February 17, 1912. J 



THE GA RDENERS' CHR0N1 CLE 



97 



for the deterioration of ths soil, thus 

 leaving a free field for the beneficent 

 plant-focd producers which are then able 

 to multiply and make much more plant 



Cucumber border was used in a cold 

 house or frame for the growth of other 

 plants without manure ; heating to 200° 



4 



cent, of 



food than was before possible. 



Plants toluol led to increases of, from 20 to 200 



grown on these treated soils made healthy, per cent, in the crop. 



vigorous growth, whilst those on the un- 



On the other hand, the treatment led to 



treated soils were badly attacked by eel- practically no improvement where the 



THE 



worm, &c, and only gave poor returns. 



plant was grown in virgin soil free 



The method consists in heating the soil from disease organisms, and regularly and 



rtpfc^T^l^tl PY^ (\\ 11 mil Iff b y steam to a temperature of 200° Fahr., sufficiently manured. In these circum- 

 Kt/iililvll.Clr? KUV 1 -U il IVIV . . j j- w x A u a «ni™*nmi« limiiH which stands it anneared that the plant was 



No. 1,312.— SATURDAY, February 17, 1912. 



CONTENTS. 



Agricultural Bulletin of 

 the Straits and Feder- 

 ated Malay States ... 105 



Alpine garden, the — 



Primula amcena ... 98 



Big-buds, spraying for... 106 



Books, notio* s of — 

 The Botanical Maga- 

 zine — 105 



Publications received 105 

 Cleistogamic flowers ... 105 

 Cyanide fumigation ... 101 

 Fiji Islands, some plants 



of the 107 



Florists* flowers — 

 Perpetual - flowering 



Carnations 100 



Formosa, expedition to 105 

 Forrest, Mr. George ... 105 

 Fruit trees in grass land 10»> 

 Games in Li.C.C. parks 105 

 Genetics, Professor 



Bateson on 1C4 



Ha ben aria conopiea 



alba ... 107 



International Exhibi- 

 tion, Continental visi- 

 tors to the 



rj.C.C. parks employee^ 

 Leptospermum bulla- 



tum 



New Zealand, notes 



from 



Obituary — 



Lister, Lord 



Maw, George 



Molden, Thomas 

 Morten- en, M. L. ... 



Swift, Thomas 

 Odo nto glossum 



Memoria Lily Neu- 

 mann 99 



Orphan Fund, Royal 

 Gardeners' 109 



Potatos, trre present dis- 

 tribution -of wart dis- 

 ease of 104 



1C5 



99 



99 



107 



105 



110 

 109 



105 



108 



K5 

 104 



100 



98 



111 

 111 

 1 1 

 111 

 111 



Rhubarb growers, com- 

 plaint from 



Rosary, the — 

 Cultural hints for 



February 

 New Roses of the 

 N.R.S. " Catalogue". 

 Scotland, notes from ... 

 Small holdings, suitable 



buildings for 



Societies — 

 Birmingham Hort. ... 

 Bournemouth Hort..-. 

 Dresden Botanical and 



Horticultural 



H^refordsh.re Fruit 



Growers' and Hort. 



Herefordshire Fruit, 



Root, Grain and 



Chrys. 



Horticultural Club ... 

 Kent Commercial 



Fruit Show 



Manchester and No« th 



of England Orchid- 

 Royal Horticultural 



J 101, 107 



(Scientific Committee) 108 

 Royal Scottish Agri- 

 cultural 

 Scottish Horticuituri 1 

 Soils, partial sterilisa- 

 tion of ... 

 Surveyors' Institution, 



the 



Sweet Pea streak dis- 

 ease 



Wntk's work, the— 

 Flower garden, the... 

 French garden, the— 

 Fruits under glass .-. 

 Hardy fruit garden ... 

 Kitchen garden, the... 

 Orchid houses, the ~ 

 Plants under ^lass ... 



Wilson. Mr. E. H. ... 



Yucca Whipk-lci (nitida) 



or in adding to it a poisonous liquid which stances it appeared that the plant was 



is given time to evaporate before any- already making maximum growth on the 



thing is planted. The liquids used in the untreated soil for the prevailing condi- 



experiments were toluol and carbon bi- tions, and therefore that the extra plant 



sulphide. The three most striking results food in the partially sterilised soil was 



shown by the plant are (1) a more com- without effect. The gross feeding Cucum- 



plete utilisation of the reserves of plant ber, however, benefited by the treatment, 



food in the soil so that larger crops are and in addition, yielded fruit of higher 



obtained ; (2) freedom from the insect and quality, 

 fungus pests that occur in the soil ; (3) 





103 

 104 



no 

 no 



no 



108 



97 

 104 



101 



103 

 102 

 If 3 

 1(2 

 1C3 

 102 

 102 

 104 

 1C6 



ILLUSTRATIONS. 



