SB ^y •- • 19/ 3 CALIFORNIA CITRUS CULTURE A. J. COOK CALIFORNIA STATE COMMISSION OF HORTICULTURE Rnnk ■ \j tO THE STATE COMMISSION OF HORTICULTURE SACRAMENTO, CALIFORNIA CALIFORNIA CITRUS CULTURE A. J. COOK State Commissioner of Horticulture Printed at the State Priutiug Office, Frieud Wm. Ilicbardsou, Superinteudeut. If/3 JAN 20 1914 CONTENTS. Page. RAPID GROWTH OP CALIFORNIA CITRUS INDUSTRY, EXPLANATION THEREFOR 5 CITRUS FRUIT TARIFF 6 EARLY HISTORY 7 LOCALITY ADAPTED FOR CITRUS CULTURE 8 WATER — LEADING REQUISITE 9 LOCAL CLIMATIC CONDITIONS - 10 FROST PROTECTION 10 PLANTING THE ORCHARD — PREPARATION OF THE SOIL — THE YOUNG TREES 12 PLANTING THE ORCHARD 13 PROCURING THE TREES 13 ARRANGEMENT OF TREES IN THE ORCHARD 14 PLANTING THE TREES 16 PROPAGATING CITRUS TREES 17 SELECTING BUDS — BUDDING 19 CARE OF YOUNG CITRUS ORCHARD 23 FERTILIZATION 25 IRRIGATION 28 PRUNING 29 SCHEDULE OF CULTIVATION 30 TOOLS AND IMPLEMENTS FOR CITRUS ORCHARD 31-34 Wagons, Plows, Harrows, Cultivators, Marker or Furrower, Subsoiler, Drills, Spraying Outfit, Miscellaneous, Singletree, Doubletree. PICKING FRUIT, PICKING AND PACKING BOXES 34 THE PACKING-HOUSE 42 GRADING 42 PLANT DISEASES 43-50 Chlorosis, Exanthema, Gummosis, Scaly-bark, Mal-di-gomma, Splitting, Puffing, Peteca, Brown Spot, Fungi, Blue Mold, Brown Rot, Cottony Mold, Gray Mold, Withertip, Damping Off, Navel Rot, Root Rot. INJURIOUS CITRUS INSECTS 51 CALENDAR OF PESTS OF CITRUS TREES 56-57 PREDACEOUS INSECTS— PREYING UPON CITRUS PESTS 60 PARASITES (INTERNAL)— PREYING UPON CITRUS PESTS 63 SPRAYS 65-67 Bordeaux mixture, Bordeaux paste. Tobacco extract (Commercial), Lime- Sulphur (Commercial), Carbolic Acid Emulsion, Resin Wash, Lead Arsenate. DUSTS 68-69 Flowers of Sulphur, Lime and Sulphur. TANGLEFOOT BANDS 69 FUMIGATION 69-82 Hydrocyanic Acid Gas, Tents (Shape, Size, Materials, Dipping, Marking, Number for Outfit, Care), Chemical Wagon, Acid Container, Water Tank, Graduates, Acid Generators, Measuring the Tents, Dosage Schedules, Mis- cellaneous Equipment, Chemicals, Sulphuric Acid, Method of Procedure, Dosage (Black Scale; Purple, Red and Yellow Scale; Mealy Bug), Length of Exposure, Time of Operation, Temperatiire, Buying Material, Block Fumigation. CONTENTS. • Pagb. DECADENCE OF CITRUS GROVES 82 THE REAL FACTS 82 SPECIES AND VARIETIES OF CITRUS TREES 83-100 Citrus trifoliata, Citrus aurantium, var. amara ; Citrus aurantium, var. sinensis ; Washington navel, Valencia late, Thompson's improved, Other Sub-Varieties, Seedlings, Homosassa, Jaffa, St. Michael, Mediterranean Sweet, Blood Orange, Citrus nobilis, Citrus decumana. Citrus japonica. Citrus medica, var. genuiana, var. limon; Lisbon, Eureka, var. acida or limetta. BY-PRODUCTS (CITRUS) 100-101 Citrate of Lime, Concentrated Lime Juice, Oil of Lemon, Salted Lemons, Candied Lemon Peel. GOPHER 101 FARMERS' CLUBS 102 REQUISITES FOR A SUCCESSFUL CLUB 102 CALIFORNIA FRUIT GROWERS' EXCHANGE 103 CITRUS PROTECTIVE LEAGUE OP CALIFORNIA 104 BIBLIOGRAPHY 105 INDEX 115 PREFACE. Since assuming the duties of State Commissioner of Horticulture, October 20, 1911, there have come to this office many requests for litera- ture on citrus culture. We could not meet this desire, as the admirable work of the late Mr. B. M. Lelong, for years connected with this office, has long been out of print. This led to the writing of this little treatise. It seemed wise and well to prepare at once something to take the place of Lelong 's "Culture of the Citrus in California" to send out in response to these requests, and hence this unpretentious booklet. I have purposely made this a manual; simple, brief, and severely practical. We might have gone thoroughly into the history of citrus culture, especially in our State, but the beginner or novice, for whom this is principally intended, usually cares little for that ; we might have discussed varieties at length, but this would be confusing and not in accord with our purpose, and so we have considered this sul)ject only so far as it is immediately practical. I am greatly indebted to Messrs. C. C. Teague, R. M. Teague, A. F. Call, C. C. Chapman, Dr. G. Harold Powell, Fred Reed, J. H. Reed, J. D. Culbertson, E. K. Koethen, R. P. Cundiff, and especially the secretary of the commission, Mr. E. 0. Essig, and many others who haye given valuable aid. A. J. COOK. Sacramento, California. Julv 1, 1913. CALIFORNIA CITRUS CULTURE. We can not but marvel at the growth of the citrus industry, especially the orange and the lemon, in California during the past two decades. In the early nineties it was a mere infant. We now have nearly two hundred thousand acres, and ship well nigh fifty thousand cars annually, for which almost forty million dollars are received, of which nearly one third is paid to transport the fruit to the markets. The following statistics show graphically this rapidity of growth : In 1891, 4,056 cars were shipped; in 1901, 21,097; in 1911, 46,399. The number of boxes per car is now 396. The reason for this rapid growth is not far to seek. "A thing of beauty if a joy forever." What can excel in beauty an orange grove loaded with ripened fruit (Fig. 1), or a lemon tree at any time or season ? We all love and are ennobled by our environment where loveliness is dominant; and so it follows that citrus fruit growers will be generally marked by refinement and culture. Indeed, the success- Jul citrus orchardist must be a student and must possess rare intelli- gence. Even the so-called learned professions at their best call for no ] setter thought or deeper study than that required by the highest suc- cess in growing and marketing the orange, the lemon and the grape- Iruit or pomelo. The grower must be a close student of details. The people of highest type enjoy most that which causes them to think and study most, and so our best folk are flocking to citrus culture as affording keenest mental enjoyment and the finest ethical stimilus. The profits in citrus production are equal to those in any line of agriculture. It is brainy work and nowhere do brains count for more. I have been a close student and observer of citrus orchards and citrus fruit production for nearly twenty years, and have known orchards for all that time that have never missed a crop. Where every detail of care is observed by the orchardist, the trees rarely fail to respond with a good and often a colossal production. A small orange grove can be cared for by its owner with very slight aid from others, and thus the greatest handicap in agriculture — inability to secure labor — is solved. I have known one man single- handed to care thoroughly well for a ten-acre orange grove, and such a grove will give generous support to its owner. I have known a man to care for forty acres, with no other aid except at time of irrigation and picking. In case pruning is extensive, it would require extra service. One can hardly picture a nearer approach to Utopia than a community 6 CALIFORNIA CITRUS CULTURE. of citrus growers, each with a grove of from five to twenty acres, and each rivalling the other in the care and intelligence of his management. The climate must be genial, for only in sneli a climate will these fruits thrive. In California, the scenery rivals the best in Switzerland, and the labor, never too arduous, is uniform the entire year through. The free, pure, outdoor air is surety for health and vigor, and a happiness Fig. 1. — Orange trees at San Gabriel tliirty years old. (After Lelongr.) and comfort that ever attends honest endeavor in the field of agricul- ture, is nowhere more certain than to the owner of a citrus grove that is properly located and well cared for. We can not wonder then that eitriLs culture has advanced by leaps and bounds, and can safely predict that the future will greatly surpass the past, and even the present, in its growth and production. CITRUS FRUIT TARIFF. There is a tariff of one and one half cents per pound on lemons and one cent per pound on oranges. The one half cent additional on lemons was added in 1910 and has greatly stimulated the planting of lemons. If this protection continues, in a few years sufficient lemons will be planted to supply the entire demand of the United States. This is now true in the case of oranges, which have been protected by a one cent per pound tariff, so that now