treatment. 



1. Bluestunk or Sulphate of Ooppek. — It is essential for the 

 success of the treatment that the genuine sulphate of copper be used, 

 and not the so-called agricultural bluestone which is sometimes sold, 

 consisting largely of green copperas or sulphate of iron. In my report 

 for the year 1900, it was shewn as the result of experiment, that the 

 sulphate of iron cannot be relied on to destroy the spores of stinking 

 smut. 



The bluestone was used at the rate of 1 lb. to every 5 gallons of 

 water and when thoroughly dissolved, the infected seed enclosed in a 

 bag, was dipped for a minute or two, till all the grain was thoroughly 

 wetted, and then hung up to dry over-night. 



2. FoRMALiK, which is a liquid, was used at the rate of 1 oz. in 6j 

 gallons of water, that is a proportion of 1 in 1000, or 1 lb. in 100 gallons 

 of water. The seed was dipped for a few minutes, and remained in 

 the wet bags over-night. It was then allowed to dry before sowing. 



3. Corrosive Sublimate or Mercuric Chloride is a very poisonoue 

 substance and therefore requires great care in the handling. It was 



