GIFT OF f. ft. ( CULTURE ./ CITRUS FRUITS Conditions pertaining Murray Valley, F. R. ARNDT ADELAIDE: Var.don & Sons Ltd., Printers, Grcte Street, 1919. _. ; _ I The CULTURE •r CITRUS FRUITS Under the Climatic and Geographical Conditions pertaining to the Murray Vailey. BY F. R. ARNDT M Author of "Fruitgrowing under Irrigation," "Possibilities of Irrigation," etc., etc. COPYRIGHT BY THE AUTHOR ADELAIDE: Vardon & Sons Ltd , Printers, Grote Street, • 1919. -ft* PREFACE During the expansion of the citrus industry that has within recent years taken place along the Murray Valley the absence of any book of a general nature dealing with the culture of citrus fruits under local conditions has often been a considerable .handicap to new growers in the laying out and management of their plantations. It is with the object of attempting to remedy this disability that this work is published, and it is the author's hope that new and prospective citrus growers may find the informa- tion herein contained of some use to them. A considerable portion of the subject matter contained in the following pages has been taken from the author's previous works — from a pamphlet entitled Orange Culture, published in 1914, and from Fruitgrowing under Irrigation, published in 1918. The whole of such extracts from these works as are herein incorporated have been revised, two new chapters have been added, and an endeavor made to present the subject to the reader in a plain and concise form. F. E. ABKDT. Berri, Eiver Murray, South Australia. 4th November, 1919. 416803 CONTENTS. Chapter. Page. I. The Murray Valley . . . V . . 6 II. Locating the Citrus Grove . „,„ «, 9 HI. Getting the Land Beady for Planting . . 12 IV. Laying out the Land for Watering . . 14 V. Varieties to Plant .. ... .. .. 1G VI. Planting .. .. .. .... 19 VII. Cover Crops . . , .«, 23 VIII. Irrigation . . . . . . ... . . 25 IX. Cultivation . . . . . . . . . . 31 X. Pruning .. .. .. .. .. 34 XI. Manuring . . . . , . .... 36 XII. Harvesting and Packing.. .. ... 41 XIII. Diseases and Insect Pests ,., . '.» 44 XIV. Cost of Bringing a Citrus Plantation into Bearing on State Irrigation Areas of South Australia 49 CHAPTER I. THE MUKRAY VALLEY. The portion of Australia supplied with the largest volume of running water is the Murray Valley. The Murray has its source in the Snowy Mountains, and fed by its tributaries, the Darling, Murrumbidgee, Goulburn, Mitta, Ovens, Compaspe, and Lodden, in normal years brings down large volumes of water, which, with the exception of the comparatively small quantity utilised for irrigation purposes, is discharged into the sea. . The greater portion of the country through which the Murray, Darling, and Murrumbidgee flow has an average annual rainfall of about 10 inches, which renders the growing of crops without irrigation a somewhat hazardous operation. Owing to the fact of large volumes of water flowing through dry, but, on the whole, fertile country, the Murray Valley is, in the natural course of events destined to become — -to a far greater extent than it already is— the seat of the chief irrigation districts of the Commonwealth. For their suitability to fruit culture the irrigation settlements of Mildura, Merebein, Eenmark, Berri, and Waikerie, all of which are situated along the banks of the Murray, have long been noted. The kinds of fruit chiefly grown consist of various varieties of the grape vine, such as the sultana, zante currant, and Gordo Blanco, different sorts of deciduous trees, like the apricot, peach, and pear, and Washington Navel and mandarin oranges. The Washington Navel thrives better here than elsewhere in Australia, the conditions favorable to its growth appearing to be practically ideal. Man- darins also thrive well and bear heavy crops, while the Valencia Late is also proving a profitable variety. WATER SUPPLY. With the exception of the Yanco irrigation area (Murrumbidgee), which is watered by gravitation, the various Murray irrigation settlements are supplied with water by means of pumping plants, lifting the water into the irrigation mains to heights varying from about 40 feet to 130 feet. Water is applied on most of the irrigation settle- ments in four or five irrigations, ranging from August to March for deciduous trees and vines, but for citrus an additional irrigation is usually given during April or early May. CLIMATE. The climate of the Murray Valley is hot and dry. The rainfall, as before stated, averages about 10 inches per annum, and is insufficient for fruit culture without the aid of irrigation. The months of November, December, January, February, and March are usually hot, the temperature often exceeding 100 degrees Fahr., and sometimes reaching 110 degrees during severe heat waves. Hot, northerly winds often accompany these heat waves. The nights during the summer months are usually cool. The climate during the autumn, winter, and early spring is mild. The days are usually fine and sunny. The night temperature sometimes sinks a few degrees below freezing point, but any considerable damage to plant life from frost is rare. During September and October the equinoxial gales often blow with considerable force and per 8 sistence, making it necessary to take precautions against the drifting of the surface soil of the looser (sandy slopes. NATURE OP MURRAY LANDS. The land suitable for fruit growing along the Murray consists of two distinct sections : the river flats and the high lands. The river flats consist of alluvial soil deposited by the river in the course of ages. These flats are, on the whole, fairly level, but usually contain numerous small local irregularities, which have to be graded off before the land can be planted. The soil usually consists of a variety of clays and loams of a fairly heavy nature, which are often overlaid with a layer of sand. The high lands generally consist of loose, sandy rises, which in their native state are often thickly timbered with pine, mallee, and other bushes. The soil is generally a red, sandy loam. The depth of soil varies from about 2 feet to 5 feet, and is usually underlaid with a loose, light-brownish marl. Land of this nature exists by the thousands of acres along the Murray Valley. CHAPTER II. LOCATING THE CITRUS GROVE. SUITABLE SOIL. Owing to the fact that citrus, as other varieties of fruits, do not do equally well in every kind of soil or situation, it is first of all necessary to select a piece of land having characteristics best suited to their requirements. Regarding the class of soil best suited for citrus trees, experience has shown that loose, rich soils which have perfect drainage have given the best results. This does not mean that citrus trees will not grow on rather heavy land. On the Adelaido plains, as well as on the river flats at Renmark and Berri, oranges and lemons do remarkably well on rather heavy clay soil ; but young trees are some- what difficult to start in such