our country produces all its own oranges. There is little doubt but that the tariff on both oranges and lemons will be reduced to one half cent by the present extra session of Congress. CALIFORNIA CITRUS CULTURE. EARLY HISTORY. In that excellent volume, by the late Mr. B. ]\I. Lelong, "Culture of the Citrus in California," will be found an interesting account of the early development of this industry in our State. It was more than a century and a half ago that the jNIission Fathers introduced the orange, the fig, the foreign grapes, and the olive. These padres came to help men to a more abundant life. They did more; they demon- strated that our genial climate made our much prized citras fruits entirely at home. California gained its great renown from the discovery of gold. Little did the early miners dream of the riches in the soil while in quest of nuggets in the placers and river gravels or the loeked-up gold of the quartz mines. Yet to-day our orchards fairly eclipse the mines in the wealth they pour into the pocketbook of the State. Except for oil, no single product of California begins to compare in impor- tance, measured by the net ca.sh returns, with that of the citrus groves. G. Harold Powell, general manager of the California Fruit Growers' Exchange, than whom no one is more able to give an authentic opinion, states that the "citrus industry represents two hundred million dollars capital invested, ten thousand growers are interested, one hundred thousand people depend upon it for a livelihood, while fifty thousand carloads are expected to be shipped from the State the present .season." We see that the citrus product of to-day is a very leading factor in the business interests of the State. There is apparent the urgency of push- ing Avith vigor all that helps to advance this important interest and of working to staj' with all po.ssible energy whatever tends to handicap it. To quote again from the work of the late Mr. B. M. Lelong: "While orange trees were among the first introduced into the State, having been brought by the Mission Fathers, it may be said that orange culture is of very modern origin, and the industry has assumed com- mercial importance only since 1880." At first it Avas supposed that only the south was sufficiently balmy to make citrus culture possible. Now we know that in the elevated mesas and the foothill valleys of both the northern coast and Sierra ranges there are favored localities where citrus culture is successfully practiced, as far north as Placer, Glenn and Butte counties. In fact, the fruit in these northern coun- ties is of excellent quality and ripens earlier than in the south. This promises only good to the State^ as we shall be able to maintain a market of superior oranges, as we do now of lemons, throughout the entire year, from January to January. This guarantee, that the best 8 CALIPORiN'IA CITRUS CUL^Ufefi. will always be at the command of the purchaser, is of gre^ impor- tance to both the producer and consumer. The northern groves pos- sess two advantages : They supply the early better market, and tlie early ripened fruit is likely to precede any possible frost. LOCALITY. There are certain reciuirements that should always engage the most serious and painstaking attention of the one about to engage in the growdng of oranges and lemons: soil, water and climate are dominant factors in successful citrus culture. The soil should be a rich loam ; either clay, or sand or gravel may predominate. We now know that humus is an absolute requisite for any productive soil or any crop, so a good suppl}^ of organic matter is essential. While in such arid soils as those of California, humus is unfortunately limited in amount, yet the nitrogen content of the humus in these soils is usually large ; thus I say, rich loam, for though we may supply this decaying organic matter, when it is meager in quantity, yet the orchardist is most favored who has in his soil a goodly proportion of this valuable humus. We have only to mention Redlands, Riverside, Santa Paula, and Porterville to prove that the best citrus fruit can be produced on quite heavy clay; even adobe soil often produces first-class oranges and lemons ; on the other hand, much of the San Gabriel Valley is remarkable for its sandy, gravelly acres. This soil may also boast of great crops of very superior fruit. The clay soils are very strong, very productive, very enduring, but they must be kept aerated and in good tilth, which is no light task. The man who cultivates a clay citrus grove must have good brain pow( '', and must use his brains to the limit. We may .'iay a grove of heavy clay soil is first best if its owner is first best. Such soils must never be tilled when not in prime condition and the drainage should be per- fect. A sandy, gravelly soil is less retentive of moisture, is not so strong, and must be abundantly fed. It can be worked almost imme- diately after a heavy rain with no serious injury, and so may be handled with less of care, less of diligence — in short, less of brains. Such soils suffer little from lack of aeration. I was told, in Sicily, that the lemons grown on clay soils were superior in quality, brought a higher price — one fourth more — and kept better than those grown on sandy soils. CALIFORNIA CITRUS CULTURE. 9 It is also necessary to have a soil that is deep and with a good subsoil. An artificial hardpau from six to eight inches from the sur- face is not uncommon in any kind of soil. A natural hardpan still deeper down is often found. In purchasing a location for citrus trees, we should never fail to dig down and find out just the condition of the subsoil — the soil just below the plane reached by the plow. King's soil tester makes it easy to learn the character of the subsoil to a deptli of five or six feet. Any hardpan is prejudicial to success. It is also very essential to avoid ])lack alkali or carbonate of soda. We have only to keep these points in mind to choose wisely in the purchase of lands for citrus fruits, so far as the soil is concerned. WATER. The purchaser must he even more wary regarding the ability to secure sufficient water for irrigation, as nearly every California soil will, with proper care and cultivation, give remunerative crops. Water is the very life of the grove. No one should ever purchase a grove, or land for a grove, unless he is absolutely sure that abundant water is always at his command. In planting, we must not forget that the older the trees the more water required. The government experts, who have investigated along these lines, caution those who are planting new groves, and state emphatically that in many localities in Cali- fornia, though not in all, we have now reached the limit of safety in planting. In some sections we have, however, come far short of developing the amount of water that may be secured from underground reservoirs by boring wells and pumping. Very much more water will be pumped for irrigation in the near future than is now secured. In a few places reservoirs above the surface may be formed to add to our water resources, and in these the winter run-off may be stored and held for use. It is also demonstrated by actual experience that by wisely distributing the water during the copious rains of winter, what would else go in the winter run-off to the sea, can be stored up in the sub- earth gravels and be utilized in the long dry season of summer. Yet we may still urge that since water is the great desideratum and the absolute necessity in citrus culture, the securing a full supply for the coming time when the groves are all mature and in full bearing, and for years of least rainfall, should engage the chief and most thorough consideration of him who is contemplating the purchase or planting of citrus orchards. We must also always be cautious that the water we use is free from alkali. 