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65.05.10

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Ferdinand von Mueller to the Council of the Board of Agriculture, Victoria, 1865-05-10. R.W. Home, Thomas A. Darragh, A.M. Lucas, Sara Maroske, D.M. Sinkora, J.H. Voigt and Monika Wells (eds), Correspondence of Ferdinand von Mueller, <https://vmcp.rbg.vic.gov.au/id/65-05-10>, accessed September 11, 2025

1
Letter not found. For the text given here, see B65.09.01.
Melbourne Botanic Gardens, 10th May, 1865.
TO THE COUNCIL OF THE BOARD OF AGRICULTURE.
Gentlemen,
I have the honor of submitting to you the Report of the Committee appointed 19th October, 1864, for the purpose of inquiring into the causes and the possible means of prevention of the rust in cereals.
The Committee, from the time of its appointment up to this date, has met almost every week. Mr. Alexander Mackenzie undertook to visit certain localities in which rust prevailed, with a view of effecting the most judicious selection of samples of soil and cereals required for examination, and to institute such inquiries as only by ocular observation on the spot could be made. Mr. Mackenzie's field labors extended over a period of five months, and in his special report to the Board he has furnished some interesting notes on various points which impressed themselves on his observation during the inspection of the growing crops. The localities successively visited by Mr. Mackenzie
2
All the places listed are in the vicinity of Geelong, Vic. Not all the persons named have been identified; those who have been are listed in the Biographical Register.
are:—
In November, 1864: The farms of Mr. Hapeth, above Point Henry, parish Moolap; of Mr. D. Mackenzie, Bellerine
3
Now Bellarine.
Hills, above Port Arlington; of Mr. J. Gray, Duneed; of Mr. J. Walters, Moodewarre; of Mr. J. Hollands, Moodewarre.
In December: The farms of Mr. J. Sinclair, Port Arlington; of Mr. J. Wyllie,
4
i.e. J. Wylie.
Clifton; of Mr. J. W. Roberts, Duneed; of Mr. J. Wilson, Connewarre; the Geelong Vineyard Company's land; the farms of Mr. Dardell, Batesford; of Mr. Jonas Webber,
5
i.e. Jonas Weber.
Marrabool; of Mr. C. Frey, Sutherland's Creek; of Mr. J. McQueen, near Moorabool; of Mr. J. Stout, Bruce's Creek; several farms on the north side of the Barwon and at Mount Duneed; the farms of Mr. J. Honey, Barrabool Hills; of Mr. J. Piper and Mr. J. Edney, Barrabool Hills.
In January, 1865: The farms of Mr. Richard Greig, Bellerine Hills; of Mr. T. Carruthers, Drysdale; of Mr. D. M'Andrew, Drysdale; of Mr. D. Sharpe, Bellerine Hills; of Mr. J. Hamilton, Bellerine Hills; of Mr. J. Wyllie, Moolap; of Mr. A. Kilpatrick, near Point Henry; of Mr. J. Coverdale, Morangurk; of Mr. J. Cann, back of Highett's Hill; the Geelong Vineyard Company; the farms of Mr. J. Riley, Fyan's Ford; Mr. P. Lynch, Fyan's Port; Mr. T. Carruthers, Drysdale; Mr. R. Greig, Bellerine Hills; Mr. W. Greig, Mr. D. Sharpe, Mr. Hamilton, Mr. D. Mackenzie, Bellerine Hills; Mr. J. Wyllie, Moolap; Mr. A. Kilpatrick, Moolap; Mr. R. Quarill, Duneed; Mr. R. Boyle, Duneed; Mr. S. Riches, Mount Morien;
6
Typesetter's error for Mount Moriac? See list below.
Mr. J. H. Ryland, Mount Morien; Mr. J. Knight, Lovely Banks; Mr. D. Urquhart, Lake Connewarre.
In February, 1865: The farm of Mr. J. Greig, Duneed; the Geelong Vineyard Company; the farms of Mr. J. Sinclair, Warren Ponds;
7
Typesetter's error for Waurn Ponds?
of Mr. Pettavel, Colac-road; of Mr. W. Underwood, Barwon Heads; of Mr. Bowden, Barwon Heads; of Mr. Mortando, Duneed; the vineyards of Mr. Hanson; of Mr. Dardell, Batesford; of Mr. Webber, Marrabool; the farms of Mr. A. Armstrong, Puebla; of Mr. D. McIntyre, Fresh Water Creek.
