318 The Spraying of Plants. 



way yields the most grain and straw. Neither of these modifi- 

 cations can be recommended for wheat without more data than 

 we now possess. 



"Potassium sulphide treatment for oats. In this treatment the 

 seed is left twenty-four hours in a one-half per cent solution 

 of potassium sulphide. The published experiments seem to 

 show that a weak solution of potassium sulphide is nearly as 

 good as the hot water. The potassium sulphide is cheapest in 

 the 'fused ' condition, in which form it costs about twenty-five 

 cents a pound. One pound of the sulphide should be dissolved 

 in twenty-four gallons of water. Place the seed in a wooden 

 vessel and pour on the solution till the seed is covered several 

 inches deep. Stir the solution before pouring it on the grain 

 and thoroughly mix the seed several times before taking it out 

 of the solution. The oats should stand in the solution twenty- 

 four hours, after which they may be spread out to dry. The 

 solution gradually loses its strength and hence cannot be used 

 more than three or four times without being renewed. 



"It will probably be best to sow the seed as soon as possible 

 and before it becomes thoroughly dry. 



" Soaking the seed twelve hours in a solution of twice the 

 strength will no doubt prove effectual. 



" Copper sulphate treatment for wheat. This consists in im- 

 mersing the seed in a solution made by dissolving one pound 

 of commercial copper sulphate in twenty-four gallons of water 

 for twelve hours and then putting the seed for five or ten 

 minutes into lime water made by slaking one pound of good 

 lime in ten gallons of water. 



" These treatments have all been tried and have proved effec- 

 tive. Probably the hot water is the best for general use. In 

 some parts of the country, seed wheat is treated in strong solu- 

 tions of copper sulphate and no lime is used. This practice is 

 much inferior, since it injures the seed, while those given here 

 prevent the smut completely and at the same time do not injure 

 the seed if carefully followed. In all forms of seed treatment 

 care should be taken to spread the grain out to dry at once, and 

 by frequent stirring prevent its spoiling. The treated seed 

 should be handled only with clean tools and should be put in 

 sacks disinfected by boiling fifteen minutes. If these precau- 

 tions are not taken the seed may be infected again after treat/ 



