12 
sulphate, he says, is a good smut preventive, but is objectionable on 
account of its injury to the seed. 
Sorauer! recommends soaking seed for sixteen hours in a 0.5 per cent 
solution as a preventive of grain smut. When seed was soaked for 
twenty-four hours in a 1 per cent solution 4 per cent of it was destroyed. 
W. Carruthers? says that where seed is soaked for too long a time in 
copper solutions the terminal cells of the radicles are destroyed. In 
some cases the plumules of the injured seeds protrude and are nour- 
ished for a time by the starch in the seed, but the plant fails to pro- 
duce roots and finally dies. 
Strebel*® tested the effect on seed of applying bordeaux mixture to 
the soil. He applied 900 liters of 2, 3, and 4 per cent solution per 
hectare, and sowed wheat, oats, and rye. The plants came up so 
quickly and grew so well that he thought there could have been no 
injurious effect from the copper sulphate as applied. 
R. Otto’ claims that copper solutions have an injurious effect on the 
roots and terrestrial parts of corn, beans, and peas, causing an abnor- 
mal growth of these parts. 
S. A. Beach’ investigated the effect on wheat, peas, and tomatoes of 
placing copper in the soil. The soils in which these seeds were grown 
contained 2 and 5 per cent, respectively, by weight of dry copper 
sulphate. 
In the soil containing 5 per cent 12 per cent more wheat, 22 per cent 
more tomatoes, and 27 per cent more peas germinated than in the 
check, although the seed in the copper-treated soil was somewhat 
slower in coming up. In the soil containing 2 per cent of copper sul- 
phate 17 per cent more peas, 6 per cent more tomatoes, and 17 per 
cent less wheat germinated than in the check. All plants grown in the 
treated soils were of a darker green color than those in the checks, 
the color becoming deeper in proportion to the strength of the mixture. 
The plants made a rather unsatisfactory root growth. 
A. Bruttini® states that wheat soaked for twenty-four hours in 1 and 
2 per cent solutions gave 86.6 and 60 per cent germination, respec- 
tively, at the end of eighteen days. 
Jensen’ reports that a 0.25 per cent solution practically prevented 
smut in oats, although the total germination of the seed was slightly 
lowered by its use. When oats were soaked for twelve hours in a1 
per cent solution 75 per cent failed to germinate, and the growth of 
those which germinated was so greatly retarded that the plants were 
1 Pflanzenkrankheiten, Vol. II, p. 205. 
2 Jour. Roy. Agr. Soc., 17, ser. 2, 1881, p. 289. 
3 Die Weinlaube, No. 44, 1893, p. 521. 
4Naturw. Wochenschr., 1893, p. 565. 
5N. Y. State Sta. Bull. No. 41, n. ser. 
6 Staz. Sper. Agr. Ital., No. 27, 1894. p. 30. 
7 Jour. Roy. Agr. Soc., 24, ser. 2, 1888, p. 409, 