In March: The farms of Mr. J. Parsons, Wabdallah; of Mr. A. MacAdam, Coolebarghurk; of Mr. L. Fynn, Mr. W. Ellis, Mr. H. Cagwon, Mr. J. MacKay, Coolebarghurk; of Mr. J. Parker, Wabdallah; of Mr. J. Wilson, Mount Blowhard; of Mr. J. Ogilvy, Ascot; various farms near Lake Learmonth, Mount Blowhard, Mount Hallowbank[,] Coghill's Creek, and Ascot; farms in the Birragurra district, Larpent district, and Ondit district; the farms of the Hon. C. Sladen, Old Missionary Station; of Mr. J. Mackenzie, Birragurra; of Mr. J. Dickman, Birragurra; of Mr. W. Sherman, near Colac; of Mr. Hugh Cameron, Larpent; of Mr. W. Walsh, Wannon Hills.
The Committee further issued a circular (vide Appendix A), which was transmitted to all the agricultural societies, urging to send such samples of soil and grain as might present points of interest for elucidations, and to accompany it by any remarks which might suggest themselves as desirable for the Committee's information. An arrangement was entered into with Mr. W. Johnson, of St. Kilda, for carrying on those chemical analyses of the corn plants and the soil, which in the progress of the inquiry might be deemed needful.
A special report, furnished by this talented gentleman, has been appended (vide Appendix B).
The following is a list of the associations and gentlemen who furnished specimens of soils and of more or less diseased cereals for examination:—
Agricultural Society of Bacchus Marsh
Agricultural Society of Glendaruel
Agricultural Society of Hamilton
Agricultural Society of Victoria
A. Armstrong, Puebla
W. Bowden, Barwon Heads
R. Boyle, Duneed
Brown Brothers
J. Cann, Highett's Hill
H. Cameron, Larpent
J. Campbell, Geelong
H. Capron, Coolebarghurk
J. Carruthers, Drysdale
— Chandler
J. Christians, Newlands, through Victorian Agricultural Society
— Corndale, Duck Ponds
J. Coverdale, Coures' Creek
J. Dardell, Batesford
E. Dickman, Birragurra
J. Edney, Barrabool
W. Ellis, Coolebarghurk
P. H. Fanning, Heidelberg, through Victorian Agricultural Society
J. Fox, Janefield, through Victorian Agricultural Society
C. Frey, Sutherland's Creek
L. Funn, Coolebarghurk
Geelong Vineyard Company
R. and W. Greig, Bellerine Hills
J. Grey, Duneed
J. Hamilton, Bellerine Hills
— Harray, near junction of Leigh and Barwon
J. Hassett, Moolap
W. Henderson, Barwon Heads
J. Holland, Moodewarre
J. Honey, Barrabool Hills
W. Johnston, Pentland Hills
A. Kilpatrick, Moolap
J. Knight, Lovely Bank
— Lindsay, Bacchus Marsh
P. Lynch, Fyan's Ford
A. McAdam, Coolebarghurk
J. McAndrews, Drysdale
J. McDonald, Holwhut
A. McFarland
A. McKenzie, Belmont
D. McKenzie, Port Arlington
J. McKenzie, Birragura
J. McKay, Coolebarghurk
J. McNair, Barrabool Hills
J. McQueen, Moorabool Plains
M. Mortando, Duneed
J. Myer, Pentland Hills
— Nicholson, Whittlesea, through Victorian Agricultural Society
J. Parker, Wabdallah
J. Parsons, Wabdallah
J. Pettavel, Colac-road
J. Piper, Barrabool Hills
R. Quarrill, Duneed
S. Riches, Mount Moriac
J. Riley, Fyan's Ford
J. H. Ryland, Mount Moriac
D. Sharpe, Bellerine Hills
W. Shearan, Colac
J. Sinclair, Barrabool
J. Sinclair, Port Arlington
C. Sladen, the Honorable
J. Stout, Murgeboluc
J. Frethowen, Connewarre
W. Walsh, Lake Corangamite
J. Webber, Moorabool
J. Wyllie, Clifton
T. Wilson, Connewarre
In a preliminary report, presented to the Council of the Board of Agriculture on the 15th of February,
8
B65.14.01.
the main results of the Committee's inquiry were briefly pointed out, with a view of rendering the information which they conveyed available to the farming community already at this season.
Moreover, on the 22nd March last, the Chairman of the Committee delivered a lecture on "Rust in Cereals," and on subjects standing to the disease in close relation, before the Agricultural and Horticultural Society of Bendigo; and by the publication of this discourse, through the courteous attention of the editor of the Bendigo Evening News, such information and advice as, at that stage of their proceedings, the Committee could afford, have been widely promulgated.