soil, and their growth for the first three or four years is slow. The deeper class of soils of the Murray uplands may be said to be practically ideal citrus land. Land of this nature is, in its native state, usually covered with pine, needlebush, or big mallee, and consists of a red sandy loam, from 3 to 5 feet in depth, underlaid by a loose, greyish-brown cal- careous marl. Local experience has shown that citrus trees do not thrive on land having limestone, either in the form of rock or rubble, within a few feet of the surface, as such land is often full of salt, or on land underlaid with a whitish, putty-like clay. The alkali problem is probably the most serious danger that the citrus grower has to face upon the Murray uplands, as such salts as sodium chloride 10 (common salt), sodium sulphate (Glauber's salt), and magnesium sulphate (Epsom salts) are highly detrimental to all varieties of citrus trees. There- fore, land likely to develop alkali trouble, such as shallow soils under 3 feet in depth resting upon limestone, or upon a hard or tenacious subsoil, should be avoided by the planter. However, as the presence of alkalies in a soil is due to defective under drainage by choosing deep land, with a loose subsoil, no damage from alkali trouble should be experienced. SITUATION NOT SUBJECT TO HEAVY FROSTS. Although, on the whole, severe damage to citrus trees due to frosts is but a rare occurrence on the Murray Valley irrigation settlements, there are yet certain situations subject to comparatively heavy frosts which should be avoided by the planter. It is a matter of common observation that frosts are the most severe in valleys, hollows, and low areas, while the adjacent hillsides or elevated lands remain comparatively untouched. This is because the cold air from the hillsides, being heavier, drains off into the lower levels and settles there, while the warm air rises to replace it. This interchange of air continues until frost occurs in the lower levels, while the higher lands escape. . A citrus grove should, therefore, never be located in a hollow, basin-shaped depression, or in a narrow gully. THE IDEAL POSITION. The ideal position of a citrus grove is on a slope facing the east, as experience has shown that the rays of the rising sun are less injurious to frosted plants than they are if the sun is some distance above the horizon before it strikes them ; while the slope of the ground will allow the cold air to drain off into lower levels. Of course, a situation facing the east, although desirable, is not essential for the location of the grove, the one thing necessary being 11 that the plantation has perfect air drainage, so that the cold air can drain away ; and therefore a position on sloping ground is the best. One thing the planter should be careful of, and that is to plant no belt of evergreen shelter trees along the boundary *t the lowest portion of the grove. Such trees, being in full leaf in winter when the frosts occur, prevent the cold air from passing freely away and force it back upon the plantation, thus causing frost on the lower portion of the grove. Should a breakwind be required along the lower boundary, it should consist of deciduous trees. GOOD DRAINAGE ESSENTIAL. As ail varieties of citrus trees are impatient of stagnant water about their roots, they should only be planted on land having perfect drainage, and, therefore, shallow soils, or very heavy soils whereon the water stagnates, must be avoided by the planter. As one of the greatest drawbacks on an irrigation area is the menace of seepage, land that is full of hollows, or that has a heavy sub-soil, should not be chosen. Seepage is brought about by the irrigation water running along the sub-soil and coming to the surface where this sub -soil is shallow or where it meets the surface of the ground. Blocks situated on sandy rises which peter out on to clay flats are liable to develop seepage, which will show itself along the line just above where the clay and sand meet. Land that contains hollow, basin-shaped, depressions should also be avoided, for unless the sub-soil of such depressions consists of deep sand, the water from the surrounding higher lands will 28 down into the sub-soil out of the reach of the roots of the plants. Provided that* the land is k3pt well cultivated, newly-planted trees do not require more than from 15 inches to 20 inches of irrigation water the first season. When once established and before they come into bearing, trees planted on sandy land can be kept in vigorous health on 15 inches and under of irrigation water per annum. One of the greatest mistakes often made by newcomers on irrigation areas is in watering too heavily. On most of the irrigation settlements the regulations formulated by the governing authorities permit the individual irrigationist to use up to 24 inches of water per acre ; but these regulations are not always enforced, with the result that inexperienced irrigationists often put far more water on to their land than is good for it. Seepage, the greatest foe the irrigationist has to fear, is more often brought about by excessive or careless watering than by any other means. Experience has shown that 24 acre inches per annum is amply suf- ficient for vines and trees in full bearing, and that with good cultivation it is possible to obtain the heaviest crops with considerably less water than this. SOME EXPERIMENTS IN IRRIGATION. To give practical illustrations of the results that may be obtained by an economical use of water combined with thorough cultivation , the writer hopes that he may be pardoned by here introducing the results of a few experiments made at his plantation, which is situated on the uplands of Berri. For irrigation purposes, the citrus plantation was divided into three different sections, each section receiving different amounts of water. . Meter read- ings were not kept until the trees were in their third year. Naming the sections A, B, and 0, the irriga- tion records are as follows : — 29 SECTION A (Five Acres). Seven Tears Old, 1919. Season. Acre inches Eainfall 1st Total Water of Irrigation July to received, in water used. 30th June. * acre inches. 1914-15 ... 17 5.3 22.3 1915-16 ... 18 7.73 25.73 1916-17 ... 10 16.64 26.64 1917-18 ... 13 13.93 26.93 1918-19 ... 18.5 8.11 26.61 SECTION B (Five Acres). Seven Tears Old, 1919. Season. Acre inches Rainfall 1st Total Water of Irrigation July to received, in water used. 30th June, acre inches. 1914-15 ... 20 5.3 25.3 1915-16 ... 24 7.73 31.73 1916-17 ... 15 16.64 31.64 1917-18 ... 21 1*3.93 34.93 3918-19 ... 18 8.11 26.11 SECTION C (Five Acres). Eight Tears Old 1919. Season. Acre inches Eainfall 1st Total Water of Irrigation water used. July to 30th June. received, in acre inches 1914-15 . . . 15 5.3 20.3 1915-16 . . . 18 7.73 25.73 1916-17 ... 11 16.64 27.64 1917-18 . . . 14 13.93 27.93 1918-19 ... 