363 GIFT OF MAK ITRUS CULTURE in the WEST INDIES i CITRUS CULTURE IN THE WEST INDIES PUBLISHED BY AGRICULTURAL BUREAU GERMAN KALI WORKS, HAVANA CUBA. LA PRUBBA, PRINTERS, OBRAPIA 99 HAVANA. , *'••'' >V; ytl THIS PAMPHLET AS WELL AS THE FOLLOWING CAN OBTAINED FREE OF CHARGE BY WRITING TO GERMAN KALI WORKS P. O. BOX 1007. HAVANA, CUBA. RU BL.ISM ED I IM ENGLISH SPANISH Bananas in the West Indies Cultivo de la Cafia en las Anti- lias Cacao Culture in the West Cultivo del Cafe en las Antillai Indies Coffee Culture in the West Cultivo de la Pina en las Anti- Indies lias Cotton Culture Cultivo del Tabaco en las Anti- lias Fertilizer Guide for the West Diversas Plantas Utiles en las An- Indies tillas. Miscellaneous Economical Plants El Cultivo del Cacao en las An- in the West Indies. tillas Pineapple Culture in the West Guia de Fertilizantes para uso Indies en las Antillas Stassfurt Industry Naranjos en las Antillas. Sugar Cane Culture in the West Indies Tobacco Culture in the West Indies FRENCH Guide des Engrais A L' usage des Antilles La Potasse sous les Tropiques La Culture du Cafe aux Antilles La Culture du Tabac aux Antilles Les Bananiers aux Antilles i CONTENTS Page. FOREWORD 7 GENERAL INFORMATION 7 PROPAGATION 7 INSECTS AND DISEASE'S 7 COMMERCIAL IMPORTANCE 8 CHOOSING A LOCATION 10 Exposure 11 Soils 11 Water 12 Transportation 12 Labor 13 Social Conditions 13 The Man 13 The Capital 14 METHODS OF STARTING A GROVE 14 The Commercial Method 14 Modification No. 1. — Windbreaks 16 Modification No. 2. — Planting from Own Nur- sery 17 Modification No. 3. — Planting Seedlings and Budding in the Field 19 VARIETIES OF STOCK AND BUD ]9 The Sour Orange 21 The Rough Lemon 21 Page. The Grapefruit and Shaddock 22 Commercial Varieties of Oranges 22 Varieties of Grapefruit 23 HOW TO PLANT A TREE 24 The Distance Apart 25 HOW THE WILD TREES GROW 25 Nature's Way 26 Imitating Nature 26 CULTURAL METHODS 28 Local Wind Protection 28 Mulching 28 Cultivation 30 Irrigation 31 Fertilizing 32 Lime 34 Potash ^4 Phosphorous 34 Nitrogen 35 Cover Crops 35 INFLUENCE OF FERTILIZERS ON THE TREES 36 INFLUENCE OF FERTILIZERS ON THE FRUIT 39 FERTILIZER FORMULAS 44 HOW TO TAKE CARE OF A GROVE 51 CITRUS ENEMIES AND REMEDIES 56 Physiological Troubles 56 Insects 58 Formulas for Solutions 59 ILLUSTRATIONS WELL CULTIVATED AND FERTILIZED GROVE 6 YEARS OLD ^-BAYAMON, PORTO RICO 9 BANANAS USED AS LOCAL WIND PROTECTION,— PORTO RICO EXPERIMENT STATION 15 VIEW IN CORNER OF NURSERY OF C. D. ABBEY - ISLE OF PINES 20 OijU NEGLECTED GROVE,— AFTER BEING FERTILIZED AND MULCHED —SANTIAGO DE LAS VEGAS 29 YOUNG GROVE, SHOWING EFFECT OF FERTILIZER ON GRASS AROUND THE TREES— ISLE OF PINES 33 ORANGE TREE 4 YEARS OLD, UNFERTILIZED,— BAY A- MON, PORTO RICO 37 ORANGE TREE 4 YEARS OLD, FERTILIZED,— BAY AMON, PORTO RICO 38 ORANGE TREE FROM UNFERTILIZED PART OF F1SKE GROVE — CEBALLOS, CUBA 40 ORANGE TREE FROM FERTILIZED PART OF FISKE GROVE,— CEBALLOS, CUBA 41 GRAPEFRUIT TREE 3 YEARS OLD WELL FERTILIZED, —ISLE OF PINES 43 GRAPEFRUIT TREE 4 YEARS OLD, UNFERTILIZED — LAS TUNAS, CUBA 45 GRAPEFRUIT TREE 4 YEARS OLD, FERTILIZED —LAS TUNAS, CUBA 46 ORANGE TREE 5 YEARS OLD, NOT FERTILIZED —LA GLORIA, CUBA 49 ORANGE TREE 5 YEARS OLD, FERTILIZED WITH WOOD ASHES AND COVER CROPS 50 VIEW OF GROVE FERTILIZED AND UNFERTILIZED — LAS TUNAS, CUBA 53 VIEW OF 2 GROVES, FERTILIZED AND UNFERTILIZED. HERRADURA, CUBA 55 TREE NEARLY GIRDLED FROM GUMMOS1S 57 FOREWORD In presenting this pamphlet to citrus growers we realize that it is impossible to treat the subject as fully as we should like to, but we hope that the condensed infor- mation given will be of value to the majority, and those who desire more specific information can obtain it from the following publications: General Information on the Whole Subject. "Citrus Fruits and Their Culture", by Hume Glen St. Mary Nurseries, Glen St. Mary, Fla. Annual Reports, Fla. State Horticultural Society, Published by the Secretary, Jacksonville, Fla. Annual Reports, Cuban National Horticultural Society, published by the Secretary, Havana, Cuba. Propagation : Circular No. 24, Cuba Experiment Station Bulletin No. 4, Porto Rico Experiment Statior Insects and Diseases: . ...,,, Bulletin No. 9, 'Cuba Experiment Station Bulletin No. 10, Porto Rico Experiment Station Bulletins Nos. 51, 56, 67, 88, -94, 97 and 106, ida Experiment Station. 8 -S ;; 1 ' ; v • V- ^ -' v > • • ." Practically all citrus growers in Cuba and Porto Rico know by experience that we are willing to furnish them whatever information we can relating to the subject of citrus growing. We should like to impress upon planters in other Islands in the West Indies that we stand ready at all times to do the same for them. Those who do not find the information they need in this pamphlet can feel free to write us. We 'Charge nothing for the information we give. COMMERCIAL IMPORTANCE Citrus fruits are not natives of America, but they were undoubtedly brought over soon after Columbus' first voyage, and all the different kinds, including oranges, grapefruit, lemons and limes, are now found growing wild in all of the islands in the Wes/t Indies. It is known that oranges were shipped from some of the Islands to the United States even during the time of sailing ships and although the trade was unimportant from a com- mercial standpoint, the West Indies was then th^ chief source of supply for the United Stales, According to Lelong, the first commercial grove in California was two acres planted near Los Angeles in 1841, but on account of undeveloped shipping facilities the Eastern States were not supplied from there until about 1880. From Florida some of the wild fruit was shipped commercially, as from the West Indies, b'lt very little cultivated fruit was shipped before 1880. From this it is readily apparent that no great amount of oranges were consumed in North America previous to 1880, but according to statistics, in 1900, just 20 years , over 10,000,000 'boxes were shipped out of Cali- 1 I & I I 10 fornia and Florida. About that time, citrus culture prop- erly speaking commenced in Porto Rico and Cuba, and some attempts were made a few years later in Jamaica. In the rest of the Islands the cultivation is yet limited, although a few limes are cultivated in some of the smaller British Islands. Most of the Islands continue shipping fruit from the wild trees, but that is becoming less remunerative as the markets are being supplied with cultivated fruit. The fruit from the wild trees is as a rule good, but the trees being seedlings, it is dif- ficult to grade it uniformly. It is also