10 CALIFORNIA CITRUS CULTURE. LOCAL CLIMATIC CONDITIONS. As regards the liability to frost, we can uot be too cautious in select- ing a locality for a citrus grove. True, the orange (the lemon is a little more susceptible to frost than is the orange) will resist a tem- perature a little below freezing, perhaps as low as 26 degrees Fahr. if not too long continued, but if the thermometer goes down to 22 degrees or 25 degrees Fahr. above zero, both fruit and tree are likely to suffer. This is the more true if the cold endures for quite a long period, and if the sun comes out clear the following morning the damage is increased. It is found in California, as elsewhere, that the cold is more pronounced in lower levels, so that it is safer to locate higher up on the mesas. The cold, like water, flow^s down into the lower valleys, so that often the lower groves will suffer harm, while those higher up escape all damage. It is a gratifying fact that seriously cold seasons do not occur in California on an average oftener than about one year in four. FROST PREVENTION. As a question of permanent public policy, it is uncertain how far protection against frost, by artificial means, may wisely be carried; but where orchards are already planted, it is surely unwise to neglect the insurance that is afforded by a proper equipment for frost pro- tection. The cost will be great, and the labor involved in the fight will be both disagreeable and exhaustive, when the cold nights come. But when not only the fruit but the trees themselves are at stake, the orchardist can not afford to take any chance. In one large lemon grove the expenditure of $6,000 fighting frost in the winter of 1911-12 saved $100,000 worth of fruit. While the year following, when the cold reached a temperature of 15 degrees above zero, it cost twice as much to save the crop. Yet at this time not only the fruit was saved, but irreparable damage to the trees was prevented. Many would have been killed outright, others greatly injured. Prior to 1911, for years, the coal baskets, one to each tree were successfully used in frost protection. The experience in 1911 proved that oil pots were preferable to coal baskets. Oil as a fuel is more CALIFORNIA CITRUS CULTURE. 11 easily handled and much more economical. This season millions of oil pots are being purchased. The oil pot now desired has a capacity of seven gallons, a down draft tube that insures the entire consumption of fuel oil or cheap distillate and regulation of the flame to greater or less heights as the degree of cold requires. These are costly but the expense is more than warranted. The soot resulting from incomplete combustion smuts fruit, but by washing the latter in warm water con- taining gold dust after a quick submergence in kerosene oil the smut is wholly removed. The lessons taught by the unprecedented frosts of January, 1913, are first : We can not count on any f rostless region in California. San Diego had never been injured before, but suffered severely last Janu- ary. The same was true of the foothill mesas along the San Gabriel mountains. Lemons, both the fruit and trees, are more susceptible than oranges; young trees than old. Apparently trees inured to cold are less likely to be damaged than are others. Severe frosts in Sacramento seemed less injurious to citrus trees than a like frost at Santa Barbara or San Diego. It was conclusively demonstrated that by the use of oil pots — smudge — the orchards could be absolutely protected. In some orchards which were thoroughly provided with pots and oil the fruit was wholly protected, and the frost was a real advantage, as the high prices are very exceptional and bring great profits to the vigilant orchardist. While the thick canopy of smoke often resulting from the fire may, and doubtless does, do some good in acting as a blanket to retard radia- tion, yet it is probable that a smokeless heater which consumes all the carbon would produce more heat and be more advantageous. While the soot can be easily and cheaply removed from the fruit, yet it is very obnoxious, as it pushes into houses and begrimes tapestry and curtains, and is a very serious inconvenience. It would seem that the ideal pot would be smokeless, one that would consume all the refuse from the oil, leaving the pot clean, would burn crude, or cheap, oil, hold sufficient oil to burn all night, if required, and so made that it can be filled with no spilling of the oil. There are two methods which are quite satisfactory in determining whether or not the fruit has been frozen. By placing the fruit in diluted alcohol of the right density, which can be easily determined by experiment, the frozen fruit does not sink and so is easily separated from the heavier unfrozen fruit. The other method is by the use of a current of water which separates the injured from the sound fruit on the same principle that gravel is sorted by a running stream. This latter arrangement originated with Mr. Harry Chase of Riverside, and 12 CALIFORNIA CITRUS CULTURE. is reported to give ju-curate deterniinatiou. Of course it need not be vsaid that frozen fruit should never be marketed. Frozen trees shoukl not be pruned until time and new growth show the exact limit of the killing of the branches. Then all dead portions should be removed. In case the cambium, or inner bark, is killed down to or below the bud then the whole of the trunk may be cut away, and new growth from the crown can be permitted to grow, and this may be budded to produce the desired variety of fruit. If branches start above the bud, the largest of these may form a new tree and no further budding will be required. If desired, the trunk can be retained for a time and will serve well to support the new growth. In this case it is well to trim the trunk of all dead limbs, when it will be easy to grow and cultivate beans among the injured trees. These will give a good profit and serve to keep up the fertility of the land. The CITRUS grower must remember that good and sufficient oil POTS ARE A WISE AND PROVIDENT INSURANCE AGAINST LOSS AND POSSIBLE RUIN. PLANTING THE ORCHARD. PREPARATION OF SOIL. In preparing to set an orchard the soil should be thoroughly and deeply cultivated, especially if it is a clay soil. We have seen that a rich supply of humus is very essential. If, then, a heavy stand of vetch, alfalfa or sweet clover could be grown and plowed under before planting, in time to become well decomposed, it would aid in making a first-class planting ground. The soil should be moist when the trees are set. THE YOUNG TREES. These should be vigorous, well formed, and wholly free from fungous affection or insect attack. Usually it will be necessary to secure them at a nursery. In such case, a reliable nursery should be sought and a careful inspection of all the trees made by an expert. In case one can do so, it is well to grow his own plants in the seed bed from selected seed. Seeds from sour stock are now thought the best. Trees from these are said to resist fungi and frost, especially when young, better than others. Those from fruit known to be produced on a very vigorous, productive tree are to be preferred. A very productive tree must possess great vitality, and the seed would be likely to partake of this character and produce excellent i)lants. Even more important CALIFORNIA CITRUS CULTURE. 13 is it to secure the buds of trees that invariably produce more gen- erously of fruit of rare excellence. Such a course would almost certainly result in producing a phenomenal orchard, for it is a well known law of nature that "like produces like." There may be ex- ceptions, but these only prove the rule. (See article by A. D. Shamel in August, 1912, The Monthly Bulletin, California Horticultural Com- mission.) The trees in transplanting must be dug from the nursery so as to disturb the root system as little as possible. They should be balled, kept moist, and planted out with the least possible delay. In setting, the earth should be firmed about the roots when practicable, by use of water, and if the planting is done in early spring (I have had satisfactory results in planting in February, though most prefer May and June) we are quite sure to have excellent success, if our subse(iuent care is what it should be. If the earth keeps cold, plant- ing may be deferred even to late summer. It is best to cut back to preserve the balance between roots and top. As this work is so vital to success, I will discuss it more in detail. PLANTING THE ORCHARD. As before stated, the land prior to planting should be thoroughly prepared. This means that it should be deeply and thoroughly cul- tivated, Avell enriched by previous cover crops plowed under or by use of stable fertilizer, at