15.5 8.11 23.61 30 Although during these five years Section B re- ceived 98 acre inches of irrigation water as against 76.5 acre inches received by Section A, yet the growth and general health of the trees on both sections, which are situated on similar soil, was, as far as all appearances went, identical. However, during the 1917-18 season, as shown by the occasional wilting of some of the trees, it was evident that Section A, with 13 inches of irrigation water, had received the minimum amount, lower than which it was not safe to go if the crop was not to be lost. Nevertheless, on Section C, during the 1917-18 season, the appli- cation of 14 inches of irrigation water proved suf- ficient to mature an average crop of four cases of fruit per tree from a section of mandarins situated on land of a similar nature to Sections A and B. PERIODS OF WATERING. In normal seasons citrus trees are watered at intervals from August or September to the following April, in five or six irrigations, on an average of about six weeks apart from each other. If the Spring is wet or cool, the first two irrigations need not be heavy, but gaod waterings should be given during the late Spring and Summer months, i.e., from November to March. On no account should the trees be allowed to get dry at the roots during this period, or the crop will be lost. For the filling out of the fruit, unless there have been heavy Autumn rains, an April irrigation is necessary. 31 CHAPTER IX. CULTIVATION. So closely connected with irrigation as to be prac- tically a part of it is the subject of cultivation. The irrigation of a piece of land is of little use unless it is followed by cultivation, as the water poured into the soil soon evaporates unless the surface of the ground is kept well stirred. Cultivation destroys the small capillary tubes along which the moisture passes through the soil into the atmosphere, and by thus forming a blanket of loose earth on top, through which evaporation can only imperfectly take plaQe,. the lower layers of the soil are kept moist. Another result of cultivation is that by checking evaporation the formation of alkalies on the surface of the ground is prevented. In arid regions, such as the greater portion of the Murray Valley consists of, the rainfall has never been sufficient to leach much of the natural salts out of the land and to carry them away in the river water. When this land is irrigated some of the salts are dissolved by the water. Capillary action draws the salt-impregnated water to. the surface of the ground, where the water is evaporated and the salts left as a residue. As some of these salts are highly detrimental to plant life, being especially injurious when concentrated on or near the surface of the ground to the crown and surface roots of fruit trees, it is necessary, were it only for this reason alone, that the work of cultivation in the orchard should be of a thorough nature. 32 During the early part of the season, while the weather is still cool, the cultivation of the whole of the orchard is not quite so essential as it is during the sumnur nunths. If cover crops intended for hay, such as wheat or oats, are grown in between the rows of young trees, these should occupy strips of not more than 6 feet wide, so that a two-horse cultivator can be driven along each side of the rows of trees. After such cover crops are mown, which will be either in October or November, the wholo orchard should be cultivated or disc-harrowed, and kept well-workod and free from weeds for the rest of the season. Where the land cannot be stirred by horse-culti- vation, such as near the stems of the trees, the land must ba kept loose and the weeds destroyed with the hoe. Young trees should receive special cultivation close to the tree, as the roots are not far from the stem, and the forked hoe, which does not cut the roots, if by accident it is inserted too deeply into the soil, is a very useful implement for this work. To ensure satisfactory growth in a young orchard too much care cannot be exercised in this work of close cultivation, as every weed is a pump drawing the moisture into the air that the young tree requires for its needs. One of the greatest mistakes often nude by new- comers on irrigation settlements is in the lack of sufficient cultivation. How often are not newly - planted orchards met with with but a 2 feet to 3 feet strip of cultivated land along each side of the rows of trees, while the rest of the land is given over to the production of a crop of luxuriant weeds, which rapidly pump the moisture out of the land, and by creating a dry belt alongside the cultivated one, rob the latter of most of its moisture. Under such circumstances it is impossible for the trees to make satisfactory growth, and the development of the orchard is retarded. The cultivation of a piece of land, by checking: evaporation from out of the ground, causes most of 33 the moisture to remain in the soil for the use of the plants occupying the land. Therefore the more thorough and more often the cultivation of the orchard takes place the less will ba the evaporation, and consequently the smaller will be the quantity of water required to maintain the plants in good condition. The golden rule for the irrigationist to adopt is to apply the minimum of irrigation with th$ maximum of cultivation consistent with the satisfactory growth of his plants. To follow the opposite principle —to make up for lack of cultiva- tion with excessive irrigation — -is to court disaster, for such a policy, if persisted in, causes either the formation of surface alkalies or the water-logging of the sub-soil, or both, and ultimately results in the death of the plants and in the ruin of the land. A cultivation of the orchard should follow every irrigation after the ground has been allowed to dry a little, so as not to puddle the soil, and also after every rain of any consequence. Where the ground is naturally hard or turns up in lumps, an additional cultivation in between each irrigation is desirable. During the late autumn and winter months, if no cover crops have been planted, weeds may be per- mitted to come up, but should be ploughed in green in the early spring. Cover crops intended for green manure should be rolled down and ploughed in when in flower, and the whole plantation should be ploughed up every season during the late winter or early spring months, after which no more weeds should be per- mitted to grow for the rest of the season. 