difficult to market it in good condition, because it is frequently not firm enough to stand being packed and s'hipped long dis- tances. Through this as well as through ignorant and careless handling, the West Indian oranges have become unfavorably known in the world's markets, but the ex- perience with the cultivated orange in Cuba and Porto Rico has clearly shown that a fruit can be produced which will in all respects meet the market requirements. Enough acre-age is now planted in the two Islands, and enough fruit is already being shipped to make the bus- iness of considerable commercial importance, and in all probability .cultivation wil'l soon be extended to other Islands alls-o. CHOOSING A LOCATION In choosing a location in which to start a citrus grove in the West Indies the following are the main consider- ations. Exposure, soil, water, transportation, labor and social conditions. In considering the last factor it is presumed that the owner wishes to live on the property and fee his own manager, but in that case his fitness as 11 a planter will of course have to be considered, and still another consideration is the capital necessary for the undertaking. Exposure is a factor seldom considered, but experience has s'hown that it is a very important one. Cyclones and storms are difficult to guard against, because such dis- turbances may occur in places reported to be free from them, it is well however to look up the weather records, if such are available. What the prospective orange grower is more interested in is the ordinary wind, its velocity, general direction and the lay of the land in re- lation to forests or mountains which may serve as a wind protection. Soils, roughly speaking, are composed of sand, clay and vegetable matter. If a soil does not stick together when wet it contains mostly sand and is called a sandy soil. If it is sticky when wet and becomes hard and lumpy in drying, it is called a clay soil. A peaty soil does the same, but peaty soils are -practically unknown in the West Indies. The vegetable matter in a soil, us- ually called humus, can be recognized by its dark color when it is wet. When found in large deposits it is called peat, but we are interested only in tBat contained in the upper 6 to 12 inches of soil. It is that which makes the soil dark and distinguishes the top soil from the sub- soil. A mixture of sand and clay, about six to one, is called a sandy loam. One part clay to four parts sand is termed a clay loam, and with diminishing sand the soil is said to be clay or heavy clay. The subsoil is of no less importance than the top soil. The roots of a citrus tree extend under normal conditions ten to fifteen feet downwards and the subsoil should be 12 such as to allow the roots free passage. A layer of im- pervious rock or hardpan within six to ten feet of the surface is detrimental in all cases. The trees do not usually show the effect of such before six to ten years old, but sooner or later there v\ ill be troubles of various kinds which can not readily be remedied. The same may be said of water. It is not safe to plant citrus trees on land in which the water stands within 6 to 10 feet of the surface for any length of time. The most desirable for citrus fruits is a sandy loam, containing a fair amount of humus. A very sandy soil is less desirable because it does not retain moisture so well and fertilizers leach through it too readily. A heavy clay soil is un- desirable because it retains too much water when wet, and in dry weather it becomes too dry, and cracks open unless it is cultivated constantly. Water is a very important factor and the following points should be considered : The record of rainfall, not alone the annual, tout the monthly and the weekly as well, should be looked up. In that way it will be possible to determine whether irrigation will be needed or not, and to what extent, also to what extent draining and ditching will be needed for carrying off surplus water. In case irrigation is needed it is well to find out if water can be obtained in large enough quantity without great expense. Transportation or rather the absence of transportation, is the one great drawback in many" places. After the production becomes large enough transportation always follows, but frequently the pioneers fail because tran- sportation is too costly. Ocean freight is fairly cheap, but railroad freight is as a rule high in the West Indies. 13 Furthermore the wagon roads are often poor, and as citrus fruit is a bulky crop, distance from a seaport should be considered. Labor in the West Indies is not very good for horti- cultural work, and a prospective grower should be pre- pared to teach rather than boss. Social Conditions may not properly be classed as a horticultural problem, but it has proved to be fully as important as any of the above mentioned. The majority of those engaged in citrus culture, not alone in the West Indies, but in Florida and California as well, are in the business because they like it. They are engaged in it be- cause it is pleasant outdoor work in a tropical climate and they are willing to sacrifice some of the monetary gain for the pleasure of living "close to nature," but churches, schools, good neighbours and good government are all necessary factors. The climate is often asked about by prospective settlers, but that is really of minor impor- tance. The climate is favorable enough in practically all parts of the West Indies for Northern people to live comfortably. The Man whether he be the owner or the manager, is of more importance to the success of the undertaking, than any of the foregoing factors. It is often the case he knows nothing about citrus growing at the beginning, and of course he must be prepared to pay for his experience. This however he can always obtain cheaper by working for another man than for himself, and it is a very good plan to begin working in well kept orange groves in different places. A year's experience of this kind will be worth more than several years In one small grove. There are few branches of agriculture as highly develop- 14 ed as citrus fruit growing, and even experienced planters find it advisable to visit other groves, from time to time in order to compare notes. The Capital necessary for developing a citrus grove is usually under estimated. Some of the earlier contracts in Porto Rico and Cuba were taken for $300.00 per acre, guaranteeing the trees planted and brought into bear- ing in 3 years. This the contracting Companies either did not do, or else they lost money. The price was later