9
B65.04.05.
In submitting now a brief general report, the Committee wish it to be understood that the inquiries before us, which of necessity must be of magnitude, and must touch on many points of all the sciences connected with general agriculture, cannot be considered as concluded.
If in Europe — where, since the days of the ancients, the bane of rust has engaged the attention of numerous observers, and among them, also, that of men of the highest rank in modern science — still disparities of opinion exist on its origin and prevention, how much more necessary is it that the corresponding inquiries in this country, where the appearance of the rust disease is surrounded with local phenomena novel to us and little understood, and where this inquiry, under peculiarities of climate and soil affecting the occurrence of the fungus, have de novo to be instituted, should be extended over a lengthened period, and certainly over several seasons, before results fully confirmatory can be obtained. In the progress of this writing, we shall draw attention to several points of inquiry worthy of future observation and experiment, and shall succinctly allude to several of the scientific principles on which rational farming depends. Though this may be deemed a deviation from the subject allotted to our investigation, we are still persuaded that these principles, nevertheless, should neither be neglected nor misunderstood, if we hope to produce field-fruits in so normal and so healthy a condition as is likely to secure them from invasion of disease.
The observations which are advanced in this document have but in a limited measure claims on originality. But it became a duty of the Committee to collect for its report once more all the well established facts which present themselves as elucidating the subject before us, although to these general attention has been drawn, in most instances, long ago, in agricultural literature here as well as abroad.
The main evidence before us, as far as bearing on this part of the question, points to the necessity of early sowing as one of the most needful measures to secure, in seasons of rust, the safety of wheat crops in this country. It is evidently preferable to incur the increased expenditure of breaking up the soil in dry weather, than to sacrifice time by postponing the preparation of the soil under the advantage of its saturation with rain. In a few instances, a recommendation to the reverse has been advanced, and it has been urged that early sown crops are proportionately more prolific in stems and foliage than in seeds. As, however, by the process of early tillage, the cereals advance into flower before excessive heat sets in, we are likely to secure the crop against those sudden enormous vicissitudes of the temperature which are prone to produce vulneration of the epidermal tissues, under their sudden alternate expansion and contraction, particularly should wetness be followed by great heat. In the sap eliquescent from points of mechanical ruptures, especially if this sap should not contain the needful proportions of incombustible elements, the seeds or spores of the rust fungus are as readily absorbed as brought into germination.
Should the weather, particularly in wet season, continue in such cases moist and warm, we will find a prodigious number of rust plants developed in rapid succession, with amazing swiftness maturing their seeds, and diffusing them over, perhaps, wide tracts of country.
The accumulation of these minute vegetating parasites, especially on the stems of the cereal, impedes the free flow of the sap, and, in consuming and arresting it, prevents the young and weak fruit spikes to assimilate the needful nutriment during that advanced season of the year when the rust fungus usually commits its ravages; while, in early sown crops, the grain will have absorbed already what is mainly needed for its assimilation and final maturation, and thus much more readily withstand the assailing fungus. Moreover, from early sowing, the additional advantage will be derived of securing in this climate the field fruits against such occasionally excessive droughts as will militate against their perfection.
A second point of importance for guarding against the detrimental effects of the rust, is to be sought in the choice of those varieties of wheat which are early ripening, and are armed with the strongest coating of epidermal silicious deposits, and which otherwise are distinguished for their hardiness.
All the so-called red varieties, and all the early maturing kinds, are therefore more eligible immediately after periods of rust. It seems preferable to forego, at least temporarily, the advantage of cultivating the more prolific but also more tender varieties, when we know that these also so much easier fall the prey of fungus growth.
Thus the red spring wheat, Spaldings, the red Tuscan, the Uxbridge, the Pedigree, the rough chaff wheat, are amongst those generally free of rust; while the golden drop, the white prolific, the white Tuscan, the club-eared, and Winslows wheat, suffered most from the disease.
Next, the Committee most encouragingly can bear out the testimony of Sir Joseph Banks, enunciated in an essay as early as 1806, and then republished in Koenig and Sims's Journal,
10
Banks (1805)
that the seed of diseased what, though its albuminous portion might have shrivelled, can be employed for seed grain as long as the embryo is fairly developed.
To this circumstance attention has been drawn by the agricultural press of this country before our inquiry. It renders the farmer, whose crop by the attacks of the rust may have become, for flour at least, comparatively worthless, independent of seed grain, whenever it should be beyond his means to secure the seed of those preferable varieties less liable to rust affections.