Chrysanthemums rooted in sterilised and unsterilised 



soils — ... — .- — 



Flowers of Yucca Whipplei (n'tida) 



Leptospermum bullatum in a Devonshire garden ... 



Odontoglossum Memoria Lily Neumann 



Tomato plants, Bhowing the effects of growth of, in 



sterili ed and unsterilised soils 



Yucca Whipplei (nitida) (Supplementary Illustration) 



97 

 1C6 

 100 



99 

 9F 



PARTIAL STERILISATION OF 



GLASS-HOUSE SOILS. 



T^OR some time past Messrs. Russell 



and Petherbridge have been investi- 



A 



FlG. 42. CHRYSANTHEMUMS ROOTED IN 



UNTREATED AND TREATED COMPOST. 



gating at the Rothamsted Experi- (A) Untreated compost, (b) Compost treated with toluol. 



mental Station the important question 



of partial sterilisation of horticultural soils. certain minor changes m the plant due to 



* " the rather altered course of nutrition. 



These effects are not equally valuable to 



They may not be worth much 



The essential principle of the method 

 of partial sterilization is the subjection of 

 the soil to treatment whereby some, but 

 not all, of its numerous inhabitants are 

 killed. As is well known, the soil c is 

 teeming with microscopic organisms, some 

 of which are beneficial and some detri- 

 mental to the plant. The authors have 

 found that the harmful organisms are in 

 general more readJy killed than the use- 

 ful ones, and have thus been able roughly 



grow 



Partial sterilisation also produces cer- 

 tain secondary effects on the plant, and 

 'these are due to two causes: (a) the plant 

 does not, as is the case when it is grown 

 in untreated soil, obtain its nitrogen in the 

 form of nitrates, but as ammonia, at any 

 rate until the nitrifying organisms have re- 

 established themselves in the soil ; (b) 

 some of the soil decomposition products 

 have a physiological action on the plant, 

 modifying it in certain ways. The first 

 effect to be noticed is a retardation of ger- 

 mination and seedling growth, which mani- 

 fests itself chiefly in the steamed soil. 

 The precise cause is not yet ascer- 

 tained, and consequently no remedy can 

 be suggested; the problem is, how- 

 ever, under investigation. The amount 

 of retardation varies with the soil, 

 the seed and the conditions of growth. 

 Ifc was very marked in a turf and a rich 

 Cucumber soil, and was more pronounced 

 the higher the soil had been heated. 

 There were indications, however, that the 

 harmful effects passed off after a time. 

 Often there was no retardation, but an 

 acceleration both of germination and of 

 dling growth in soil heated only to 

 130° Fahr. Poor seeds and old seeds ap- 

 peared to be most affected ; Tomatos were 

 specially susceptible, more so perhaps 

 than Cucumbers. Soon after the third 

 and fourth leaves are out, however, the 

 plants make more rapid growth and socn 

 catch up those in the untreated soil. 



The root action is sometimes, but not 

 always, retarded in the early stages of 

 growth on soils heated to 200° Fahr. Like 

 the retardation of germination^ the effect 

 is erratic. The same grower has obtained 

 good root development in August, 





a 



to separate the bad from the good, and compost made much better growth, as 

 leave in the soil a more useful population 

 than it normally possesses. Thus, start- 

 ing with Tomato-sick or Cucumber-sick 

 soils 



very poor one in January, in 

 soils. Later on, however, the 

 soil heated to 200° Fahr. stimulates root 

 action in a most remarkable way. Fig. 43(c) 

 shows a root of a Tomato plant grown in 

 the heated soil, B, the corresponds <? 

 root in the untreated soil, and A the root 

 in the soil heated to 130° Fahr. When 



v _ _ _ _ applied as a top dressing to pots contain- 



shown in Fig. 42, than those struck in un- ing Tomato plants, or to borders where 



to the man who has abundance of virgin and a 

 soil and manure at his d sposal, but they heated 

 are of great importance to growers less 

 favourably situated. 



Very good results were obtained in 

 cases where the plant was left without 

 regular supplies of manure. Thus, Chry- 

 santhemums struck in partially sterilised 



treated compost ; they had larger leav 



Cucumbers were growing, the heated soil 



stouter stems, shorter internodes, and also caused rapid growth of fibrous roots, 

 worn out and infested with eel- generally a sturdier and altogether more Plants grown on steamed soils showed, 



worm, it was found possible to destroy 

 the micro-organisms that are responsible 



promising aspect. The same result fol- in comparison with those grown on un- 

 lowed when a compost thrown out from a heated soils, larger leaves, stouter stems, 