least ten big loads to the acre. In a virgin soil manure may be safely deferred for two or three years. The ground should also be leveled and graded to perfection, as this will save immensely in labor and peace of mind in the future care of the orchard. A uniform grade is desirable with a minimum of one per cent fall if possible. We should never grade off the surface soil where contour or change in direction could make it unnecessary. The reason is obvious. The surface soil is usually better supplied with the necessary soil ele- ments.' I fear not all will follow this advice, but those who do not will surely realize their mistake later. PROCURING THE TREES. It is wise to see the trees before purchasing, to make certain that they had been grown under proper conditions. One had best purchase some months before jilanting, as he is more likely to secure good trees. The price usually runs from forty cents to one dollar per tree, varying with size, supply and demand, and number purchased. If possible, one may well buy selected trees, paying more. This is one signal advan- tage among many of growing one's own trees from seedbed to orchard. Too much care can not be exercised in removing budded trees from 14 CALIFORNIA CITRUS CULTURE. the nursery and preparing them for shipment. There are tw^ methods : the open-root and the balling. A ditch, eighteen inches deep on one side, eight inches from the row, permits cutting all the roots on that side, and also the tap root or roots. Then for open roots, the tree may be crowded into this trench, breaking as few roots as possible. This is allowable only for near-by planting. A long, sharp spade makes it easy to cut the roots on the other three sides. If we wish to ball, M^hich is best in most all cases, we tamp the soil, shape the ball and lift the tree on to burlap, which is then folded and tied about the trunk. Haste in transportation is always in order. The trees upon arrival at their des- tination should be heeled-in, pointing southwest, in case of open roots, or planted at once. A furrow with a 45-degree slant on one side makes heeling-in easy. None but the open root trees should be heeled in, and it were always better to set at once. If one grows his own nursery stock, this is the more easily accomplished. No one should order trees until he is ready to set them. From the heeling-in furrow to the orchard, trees should be handled with as little delay as possible, and unless balled should be covered with a wet blanket, especially if the day is hot. ARRANGEMENT OF TREES IN ORCHARD. There are four methods of planting as to arrangement of trees : rectangular, triangular, quincunx or hexagonal. The first, square or rectangular, is simplest and most common. Indeed, it is the almost universal method to-day. If in squares (Fig. 2), the trees are often planted twenty feet apart, which gives one hundred and eight trees to the acre. Most prefer to plant further apart, at least one way. If twenty by twenty-five feet, then we have eighty-seven trees to the acre. It is quite common to have the squares twenty-two by twenty-two feet, which takes ninety trees to the acre. This is quite close" enough, and there is wisdom in increasing this. The squares are often twenty-four, twenty-five or twenty-six feet on each side. In the triangular system (Fig. 3) the trees are parallel to one mar- gin of the field in one direction and diagonal to this the otlier way. The trees will be further apart on the diagonal lines. Suppose we wish to plant twenty feet apart in the rows parallel to the margin. We then lay off the orchard in twenty-feet squares. The first row will be at the angles of the squares, next to the margin of the field. The trees of the second row will be at the middle points of the opposite sides of the squares, etc. Each alternate row will have trees at the angles, the next at the middle of the sides of the squares. This gives ninety-eight trees to the acre. The trees will be twenty feet apart one way and a little more than twenty-two feet the other way. This has no advantage, except it permits cultivating or working the ground in three directions. CALIFORNIA CITRUS CULTURE. 15 u... ... u..... i ....»-.... u... ...i-.- u L.^. 1 i i „..L.. ... L u... ....L... .. (..... _,L.. _.u... ..„.L u... _..L_.. ...L... U..„ 1 ..,.k... u ir... i .,..:t'. '.. -ir ■• ■ -^ ■■•! U 'i::. ■:l' — •> 'f •• -"•' ■ '•■ ' ■• • \ '■•■ 1 i •S-. <%. ^ ^L. ^^L ^- ^ %. '^ ^ '4. ^-. ^^ . ^4= C -^ 4. '^_ %. t 4^ 1 - 4^ 4 . C 4=. 4=- iL Fig. 2 , — The square system. (After Lelong.) Fig. 3. — The triangular or alternate system. (After Lelong.) |,. [-. l- ....[- L [- :\ :H ;"'--ir ''■ ■-^ ;'"-^ ^ U .: j. ...J::i ■\U. ....'■. .U...- .H ; \ : -L. ;'-L ^ • u ; ■■■L. ; .U .-L- ""-.w.,. .;'.4- "-.k '■-■i j \U : ■■•••V i -^l- . ^- It ■ '-i- ': I Ir. '.:::L ::.!:. ::::i... \..l C C, <%- ^ C 4^ ^ '^ %. C % ^ %^ ^ ^ ^ '^l. C ^L. ^L. C ^ q_ ^ C_ viL ;:4-ife:--l--- k. U— I. ....\r L p-4ii--K.i;:-I^:;:-l{-. ;.. U.. .U •...I. -L. i>:>; L -V l'--i- I -u \, ^...i;-.:..;i ;.. ^-.-:i. i'-i. ..U ■■-.j.^.- .'^.j ^ . i' : 1' ^-^ 'U u^- -U U" • -L L_U'...1-; .,U.-.U ;;.u.__u ..'. U" -L.. <1^ ^.^ ''L. '^ ^L '^ ■ -L '-L ^ -^^- ^1^^^. , ^L^ . -:L -4^ ^ ^^. *.: 'L '^^ ^-L ^- '4. -'L 4^^1» ^.-^^ . ^^-.- ^^ .. 'L "fi- ^ ^L i. 4. ^L --L -^ --L ^L ^i.^:?»^4.4 ■"■iL --i^ .^%. ^L ^^ '^'L. ^L. ^:^^ 4.4.%. t.-^'k ^L=^ ^4.-^ 71 "l. Fig. 4. — The quincunx system. (After Lelong.) Fig. 5. — The hexagonal system. (After Lelong.) 16 CALIFORNIA CITRUS CULTURE. The quincunx system (Fig. 4) is like the rectangular, ^xcept that a tree is planted in the center of each square or rectangle. This adds to the number of trees. If the square is twenty feet on each side, there will be one hundred and ninety-nine trees to the acre. It also serves when more trees are desired in a young orchard, some of which will be removed as the trees age. It makes this removal easy, without affecting the symmetry of the grove. In the hexagonal or sextuple system (Fig. 5), six trees mark the angles of an equilateral hexagon, with an extra tree in the middle point between them. In case the trees are twenty feet apart, the first row will be parallel to the one side of the field, and the trees twenty feet apart. Two twenty-foot lines stretched from the first two trees of this row towards the opposite side of the field, approximating each other, will fix the location of the center tree where they meet. This will be the first tree of the second row, which will be parallel to the first row. The trees of the third row will be exactly opposite those of the first. Here alone, of all the systems, each tree is equally distant from all adjacent trees. If the trees are set twenty feet apart, then one hundred and twenty- four trees will be set on each acre. Here the trees may be cultivated diagonally in two directions and in a third direction parallel Avith the side. PLANTING THE TREES. Citrus trees may be planted at almost any time ; better from February to August. I prefer February — when the trees are more dormant, though the heaviest plantings are in April and May, and as late as June. This avoids frost, and the trees will respond to the temperate heat of spring. The holes may best be dug just prior to setting the trees and should be ample in size, not less than two and a half feet in diameter. They should be dug a little deeper than necessary to accom- modate the trees, the extra space being filled with fresh, rich fertile soil. The bruised roots of each tree should be cut off diagonally with a clean cut, just above the wound, and the top cut to balance the i-oot pruuing and to give all the trees similar and sym- metrical heads. Some of our growers leave all the top and foliage intact; others prune the top heavily, ^ removing all the leaves. I think the above course, Pig. T—^"ung" roots trimming to balance top and root sj'stem, is preferable. fnpSfng^^( After ^^^ the trccs are placed in position, the roots, if the Leiong.) trees are not balled, should be evenly separated (Fig. 6) by hand, and in every case the hole filled three fourths full CALIFORNLi CITRUS CULTURE. 