34 CHAPTER X. PRUNING. " *- n As a whole no class of fruit trees require less pruning than citrus trees. At the time of planting \ the young trees should be cut down to about 18 inches to 2 foot. When growth commences young shoots will spring out all along the stem. All shoots below a foot from the ground should be rubbed off, thus allowing a clean stem of at least a foot where the trees have been cut back to 18 inches. Where the trees have been left 2 feet high a clean stem of 18 inches should be left. Some years ago it was the custom to grow high -headed trees having a bare trunk of 4 feet or over. Experience having proved that high -headed trees are more liable to suffer from strong winds, more liable to have their stems injured from sun burn, and that the fruit was not so cheaply to gather as from low-headed trees, some citrus growers went to the other extreme, and headed their trees but a few inches above the bud. This made for a low, bushy tree, with branches very close to the ground, which brought a portion of the fruit into contact with the earth, and with the limbs so low as to be in the way of horse cultivation. It was therefore found that a clean stem of about 18 inches in height gave the best results. Citrus trees usually make from two to four growths during the season. The growth of young trees is often so rapid that it cannot support) itself , and bends down until it touches the ground. It is not advisable to have the branches as low as this, as on frosty nights 35 the cold is greatest nearest the ground, and the fruit is liable to be frost bitten. Therefore, whenever the branches bend down too low they should be cut back to an upward bud at the place where the downward arc commences. The main branches of a citrus tree should have an upward tendency. The natural drooping habit of a citrus tree so trained will soon assert itself again through the formation of side branches, and through the weight of the fruit. Citrus trees that have become too dense in the head should be thinned out somewhat, so as to let in a little light and air, as darkness is conducive to the growth of insect pests. All dead wood should also be removed. All water-shoots growing out of the old wood are best removed, as these often grow with excessive vig >r, and by taking up a great portion of the sap of the tree rob the other branches of nourishment, thus making for a lob-sided development. The best time to prune citrus trees is during spring and early summer, as if left too late in the season growth will often have taken place on shoots or branches that would have been pruned away at the spring pruning, thus resulting in waste of energy. CHAPTER XI. MANURING. Of all the operations connected with the growing of citrus fruits tho subject of manuring is one of the most important. However rich the soils may naturally be, through continual cropping they will, sooner or later, become impoverished, unless sufficient fertiliser is applied to the ground to replace the plant food removed. The elements which enter into the composition of plants are carbon, oxygen, nitrogen, hydrogen, potassium, calcium, magnesium, phos- phorous, sulphur, and iron. Of these, all except nitrogen, potash, phosphorous, and sometimes lime, are usually present in sufficient quantities for the needs of the trees. Young citrus trees require a liberal supply of nitrogen if they are to make vigorous wood growth. When the trees come into bearing very large amounts of nitrogen are no longer necessary, as they impair the fruitfulness of the trees, wood formation taking place at the expense of fruit. Citrus trees of all ages should always be supplied with a liberal supply of phosphoric acid (phosphates) or the health of the tree will suffer, and the fruit will not develop normally. For the formation of citrus fruits a plentiful supply of potash is essential. Harold Hume, of the Univer- sity of Florida, the American citrus expert, says of potash manuring in respect to citrus trees : — "If large amounts of potash are taken up by the trees it will be found that the rind of the fruit will be much thinner than otherwise and the amount of rag will be greatly lessened. A plentiful supply of potash in the fruit has an excellent influence on its keeping 37 quality. If too little be present the fruit will be soft and is likely to break down shortly after, removal from the trees. To increase the keeping and carrying quality of citrus fruits a large amount of potash and a small amount, of nitrogen should be used." STABLE MANURE. Stable Manure is one of the best of fertilizers to to the soil, having a fairly high nitrate con- tent as well as being valuable for adding humus to the land. Four one-horse drays will hold about one ton of this matter in a dry state, which, if spread over an acre of land, will enrich the soil with humus to about the same extent as an average cover crop, although its nitrogen -enriching properties are con- siderably less. A ton of stable manure to the acre would be a very light dressing to give, so light, in fact, that it would be a somewhat difficult matter to spread it. over the land thinly enough to go round. A dressing of four or five tons to the acre applied every third year would give satisfactory results, and keep up the humus content of the soil. The fertilising elements in a ton of rotted stable manure have been variously computed to consist of from 6 to 7 Ibs. phosphoric acid, 6 to 12 Ibs. of potash, and from 8 to 15 Ibs. of nitrogen. This would be equal to about 21 Ibs. of superphosphates, 12 to 24 Ibs. of sulphate of potash, and from 75 Ibs. to 120 Ibs. of blood manure. This is from manures in a partly rotted state, hence containing considerable quantities of water, but the quantities of these ingredients from a perfectly dry sample would probably exceed this amount to some extent. CHEMICAL FERTILIZERS. As in many instances it is not possible to obtain sufficient quantities of organic matter to bring on to the land to make up for all the nourishment from the soil by continuous cropping, 38 chemical fertilizers have to be used to make up the deficiency. As Australian soils generally appear to be somewhat weak in phosphoric acid, phosphates are usually the first kind of manures used to main- tain the crop returns from the land. Commercial varieties of phosphates are of two kinds, the organic classes, such as bone dust and bone superphosphate, and the inorganic forms, made from various kinds of phosphatic rock. Of these bone dust is the slowest in its action, lasting about two seasons in the soil before being entirely dissolved. By not being so water soluble as other kinds of phosphates, the manurial properties of bone dust are not so readily leached out of the soil by heavy rains or irrigation, and, therefore, although slower, last longer in the soil for the roots of plants to feed on. The mineral superphosphates are usually water soluble to a great extent, hence their action on plant growth is rapid, and for this reason their effect is not lasting, there- fore must be applied annually to keep up growth and crop returns. Potash as a fertilizer is also needed on most soils that are being continuously cropped. As has been previously mentioned, potash is usually contained in considerable quantities on many classes of clay lands, but it often needs applications of gypsum to make it available for plant growth. Lime may also be applied on many soils with