VOL. LY.— N"o. 3,044. 



Saturday, march 2, 1912 



THE 



GARDENERS 



9 



MAGAZINE 



NOTE OF THE WEEK. 



and manures as are the best suited to his thus it comes about that neither the crops 



Sterilisation of Soil. 



crops, carefully regulates the temperature, 

 ventilation, and water supply, and then 

 finds that the warmth, moisture, and food 



A short time since we called attention to that he so liherallj^ supplied also encour- 

 the report by Dr. E. J. Russell and Mr. ages a host of other things, including eel- 

 F. R. Pethridge on the investigations they w(Uins and fungi. Not infrequently he 



food-producing 

 to their full development under the com- 

 petition ordinarily going on in a glasshouse 

 soil. The investigations made by the two 

 scientists here mentioned liave shown that 

 it is possible to a])precial)ly simplify the 



The different inhabi- 



0 



have made at the Rothamsted Experiment linds his own crop faring badly through ])opnlation of a soil. 

 Station in the partial sterilisation of soil tbe activity of these parasites, the roots tants have been found to vary ver\ 



used in the cultivation of various nseful 



being invaded hy eilwnrms, the stems and 



siderablv ni their susceptibility to 



con- 

 heat 



croDS and ornamental plants grown under leaves by parasitic fungi, and the fruits and j)oisons, and, fortunately for the cul- 



glass. In oxiv reference to 

 the work that had been ac- 



complished, 



we gave a 



brief 



summary of the conclusions of 

 the authors of the report, biat 

 in view of the importance of 

 the subject, and the interest 

 evinced by our readers, we 

 again refer to it for the 

 purpose of directing attention 

 to a few of the more im- 



greater 



more 



portant points witli 

 fulness than Avas previously 

 possible. The sterilisation of 

 soil used for cultui'al pur[>oses 

 is not a new feature of gar- 

 den practice, and liori icnl- 

 turists will rememluM- that 

 from their youth upwards 

 they have been advivsetl to 



I 



sterilise soil required for f^l' 

 mg pots in which choici' setnls 

 or fern spores are to bt* 



; sown by subjecting it 



' high 



to 



ft-- 



fi' 



temperature, 



a 



water as near 

 l)oint 



pouriu^ 

 the boiling 



as possible ovrv the 



soil when the pots have been 



filled being the procedure 

 usually 



recommended. 



The 



tivator, the least susceptible 

 to the effects of these are the 

 spores of the food-producing 

 bacteria. Thus it has been 

 proved to demonstration that 

 It is possible, by the use of 

 suitable noisons. or of 



mg 



poisons, 

 ([eo roes of heat, 



vary- 

 to kill 



off various groups of organisms 

 in the s<ul. It has been found 

 also that certain other effects 

 are produced, for the poisons 

 ]iave some chemical or other 

 action on the soil, and heat 

 causes some decomposition, 

 but, in the words of the in- 

 vestigators, ^' the net result of 

 treatment with less violent 

 poisons and degrees of heat, 

 is that the food-making bac- 

 teria now have a clearer fiekl, 

 and can multiply and make 

 much more food than before. 

 Such heated soils are, there- 

 fore, well suited for glasshouse 

 work, because they are fret 

 from harmful and competing 



organisms. 



advice may not have been 

 a(t(Hl u]>on very frequently, 

 ^0 oft(Mi as it slundd have 



tor, as 

 tinn o^- tlu 



in 



shown 

 his 



I 



Mr. 



si rea k 

 I he 



m vesi iga- 



( 



I isea: 



iS( 



Mli. (IIAHLKS WAlvKLV. 



o\ver,s are sown will en- h\ 



i>»'as. I he St erihsa- 

 ll'c M.il in which the 

 ^'^'ds ef these il 



j 1 . ' " ' »^ II will I ■ M- 



' t.io |.hmts lo pass through the most 

 ^"ti<-al i),.nu,l of tlioir litV froo f.-..n, i Ih' 



of tlie iungtis l,v wlii.-li the disoas.. 

 '■^ '■'iis(Hl. I„ then- i.nosti-ations of lh.. 



^ Ictlnidge liave takiMi a imicli hroador 

 ye« of the questions involved than tho 

 ♦K'^tnictioi, of gorms of thr vari 



I't*' Idudy to he injurious to ph.nl 

 <':>ilu.r stages of tlien- development. 

 ^" n.hnirahly stated in the rejH.rr. tlie 



"f <i-(>])s und 



are 



I ■ 



various .lisea^o-produciiig organisms. 



e are tohl, liis soil 



Ueiere verv long. \\ 



Ml infested with the germs <if all 



betttM" 



littU 



ious forms 



niav 



these initlesir-ihles that it is 

 than a di^ath-trap tor h s plants, and has. 



Tlu' act-ve 



il a hc^alrhy growtli (tf 

 el>ewluMe. 

 whieh 



tiuM-efore. to he thrown out. 



ai 



• 



ents in proiuotm^ 



ei u 

 to 



])s under glass, as 



ari 



tlu 



IM 



. d-producing bact(M-ia 

 (■(Uiutle^v millions m eulrivated sod. 



1 



so 



Kl'OW(M 



iJial 



E»])S 



and season 



glass 



workin 'i 



is compelled to eii 



*'Vory condition as taNuinahle as |)os- 

 I'l^^ phuits. He provule.s such soils 



tetMU m 



Hnt 



large as are tlu-u' nuiuhers, tlu\v do not. as 

 Dr.'^Hussell an<l Mr. IVtluidge are caretul 

 to point out, work at their maxinmm efh- 

 ,.v un(ier natural conditions. 1 hey 



iiax e" other hacteria lhat are more or less 



an( 



The experiments 

 have further shown that the 

 food-making |)rocesses in tln^ 

 soil iwc increased, and th<^ 

 plants ohtain a laigei' sn]>i)ly 

 of food than lu^tnie ; i)Ut tlie 

 food is not <^\actly the sanu' as 

 usual, and the ])lants grow 

 somewhat differently ; more- 

 over, the disease germs 

 killed. The several classes of 

 plants that were utilised in the course of 

 the investigations included clirysanthe- 

 mums. carnations, cinerarias, clarkias. ver- 

 benas, melons, tomatoes, incumbers, and 

 spinach, and all without exception gave 

 In^ttiM results in s(h1 that had bceji par- 

 tiallv sierilised than in that which had 



■ 



not been treated, 

 santhemums the soil in whic^h tlie cuttings 

 uer(^ siruck was ilivided int<» three ]>;.its, 

 one iRMUg heated by steam to 'JdO-21i) de- 

 grees, one tr(^ate<l w ith toluol (.\ ])er <ent.), 



the tbir<l nntreate<l. 



In the case of the chry- 



ami 



c 



During the 



arlier stages tluu-e was not much differ- 



injurious to them to contend with 



1 



rnct^ ht^twcen tlie several sets of plants", but 



in \]w course of tlu' summer the plants 



---I 



J ■ 