17 with ffood surface soil, when enough water should be added to settle the soil thoroughly about the roots or ball and to crowd out all the air and saturate the ball through and through, after which fill in to the top, leaving the trees a little higher than they stood in the nursery, as they will settle slightly after they are planted. The bud should be some inches above the earth. Not only should the bud be well above the ground, but it is equally important, probably more important, not to plant the roots too deep. Preferably the crown roots should not be planted more than two inches below the mean surface level of the crown. As soon as the trees are all set they should receive a thorough irriga- tion, especially if not balled, and a good cultivation as soon thereafter as the soil is in proper condition, both of which as we have seen should be deep. PROPAGATING CITRUS TREES. More and more, I think, will our citrus growers start their own. trees. Yet nurserymen need not shiver at this advice, as few will follow it. The orchardist can then select seeds and buds, and can care for the plants from the very first, and very likely such care, costing but little, will double the annual income as the trees come to maturity. I know starting trees is a complex matter — a trade to be learned, but I have great faith in Yankee gumption. As large seeds are preferable, seeds of the sour orange, sweet orange and pomelo are to be preferred, the largest seeds always to be selected. These should be secured from the fruit of trees of maximum perform- ance and thrift. Whether or not the stock affects quality of scion or bud so as to influence quality of fruit, surely every plant and animal lias better promise if the parents are full of vigor, health and action. In Europe sour stock is everywhere preferred and almost universally used. We are now rapidly coming to the same practice. Seed are secured by cutting selected fruit, squeezing out pulp and seeds and sieving; or the fruit may be decomposed in water and the seeds washed free from the pulp by use of the sieve. The seeds should never be permitted to dry, and to prevent this they may be stratified in moist sand till needed for planting. Seeds from Florida come dry, but will germinate readily if soaked in water about seventy hours before planting. Mr. R. M. Teague, one of our most successful growers, always plants in the open, with no protection. He thinks this gives him hardier trees and a better root system. It is to be said, however, that his loca- 2— cc 18 CALIFORNIA CITRUS CULTURE. lion is in a very protected district. But most of our nurserymen protect the young plants by use of a lath cover. The seeds should never be planted until the earth is warm or they may decay. In any case, the soil should be rich, loamy, and with a surface of sand at least for two or three inches. If this is slightly ridged, and the seeds planted on the ridges, the drainage will be more perfect and the damp- ing-off fungus will not be so likely to put in its deadly work. From March to May, depending upon season and soil, is the time to plant the seed bed. The seeds are best planted in rows one foot apart. The seeds are covered about one inch with soil that has been screened. Fig. 7. — Young seed bed orange stock. (After Lelong. ) It is easy to irrigate between the rows and to cultivate with a hand cultivator. The seeds will come up in about three wrecks if the weather is favorable. The young seedlings should be well watered and culti- vated and left in the seed bed for one year. As already stated, many prefer to protect the young seedlings. The earth must be kept moist, but not too wet or the plants will die of fungus attack. The early spring is the best time to plant not only the seeds but to transplant the seedlings. The young plants from the seed beds (Fig. 7) should be transplanted to the nursery in rows at least three or four feet apart, or so as to CALIFORNIA CITRUS CULTURE. 19 admit of cultivating by horse without injury, and fifteen inches apart in the rows. This gives ample room for digging and balling. The plants are easily loosened in the seed bed by the use of a long spade, and should be quickly set, as the roots must not be permitted to become dry. Only robust plants should be transplanted to the nursery. As Mr. R. M. Teague says, "the best are none too good." Some advise keeping puny plants for two years in the seed beds. It were better to discard them entirely. To take up the seed bed plants, a four or five tined potato fork is excellent. It will not cut the roots as will a spade. If the weather is hot it is well to place shade boards above the young plants. The nursery should be carefully watered and cultivated for two years, when the nursery trees should be ready for budding. This insures larger and stronger trees, and the buds can be set six inches above the ground. Budding is possible whenever the bark slips easily, and may be done in March and April. Summer budding is not uncom- mon, though the best time to set the buds is in September and October. The buds will start as soon as the sap begins to flow ; will become strong before fall and will resist the cold of winter. Here, again, it is well to select only the best of the young trees. The bud union is the weak place in a citrus tree, and should be well above the reach of irrigating water as a preventive of gum disease. SELECTING BUDS. The selection of the buds is, I think, the most important step in the whole range of citrus culture, and is reason enough for one to grow his own trees, at least from the time they are set in the nursery. Only buds from tested trees, whose performance has been most excellent in both quality and quantity for a number of years, should ever be accepted. This gives us pedigreed stock. In this way we hope to double our output and profit. "We must remember what selection has done for corn in Illinois and Iowa. (See article on breeding citrus trees, by A. D. Shamel, The Monthly Bulletin, California State Commission of Horticulture, Vol. I, No. 9, August, 1912.) Mr. R. M. Teague uses only selected buds. He allows his patrons to furnish their own buds if they so prefer, though this privilege is rarely accepted. The past season only two persons accepted the offer, though he sold over two hundred thousand trees. Only plump, vigorous buds should be used. The method of inserting the bud is explained by Figs. 8 and 9, where is shown the T-shaped cut, the peeling of the bark and the cutting and insertion of the bud. The tying by budding twine or waxed strip of cloth is well shown. Some of the twigs with foliage are left on the young plants to promote vigor (Fig. 10), though not many, 20 CALIFORNIA CITRUS CULTURE. Fig. S. — Preparing the slock to receive tlie hucl. (After Lelong.) Fig. !). — Cntfins the hiul from the scion. (.Aftor Lclong. ) CALIFORNIiV CITRU^^ CULTURE. 21 as we wish to throw sap to the ])uds. After the buds are well started the old twigs may be gradually removed. One or two years after budding the young trees are ready to set in the orchard. Large trees may be budded if a change of variety or if a better tree is desired. Here the buds are inserted into the branches (Figs. 11 and 12), some of which are permitted to remain to insure thrift, and removed as the new growths from the bud become large and thrifty. The trunks in this case should be protected from the sun's hot rays by whitewash, or by wrapping with some protecting cover. It is also well to protect young trees in the orchard in similar fashion. All pruning Fig. 10. — Showing bud inserted and the wrappings. In some cases a. few limbs are left to promote vigor. (After Lelong. ) of orchards should be close, and the fresh cut at once waxed over. In case Fuller's rose weevil attacks the buds, as they are wont to do, the insects may be headed off by winding loose cotton about the trunk below the bud. The beetles are wingless, and so can reach the buds only by crawling up the trunk. The cotton will prevent this. Citrus trees can be started by grafting, by slips, or by layering, but as none of these methods are now in vogue in our citrus orchards it is needless to discuss them here. 22 CALIFORNIA CITRUS CULTURE. Fig. 11. — Orange tree cut back to force it to throw out shoots from the main branches, which are budded. Tlie body of the tree is protected witli burlap or wliitewash. (Aftei- Lelong. ) J.^J.'T*' Fig. 12. — Large seedling orange trees worked over by budding in the main branches. (After Lelong.) CALIFORNIA CITRUS CULTURE. 