great benefit, especially on heavy clay lands, which are rendered looser and generally more productive by the action of the lime in making more available many of the plant foods contained in the soil. DEPLETION OF SOIL BY CROPPING. The depletion of a soil by cropping depends, of course, upon the nature and extent of the crop. Accoring to Hume, in his work on Citrus Fruits, 800 Ibs. of oranges will remove from the soil J Ib. phosphoric acid, 2 Ibs. potash, and 1 Ib. nitrogen. A crop of 400 Australian cases, weighing about 39 20,000 Ibs., would at this rate deplete the soil to the extent of 12 \ Ibs. phosphoric acid, 50 Ibs. potash, and 25 Ibs. nitrogen. In addition to this, allowance must be made for a quantity of plant food necessary to make good leaf, branch, and root growth, and for the amount of these ingredients leached out of the soil by rain or irrigation. Assuming the total amount of plant food removed from the soil by these agencies to be three times that taken out by the fruit alone (Hume's estimate) then the quantity of these substances lost to the land would be : — 37 \ Ibs. phosphoric acid, 150 Ibs. potash, and 75 Ibs. nitrogen. Allowing for an 18 percentage of phos- phoric acid, a 50 percentage of potash, and a 20 per- centage of nitrogen, this is equivalent to 2 cwt. of superphosphate, almost 3 cwt. of sulphate of potash, and 4 cwt. of sulphate of ammonia, or to a total of about 9 cwt. of chemical fertilizers. Supposing such a crop of 400 cases of fruit were removed from one acre of ground, 9 cwt. of chemical manures would, therefore, be required to make good the deficiency in the soil caused by the production of this quantity of fruit. METHODS OF APPLICATION. Different classes of fertilizers may be applied at various times of the year. Such slow -acting manures as vegetable mould or bone dust, which contain ingredients not easily leached out of the soil by rain or irrigation, may be applied during winter or early spring, as but little plant food would be lost before the root activity commences. On the other hand, fertilizers containing highly soluble ingredients, such as most mineral superphosphates and the various classes of nitrates, are best applied during early spring or summer, when the roots of plants are active^ Generally speaking, phosphates should not be put into the ground later than October if the current crop is to receive their full benefit, but nitrates may often be advantageously applied, as in 40 the case of citrus, during summer as well as spring- time. Manures may be put into the ground either by being drilled in, broadcasted and ploughed in, or by being scattered along the bottom of plough furrows and ploughed in. Drilling in manures with the wheat seed drill cannot ba recommended, unless the land is ploughed deeply afterwards, as the drill only penetrates the soil for a few inches, and the manure is placed thereby too near the surface of the soil for the roots to obtain, especially where the furrow system of irrigation is practised and the water does not leach the manure down to the roots. Broadcasting and Ploughing in the fertilizer is theoretically the best way to apply manures, as every portion of the orchard is then evenly supplied. In practice, however, unless the land is cleanly and deeply ploughed, all the fertilizer will not be turned into the bottom of the furrow, and, moreover, where the- furrow system of watering is used, a great por- tion of the manure will not receive sufficient moisture to carry it down to the roots of the plants because it is not evenly distributed. Manuring in Furrows, despite its disadvantages, is the best way to apply fertilizer where the furrow system of irrigation is used. One or more deep furrows should be ploughed along the rows of trees or vines, not closer than four feet to the stems of bearing trees, and the manure scattered in the bottom of the furrows — -the furrows then ploughed in and the new furrow thus formed used to water the plantation at the next irrigation. By this method the fertilizer is put deeply into the soil, thereby tending to keep the roots down in their search for plant food. By being in close proximity to the irrigation water the fertilizer is easily dissolved for the use of the roots of the plants ; but for this reason an extra heavy irrigation should not follow the application of manures, as some of the properties may be washed too deeply into the sub-soil for the plants to reach. 41 CHAPTER XII. HARVESTING AND PACKING. Along the Murray Valley, in normal years, man- darins ripen in June and July, the Washington Navel during June, July, and August, and the Valencia Late during October and November, but the last- mentioned variety will often hang on the trees until the end of the year. Oranges should not be picked until they are well colored, as if gathered and placed upon the market while the skin is still partly green the acidity of the fruit has a detrimental effect on both the demand and selling value. In picking oranges secateurs are generally used. The fruit is first severed from the tree with a stem of twig about an inch in length adhering to it. This stem is then carefully removed by cutting it off as closely to the skin as possible without injuring the rind, and the orange is then placed in the picking bag or receptacle used for holding the fruit. The use of the double cut has been found to result in speedier and neater harvesting operations than if it is attempted to sever the fruit from the tree by cutting quite close to the rind by means of a single cut in among the branches and leaves of the tree. The object of cutting the stem away quite close to the fruit is because if it is left projecting it is apt to injure the other oranges while standing in the picking tins or boxes by piercing or otherwise injuring the rind. Oranges are either firstly picked into picking bags, or placed into picking tins or picking boxes direct. 