DISEASES OF PLANTS. 559 



strength of solution double that which the trees would stand during 

 the later period of the season. The cost of spraying peach trees, when 

 conducted on as large a scale as these experiments, amounted to 1£ cts. 

 per tree for each application. The author states that four applications 

 can be made on fairly level orchards for less than 6 cts. per tree, this 

 estimate covering the cost of both labor and spray materials. 



Smuts and rusts of grain in Idaho and the most approved 

 methods of dealing with them, L. F. Henderson {Idaho Sta. Bui. 

 11, pp. 34, figs. 15). — The author has given descriptive notes, largely 

 compiled, of the stinking and loose smut of wheat, loose smut of oats 

 and barley, and corn smuts, together with notes on the rusts of various 

 cereals. For the prevention of the smut of wheat, in 1895 and 1800 

 experiments were conducted with different strengths of copper sulphate 

 and the hot-water treatment. Deductions are drawn from the experi- 

 ments of the first year, no record having been kept of the yield of 

 grain and straw in the second year's tests. The plats seeded with 

 untreated grain averaged about 8b' per cent smutted grain, while those 

 treated with different strengths of copper sulphate and those given 

 the hot- water treatment showed that both methods were very effective 

 in suppressing the stinking smut of wheat. 



After a general discussion of the rusts of cereals the author suggests 

 the fallowing of wheat fields as a possible method of keeping down 

 the attacks, the fallow lands being closely pastured before plowing. 

 Where one crop of cereals follows another the stubble and all infected 

 straw should be burned. While all varieties of wheat seem to suffer 

 from rusts the early ripening varieties are least affected, and those 

 varieties with straight stiff leaves are less affected than those having 

 weaker foliage. It is thought that the red wheats are less affected 

 than the white varieties, notably the Velvet Chaff, which is extremely 

 subject to attack. Poor drainage and an excess of nitrogen in the soil 

 seems to aggravate the disease. 



Concerning the red rust of the currant, J. Eriksson (K.Landt. 

 AJcad.Handl. Tidskr.,37 (1898), No. 3, pp. 194-201, pi. J).— The author 

 studied the rust (Puccinia ribis) found on the fruit and foliage of red 

 currants. The investigations disclosed the fact that this rust is a true 

 micropuccinia, producing only teleutospores, which do not become 

 viable until the spring after they have been formed. A so-called 

 specialization is found also in case of this rust, which attacks red and 

 white currants (Kibes rubrum), but not black currants (B. nigrum) or 

 gooseberries (B. grossularig,). The disease reappears in the spring 

 through infection from wintered spores, after an incubation period of 

 29 to 39 days. 



The precautions to be observed in case of an appearance of this 



disease are given as follows: In the fall, carefully gather, remove, and 



burn leaves and berries which from time to time fall from diseased 



bushes; in the spring, when the currant bushes are about to leaf, one 



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