23 CARE OF THE YOUNG CITRUS ORCHARD. Humus is very essential to the best growth and vigor of our trees. Therefore, a good application of well-rotted stable fertilizer will be welcomed by the young trees even the first year. The trees must never feel the lack of abundant moisture. At first basins about the trees for irrigating are allowable, but furrows, even in the young orchard, are usually the cheapest and the best. In any case the water should not touch the tree trunks, and the irrigation should be deep, then the roots will go down deeply, where they always should be. We often talk of trees as being deep or shallow rooting, but are not these condi- tions the results of our special methods? The roots will go where the water or moisture is. The elms in the eastern swamps are very shallow rooting. I have grown them here in California, and found the roots deep in the soil. Surface irrigation invites the roots to the surface, while if the water is placed deep down the roots are impelled to push down to secure it. Shallow rooting trees in an arid soil will always sufi:'er in times of drought; while trees with roots deep in the soil will usually suffer not at all. I have trees that I have set and cared for for i !<;. i-i. — Orange trees pruned higli. (After Lolong. ) fourteen years, always irrigating in deep basins or furrows, and now, when I plow deeply in fall or spring, the roots are never harmed. In clay ground it is well to plow deeply, and one can do so safely where the roots are beyond harm's way. I repeat, the roots should be kept down, but if, from improper cultivation and irrigation, this has not been done, the wrong may be righted by plowing each succeeding fall and spring a little deeper. Such a course is certainly wise. I urge 24 CALIFORNIA CITRUS CULTURE. again, the first year the trees must never feel the want of ^ater. As with young animals, dwarfed in youth, always dwarfed. The second season the trees nmst be pruned to form a head that is shapely, but this pruning should be as light as possible to produce a Fig. 14.— Ora-ngu tieo headed low. (Photo by A. U. Sha,iiicLj symmetrical tree, as the abundant foliage is of signal use at this period. In Italy the trees are headed high (Fig. 13), so that one can walk under the lower limbs. The practice of lower heading (Fig. 14) is much to be preferred. The lower branches should leave the trunk at varying heights to avoid crotches and splitting. CALIFORNIA CITRUS CULTURE. 25 FERTILIZATION. In the young orchards — in all orchards — -a winter cover crop of vetch, Canadian field peas, burr clover, or other vigorous legumes (vetch is probably the best) is very desirable. This insures against washing of the soil in case of heavy rainfall, supplies the needed humus, and also adds to the soil the most expensive, and possibly the most deficient, soil element — nitrogen. The roots of this cover crop also liberate other elements of fertility. The soil bacteria take the free nitrogen from the air and combine it with the: soil salts, when it is in form to be utilized by the trees. This is emphatically the cheapest way to secure the valuable and greatly needed nitrogen. We must have abundant water for both the cover crop and the trees. This cover crop should be plowed under not later than February, that it may be decomposed or converted into humus in the early spring as the probable moisture at this season promotes decomposition. To plow this under at so early a date and yet permit the plant to reach its full development requires that the seed of the cover crop be planted early — not later than September. In case of light rainfall in the autumn irrigation must be practiced, not only as the seed is drilled in, but also when needed afterwards. In this case broad, shallow furrows must be left so that irrigation can be accom- plished whenever it is desired to water the plants. Some of our best citrus growers advocate and practice the planting of cover crops in summer, using at this season cowpeas. This may be wise in case one has abundant water, especially in a young orchard, but in this case we must be very careful that our trees are not robbed of the required amount of water. I can but believe that this is a questionable practice. The questionable practice of growing alfalfa in citrus groves is an increasing one. This makes a heavy demand on the water supply. Dr. E. W. Hilgard used to say that alfalfa hay was easily worth eight dollars per ton to plow under as a fertilizer. Dr. C. G. Hopkins main- tains that growing alfalfa, just to use to fertilize our orchards, is well worth consideration. (See the Monthly Bulletin, Vol. I, No. 9, page 641.) Many utilize the space between the young trees by growing an extra summer crop of some useful vegetable. In such case nothing is better than beans, as these tend to make the soil loose and friable, and as these are legumes, they really enrich the soil by adding nitrogen, as we have already explained. Beans are also one of our most profitable field crops. Many, however, grow no secondary crop, preferring to give the trees, old or young, all the fertility that the soil possesses. As the grove reaches on toward maturity the presence of abundant humus is more and more important, and so the cover crop must not be 26 CALIFORNIA CITRUS CULTURE. neglected. Stable fertilizer should be used in generous pioportions, Math scarcely any limit in the case of clay soils. Straw, especially bean straw, is particularly valuable. Commercial fertilizers are also to be recommended. While the abundance of potash in our California soils would seem to sustain Dr. Hilgard's contention that we need not add this element to our soils, yet some of our most intelligent growers feel sure that they have secured much advantage in the use of this soil element. Dr. Hopkins maintains that limestone, ground coarsly, is often more needed than potash. (See The Monthly Bulletin, State Horticultural Commission, Vol. I, No. 9, page 424.) Dr. Hilgard urges also that the phosphates are likely to be the first fertilizers that will be called for by our California citrus orchard soils. It is never safe to neglect advice of one so thoroughly informed, and one who has had such valuable observation and experience as has had Dr. Hilgard. Dr. Hopkins states, as already mentioned, that many soils are more likely to be deficient in lime than in potash. The reason for this is, the greater solubility of the lime permits it to be washed from the soil. (See The Monthly Bulletin, State Commission of Horticulture, Vol. I, No. 9.) It makes no difference whether we use rock or bone phosphates, as phos- phates are phosphates, whatever their origin. In case either of bone or rock, the treated or superphosphates are more readily and quickly avail- able, but if the untreated are ground very fine and added to a soil rich in organic matter, and if the bone is steamed, they will answer well and in time will all be utilized, so that really nothing is lost. The potash and phosphates should always be placed deep in the soil. The presence of humus insures organic acid, which renders the phosphates available. The phosphate slag affords also a cheap and valuable fertilizer, when procurable. The most costly fertilizing element — nitrogen, so necessary because it enters into every living cell, plant or animal — will be much in evi- dence in case we have followed the foregoing advice regarding the use of cover crops and stable or barnyard manure. Yet we may find it advisable to secure it in more ample quantities. Many use Chili salt- petre or nitrate of soda. This in the cool days of early spring brings a quick response from all vegetation. It is, indeed, very quickly available as it is very readily soluble. For this reason it is quite likely to be washed out of the soil and lost. The late Dr. Frank H. King, one of our greatest soil chemists and long time professor in the University of "Wisconsin, urged great caution in the use of this sodium nitrate. The nitric acid is very likely to let go of the soda and unite with some other base, and the carbonic acid of the soil will at the same time couple with the soda, and thus we will have formed sodium carbonate, the black alkali, which, as we know, is a very serious enemy of nearly all plants. CALIFORNIA CITRUS CULTURE. 