42 In handling, the greatest care should be exercised that the rind is not bruised or cut, as fruit so dam- aged quickly developes decay. After being har- vested, oranges should be allowed to sweat for a few days in the picking boxes before they are sent to the packing house, as the skin in shrinking becomes somewhat tougher and is in consequence not so easily injured whilst the fruit is being packed. In packing, oranges are first graded, either by mechanical graders or by hand, and are then packed according to the diagonal system of packing into standard bushel cases. The number of Washington Navel oranges thatrf are packed to the case varies from about 53 for very large fruit to about 200 for small fruit — the sizes at present most favored by sellers at Melbourne (the chief market for navel oranges in Australia) being those of medium size, i.e., fruit going from about 83 to 154 per case. Mandarins are usually packed on the diagonal system, and vary from about 200 to 300 per case. After having been stencilled, packed, and nailed down, the number of fruits each case contains is branded on the outside of the case. At present, the packing and marketing of citrus fruits is carried on by both individual growers and by associations of growers in the form of co-operative societies. Although it may pay individual growers harvesting large quantities of fruit— such as 1,000 cases or over— to erect private packing houses with all up-to-date appliances, such is not the case with smaller growers who have but a comparatively small quantity of fruit to handle. In such instances growers have either to hand-grade, pack, find markets, and consign their fruit themselves, or to send it to a packing association to do this work for them. As the Quantity of citrus fruits produced yearly increases, due to the large plantings made in recent years, thereby making increased marketing facilities 43 essential, both in the Commonwealth and overseas, it seems highly probable that individual growers, acting independently of each other, will not be able to cope satisfactorily with the situation in the future, and that the handling of the fruit through large co- operative organisations will become necessary. 44 CHAPTER XIII. DISEASES AND INSECT PESTS. MAL-DI-GOMA. One of the worst diseases of citrus trees in America is mal-di-goma, or foot rot. It is also prevalent in Australia, although not to so great an extent. Foot rot attacks citrus trees at the crown roots, extending a foot or so above the ground and downward among the roots. The presence of the disease is first noticed by the discharge of gum at the diseased spot. Later on the bark rots away, and the tree eventually dies. The disease seems to be caused either by water standing around the roots, the crown roots becoming injured through Careless cultivation or otherwise, or too deep planting. As these matters rest greatly in the hands of the grower, the careful orchardist will see that his trees do not needlessly suffer from these causes. Where the land has to be flooded to water the trees the trees should be budded on the Seville stock, as experience has amply proved that both sweet orange and lemon stock are liable to suffer from foot rot if planted in wet situations. Affected trees should have the earth removed from around the main roots, the decayed portions of the bark cut clean away, and after the ground has been well aerated, fresh soil obtained from outside of the citrus plantation should again be placed around the roots. MOTTLED LEAF. A A disease that has been doing considerable damage to some of the citrus plantations of the Hurray Valley during recent years is that known as "mottled leaf." 45 This disease is due to the partial absence of the green coloring matter, or chlorophyll, in the leaves of the tree, and gives the leaves the appearance of being variegated yellow and green. As the disease progresses, the yellowing of the leaves increases, until these turn practically all yellow, the branches die back, and little, if any, fruit is set. In his valuable book on "Citrus Fruits," Professor J. B. Ooit, of the California University, mentions that this disease was probably the most serious problem that Calif ornian citrus growers had to face. At the present time the cause of this disease is but imperfectly known, but as many Californian experimenters are now investigating this citrus malady it is to be hoped that a satisfactory solution of this problem will aoon be found. The writer has seen trees badly affected on land showing signs of over-irrigation, on land showing traces of alkali trouble, and to a lesser extent in situa- tions where the conditions for citrus culture were apparently ideal. That mottled leaf may in some instances be over- come by the application of somewhat heavy dress- ings of organic nitrogenous manures, the writer has proved from his own experience. The trees on a portion of his citrus plantation growing in a deep, red soil, which was but poorly supplied with humus, developed mottled leaf to a considerable extent, -so that their growth became very slow, and no fruit was set. A dressing of stable manure equal to about 5 cwt. per tree was spread over the land and ploughed in early in the Spring. Within a few months the trees were showing signs of recovery, and after a year the mottled leaf had practically disappeared ; the trees were making vigorous, healthy growth, and have remained in good condition ever since. Growing among the other perfectly healthy trees of the writer's plantation, odd trees here and there developed mottled leaf, although the conditions 46 favorable to their growth were to all appearances perfect. These trees were treated with organic nitrogenous manures applied in liquid form, from one to three applications being given, and within a year from the first application the mottled leaf had disappeared and the trees were making strong, healthy growth. ORANGE SCALE. Red Scale is a small circular insect of a reddish brown color, which increases very rapidly under circumstances favoring its growth, which are moist and muggy atmospheric conditions. The only effec- tive way of getting rid of it is by fumigating the trees with hydrocyanic acid gas, which is generated by treating potassium cyanide with a diluted solu- tion of sulphuric acid. Fumigation is done in the night time, the gas being liberated under a tent, which covers the tree. For 100 to 150 cubic feet of tent space the amount of ingredients generally used are 1 oz. potassium cyanide, 1 oz. sulphuric acid, and 3 ozs. of water. The red scale, which is the most harmful of all insect pests to the orange tree, has up to the present time not made its appearance among the orange groves of the South Australian portion of the Upper Murray Valley. Brown Scale. This variety of the genus of Leca- nium, or unarmored scales, is fairly well known to the citrus growers of the Murray Valley. The full- grown insect is about one-eighth of an inch long, broadly oval, convex upon the disc, surrounded by a thin flat margin, and of a brownish color. The scale thrives upon the bark and leaves of the branches of the tree by sucking out the sap, and is generally found in the greatest numbers in situations not directly exposed to the sun. SPRAYING. The usual methods used for combating this scale are by means of sprays made of oils of various kinds and of resin compounds. Fed Oil. Various brands of ''red oil" mixture are upon the market. The usual methods of mixing are to take equal quantities of rainwater and red oil, place the oil in a bucket or spray pump, add the water slowly, stirring or churning vigorously the while. When, the oil and water have thoroughly emulsified, add twenty times as much water as there is emulsion — .that is, forty times the amount of oil used— and mix up well in the barrel of the spraying outfit. This mixture may be considered as full strength, and a stronger solution than this is not advisable. The chief