But still more important is the fact, over and over proved on Victorian fields, according to the information gained by Mr. Mackenzie from many a farmer, and according to numerous specimens selected and transmitted by him, that seeds of rusted wheat, in most instances, produced a richer yield than crops raised from the best of imported grain, the latter, we need not say, taken from plants free of rust. This apparent anomaly, rendered known, we believe, only through the experience of the past season, is, as yet, not satisfactorily explained. It suggests itself, however, to our understanding, how, probably, crops may arise quite of moderate fertility, from emaciated grains in rich soil; while from the seeds of a cereal grown in soil of a different geological origin, abnormal or even over-luxuriating crops may be produced, apt to be carried off by disease.
Neither chemical analysis nor comparisons of growing crops have, as yet, been carried on to a sufficient extent to warrant to establish a theory on this subject; but it would appear that the plants which succumbed under the fungus were generally of an undue succulence, flacidity, and softness. This observation is borne out by a striking fact recorded by Mr. Ibotson, of Herefordshire,
11
At its meeting of 21 June 1865, i.e. after the date of M's report, a letter was received from Charles Ibbotson of Geelong stating that he had, by way of experiment, shipped a parcel of Adelaide wheat to his brother, 'a practical farmer in Herefordshire', who gave details of his trial, in which the wheat turned out rusty (Age, 22 June 1865, p. 5). Either M had been informed of this letter before it was read to the board, or he amended his report before it was printed.
who imported some Tuscan seed wheat from Gummoracka, South Australia, but found, that while on the same fields the English Pedigree, the Spaldings, red and rough chaff white wheat, remained perfectly free of disease, a crop raised from the South Australian seed turned out very soft, and was ruined by rust. This singular fact clearly demonstrates that the occurrence of rust is not dependent on climatic conditions alone, but more likely on the effect and reaction of a variety of causes and of circumstances, none in themselves, perhaps, sufficient to produce the disaster. It would point also to an innate susceptibility of certain varieties to suffer from the devastations of the fungus.
Next we have to pass to a consideration of the chemical results which were gained in this inquiry by Mr. Johnson.
The investigations of this gentleman, carried on to a recent date, have almost invariably revealed a deficiency as well of phosphoric acid as of lime and magnesia, in the many samples of both surface soil and subsoil subjected to examination. Mr. Johnson, with great propriety, points to the desirability of adding to such soils lime, not merely to render it available as such, but also to liberate by decomposition from the clays silic acid and alumina, as well as potash and magnesia. To offer the phosphoric acid and the alkaline and earthy bases necessary for a grain soil, either crushed bones, or, for speedier action, hypophosphate of lime or any kind of guano rich in phosphates, or even merely well-collected and well-prepared farm-yard manure, should be employed. We cannot refrain from dwelling on this subject, inasmuch as soils deficient in any of the requisite alkalies, in alkaline earths, and in phosphoric acid, cannot possible produce a normal crop, nor indeed a plentiful yield of grain. The cereal thus arising under insufficient nutrition cannot be constitutionally so vigorous as to withstand equally well the inclemency of weather or the temperature, or the humidity of a season, or the abrupt alterations in the air, which are not unfrequently concomitant to the invasion of rust, as those cereals strengthened under normal assimilation of abundant incombustible food.
But, nevertheless, certain varieties of cereal plants have a tendency to a lesser consumption of mineral substances than others; and these varieties, away from a climate genial to their growth, or influenced by a season of severity or humidity, may suffer from parasitical maladies which, on the stronger constituted cereal plants, have little or no effect.
Not sufficient time has been allotted to compare by rigorous analysis the contents of a considerable series of cereals free of rust, and others affected with this fungus, for the purpose of throwing full light on this important question, one on which to pass an opinion from limited data would be unjustifiable. We beg, therefore, with Mr. Johnson, to suggest that the elucidation of this subject by chemical means should be further pursued.
The analysis of virgin soils from forty different localities in Victoria, independently conducted for the Board of Agriculture by Dr. Macadam, has taught us that the incombustible substances on which plants rely for nutrition are largely wanting even in many sols of our colony previously uncultivated. We again, therefore, urge on our farmers the advantage of causing the sols of their estates to be subjected to chemical tests, so far as to learn whether the main elements for the successful cultivation of any intended field fruit are accessible; and if such is not proved to be the case, the agriculturist should seek to be advised how, either by any special fertilising agent they could realise the desired crops, or what field fruit without the extraneous aid of manure might be most advantageously raised on their special grounds.
