Novi:mber, 1910. 



KNOWLEDGE. 



431 



when 



Chapel College of Agriculture and Horticulture. 

 "clo\er was untouched 

 crop was spra\ed with 

 one hundred gallons of 

 a 4 per cent, copper sul- 

 phate solution. In 1899 

 a 4 per cent, solution 

 of the sulphate (one 

 hundred gallons per 

 acre) completeh' killed 

 Polyfioiiiini Persicaria. 

 but c 1 o \- e r was u n - 

 injured. A 4 per cent, 

 solution of copper sul- 

 phate (fifty gallons per 

 acre) was also used to 

 destroy charlock in 

 mangolds. the latter 

 being uninjured. 



Experiments at the 

 Agricultural Experi- 

 ment Station of the 

 Universit\- of Wis- 

 consin showed ^ that a 

 20 per cent, solution 

 of iron sulphate (tifty- 

 two gallons per acre) 

 did not injure cereals, 

 clover seedlings or 

 lucerne, but cockle-bur, 

 ragweed, dandelions, 

 daisies, wild lettuce, 

 and several common 

 farm weeds were partl\- 

 eradicated. Sow-thistles 



FiGURl 



and creeping thistle 



Corn 1-iiitterciip iRiTnuiiculns 

 arvciisis L.I X 1. Often very 

 troublesome in corn fields on 

 .^11 soils, especiiilly on chalU. 

 Often termed " watch wheels "" 

 from the flat spiny fruits. 



spra\'mg 



were not effectively 



spra}-ed, and it was 



concluded that their eradication b\ 



is not practical for the average farmer. 



In demonstrations conducted throughout 

 Ontario, the effect of copper sulphate was 

 observed in relation to twentv-eight weeds, + and 

 while charlock was the only species readily 

 destroyed, it was found that the flowers of field 

 bindweed and white cockle, and the leaves of 

 creeping thistle, sow-thistle, blue weed i Echiuin 

 viilgarel. and bull thistle iCiiiciis laiiciohifiis i. 

 were ver\- sensitive to the spray, and largely 

 destrox'ed. 



At the Yorkshire College, Leeds, experiments 

 showed ; that clovers were practically uninjured 

 when sprayed with a 12 per cent, solution of 

 sulphate of iron, while peas, beans, carrots, 

 onions, beet, and j^arsnips were but slightl\- 

 damaged, and this was the case also with swedes, 

 turnips and mangolds. 



Spurre\- iSpcr^iila arvensis) has been found to be 

 checked hv spraving with a 3 per cent, solution of 

 sulphate of copper (fortv gallons per acre), 

 flowering and seeding being checked . 

 In another trial ' the results were held 

 to show that a 5 per cent, solution of 

 copper sulphate (fift\- gallons per acre) 

 ma\- be relied on to kill spurrey. 



.At the Woburn Experimental Farm it 

 has been shown hv pot trials that the 

 common poppy [Papavcr Rhocas) is much 

 injured hv a 2 per cent, solution of 

 copper sulphate : w hen the solution was 

 applied to both surfaces of the leaves 

 these ■■ turned brow n. became shrivelled, 

 and to a great extent the plant was killed. 

 for the seeding was almost entirely 

 prevented, the flower heads withering 

 up." vj It has also been stated ** that 

 the common scarlet poppy is ver}- sensitive 

 to a 13 to 20 per cent, solution of iron 

 sulphate. 



At the Woburn Station also experiment 

 showed that the wild 

 onion i AlUtun vincdle) 

 may be destroyed or at 

 least largeh' reduced by 

 spraving with a 5 per 

 cent, solution of pure 

 carbolic acid. + + 



Dr. Hiltner found 

 that dodder on clover 

 m'A\ be destro\ed by 

 S[)ra\ing with a 15 per 

 cent, solution of sul- 

 phate I if iron, so applied 

 that it hits both the 

 [jlants and the surface 

 >oil with some force. 

 Tile clover was black- 

 ened at first and 

 appeared to be ruined, 

 but sprouted strongly 

 afterwards. » ^ 



Sulphate of iron has 

 been found to destroy 

 charlock if applied in 

 the powdered condition 

 w hen the dew is on the 

 leaf, three to four cwt. 

 per acre being necessary. 

 This is considered by 

 M. Hitier to be more 

 easy of application than 

 in the form of a solution, 

 and more practical on 

 small areas. 



FlGl'KE 12. 



Shepherd's Needle. N'enus' Comb 

 tScaiitiix Pcctcn-Vcncris L.(X1. 

 .\n annual corn-field weed some- 

 times extremely troublesome on 

 light and chall; soils. 



* Bulletin No. 179. 1909. ' .\nn. Report. D.-pt. .\-ric.. Ontario. 1904. Vol. I., p. 39. 



; Report cm the Spraying of Charlock and Hunch. 1899. Rept. on l-:xpts.. Midland .Agric. and Dairy Inst.. 1900. 



• Uni\ . Coll. of North Wales. Bangor. Bull, ii., 190.S. ? Jour. Roy. .■4.s,'ric. Soc. 1902. p. 360. 



** Fr. Maier-Bode. Die licMiupfuiifi der .Acker-Unkrauter. 1908. ' ' Jour. Roy. .Aoric. Soc. 1900, 1901 and 1902. 



l^rak. Bhittcr tiir Ptiaiizciibaii mid l\tiaiizcnsclinfz. .\p. 190S. Bull, dcs Scmiccti Soc. \at. d'.Agric. 1909, No. 5. 