thing to see to at mixing is that the oil and water emulsify thoroughly, which will not be the case if the water is at all hard, and should it be in this consition it should first be softened by dissolving a handful of washing soda in it before mixing it with the oil. The usual time for using red oil spray is in the summer months, generally during the months of January and February, and to guard against sun- scald of the leaves and fruit is best applied during a cool spell during these months. Should the weather be warm to hot when the spraying is being done, a solution of one gallon of oil to 50 gallons of water will be found strong enough to kill the scale. Kerosene Emulsion is preferred by some growers for spraying purposes. This is made up in the pro- portion of 2 gallons of kerosene, \ Ib. soap, 1 gallon water. The soap is dissolved by boiling in the gallon of water. The water is taken off the fire, and the kerosene added slowly, the mixture being churned with a spray pump for ten minutes or so, until a stable emulsion is formed. Another gallon of warm water is then added, bringing the solution up t«> 4 gallons. 48 Spraying is usually done in the summer months in between the growths, that is, when one growth has finished and before the next starts. For spray- ing at such times each gallon of the emulsion is diluted with not less than ten gallons of water ; but for trees that are in active growth fifteen gallons of water to one of the emulsion will be strong enough for the young foliage to withstand. For badly affected trees two sprayings about a fortnight apart may be necessary to eradicate the scale. Resin Wash. Owing to the scalding effect upon the leaves and fruit that sometimes follow the use of the various oil sprays, some growers prefer spray- ing their citrus trees with a resin wash made up in the proportion of 1 Ib. resin, 1 Ib. washing soda, J Ib. soap, to 5 gallons of water. This is applied in a similar manner as the oil sprays, and usually but little damage to the foliage of the trees is done. NoU. — -No spraying of citrus trees should be attempted if the trees are in want of moisture, as when in this condition the leaves of the trees have often not sufficient vitality to withstand the suf- focating effects of the spray, and so fall off ; whereas it the spraying takes place when the leaves are full of moisture, such as after an irrigation, and other conditions are favorable, ill-effects seldom follow. 49 CHAPTEB XIV. COST OF BRINGING A CITRUS PLANTATION INTO BEARING ON STATE IRRIGATION AREAS OF SOUTH AUSTRALIA. To estimate the amount of capital required to bring a citrus plantation into bearing is a some- what difficult subject, as the price of material and of labor is a fluctuating quantity, and, further, owing to the fact that the expenses per acre will vary with every holding, as no two pieces of land will cost the same to clear, grub, grade, and to maintain in good condition. However, a rough average, both on the capital outlay and upon the income per acre, can be struck, and the estimates here drawn up have been chiefly compiled from Berri data. As the price of labor, material, water rates, etc., have greatly risen since the beginning of the war, and as this increase in prices shows no immediate likelihood of falling, the estimates here drawn up show an advance on those quoted in my book, Fruit- growing under Irrigation, which were compiled according to normal pre-war costs. As this chapter is chiefly written for new settler* on the State irrigation areas along the Murray Valley in South Australia, it has been taken for granted that the assistance of the Irrigation Depart- ment in fencing, grading, grubbing, and channelling has been availed of. Where this has not been done, the initial outlay will probably be increased by £10 per acre. 50 ORANGES (WASHINGTON NAVELS). CAPITAL OUTLAY ON ONE Actss. Initial Outlay. £ s. d. 15 per cent, deposit Irrigation Depart - ment for channelling, grubbing, at £12 per acre .,' 1 16 0 Ploughing .. .. , .," ;,. .'*'..*., 100 100 orange trees .. .^ .. Vr 10 0 0 Pegging out and planting 1 10 0 Total initial outlay v ":; . . £14 6 0 UPKEEP. Cultivation for five years .. .. *.,*; 25 0 0 Water rates and rent, five years . . s-Cl . , 717 6 Pruning and spraying, five years .. "... 500 Net expenses for sixth year, after de- ducting net income .. ;..'.."'.' '">-•*•'' 300 Total upkeep .'"..' • ?^ .. £40 17 6 HARVESTING PLANT. £ s. d. Picking or sweat boxes *f> .. .. 200 Proportionate expenditure on storing or curing shed riri^?« ,.;. ve<> *. 800 Total ] ^ , *ti >.; .. £10 0 0 £ s. d. Interest on initial outlay and upkeep for six years .. .. .. .. .. 10 10 0 Owing Irrigation Department after five years 10 0 0 Total capital outlay . . . . £85 13 6 51 The initial outlay for planting an acre of oranges is greater than that of any other class of fruit, owing chiefly to the greater cost of the trees themselves. In planting, also, greater care than is necessary with other trees has to be taken, and if the season is dry a special irrigation will be needed at planting time. On calculating the annual expenses of cultivation and irrigation at £5 per acre a low estimate has been taken. A glance at the young orange planta- tions at Berri at once reveals the blocks that have received the best cultivation. So readily do orange trees respond to good cultivation that a first class looked after orange grove will come into profitable bearing at least? a year before a block that has received but average attention. Orange trees ought to produce some fruit in their fifth and sixth years. Allowing for half a case per tree at six years, at the price of 5/ per case net. This would still mean a net expense of £3 per acre, after deducting all working expenses for the year. As well as other fruit, oranges require a harvesting plant. In addition to picking cases or sweat boxes, a storeroom or curing shed will have to be erected, as oranges, after being picked, are generally stored or "cured" on shelves or shallow boxes for a few days to a week to allow the skin to shrink and become leathery before being sent on a long journey. Through orange trees taking so long to come into bearing, the loss of interest on the capital invested is considerable, and after six years amounts to £10 10 /, thereby adding that sum to the cost per acre. A total capital outlay of £85 per acre for six years appears, no doubt, a * large sum ; but on careful consideration I cannot see how it can be reduced. In the above estimate no loss is allowed for treea dying in their first year before they are established, neither for special irrigations at planting or other times, or for carting water to young trees during dry spells in between irrigations. So, if anything, the total expenditure could easily be increased. 