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solutions destroy nearly all the primary rvots and stunt the plant so as 
to often prevent the development of lateral roots in time to sustain the © 
young plant. It also causes an abnormal growth of the aerial parts of 
the plant, often resulting in distorted stems and tightly rolled leaves. 
(3) Solutions of 0.5 per cent and 1 per cent copper sulphate may be 
used for treating oats without doing serious injury to the seed. Numer- 
ous investigators quoted in the earlier portion of this paper have 
shown that by the use of solutions of such strengths for one to two 
hours it is possible to prevent most, if not all, smut infection, and if 
confidence is to be placed in their experiments there is no necessity for 
using solutions of greater strength or for longer time. 
(4) When stronger solutions are used or the period of soaking is 
greatly extended, the seed should receive a second soaking for from 
five to fifteen minutes in limewater, or should be dusted over with 
powdered air-slacked lime to prevent the long-continued action of the 
fungicide. 
(5) It seems probabie that soaking seeds in water for a few hours 
prior to subjecting them to the copper solution might prove beneficial, 
as it is shown in this paper that such treatment greatly increased the 
germination of seed soaked in the stronger solutions. No experiments 
are known to have been made to ascertain the effect of such treatment 
on smut prevention, and such treatment might not prove advantageous 
when tested on a large scale. 
(6) Much stronger solutions of copper sulphate may be used without 
injury, provided the seed after soaking are immediately placed in the 
soil instead of being tested in germinators or grown in water cultures 
or in sand. This is probably due to the presence of lime in the soil 
forming an insoluble oxide of copper, as well as the leaching away of 
some of the adherent copper from the seed. 
(7) Copper in an insoluble form is probably not injurious to plants, 
and it is only the corrosion induced by the action of the soluble sul- 
phate that causes the injury to the seed. 
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