The outlay for these simple inquiries is most trifling, and rewarded a hundred, or, perhaps, a thousand fold by a scientific insight into the soils, and by the secure results of a method which clings not merely to blind empriicism.
Should, for instance, a soil appear ever so rich, it may still be wanting in one of those ingredients on which the maturation of the crop depends, or it may be deficient of one substance without which the others remain inert.
Some basaltic soils, for example may be of great apparent richness, yet they are, in some instances, exceedingly poor in lime, and almost devoid of free potash and magnesia, and, therefore, not directly eligible for the cultivation of cereal crops.
The careful gathering of bones and other phosphatic animal substances, the provident storage of manure and of any other fertilising material, cannot (after what chemical analysis in many instances has taught us) too strongly be recommended. Silicate of lime and potash are as indispensable for the formation of a cereal stem of healthy firmness as phosphate of lime and magnesia to the formation of the bones of the animal frame. And again, without the very elements of the latter being naturally present in a soil, or artificially offered to it, the formation of cereal grains becomes absolutely an impossibility.
Moreover it is not sufficient that the presence of the important incombustible substances, by which the nutrition of plants is effected, should be proved. The agriculturist should further be aware how far they are available in that assimilable state in which they alone can be active and of immediate utility. it may not be deemed beyond the limits of this report, if here we refer to an error which modern chemistry has refuted, and which, if not recognised, may cause a needless waste of labor and material in manuring processes, especially since so much of our soil stands in need of re-fertilisation. Huxtable, Way, and Thomson
12
Cited by Liebig (1859), p. 27.
have dispelled the error that potash, silica, ammonia, and phosphoric acid are widely carried in solution; but, contrary, that from their dissolved state these substances are disengaged, while a solution of such percolates through a soil. Of the enormous power thus possessed by soils, an approximate estimate may be formed when the practical experiments of the named investigators teach us that an acre of ground, rich in lime or clay through its surface stratum of 10 inches depth, will disengage from a solution 4000 lbs. of potash; or, from a solution of phosphate of magnesia and ammonia, 2000 lbs. of this salt. Liebig, in the more recent of his luminous writings,
13
Liebig (1859), 'Letter II', pp. 18–29.
has brought the significance of this fact more generally before the agricultural world. Hence we learn, that by a wonderful law in the creation, the very substances always wanted for the nutrition of plants—and these only—are thus stored up and retained in any soil to which they attain access. But this law shows also, how very imperfectly can be relied on the action of capillarity for bringing the incombustible elements of food of vegetation into contact with the roots of plants, and how needful it becomes to bring from the deep strata, wherever available, the assimilable elements, after any exhaustion of the surface soil, into action, unless (and it is rarely so) re-fertilisation holds the scale to abstraction.
This capacity of soil to condensate the solid, soluble, fertilising particles, Mr. Johnson ingeniously suggests, might, perhaps, advantageously be turned to account for fixing, by a simple process of saturation, these most valuable salts from sewage, with a view of removing soil fully charged with them to arable land in the vicinity.
In that wide and minute distribution of potash, ammonia, silic acid, and phosphoric acid through the soil, indispensable for their being assimilated, carbonic acid plays an important part. It is this gas, evolved from humus soil, from decaying animal and particularly vegetable remnants which acts, together with humic and allied acids, as a solvent on the incombustible food.
Liebig has most ingeniously suggested
14
Liebig (1859), pp. 47 ff.
that probably the salts of ammonia, the Chili saltpetre, and common salt act merely as means of diffusion of the essential phosphates of alkalies and alkaline earths; and therewith explains the true action of humus, of nitrate of soda, ammonia salts, and chloride of sodium, all by combination with the earthy and alkaline phosphates, rendering the latter so very much more soluble.
The addition of common salt to ammonia combinations for manuring purposes, has generally doubled the crops. It is thus explained that this salt, and many others, not entering generally into the food of ordinary culture plants, act merely as the means of diffusion of the actual fertilisers. In soils rich in vegetable substances, the application of the above-named solving agencies seems therefore to involve a needless expenditure. But, while taxing by these agencies the fertility of a field, we have as important to bear in mind, that in the same extent in which we facilitate by artificial means the assimilation of the phosphates, in the same degree we accelerate the the
15
Word repeated.
exhaustion of the soil, and urge on the necessity of relying on a restoration of the fertility of the latter. Unless, therefore, a spoilation system be introduced into our husbandry, a system which would render ere long our arable lands worthless, or often subject its scanty crops to disease, it becomes an imperative necessity to counteract the otherwise increasing exhaustion of the soil by every available restorative measure.