52 PROBABLE INCOME FROM AN ACRE OP ORANGES. Oranges planted in good, deep soil usually com- mence to bear in their fourth year. The crop, how- ever, will be inconsiderable ; and the fifth year's crop will also be small. At six years half a case to the tree may be expected, while at seven years the trees should be bearing a case or more to the tree. R Regarding prices, it is obvious that, owing to the decreased purchasing power of money, due to the increased cost of living that has taken place in recent years, the minimum price at which oranges will pay to grow is considerably higher now than it was a few years ago. If the minimum payable net price was 4/ per case two or three years ago, then it is at least 5/ per case to-day (1919), and should the purchasing power of money continue to fall, then the payable minimum price must show a correspond- ing rise. Therefore, under the economic conditions existing in these changing times, the following cal- culations can only represent some general approach to accuracy for probably the next few seasons. Allowing for net prices to the grower of 5/ and 6/ per case, and calculating 100 trees to the acre, this makes an income of £25 and £30 per acre respectively at one case per tree. In my estimates for full bearing trees the annual expanses have been estimated at £28 5/ on a crop of two cases per tree. But on a crop of one case par tree the expenses of manuring (£4) and of harvesting (£8) will only be one half of that of full grown trees, so a reduction of £6 per acre must bo allowed for this, thus reducing the annual expenses to £22 5/. A crop of .one case per tree, at 5/ net per case, would, therefore, just pay a little over working expenses if no allowance for depreciation were made. Coming to the subject of depreciation, no deduc- tions have been allowed for the firsfc 10 years of the plantation's existence, as the irrigation channels or pipes should still be in good repair, and if the site of the plantation has been well chosen, as regards soil and position, seepage troubles should not have made an appearance in so short a time. I have estimated the total life of the trees at 30 years. The first six years as a period of infancy, I the time from the seventh to tenth years as the age of coming into bearing and paying working expenses and somewhat over, and the period from the tenth to thirtieth years as the age when in full bearing. During these last 20 years an annual allowance of £2 per acre has been debited for depreciation on harvesting plant, channels, and for provision for drainage, as well as an additional depreciation of 5 per cent, per annum on the capital outlay of £85. In the estimate I have calculated the average crop at 200 cases per acre, commencing in the tenth year of the orchard's existence, and continuing at that rate for the following 20 years : — PROBABLE INCOME FEOM AN' ACRE OF WASHINGTON NAVELS £ s. d. 200 cases at 6/ per case net . . .. 60 0 0 200 cases at 5/ per case net . . . . 50 0 0 ANNUAL EXPENSES. £ s. d. Cultivation, ploughing, irrigation . . 700 Pruning and spray, ng . . -. . . . 500 Water rates and rent .. .« - .... 2 5 0 Manures .. .. .. .. .. 400 Harvesting and curing expenses .. . ^ 8 0 0 Expenses of management and superin- tendence . 200 Total .. . £28 5 0 54 • DEPRECIATION. £ s. d. On harvesting plant, channels, provision for drainage .. .. '.. V-- 200 On orangery on 5 per cent, of capital outlay . . . . . . ... ... 450 Total depreciation . . .;'„/. Total annual expenses •- .;. £ s. d. Net profit per acre, at 6/ net per case . . 25 10 0 Net profit per acre, at 5/ net per case . . 15 10 0 According to the above figures oranges will pay to grow if 200 cases of saleable fruit, averaging 5/ per case net, or over, to the grower, are harvested per acre. At less than this price, however, oranges cease to be profitable as an investment, as the same amount of capital would probably show a higher rate of interest if invested in other industries. 55 PRESS COMMENTS "From the author (Mr. F. R. Arndt) a copy of Fruitgrowing under Irrigation has been received. The work is devoted especially to the conditions in the Murray Valley, and is an exhautive treatise on a subject of great importance at the time the use of Australian rivers is being considered. . . . The man who intends to enter the fruitgrowing industry will find valuable information in the chapter devoted to the cost of starting an orchard and the time that must elapse before any return can be obtained." — Daily Herald, Adelaide, 24th December, 1918. "From Mr. F. R. Arndt, of Berri, has come to hand copies of his exceedingly interesting and informative book on Fruitgrowing under Irrigation. The publication contains about 120 pages of facts and comments, which every irrigation fruitgrower should be acquainted with." — South Australian Register, Adelaide, 24th December, 1918. "For the large and growing number of settlers in our irrigation areas who, in becoming irrigationists, are adopting a mode of life new to them this book will be found of great value, and there are few among the ranks of experienced irrigationists who may not derive some benefit from its perusal." — Murray Pioneer, Renmark, 3rd January, 1919. "I have carefully read Mr. Arndt's book on Fruitgrowing under Irrigation. ... It is, to my way of thinking, the best con- nected study on the subject published in Australia, on an Aus- tralian basis. The explanations in relation to all field operations are simple and to the point, and most practical in character. My personal opinion is that a copy of this book should be in the hands of every new settler or intending settler who proposes entering upon fruitgrowing on the irrigation areas of the Murray- Valley." — GEO. QUINN, Horticultural Instructor to the S.A. Government, in the Journal of the Department of Agriculture of South Australia, April, 1919. University of California, College of Agriculture, Berkeley, 18th February, 1919. Dear Mr. Arndt, — I have read with deep interest your book, Fruitgrowing under Irrigation. Your statements are very clear and straightforward, and the information conveyed must be very helpful to anyone undertaking fruitgrowing under your conditions. I congratulate you on a good piece of work. (PROFESSOR) E. J. WICKSON. University of California, Agricultural Experiment Station, Berkeley, 24th July, 1919. Dear Mr. Arndt, — I have just returned to my office from an 18 months' war emergency job . . . (and) find on my desk the book entitled Fruitgrowing under Irrigation I find it intensely interesting. J. ELIOT Corr, Professor of Citri culture. VARDONS LTD. PRINTERS ADELAIDE UNIVERSITY OF CALIFORNIA LIBRARY, BERKELEY THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW Books not returned on time are subject to a fine of 50c per volume after the third day overdue, increasing to $1.00 per volume after the sixth day. Books not in demand may be renewed if application is made before expiration of loan period. NO'/ 14 NOV 14 1935 USE 1 6 -I"' fil Syracuse. N. Y. PAT. JAN. 21, 1908 UNIVERSITY OF CALIFORNIA LIBRARY