raised to $500.00 per acre, and again in some cases to $1,000.00 per acre, extending the time to 5 years. As a matter of fact, no 'general rules can be laid down, be- cause the capital needed will depend upon all the factors discussed above. Practically all the failures coming under the writer's observation could be attributed to the one thing, lack of knowledge. A planter who knows how, can accomplish more with a small capital, even under unfavorable conditions, than the one who does not know can with a large capital under the best of conditions. M&XHODS OF STARTING A GROVE There is one general method employed by most plan- ters in all places, and also a number of modifications em- ployed by more progressive 'planters wherever local con- ditions demand such changes. The Commercial Method consists in clearing the land if it contains trees and shrubs, after which it is plowed usually without removing the larger stumps. It is then staked off in absolutely straight lines for which purpose a surveyor's instrument is often used, especially for large tracts. The holes are then dug and the trees planted 16 immediately. The trees are usually secured from a com- mercial nursery, often from some neighbouring island or from Florida. Modification No. 1 : Windbreaks. — If was observed in Porto Rico shortly after commercial planting commenced, that trees protected from the wind grew much better than those exposed, and sin-ae then, systems of wind pro- tection for young groves have been tried out in various places with excellent result. Where the land is « covered with thick forest, a successful method is to clear off the native growth in strips 200 to 500 feet wide, leaving uncleared strips 20 to 25 feet between. Such strips of forest growth at right angles to the prevailing wind di- rection is of great protection to the young citrus trees, Many planters object to the system because the forest trees take nourishment from the citrus trees, and the wind belts serve as a harbour for insects, such as the parasol ant. These objections are frequently very serious and should of course be considered. A windbreak of large trees always impoverishes the soil for some distance away, but this can to some extent be prevented by deep plowing and subsoil breaking in which way the roots are cut below the feeding limit of young trees. If ants are troublesome it may be necessary to clear off the under- brush in the windbreaks, and keep the surface soil clean until the nests can be destroyed. Where there are no forest trees on the land or where there are but a few scattered trees of no value for windbreaks it has been found advisable to plant artificial windbreaks. This has been done and is being done with more or less success in different places, but usually not until the planter sees the necessity of it. That is, after the young orange trees 17 have been planted a year or more, and do not show a satisfactory growth. Unfortunately a great deal of dam- age has then been clone, and a great deal of time his been lost. A better method is to plan windbreaks as part of the grove and plant belts of quick growing trees suit- able to the locality a year or two years before planting the citrus trees. Modification No. 2 : Planting from Own Nursery.— This method is frequently followed by the more experienced planters, and there can be no question about the advis- ability of it, for those who know how. It is claimed that it takes too long to start a grove in this way, but while it does take longer to start, it does not necessarily take longer to produce bearing trees and usually it does not take as long. In following this method the planter selects a piece of land on his property that is close to a water supply, and on which the soil is preferably a clayey one. This land in cleared, plowed and cultivated thoroughly in order to make the soil mellow and fine for seed bed. Rows are then laid off 4 ft. apart and furrows made and a fertilizer composed of about equal amounts of Nitrogen Potash and Phosphoric Acid is applied at the rate of »t least l/2 ton per acre. This is mixed thoroughly with the soil after which the seeds are planted 2 to 3 inches apart. The seeds should be covered with about an inch of soil and a light mulch of grass should be spread over, 'Cover- ing the rows. The ground should then be irrigated jr watered by hand, so as to keep it constantly moist. The seeds will germinate in a few days and in about two months the plants can be thinned out, leaving the most vigorous at a distance of about 3 ft. apart. By constant 18 cultivation or mulching, together with irrigation when needed, and a sprinkle of Nitrate of Soda, the plants will have attained the size of a lead pencil in about 5 months from planting, and should then be budded. The buds should be tied to stakes in order to grow straight and when 2 ft. high the top should be nipped off to make the trees branch. In about 18 months from the time the seeds were planted these trees will be as large as the average nursery tree sold commercially today. At the time the nursery is planted the land should be prepared for the grove. It should be cleared, plowed and planted to legumes. The windbreaks should be planted and ants nests destroyed. Quickly maturing legumes such as cow- peas may be plowed under in 6 months and another crop planted, but the last crop should be plowed under about 4 months before the trees are to be set out. Then the land should be staked off, placing a stake wliere each tree is to be planted, and 3 to 4 rows of pidgeon peas or other similar plants should be planted between each tree row. The holes for the trees should be dug at least 4 ft. broad and 2 ft. deep and should again be filled up with vegetable matter and top soil. When the nursery trees are large enough they may 'be transplanted without being materially checked in growth. This is accomplished by digging a trench on each side of a row not closer than 12 inc'hes to the trunks of the trees. Then by start- ing at one end of the row the trees can be removed one by one by digging horizontally at a depth of 12 to 15 inches, leaving a ball of earth around each tree two feet square and 12 to 15 inches deep. If the soil is clayey it will adhere when moist, and the tree can be transported to the grove if the ball is wrapped in burlap. The tree 19 needs no pruning before planting if it has been prop- erly pruned in the nursery, and if planted with reason- able care it will in three years reach the size of a 5 year old tree planted in the old way. Modification No. 3: Planting Seedlings and