In discussing some of the laws on which the nutrition of plants depends, it may appear we enter on a subject foreign to our question. But it has been previously observed how inadequate nutrition of the cereal, its debility and often disease, stand in constant relation; and though we do not wish to assert that with these inevitably the ravages of rust are initiated, we may be justified to contend that whenever, in unfavorable seasons, the dreaded fungus shows itself, the crops least fortified by normal assimilation will suffer more extensively. We hasten, moreover, the ripening process by abundant nutriment, and thereby we may carry with rapidity and safety our epidemically-affected crop to that stage at which the fungus exercises no longer any injurious effect.
Proceeding in our endeavors of pointing out any of the probable preventatives of the rust, we would next allude to the circumstance of Mr. Mackenzie and other observers noticing the fungus most extensively on plants in new soils, sown immediately after ploughing. Whether the want of disintegration and of aeration of such soil causes—especially in wet seasons, when the fungus prevails—the cereal to acquire too aqueous a sap, or whether the chemical and physiological effects stand thus not in proper corelation, and produce from the very beginning a plant prone to suffer, or whether any other perhaps unregarded circumstance tends thus to develop the rust fungus, can as yet not positively be affirmed. Suffice it, therefore, to record here the fact without an attempt of full explanation.
Want of drainage, which evidently favors the growth of the uredo, though it perhaps not originates it, in a similar manner, by depriving the plant of a duly elaborated sap, promotes the disease, irrespective of the certainty, that the rust spores will hover over a soil in which both humidity and decay continually arise. When stagnant and superabundant moisture exists, the assimilation of the incombustible food cannot possibly keep pace with that of the watery fluid.
Want of drainage, moreover, lowers the vitality, and therewith the vigorous growth of plants; it chills, and therewith causes stagnation or inactivity of the sap; renders the latter too watery, the plant devoid of firmity, and precludes the benificent action of air and heat on the soil. Can we wonder, therefore, if many observers concur in assigning to the absence of drainage the origin of the rust parasites in wet corn-fields; for evidently the rust spores, everywhere present, with every respiration of a plant conveyable through its stomata, will lodge and germinate on sickly plants, while the vigor of healthy plants would much more readily preclude their attack; in due consequence the vital fluid of a suffering plant, instead of serving nutrition, is absorbed by the assailing fungus.
A perfect system of drainage is a lasting boon to any farm, whatever may be its influence on suppressing the development of the rubigo. Were it not needless to explain its advantage to the sagacity of our intelligent agriculturists, we would refer to rural statistics. To these we might point, also, for showing the marvellous effect of irrigation, a subject that we must here cursorily pass as not bearing directly on the rust question. We content ourselves, therefore, to instance on this occasion, that on a farm at Talbot the produce of grain was augmented simply by the means of irrigation from 16 to 40 bushels on the acre. Such facts are after all readily enough understood. Irrigation serves for the comminution of a soil, while the filtration of water, which, in the wise process of nature's economy returns the ammoniacal exhalations of decaying organism along with carbonic acid from the atmosphere, sets free many particles of the soil for the consumption of the vegetable world, otherwise unattainable. Storage of water for percolation in seasons of aridity, how easily might it often be accomplished.
Should, on the vegetation of undrained soil, or on otherwise abnormal plants, the rust originate, and that this is frequently the case can scarcely be doubted, it may require merely combined heat and humidity to spread on the waves of the air the destructive spores over all adjoining fields, and, perhaps, over wide tracts of a country; while had the fungus not existed on low-lying ill-drained spots, or swiftly multiplied on sickly plants, the previously healthy crops might with safety have withstood the transient or even lengthened influence of unfavorable weather and the uredo in its sequence.
A succession of hot summers will, it is hoped, free us of this vegetable bane, like the frosts of colder climates in their opposite extreme subdued the same vegetable parasitism.
Among the varied causes which combine to induce the development of rust on our cereal fields, some are clearly within, others beyond our means of prevention.
To sow corn so thickly as to render a free access of air impassable, is intercepting the evaporation of superabundant moisture, and is improperly limiting the beneficient influence of air, heat, and light on the soil and its plants. The injury thus arising will be greater in proportion to the moisture of foggy valleys or of humid depressions. Even if a corn-field is attacked with rust, the progress of the fungus may be retarded or checked by dryness and heat of the weather, provided an undue density of the vegetation prevents not the evaporation of superabundant moisture and the rapid progress of maturation.
If, as we are inclined to believe, the doctrine can be admitted, that the conditions of healthy and vigorous growth are also the safeguards against the origin of the rust disease, then we have not to seek far in many instances for the causes of the fungus.
