October, 1910. 



KNOWLEDGE. 



i93 



of the seeds or 

 flight organs) 

 adhering to animal 



mangolds \-ielded over thirt\- 

 sev'en tons per acre, but when 

 unweeded the yield was only 

 slightK- over sixteen tons per acre. 

 (5) If the real value of agricul- 

 tural seeds, owing to impurit\- and 

 low germinating power, be only 

 76 per cent., then the (initial) loss 

 in cash would be 24s. in £5 if 

 bought at the rate for best seed. 



The Distribution of Weeds. 



Regarding the manner in which 

 weeds are distributed, it mav be 

 said shortly that the seeds are 

 scattered in the same general 

 way as with other wild plants — 

 by transportation through the 

 agency of man, railways, shipping, 

 and so on : by rivers and floods, 

 by birds and wild animals, bv 

 wind (owing to extreme lightness 

 to their bearing 

 and by seeds 

 lor man) b\- 

 means of hooks, and so forth. 

 In other cases broken 

 portions of the rootstock 

 may be transported and 

 give rise to new centres 

 of infestation. 



Cooperative 



Destruction of 



Weeds. 



\\'e ma\" now consider 

 the means at the disposal 

 of the farmer for the pur- 

 pose of destroying weeds, 

 and all mav be covered b\- 

 cooperation, which should 

 be devoted to : (1) The 

 supply of pure seeds, free 

 from the seeds of weeds ; 

 (2) The mechanical de- 

 struction of individual 

 species which mav prevail 

 in a given district, by 

 means of the ordinary 

 routine methods practised 

 on the farm, as well as b\' 

 special measures ; and (,3) 

 The destruction of weeds 

 b\- spraying. 



If farms are to be kept 

 free from weeds, and 

 farmers are to be prevented 

 from causing infestation 

 of a neighbour's farm by 

 neglect of their own, it 

 must be by compulsory 



eradication or b\' cooperation- 

 fanners must icorh together. 



Regarding (1) it is 

 combination among 



Figure 5. 



Field Mint (Mentha arvciisis L.) X i. Pest 



(if arable land, and most difficult to eradicate 



owing to the creeping root-stocks. 



/ I,-. 'i'vi//i J>y y. C. I'arty-Simtli. 



Figure 6. 



Knot- weed I Polygonum Avicidare Lj reduced. A serious 



trouble of fanners. Often occurs in incredible quantities on 



light sandy soils. 



Juurn. Dcpt. Agric, Victoria, 1908. 



clear that 

 say fifty 

 farmers in a district will enable 

 them to purchase large lots of 

 high-class seeds at a fair price, 

 under guarantee, and to have 

 them sampled and tested. A 

 pure seed supph' will thus be 

 ensured. 



In relation to (2) it may 

 be suggested that mechani- 

 cal destruction should include 

 cooperative eradication of docks 

 and thistles by the use of docking 

 irons, spuds, thistle cutters; 

 regular cutting of many weeds 

 by hand and by power machines ; 

 cutting of weeds on waste lands 

 and roadsides to prevent the 

 formation and distribution of 

 seed : the collection of seed shed 

 at harvest time by the use of 

 box attachments to reapers and 

 binders ; thorough cleansing of 

 thrashing machines before 

 tlie\- go to the next farm ; 

 cooperative purchase and 

 use of surface weeders 

 like the poppv killer, 

 .\merican weeder ; and so 

 ft)rth. A year or so ago 

 Dr. Ewart, Government 

 Botanist of \'ictoria, 

 suggested * that school 

 children should be offered 

 prizes for collecting certain 

 weeds. A police magistrate 

 offered prizes, and 12,000 

 plants of Ragwort (Seiiecio 

 Jacohoea) were brought in 

 during the first four days, 

 the number quickh' rising 

 to 20,000 plants. 



(3) The destruction of 

 w eeds by spraying is what 

 most concerns the readers 

 of this journal, and is 

 dealt with below. 



The Destruction of 

 Weeds by Sfr.wing. 



It is only in recent years 

 that attempts have been 

 systematically made to 

 destroy weeds by means 

 of chemical substances, 

 these having been chiefly 

 applied in the form of 

 simple solutions. The 