Budding in the Field. — 'This method can not be practiced under all conditions, and it has no real merit except in a case where a planter wisheis to start a grove -cheaply. In a forest all the larger trees may be taken out, leaving all the brush and small growth. The lines can then be staked out and a place 4 ft. square prepared at each stake. A few seeds can be planted there and some mulch spread over after which it can be left to take care of itself, except the surplus plants should be pulled up after a few months, leaving only one in a place and of course vines and tall grass should be cut off occasionally so as not to smother the young trees. The trees will not grow as fast as in a nursery, but they may be budded when about two years old, and will have the advantage over trans- planted trees that they are never planted too deeply, also they will be less liable to gum diseases. Of course after the trees are budded they must be mulched or cultivated, and a space several feet wide must be kept clean around each one. VARIETIES OF STOCK AND BUD Citrus fruits can not usually be reproduced true to seed, and the commercial growers plant nothing but budded trees. A budded tree consists of two parts, the lower part originating from the seed which is called the stock, and the upper part, originating from the bark of another tree which is called the bud or the scion. 21 In selecting seeds for nursery stock the following points should be considered. The soil on which the grove is to be located, and the variety of fruit to be grown. All of the different species and varieties of the citrus family can be budded one on to another, but some suc- ceed better on one stock than on another. The same is true of soil, ail kinds of citrus trees may grow on any particular soil, but on account of different root .systems and different feeding habits, some are much bet- ter adapted to certain soils than others. The Sour Orange seems to be more universally adapted than the rough lemon, the grapefruit, etc., but it is less vigorous than these, and in light soil the growth is often .slow for commercial purposes. During the first few years the sour orange makes a slower growth than the rough lemon, grapefruit or shaddock, even on heavy or medium heavy soil, but after the root system becomes well devel- oped, the difference is not very great. The root system is deep, for which reason it is often recommended for dry soil, which is quite right, provided the soil water is not too far down, but even if the tree can reach water when it becomes old enough, it should be well remem- bered that moisture close to the surface is necessary dur- ing the first few years. Where the sour orange can be •especially recommended is on heavy moist land, because it is less subject to gumming than the other stocks. The sour orange is a good stock for the grapefruit and the common orange, although it can not be recom- mended for the navel. Neither should if "be used for satsuma nor kumquat. The Rough Lemon is more vigorous than the sour orange and is especially desirable for light soil poor in 22 plant food. It should never be planted on moist land, because it is very much subject to gumming. The root system is shallow and in some soils the tap root is entirely absent. The rough lemon is suitable as a budding stock for any of the commercial citrus fruits. It induces early bearing because of its vigour, but the first couple of crops of fruit are usually large, coarse and juiceless. It produces a larger tree of any variety 'budded on to it, than does the sour orange during the first 4 to 5 years, but later there is almost no difference in size, unless the soil is very poor. The rough lemon is especially well suited as a stock on which to bud King, Tangerine and Kumquat varieties. When grapefruit and orange varieties are bud- ded 011 to it the tree seems to be especially subject to gumming on heavy soil. The Grapefruit and the Shaddock are very good bud- ding stocks, the shaddock especially being very vigorous. The root system is deeper than that of the rough lemon, and it is suitable for the same class of soil as that. It is not much more subject to gumming than the sour orange, and less so than the rough leinnon, and as it is suitable as a stock for all kinds of citrus fruits it is worthy of general use. Commercial Varieties of Oranges as advertised in nur- sery catalogues are almost legion and practically all of them have been planted in the West Indies, the names are still retained but there is considerable variation, which is however of minor practical Importance. The question is not what an orange is called, but what the quality and appearance is. The most desirable size is 2 |'$ inches in diameter, packing 176 to the box, form 23 round, color bright, peel thin smooth and silky. The flesh should be a rich orange 'Color with but little fiber and few seeds. The juice should be plentiful, subacid and distinct orange flavor. The time of ripening is of no less importance. In October and November a good orange sells well, later the competition becomes great and those who can not have extra early oranges should plant late varieties, and fertilize with a large percentage of Potash so as to have them mature after March. The home consumption is becoming to be of some importance in some of the Islands, and for this purpose the Navel is one of the best on account >of its large size and its sweer- ness. The Navel can not however, be successfully pro- duced except 'on medium heavy soil and with irrigation. Varieties of Grapefruit may be summarized like the oranges. A good size is 4 to 5 inches in diameter, color light yellow, form round to fiat, not pear shapped, peel TV inches thick, bright and smootli. The flesh should be a bright y-el'low in color with not too much fiber or rag and few seeds. The juice should be plentiful with a flavor of bitter and subacid. A number of varieties described in nursery catalogues conform to this stand- ard, and it may be said that any of the well known good varieties are desirable for planting in the West Indies. The soil, cultivation and especially the fertilization is frequently of more importance than the variety. For instance in Cuba the fruit from young trees on some of the heavier soils is large, coarse and pithy unless it is properly fertilized. It is probable that certain varieties are specially adapted to certain soils, but that has not been thoroughly worked out yet. Seedling trees of which the origin is unknown have been observed to yield better 24 fruit than well known Florida varieties which