Again, absolute unacquaintance with the ingredients of his land leads many an agriculturist among us to the choice of culture plants for which the soil of his farm may neither directly nor indirectly be fitted, without the application of judiciously chosen fertilising substances. Not rarely we may find also farm land overrun with weeds, and thus by useless consumers the strength of a poor soil still further impoverished, to the detriment of the growing crop. The means recommended as direct preventatives of the rust are varied. In Northern Italy, the seed grain of wheat is, immediately before sowing, steeped in a concentrated mixture of slack
16
slaked?
lime and water; 2 lbs. of lime being employed for each bushel of grain. Possibly the young cereal seedling in its earliest stage of development, while assimilating this alkaline earth, when such is offered in so accessible a form, may become to so great an extent invigorated, as to advance under continued strength to maturation, and may therefore best be calculated to withstand the injurious influence of any parasitical affections.
Furthermore, a dressing of lime has been recommended, as serving usually for the prevention of rust. But this remedy has not proved infallible for precluding the ingress of the fungus. When it failed, we may assume that either some other particles were wanting in the soil for correcting defective nutrition, or that to ill-cultivated fields the disease was attracted, or that a perfectly healthy crop succumbed, as well may be the case, under the incessant prey of the uredo-spores carried to it from surrounding fields.
The dressing of land with common salt also has been recommended, as obviating losses through rust-disease. We have remarked already, that its active powers, inasmuch as it is not necessarily assimilated to any appreciable extent by the cereal, must be mainly sought in its solvent action on the phosphates of alkalies and earths. The sea-breeze, in diffusing minute particles of chloride of sodium and other salts, seems, according to our observation, not alone sufficient to keep off the rust fungus.
Rolling of land after sowing and feeding off the seedling plants by sheep, will protect and strengthen in exposed localities the roots of the young crop, irrespective of the soil thereby being fertilised. But advantageous as this procedure may locally prove under certain circumstances, it cannot be regarded, as some maintain, as a sure preventative of rust. A series of interesting experiments of the effect of ozone on growing wheat have been commenced by Dr. John Day, of Geelong, who noticed that a prevalence of this gas has seemingly a destructive or hurtful effect by coagulation on the albuminous portion of the plant. He thinks that ammonia would suspend the oxydising power of the ozone.
17
Day was regarded as a local expert on ozone; see R. L. J. Ellery, Transactions and proceedings of the Royal Society of Victoria, vol. 7 (1866), pp. 131-5. He may have communicated his results to M without publishing them.
For absolutely guarding against successive failures of crops through the ravages of parasitic fungi, when their vast spread in a previous season lead us to dread their reappearance, the farmer can only rely on the selection of varieties and kinds of grain, which remains free of the attacks of the parasite.
When land is sufficiently rich in potash, or is dressed where this alkali can be readily procured with wood ashes, farm-yard manure, or other alkaline substances, maize might be adopted for replacing, at least for a season, other cereals.
This corn carries moreover with it the recommendation of being, in a climate and soil favorable to its growth, more productive than any other, and being in a more diversified manner available for food. If, as has with seeming justice been asserted, potassa secures an immunity of rust, then it is no longer an enigma why maize, which is classed among the potash plants, should be exempt of the assailment of the uredo.
And here attention might be drawn to the circumstance how wood ashes, immediately after bush fires, wherever ranges are near, could profitably be collected. Besides the large quantity of potash which in the majority of cases such ashes contain, they yield also generally a considerable portion of phosphate of lime and magnesia. For root-crops especially, an application of potash to the soil will always prove of great benefit. Though the quantities of potash are varying in different plants to some extent, according to the mineral constituents of the spot, it will be of interest to observe that the results of the examination of some specimens kindly contributed by Mr. Johnson, proves at least several of our timber trees rich in potassa.
The ashes of the trunk of the ironbark-tree contains in 100 parts 30.9 pure carbonate of potash; ashes of the leaves and branchlets, 22.3; ashes of the bark of the stringybark-tree, 12.1; ashes of the wood of the exorayms or so-called cherry-tree, 9.4; ashes of the casuarina or so-called she-oak, 7.
In discussing the probable means of prevention of rust, we cannot pass the observation of Mr. Mechi, in Australia, already recorded by Mr. F. Montague Smith,
18
Smith's essay has not been found but was cited by M in his Bendigo lecture on rust (B65.04.05), in the context of describing this work. See also Smith's letter in Maitland mercury and Hunter River general advertiser, 15 October 1864, p. 5.
that by thin sowing, deep drainage, and saturation of his English clay land with liquid manure, he banishes, even from low-lying localities, the rust fungus with complete success.