27 In soils that are poorly draiued we often have too much of this black alkali without adding any more. Its presence may not be apparent at once, but we are storing up trouble for our children, or the future owners of the land, if we use this Chili saltpetre, especially on poorly drained soils. If, however, sodium nitrate is used in connection with gypsum less harm will occur. The organic nitrogen secured in dried blood and tankage is without objection, and though slower to act, is very sure to be available sooner or later, and can be used with little or no loss. It is well to remember that the Germans, among whom are many expert scientists, advise and use much commercial fertilizers, nuich more than we do in America. It is also significant that their crop production is often much heavier and of finer quality. We must remember that our citrus trees are tremendous producers, and so must be very generously fed. Indeed, our most successful growers in Cali- fornia are generally those who use commercial fertilizers in greatest abundance. It i.s not presumptions, I think, to predict that in the near future all citrus growers will grow luxuriant cover crops, will use abundant stable fertilizer, and will supplement these by a liberal use of commercial fertilizer. I am glad to append here the practice of some of our best orchardists. The late Judge A. F. Call, of Corona, California, was a successful citrus grower and spoke from experience. He thought lemons need more nitrogen than do oranges; preferred organic or a slow-acting nitrogen ; supplied the orange with nitrogen in the spring and the lemon in both spring and fall ; he used no potash ; he believed phosphoric acid valuable, would apply it at any time, but wished it drilled deeply in the soil; he was a firm believer in cover crops. Mr. Frank L. Palmer, of North Pomona, would use for phosphoric acid high grade tankage early in the season; or, if bone meal is pre- ferred, plows it under in the early winter. He often adds superphos- phate in midsummer, drilling it in after irrigation. He believes in sulphate of potash, applied with drill in the fall. He decides at the beginning of the year how much of each fertilizer he will use throughout the season, and then uses the separates to supply the amount desired. Mr. C. C. Chapman, of Fullerton, uses from fifteen to twenty pounds of complete fertilizer, containing nine per cent nitrogen to each large tree. He supplements this with three to four pounds nitrate of soda in the early spring. He applies five to seven pounds of potash and ten to fifteen pounds, running eighteen to twenty per cent of superphosphate, or eighteen to twenty pounds, running twenty to thirty per cent of ground bone. He drills in deeply, all but the nitrate of soda. The question of using home-mixed or separate, fertilizers, or a com- plete fertilizer, is not easy to answer. That the latter is most expensive there is no question. If one is willing to study the question thoroughly 28 CALIFORNIA CITRUS CULTURE. and proceed with wisdom and energy, there is little donht but that to use the elements separately, or to mix tliem at home, will save much money and will give good results. IRRIGATION. It has already been suggested that trees should never be allowed to feel the need of water. Lack of proper irrigation is the cause of many of the failures in citrus culture. Irrigation should be deep down. If the grade in the orchard is slight, the run need not be so long. If great, it should be longer and the stream smaller. Cross furrows made with a subsoiler twelve or fourteen inches deep will often give excellent results. Zigzagging the furrows among the trees, so as to get water on all sides of each tree, gives the water better chance to get down to the roots, and is often practiced with no little satisfaction. The great desideratum is to give plenty of moisture to all of the roots all of the time. It will pay admirably to dig a ditch from just under the trees to the middle point between four trees at different parts of the orchard, and at not too long intervals of time, to note just the condition of the soil as to moisture and the way the roots are developing. Such practice will often bring great surprises to the orchardist, who vainly imagines that his trees are being liberally supplied with all needed moisture. The King soil tester is less valuable only as it fails to show root distri- bution. It costs about seven dollars, and is worth many times that amount. It enables one to investigate the subsoil six feet down from the surface very quickly, easily and cheaph'. In case of a side hill, we may follow the practice so common in Calabria, Italy, and in parts of Switzerland, of terracing the hill slopes, though it is usually more satisfactory to contour the slope as we plant our trees, and thus we may irrigate as easily as we can on a more level field. The great Arlington orchard of Riverside County, and the Limoneira orchard of Ventura County are examples of where this last method is practiced with entire satisfaction. As previously stated, the grade of the orchard must be made perfect before trees are planted. In the citrus groves, no matter what age, filling the furrows and cultivating the ground should be practiced just as soon after a rain or irrigation as it is possible to get on to the land without injuring it. Indeed, the ground should never be permitted to bake. The gauge to proper tillage with a clay soil is the entire absence of lumps or clods. In plowing clay soil it is the wisest plan never to leave the field until all the day's plowing is thoroughly harrowed, as the possible lumps are easily pulverized while they are yet moist. It remains to be said that clay soils are more retentive of moisture than are sandy soils, and will need less and less frequent irrigations; CALIFORNIA CITRUS CULTURE. 29 that sandy soils will be more retentive of moisture if well supplied with humns ; and all should remember that no thorough orchardist will wait until his trees show by wilt of foliaii'e tbat they are thirsty before he turns on the water. PRUNING. After the shaping up of the yearling orange tree little more pruning is called for, other than to cut out all the dead limbs or to cut back or off the too ambitious suckers or water sprouts ; though if the trees are headed low, as they should be, it will be wise to trim up from the ground only enough to permit cultivation of all the surface soil close up to the trees. This low heading protects the trees from the sun. Some of our most excellent orchardists prune, even the orange, more thoroughly, cutting out the weakest of all competing branches and letting in the sun, believing that they thus secure larger foliage and more fruit wood. With the lemon, more pruning is usually done.. It is found that more and better fruit is secured if the trees are cut back and the centers somewhat thinned. It is now the common practice of our best lemon growers to thin out and cut back the branches every year. These primings in small orchards may be cut up by the use of a hand pruner, though many orchardists use a cutting box, which runs by power and is drawn between the rows of trees, to cut these prunings into rather short lengths, which are then plowed under. I believe this is a very wise practice. Those with small holdings may combine and secure a power cutter to be used in common. There is one custom among almost all citrus fruit men that I can but believe is wholly \\T:'ong. I refer to the fact that the branches are permitted to hug the ground. This precludes cultivation close up to the trees, and if there is a growth of grass or weeds under the trees in early spring and on up to summer, this is likely to be untouched, and there is a heavy loss of M^ater by transpiration from this undergrowth. If the soil is not broken up, it is dead soil, and there is great consequent loss. I am firmly of the opinion that the whole soil close up to the tree should be mellowed deeply at each cultivation of the orchard, even though general practice is to the contrary, so that there may ha a splendid, dry, fine earth mulcJi, of at least four inches, alivays covering the entire surface of the ground. Some of our ablest orchardists, notably Mr. C. C. Chap- man of the ''Old Mission" lu'and. practice