would indicate that varieties better adapted to the West Indies may be found. That however should not induce planters to buy native varieties unless t'hay know the origin, be- cause there are a number of so called grapefruits in the West Indies that are nothing more than improved types of the shaddock. HOW TO PLANT A TREE There are seemingly more mistakes made in planting trees than in any other operation connected with the business. If it were not for that this chapter would not have to be included. The following directions if followed will obviate any mistakes in planting. Dig the holes large and deep. Fill the soil in again with the t^p soil and vegetable matter in the bottom and heap it up. Leave it for some weeks until perfectly settled. When planting the tree without a ball of earth use a planting board, that is, a board 6 to 8 feet long with a notch in the middle and a block under each end. Make an ex- cavation in the previously prepared hole. Place the board over this with the blocks resting on the level ground. Insert the tree in the notch with the roots close to the board. Then fill the soil in around the roots and firm it down weld, using plenty of water. In this way tlie tree will stand as high above the level of the soil as the thickness of the blocks under the board. In sandy soil these blacks may be but 3 to 4 inches thick according to whether the soil is very wet or not. In soft and very wet .soil the trees settle more than in drier soil. In clay soil when planting in rainy weather the blocks should be 6 inches thick, because the trees will settle a great deal 25 and they should stand with the crown roots about 2 inches above the level when fully settled. In heavy clay soil or in land with impervious subsoil in which citrus trees are frequently planted, although it is unsuitable, the writer has observed standing water in the holes all through a rainy season. Trees planted under such conditions start gumming almost immediately, and frequently the roots decay. This can be remedied by subsoil draining or even surface draining, connecting each hole with a drainage ditch. The Distance Apart at which trees should be planted is frequently a subject for discussion. The tendency is to crowd too many trees on to an acre, because they look so small when planted and it is hard to realize that they will grow so large. In general 25~x 25 feet apart (70 trees per acre) is the most suitable distance. Some have planted this way with a tree between each four trees making the number 126 per icre, but those extra trees had to be taken out before they 'bore fruit. Others have planted 20 x 20 (108 trees per acre) which is excusable on light soil, but on the heavier lands like eastern Cuba, and the banana soils of Jamaica, 70 trees per acre is enough. HOW THE WILD TREES GROW Citrus trees grow naturally in the West Indies without any care, which is fully attested by the great number of seedling trees found in all of the Islands. Why is it then that a planted grove requires so much care? It is because in the average grove the natural conditions have been lost sight of, and with an artificial start the artifi- cial conditions must be kept up. 26 Nature's Way is to drop seeds promiscuously wherever they happen to fail, but only those dropping in favorable spots in the forest or in well protected fence corners survive germination, and after germination only the most vigorous plants overcome the obstacles to which the bud- ded trees are subject. Unfortunately it is not possible for the planter to exercise such rigorous selection, but it is practical in many instances to copy nature's methods of growing trees. The tree growing in the cool moist forest atmosphere is not subject to scale insects, because those conditions are favourable to the .growth of fungi, which will keep the scale in check. The surrounding trees and shrubs take up a great deal of nourishment and rob the citrus tree of food, for which reason it grows slowly. On the other hand those surrounding trees and -shrubs shade the soil, keeping it cool and moist. The mulch or leaf mold protects the soil from baking by the sun, beating by the rains and cracking from drought. Imitating Nature is the cheapest method of culti- vation, and considering that a tree planted is capital in- vested it pays well to take advantage of it. In the 'Com- mercial method of starting a grove spraying is one of the first operations, and in many of the earlier groves more money was spent on that, tharT on all other work ^combined. The more advanced planters who have prac- tical experience and theoretical knowledge do not "lay awake nights" studying up new cures for tree diseases. They plan their work in such a way as to keep the trees healthy and that is the keynote to success. The grove is in the first place started with windbreaks around and smaller plants between the rows. This is imitating forest conditions and the trees will not have 27 to be sprayed for scale. The next question is how to keep the soil moist. In this it is also possible to imitate nature, but it is not always practical. The air and soil in the forest are humid -because of the dense shade and the leaf mold covering the ground but in the grove the shade must not be dense, and enough mulch to effectually pro- tect the soil can seldom be obtained. The remedy is continual cultivation during the dry season, but experi- ence has shown that that method does not fill all the re- quirements. Irrigation is frequently necessary and in many localities it is one of the best paying investments. Nature also teaches a lesson in feeding plants and in the case of citrus trees the lesson is a most valuable one. A self-planted seedling tree growing in uncultivated soil does not suffer from die-back, gummosis, foot-rot, etc. It takes up no more food than it can readily digest. It does not grow fast, but nature is not in a hurry. The fruit may be too soft to ship or too sweet to suit the palate of some people, but it suits the mocking bird and the wild parrot and nature is satisfied. The budded tree planted by hand and forced into quick growth by constant cultivation of the soil is under many disadvantages. If the soil is rich enough to produce a tree it is usually too rich in nitrogen to produce a healthy tree. This may cause no harm if the soil is not cultivated, but in that case a young tree would not grow fast enough to suit commercial demands, and it would not survive because of the artificial" conditions under which it is placed. In cultivating virgin soil the nitrogen is liberated faster than the