The undersigned, on another occasion, dwelt already at some length on the ruinous effects which the extensive prevalence of the present spoliation system of culture in this country will unavoidably entail on our arable land. He deems it his duty to pass, on this subject, here again a few warning words, not merely because the failures of crops seem in very many instances clearly traceable to the infertility of the land, but because in glancing around we become everywhere cognizant that the very means for the restoration of the fertility of the soil are often absolutely wasted by want of foresight, circumspectness, and exertion. Let us instance alone the enormous loss which is continually sustained in the waste of the sewage and liquid and solid egesta of centres of population. It suffices not to adopt rotations of crops, which only partially, under the present Australian system of farming, will return to the soil the very elements of incombustible food without which cultivation will finally become extinct. It is equally useless to rely on resting of the land by fallow for its re-invigoration. Unless consumption of the food of plants drawn from a soil stands in a fixed relation to the means of restoration; absolute unproductiveness will only be deferred in the same degree as the natural incombustible food of such land may hold out. To restore, from sterility, land to fertility, when even finally its lower strata have been exhausted, will become as difficult as unprofitable. We shall at last have to look to imported restoratives, when pastoral pursuits will but sparingly afford them, and, finally, misery and famine, with all their terrors, can no longer be obviated. The true maxim should be for agriculturists to aim at a full retention or even augmentation of the fertility of their land, and thus to afford, not merely for the present, but also for futurity, the means of realising from each square acre of ground the largest possible uninterrupted return of field fruit for the support of an ever-increasing population.
The agriculturist should also be warned of the ruin to which, unavoidably, he will expose his land by taxing it with the continued growth of those crops the most remunerative at the time, without provision having been made for the reparation of the losses his soil thereby constantly sustains. The cultivation of commercial plants, such as tobacco, hops, flax, hemp, mustard, as well as of leguminous plants and others, unless under judicious arrangements for the reservation of the strength of the land, becomes the most dangerous. So, for instance, it is hopeless to obtain a crop of tobacco whenever we have neither potash and magnesia, nor, especially, lime and soda within our reach. The most lucrative farming also most rapidly exhausts the soil, by the production of corn and flesh, as Liebig warns us, to the greatest extent possible,
19
Liebig (1859), passim, especially pp. 142-7.
and it cannot be continued, unless the fixed chemical elements of nutrition are conscientiously returned to the soil. Undoubtedly it is the object to produce the largest means of sustenance on any given space, but assuredly this should not be done at the expense of future generations. On the subject of restorative means for husbandry, whether viewed as advantageous in the abstract, or as sheltering, perhaps against vegetable epidemics, ample scope exists for legislation.
Local consumption of commodities, from the residue of which fertilising agents can be obtained, will always be, to a thoughtfully reflecting community, a subject of the utmost importance. Hence factories of oil, starch, spirits, &c., if they could be more generally established throughout the land, would confer lasting benefits. Under such and other judicious arrangements the agriculturist need not look to the importation of foreign fertilisers. Night soil, the most important of all manuring agents, is in this country largely lost for the re-fertilisation of our fields.
Wonderful changes will, by the activity and intelligence of our rural population, unquestionably be effected in the husbandry of this country. A greater choice of field fruits from countries of a climatic zone similar to ours will be drawn into cultivation, and therewith the exposure to losses on our farms during unfavorable seasons greatly lessened. With vine, also tobacco, maize, the teaplant, olives, plants nourishing silk-yielding insects—and perhaps, also, as Mr. William Storey in his not sufficiently regarded Prize Essay has pointed out
20
That is, Story (1861): cotton, pp. 125-172; rice, pp. 66-67.
—in the milder parts of the colony the cotton plant and the rice, should come within the range of extensive culture.
More extended cultivation of green and root crops for local consumption, and therewith a more extended direct combination of pastoral and agricultural pursuits, will tend much to maintain the fertility of our arable sol; an object on the accomplishment of which, in a great measure, the permanent prosperity as well of the individual as the state must rest.
The steam plough, in upturning the deeper and richer strata of the soil, will vastly enhance the healthy productiveness of our fields. Imitation of the systems of irrigation and ferttilisation, which have transformed many of the rural districts of Italy into eternally-verdant gardens, would also become on the estates of this country the source of unfailing wealth; and all these united means one of the principal safeguards against the cessation of the prosperous tranquillity of the state.
Ferd. Mueller, M.D., F.R.S.,
Chairman of the Committee.