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Scientific Proceedings, Royal Dublin Society. 



an area of about twenty-five square yards was treated in each case, and the 

 plots were situated close to the field laboratory at Boghill. 



Copper Sulphate. — Affected seeds were lightly sprayed with an atomiser with 

 5 per cent, and 10 per cent, solutions of copper sulphate respectively. After 

 spraying the seeds were spread out and dried for twenty-four hours at 40^C. 

 The treatment had no adverse effect on the germination of the seed wlien 

 tested in the usual way. The plants arising from the treated seeds when 

 sown in the field, however, were not free from the disease. 



Mercitric Chloride.— Similar trials were made with O'l per cent., 

 O'o per cent., and 1 per cent, aqueous solutions of mercuric chloride, and the 

 percentage of germination of the treated seed was found not to be appreciably 

 lowered. Seedlings arising from seed treated with the O'l per cent, solu- 

 tion were, however, seriously diseased. The stronger solutions were more 

 efficacious in checking the disease, but neither of them suppressed it entirely. 



Burc/iondy Mixtures. — Affected seeds were sprayed with Burgundy mixtures 

 of different strengths made by neutralizing 2 per cent., 10 per cent., and 

 15 per cent, aqueous solutions of copper sulphate with the requisite quanti- 

 ties of sodium carbonate solutions. The seeds were then dried, and the 

 adhering blue precipitate remained as a coating on their surfaces. Germina- 

 tion tests shov/ed that the vitality of the seed was in no way injured by the 

 treatment. It was found, however, that the plants derived from such treated 

 seed were not less affected with "browning" and "stem-break" than were 

 those derived from untreated seed sown in an adjoining control plot. 



Formaldehyde Solution : Steeping. — Affected seeds were steeped (with 

 occasional shakings to ensure thorough wetting) for periods of five and ten 

 minutes in weak aqueous solutions of formaldehyde having strengths of 

 0-09 per cent, and 018 per cent, respectively. After steeping, the seeds 

 were separated from one another, placed on absorbent paper, and then dried 

 for forty-eight hours at 35°C. Tests were made before and after treatment 

 both of the germination of the seeds and of the viability of the conidia of the 

 fungus. The results are summarized in the following table : — 