other plant foods and the tree becomes unhealthy from improper food. If it sur- vives and bears fruit it will usually not be firm enough 28 to ship and frequently too insipid to be marketable. Therefore when interfering with nature in trying to pro- duce quick growth and marketable fruit, the planter must be prepared to feed his trees according to requirement. CULTURAL METHODS The proper method of treating a grove is a local proo- lem. General directions can not be followed explicitly, but by the use of common sense a planter may adapt any of the usual cultural methods to suit his special condi- tions. In the young grove the main problems are how to keep the air and the soil cool and moist during the dry season, and how to keep the soil supplied with the proper amount of plant food. Local Wind Protection is, as previously, stated of great benefit to young trees because in that" way it is possible to duplicate forest conditions. Many different plants may be used, such as pidgeon peas, corn, castor beans, bananas and even sugar cane. One or more rows of such plants between each row of citrus trees will serve as an ef- fective windbreak and soil shade, but like forest trees they will rob the citrus trees of plant food. This must be guarded against by plowing deeply close to the plants to prevent the roots from spreading too far. Such plants may also serve as a harbor for insects, such aa leaf eating beetles or ants and if so the method is of course impractical. Mulching consists of covering the soil with a layer of dry vegetation, thick enough to prevent evaporation of soil moisture. It is the most natural method of preserv- ing the moisture and preventing the weeds from grow- ing, but it is not always practical. A mulch to be ef- I 3 30 fective must be thick enough to keep the soil from drying out during the dry season and suc'h large amount of grass or any other kind of .plants can .seldom be obtained without too great cost. Another drawback is the danger of fire in a grove mulched all over. These objections can be overcome in young groves by mulching around the trees only and cultivating the middles. In this way less mulch is needed and thie danger of fire is lessened. In mulching trees the roots form in the surface soil and for that reason it is necessary to remove the mulch and cultivate the ground during the rainy season^ in order to keep the root system from becoming too shallow or else to continue mulching without interruption during the life of the tree. Cultivation is a broad term denoting all work in con- nection with weeding and stirring the soil. In young groves it is strictly necessary to keep the weeds away from the tree and unless mulching is used it is necessary to work the soil with some instrument in ordeFto prevent the moisture from evaporating too quickly. This is on the same theory as mulching. The moisture rises to the surface in compact soil like the oil in a lamp wick and from there it evaporates by the 'heat of the sun. In order to prevent this the surface is broken and pulverized, the moisture then rises to the pulverized layer and no further. To receive the practical benefit from cultivation a planter imuist .plow his soil just before the rainy s 5 £ ;3 34 i planter. These are Lime, Potash, Phosphorous and Ni- trogen. Lime is usually present in the soil in fairly large quan- tity, and it is seldom necessary to apply it as a fertilizer,, because all fertilizers containing phosphate contain enough lime to satisfy the needs of the average plant. But lime is also used to correct acidity in sour soils aad is often needed for that purpose. A soil that is sour is not, suitable for citrus trees and such soils are always benefit- ed by 1000 pounds or more of burnt lime or several tons of finely ground limestone according to the amount of acid it contains. Potash is the one plantfood of especial importance to citrus trees, not alone to the growth of the trees, but more so to the health and especially to the quality of the fruit. Potash is present in the different soils in varying quantities. For instance sandy soils are usually poor in potash and >clayey soils contain comparatively large quantities, but the actual amount present is not what the planter is so much interested in because often the clay soils showing large -quantities when analysed are most bonefitted by an application of potash salts. This. is due to the fact that the potash in the soil is usually present in insoluble forms which are not available to cultivated plants. The potash used for fertilizers comes- from the potash mines in Germany. It is found there in several forms and sold as Sulphate of Potash, Sulphate of Potash Magnesia, Kainit, etc. Phosphorous or phosphoric acid is another plant food. It is used for fertilizer in the form of phosphate of limo, that is, a combination of phosphoric acid and lime. It is sold as acid phosphate or superphosphate also as double ,- ,;:..' ••_., ,, . 35 acid phosphate and as basic slag, "all of which contain various amounts of phosphoric acid. Bone meal is also a phosphate fertilizer and so are the various bat guanos. Nitrogen or ammonia is the third element contained in fertilizers. It is present in all organic matter such as the vegetable matter in the soil, and also in the air, from which latter source leguminous plants can supply them- selves. New land recently cleared from forest and con- taining much vegetable matter is rich in nitrogen, and frequently trees planted on such land suffer from gum- ming, -die-back, etc., because they take up more of that than of potash and phosphoric acid. For the same reason, stable manure can not be used in large quantities for citrus trees. For fertilizing purposes, nitrogen is sold in the forms of nitrate of soda, sulphate of ammonia, dried blood and the various slaughter house and fish scrap offals as well as nitrate of lime which is the new product -made where nitrogen is obtained from the air. Cover Crops is a name applied to plants grown in the grove for the purpose of benefiting the soil. A cover crop may or may not be a fertilizer according to what kind of plant it is. Common weeds such as grasses usually found in uncultivated groves do not add plant food to the soil. They feed on whatever plant foods there are in the soil and when they decay there is nothing more nor less left than what there was before. There is a gain however because the humus formed improves the physical con- dition of the soil and the plant foods in dead vegetation are in a form readily available for other plants. Leguminous plants, such