DISEASES OF PLANTS. 341 



Corn smut was foinul to siirvivo solutions of P.orde;uix niixnirc nf full 

 strength nnd double strength, but was destroyed by one-half and one-fourth 

 strengths. Macrosporiuni was not quite so resistant as corn smut, but grew 

 readily in half-strength solution. The spores of (Jlomerella did not grow in 

 any of the Bordeaux mixtures. 



The last chemical tested was the supernatant liquid of Bordeaux mixture. 

 and this was found toxic to Glonierella spores when u.sed in a dilution as weak 

 as 1 : 10. In double strength it was also toxic to spores of Ustilago and 

 Macrosporiuni. 



Fungicides and insecticides, F. T. Shutt {Canada Expt. Farms. Rpts. 

 1901, PI). 165-17 J). — Studies are reported on the effect of exposure on solutions 

 of formaldehyde, the action of certain fungicides on the vitality of wheat, and 

 the composition of lime-sulphur washes and a number of proprietary insecti- 

 cides and fungicides. 



Formaldehyde in uncorked bottles or open dishes is said to concentrate rap- 

 idly, becoming polymerized and in part solidified, so that the strength of the 

 solution increases very materially. 



In studying the action of certain smut preventives on the vitality of wheat, 

 comparisons were made between different strengths of formaldehyde and cop- 

 per sulphate solution. It was found that there was some depreciation in vital- 

 ity in all the lots treated, the greatest loss being where a strong copiier sulphate 

 solution was employed. The effect of allowing grain to stand after treatment 

 was also investigated, and as a result it is recommended that but little delay 

 in sowing the grain should follow after treatment. Where seed grain has been 

 injured by frost, in treating it for smut a solution of formaldehyde not stronger 

 than 1 lb. in 48 gal. should be used. 



Analyses are reported of lime-sulphur wash used for San Jose scale and 

 fungus diseases, 2 trade preparations of the same, and 2 proprietary fluids for 

 which value as insecticides and fungicides is claimed. The proprietary fluids 

 consisted in the main of crude carbolic acid, nonsaponifiable petroleum oils, 

 saponiliable oils, and caustic soda. Vaporite, another commercial product, was 

 analyzed and found to consist of 25 to 30 per cent naphthalene oils and 70 to 75 

 per cent gas lime. Anti-fungi, a trade preparation, was found to consist of 

 54.5 per cent iron sulphate, 44.9 copper sulphate, and a small quantity of 

 ether extract. While the material has a fungicidal value, its cost is believed to 

 be entirely out of proportion to the price of the chemicals. 



Treatment of grain for smut, C. A. Zavitz {Ann. Rpt. Ontario Agr. Col. 

 and Expt. Farm, SJf {1908), pp. 1S3, IS/f). — For several years, as previously 

 noted (E. S. R., 19, p. 1150), studies have been carried on for the prevention of 

 smut in wheat and oats by treating the seed in different ways. The treatments 

 have consisted of immersion and sprinkling with dilute formalin, innnersion in 

 hot water, in copper sulphate solution for 12 hours, in copper sulphate solution 

 for 5 minutes, and in potassium sulphid solution for 2 hours, and sprinkling with 

 copper sulphate solution. 



The results, as shown by inspection of the fields, are tabulated, from which it 

 appears that the several treatments have been quite succ(>ssful in preventing the 

 development of stinking snuit in wheat and loose smut in oats. There was some 

 slight injury to the germination of the seed in some instances, but the greatest 

 yields of both winter wheat and oats per acre were produced where the seed 

 had been inunersed in the formalin solution. 1 pt. to 42 gal. of water, for a 

 period' of 20 minutes. 



Diplodia disease of maize, E. F. Smith and Florence Hedges {Science, n. 

 ser., 30 {1900), A'o. 75S, pp. 60, 67). — A preliminary report is given of investi- 

 gations which the authors have been carrying on for two years with special 



