SEEDS WEEDS. 463 



7 days in the atmosphere of hydrocyanic-acud gas will remain inactive while in the 

 gas, and lor from 7 to 12 days after removal, bnt will eventually <ierniinate to some 

 extent if the streni^th of fj;as used does not exceed 0.05 gni. per cubic foot. Wash- 

 ing seeds immediately after treating witti the gas greatly removes the injurious 

 effects of the treatment. Dry seeds treated for .several days with iiydrocyanic-acid 

 gas of any strength will not be injured for food, while damp seeds treated even for 

 short periods of time should»not be used for food until several hours after removal 

 from the gas. The effect of the gas appears to pass off and the grain may be eaten 

 with safety, although long exposure seems to render it unpalatable. (Train and 

 other seeds may be fumigated with hydrocyanic-acid gas for the destruction of insect 

 j)ests without injury to the germinating quality of the seeds and without rendering 

 them injurious as foods. 



The data upon wliich this bulletin is based are also published in Botanical Gazette, 

 31 (1901), Xo. 4, pp- Ul-264. 



Report of the seed control station at Gratz, 1900, E. Hotter {Ztarhr. Landw. 

 Vermclisw. Oentfirr., 4 {1901), No. 4, pp- 337-345).— X brief report is given on analyses 

 of 913 miscellaneous articles and 337 samples of seed, 257 of which were samples of 

 clover seed. 



Report of the chief inspector of noxious weeds, T. N. Willing {Rpl. Dept. 

 Ayr. Xortfnveiil Territories, 1900, pp. 34-45). — A report is given of inspection trips 

 made by the chief inspector, as well as his assistants, and the weeds observed in 

 various parts of Manitoba, Assiniboia, etc. The inspection work of the season was 

 carried on at considerably less expense than usual, owing to the dry season which 

 prevailed. It was found that many farmers did not recognize the various proscribed 

 weeds, and when their attention was called to them they were willing to comply with 

 the regulations requiring their destruction. A beneficial effect is noted in the atti- 

 tude of managers of mills and elevators throughout the territory. As usual in the 

 prosecution of such work the educational features must be given prominence. 



Destruction of charlock by spraying [County Councih Oumberland, Durham, and 

 Northuiitberlaud, Tech. Eduratiou, Rpl. 9 (1900), pp. 108-110).— A tabular report is 

 given of the results obtained by spraying with copper sulphate solutions for the 

 destruction of charlock at 5 different places. Strengths of solution varying from 

 1^ to 4 per cent were employed, the amount of solution used varying from 25 to 100 

 gal. per acre. The results obtained show that, if properly applied, copper sulphate 

 solutions may be depended upon for the destruction of charlock without seriously 

 injuring fields of grow'ing grain. The application should be made when the weeds 

 are about 2 in. high during calm dry weather. If properly applied the H per cent 

 solution at the rate of 50 gal. per acre is sufficient. If the weed is exceedingly 

 abundant or well covered by the grain the quantity of solution may be increased. 

 When applications are made late in the season the amount used shfuild be greater 

 than when earlier sprayings are given. When the herbicide is used in damp or 

 threatening weather it is recomineiuled to increase the strength of solution rather 

 than the quantity. 



On the destruction of cuscuta in alfalfa, M. Baille {Rev. VI t., 15 (1901), Xo. 

 372, pp. 130, 131).— The ordinary means ot combating the cuscuta, which consist of 

 burning over the infested patches and exercising care in seed setection, are reviewed. 

 Where this parasite has become especially troublesome, the author states that it may 

 be absolutely destroyed by the application of powdered sulphate of iron to the soil. 

 This will not only <lestroy the cuscuta but the alfalfa also, its action l)eing due, 

 according to the report, to the formation of a tannate of iron in the inner tissues of 

 the plant. This does not act as a poison, but obstructs the vessels of the plant in su<l) 

 a way as to destroy it. The roots oi the alfalfa are not injured and the {)iants (juickly 

 regain their normal condition. The cuscuta, however, is said to be completely 

 destroyed. .\s a cheap source of iron sulphate the author recommends the utili- 