as beans or peas do not alone improve the physical condition of the soil but they also add something to it. They feed on nitrogen, taking it 36 directly from the air, and for this reason they are called green manure crops. In citrus groves a number of legumes are used such as cowpeas, velvet-beans, lablab beans, canavalia, etc. The practice is to plant a crop between the trees at the beginning of the rainy season, and stop all cultivation as long as the rains last, except keeping the vines from climbing up the trees. In this way the soil is greatly benefited by the large amount of humus and the fertilizer bill is greatly reduced, because it is necessary to apply only potash and phosphorous, and these ingredients are cheap compared to the nitrogen which is in this case supplied by the cover crops. INFLUENCE OF FERTILIZERS ON THE TREES In sandy soils there is no question about fertilizers being needed, because experience has shown very thor- ourghly that a citrus tree will not make satisfactory growth without it. Those who start groves on heavier soils such as clay and clay loam often do so because they figure that they will not have to use fertilizers. This is unfortunately a mistake, and the sooner a planter realizes the fact the better it is for him. It is undeniable that citrus trees often grow faster on such soils without fertilizer than on lighter soils with fertil- izer, but too frequently the loss is very great from gum- ming. On light soil a tree will begin to bear when three years old if properly .fertilized, but on many of the heavier soils trees 5 to 6 years -old do not even bloom. Such soils do respond 'to fertilizers however, and a med- ium heavy soil if well drained can be handled very satisfactorily and usually cheaper than a light sandy soil. The thing to remember is that virgin soil containing Orange tree 4 years old. Average tree in unfertilized plat, Dr. H. G. Leonhart's grove, Bayamon, Porto Rico. Orange tree 4 years old. Average tree in fertilized plat, Dr. H. C. Leonhart's grove, Bayamon, Porto Rico. 39 much humus is rich in available nitrogen and unless potash and phosphate is supplied artificially the growth is liable to go 'to wood instead of fruit. Also the growth is liable to be unhealthy, the wood soft and the tree attacked with gummosis. What fertilizing will do in different soils and under varying conditions is best illustrated by photos, and those shown in this pamphlet are absolutely true. Any planter can duplicate the experiments by trying for him- self, using the formulas recommended here. INFLUENCE OF FERTILIZERS ON THE FRUIT While it is fairly well known what fertilizers will do in regard to tree growth and fruit production, the tre- mendous influence on the quality of the fruit and time of ripening is not generally recognized. This is probably due to ithe fact that experiments have been conducted' principally on light soil and the influence seems to be more noticeable on heavy soil. Following we give some results: At the exhibition held by the Cuban National Horticultural Society, Jan- uary 1909, some oranges were exhibited by Mr. D. H. Howell of Ceiba Moc'ha, which were commented on as being insipid and stale. It was decided to try and remedy this and in June, 4 Ibs. high grade sulphate of potasJi was applied per tree on 40 trees. The soil was a red clay, fairly deep, underlayed with coral rock. The grove was not well cared for that summer on account of the owner's absence, and it was found necessary to pick the fruit early to prevent it from being stolen. The data was taken in December and several people were asked to give their opinion on the quality of the fruit. All who tasted it 42 remarked 011 the great difference in flavor and acidity, the unfertilized fruit being even at that early date in- siped and inclined to be stale, While the fertilized fruit was of good flavor but decidedly acid, indicating that it lacked 4 to 8 weeks in being ripe. In 1910 part of a five hundred acre grove at Ceballos, Cuba, was fertilized with a regular fruit fertilizer 3% Nitrogen 1% Phosphoric Acid and 12% Potash and the results were noted in January 1911 by the writer in. com- pany with Mr. Gustschow, the manager of the grove. At that time nearly all the fruit had been picked from the unfertilized part and what was left was over ripe, while on the fertilized part the fruit was still hanging on the trees and not tO'O ripe for hanging 3 to 4 weeks longer. In April 1910 an experiment was started in the grove of the Cuban Development Co., Victoria de las Tunas, Cuba, and the result noted January 1911. There were several plots with various fertilizer combinations from which the results were not very clear cut, but the dif- ference in flavor and acidity due to different stages of ripeness was observed to be as in the above mentioned experiments although less pronounced. In Porto Rico t'he same results w-ere obtained in the Southern Cross grove one year, but: it was seemingly not duplicated the next year. From Dr. H. C. Leonhardt's grove, Bayamon, Porto Rico, ten boxes of fruit from plats fertilized with different combinations of fertilizer were shipped to New York and from there to Havana in Jan- uary 1911. This fruit was carefully noted and showed great variation in flavor and shipping quality due to fertilizing. More observations might be given but this will serve w 44 to show that a fruit fertilizer like formula No. 2 or No. 3 in connection with leguminous cover crops has a very beneficial influence. A fertilizer high in potash con- tent or even potash alone where nothing else is required seems to have a decided retarding influence on citrus fruit. This is very important in the West Indies where it is advisable to hold the fruit until the bulk of the Florida and California fruit has been marketed. Of course the flavor and carrying quality is improved also, but this may, as shown in some of the experiments cited, be due to the difference in time of ripening. A fruit when just ripe is of good flavor, but when it is over ripe it becomes stale and doses its good flavor. Also a fruit may be just ripe when picked, but if it is mussy when it reaches the market, what is the use ut shipping it. On asking a number of fruit venders "Why do you handle the California Navel when there are other better quality oranges in the market?", The substance of their answers was because it looks good and it keeps. That is the keynote of the marketing problem, it must look good and keep well after reaching the market, and proper fertilizing is the only thing that will accomplish it. FERTILIZER FORMULAS The following formulas will be found referred to in the text by numbers. Formula No. 1 for young trees on light soil : 3% Nitrogen 5% Phosphoric Acid 5% Potash. This -can be obtained from reputable fertilizer dealers, 45 or it can be mixed by the planter himself from the fol- lowing materials: 400 Ibs. Nitrate of Soda containing 15% Nitrogen 500 „ Basic Slag „ 20% Phos. Acid 200 „ Sulphate of Potash „ 50% Potash 900 „ Dry earth as filler. 2000 Ibs. or 300 Ibs. Sulphate of Ammonia containing 20% Nitrogen 250 „ Acid Phosphate „ 40% Phos. Acid 375 „ Sulphate of Potash Magnesia „ 27% Potash 1075 „ Dry earth as filler. or 430 Ibs. Dried Blood containing 14%; Nitrogen <670 „ Acid Phosphate „ 15% Phos. Acid 200 „ Muriate of Potash „ 50% Potash 700 „ Dry earth as filler. 2000 ibs. Neither the dried blood nor the muriate of potash as used in the last mixture is considered well suited for citrus fertilizer. Dried blood and other organic forms should not be used where the trees are subject to gummo- sis. Muriate of potash may be used for young trees and probably for bearing trees as well, but the influence of chlorine on the fruit has not yet been determined. Any of the above mixtures contain approximately 3% nitrogen, 5% phosphoric acid and 5% potash when mixed with filler to bring the weight up to 2000 Ibs. Filler is not strictly necessary especially if the fertilizer is used shortly after mixing, but in that *case corresponding smaller amounts should be applied. For instance of the A O c+ B > II I! si r I 48 second mixture without filler 1 to 3 Ibs. should be applied per year to trees under six years old instead of 2 to 6 Ibs. of the mixture 'Containing filler. Formula No. 2, for bearing trees on light soil : 3%| Nitrogen 6% Phosphoric Acid 12 %\ Potash. If a formula like this can not be obtained it may be made by mixing the folllowing materials : 400 Ibs. Nitrate of Soda containing 15% Nitrogen 600 „ Basic Slag „ 20% Phos. Acid 480 „ Sulphate of Potash „ 50% Potash 520 „ Dry earth as filler. 2000 Ibs. or 30u Ibs. Sulphate of Ammonia containing 20% Nitrogen 300 „ Acid Phosphate „ 40% Phos. Acid 900 „ Sulphate of Potash Magnesia „ 27% Potash 500 „ Dry earth as filler. 2000 Ibs. This like the former may be used with or without filler. With filler a fair application is 9 Ibs. the fourth year, 12 Ibs. the 5th. year, 15 Ibs. the 6th. year, and uip to 30 Ibs. or more later according to the amount of fruit produced. Formula No. 3 for trees on land containing consider- able humus and nitrogen, the same amounts of potash and phosphoric acid as used in formula No®. 1 and 2 may be used in this mixture but half or all of the nitrogen can be omitted according to the 'character of 49- the soil. A rich dark loam or a soil producing legumi- nous crops continually for any length of time will need but little nitrogen and in many cases none at all. Fre- quently such soils ^contain so much nitrogen as to cause gummosis in young trees and potash and phosphate 'must be applied to rectify the trouble. Formula No. 4 for leguminous plants : Leguminous plants can supply themselves with nitrogen from the air by means of bacteria which live in nodules on the roots, but as they can obtain no nitrogen before such nodules have formed it may be necessary to apply some for the first crop on poor sandy soils. A good formula for such is as follows : 250 Ibs. Nitrate of Soda 600 „ Basic Slag 300 „ Muriate ol Potash 850 Dry earth as filler. 2000 Ibs. or 200 Ibs. Sulphate of Ammonia 3oO „ Double Acid Phosphate 300 „ Muriate or Sulphate of Potash 1200 „ Dry earth as filler. 2000 Ibs. This can be applied to three acres either with the filler or without. That is, the application should be about 633 Ibs. per acre of the last formula with filler, or 266 Ibs. without filler. For the second and successive 'Crops the nitrogen may be omitted entirely. HOW TO TAKE CARE OF THE GROVE The young trees should preferably be mulched as soon as planted. If no muLch is available the soil should be 01 * SB a& £ « S? o ft o - .52 stirred and kept well pullverized on top in order to prevent drying out. In light soil an application of fertil- izer, should be made two or three months after planting, using y2 'lb. per tree of formula No. 1. This should be scattered around the trees not closer than 6 inches to the trunk, and the application should be repeated every three months during the first year. If plants are used for wind protection they should be cultivated and if cover crops are planted, strips on each side of the citrus rows or circles around each tree, should be kept iclean. At the end of the rainy season the cover crops should be cut and used as a mullch immediately around the trees, and the middles should be plowed and cultivated often enough to prevent the moisture from escaping. During the first three years this treatment may be kept up. Fertilizers like formula No. 1 should be applied from two to four times per year gradually increasing the amount from 2 to 6 Ibs. and gradually increasing the width of the circle and distance from the trunk of the tree. On flight soil the first ieover crop should be fertilized with 300 Ibs. to 600 Ibs. of formula No. 4, and if a large portion of the crop is us>ed for mulching the trees less fertilizer will be needed for them. With heavy growth of cover crops plowed in every year, formula No. 3 should be used for the trees after the second year. The kind of formula to use can largely be determined by the collor of the leaves, a dark green color and vigor- ous growth indicates an abundance of nitrogen, whereas a yellowish color indicates lack of nitrogen. On heavier soil where ordinarily no fertilizer is needed during the first 3 to 4 years, formula No. 3 can profitably be used if the trees show a tendency towards gumming. ll 54 Bearing trees should receive essentially the same treat- ment as young trees during the first few years, with the exception that fertilizer formula No. 2 should 'be used and the quantity should be gradually increased reaching 15 Ibs. per tree on light soil by the time the tree is 6 years old. On soil naturally rich in vegetable matter or one producing large crops of legumes, formula No. 3 should be used. It is usually understood that a citrus tree will begin to bear when three years old, and it will do so if treated as here recommended. If however the tree is neglected a planter is lucky if he can harvest fruit in quantity at the end of 5 years. The fruit from a three year old tree may be of good quality, but it usually is not so unless the tree has be