this low pruning, and are 30 CAIJFORNIA CITRUS CULTURE. not content unless all of the soil is mellowed everywhere, even up to the very trunk of the tree. It is only in a mellowed, aerated soil that the bacterial action, so necessary to root activity, can take place ; so all imcultivated area is waste land. He who leaves the earth under the tree hard and uncultivated is satisfied with the "half loaf" when a whole one is entirely within his reach. SCHEDULE OF CULTIVATION. The first cultivation of the calendar year will generally be when the cover crop is plowed under in February. If a too wet soil forbids work in February, then as soon thereafter as the soil is in condition to be worked. This early plowing promotes rapid decay, as the moist soil induces bacterial action, and is best done by the use of a disc plow, and disc harrow following right after, as any other will tear up some of the vetch, etc., which should be kept wholly under the surface soil. In ease cover crops are not grown, many prefer to plow in January. This is a good time to plow under bone meal, tankage or other organic fertilizers. The cultivation after this, until September, should be just sufficient to preserve the four to six-inch dry earth mulch. Cultivating at varying depths prevents the formation of irrigating hardpan, which must never be permitted to form. Early deep plowing also helps to prevent the formation of plow sole. Of course cultivation will follow irrigation as soon as the soil can be worked without injury. In Sep- tember the seed for the cover crop will be drilled in after the phosphates have been placed deep down in the soil. ThCvSe latter may be placed in the furrows or drilled in in case one does not plow. If necessary, the cover crop should be irrigated in the fall months, and if desired, the crop can be grown in drills far enough apart to be cultivated. Some excellent citrus growers are growing alfalfa in their orchards as an experiment, in which case no cultivation is required, and bacterial nitrogen is being manufactured in the soil every week of the year. In this case much water must be at one's command and most liberally used. This is better grown in alternate rows of the orchard for three years, then plowed under and the other rows utilized for alfalfa as before for the same period. This practice has not been general at all, but some, notably Mr. Hampton, of Corona, who have tried it have expressed themselves well pleased. Dr. Hopkins suggests that alfalfa be grown in a separate field, hauled to the orchard, and worked into the soil. He says it is as well to convert this into concentrated fruit products, like oranges and lemons, as into beef, poi'k and mutton. CALIF0RNL4. CITRUS CULTURE. 31 TOOLS AND IMPLEMENTS FOR CITRUS ORCHARDS. By one of the most experienced and successful citrus growers of California. Wagon. Perhaps first of all is needed a substantial wagon with strong bolster springs for hauling fruit and other miscellaneous pur- poses about the place. Most orchardists prefer low wheels for con- venience of handling. Plows. A strong 10-inch or 12-inch share plow is almost indis- pensable, as is also a smaller 6-inch or 8-inch plow. The old-fashioned mold-board plow with roller coulter and chain is considered a superior tool for plowing under the cover crop. When properly handled, and not always run at the same depth, it most effectively stirs the soil and buries the green manure deep below the surface. The disk plow throwing one or two furrows is in very common use for orchard plowing, and for handling a heavy growth of vegetation it is easily operated without the annoyance of coulter and chain. It is also well adapted to stony ground, though its work, even there, is not the equal of mold-board plowing. Either the mold-board or disk plow will require two, four or six horses, according to depth. Large horses, or better, mules, are a requisite in citrus culture. Whether using the mold-board or disk plow it is usually necessary to break out the first furrow or two next the trees — or the last furrows, as the case may be — with the smaller walking plow drawn by a single animal, or by two hitched tandem. Harrows. The adjustable tooth-harrow is in frequent demand for following the plows on cloddy soil and for dragging over the irrigated furrows in advance of the cultivator. The disk harrow is indispensable for use on ground covered with litter of any sort. The orchard extension-disk harrow is so designed that it may be operated well back under the trees when desirable, and at other times altered so as to cut no more than five feet wide. When extended one group of disks works under the tree while the other group works out in the center of the space, leaving six feet between them to be worked with another disk or to be disked later when the extension rods have been removed and the two groups of disks set close together. Cultivator. The cultivator must be strong enough to cultivate freely to a depth of ten inches when desired, and it must be so con- structed that it may be operated at varying depths and forced to those depths by its full weight and the proper type of shovels or chisel teeth. Hinged extensions on the ends of the cultivator beam are often used for cultivation under low-hanging and wide-spreading trees. 32 CALIFORNIA CITRUS CULTURE. Marker or Furrower. The marker, for making the irrigation fur- rows, is not unlike the cultivator in strength and design, except that it carries on its beam only two, or three, sometimes four or five, stout broad shovels, depending on the number of furrows desired. It is a common practice among smaller growers to alter the cultivator each time marking out is necessary by the mere substitution of shovels for the teeth, reversing the operation again before cultivation is necessary. Thus one tool serves a double purpose. The marker may be extended in the same way as the cultivator. Subsoiler. (Fig. 15). This is a most important tool in the citrus orchard, and yet it is probably the tool that has been used least of all. Cross subsoiling to a depth of from sixteen to eighteen inches at right angles to the irrigation furrows and midway between the trees greatly facilitates deep irrigation and improves the aeration of all of the soil. l'"ii:. ] r..-- Siilisiiiler at work in an orchard. (After Lelong.) An occasional subsoiling, say every third year, of the entire cultivated area at intervals of two feet and in two directions to a depth four inches below the deepest plowed and cultivated depth will break up plow sole or irrigation hardpan and supply the much needed air that is too often shut out from the roots. Drills. The seeding of cover-crops is usually done Avith the drill. The "disk" drill instead of the "hoe" drill has many advantages where trashy ground may be encountered. Commercial fei-tilizer is usually drilled into the soil and to as great a depth as possible. A tendency to believe in applying a part of the CALIFORNIA CITRUS CULTURE. 33 fertilizer underneatli the spread of the branches or as close to them as possible has called for a low, squat drill with seeding box extending out at either end beyond the wheels. This is well exemplified in some of the later models of orchard drills now on the market. Efforts to put on the market a satisfactory combined seeder and fertilizer drill that will handle all kinds of both materials in the proper quantities per acre have not as yet been altogether a success. Such a drill is greatly needed for the smaller orchardist. He who has but a few acres may more profitably hire his seeding done, or rent a drill, or perhaps own a small interest with others in a community drill, because the tool is used so very seldom during the year. The same applies to the fertilizing. Spraying Outfit. In most localities the spraying of citrus trees at one or another season of the year is a coinmercial necessity. Small orchardists usually find it cheaper to buy and mix their own materials and hire the owner of a machine to come and do the spraying. In the larger grove the power spray outfit, with gas engine, force pump and 200-gallon to 250-gallon tank with agitator, is now a part of the regular equipment. Very satisfactory work is being done with the barrel spray pump in some small orchards. This requires one man to operate the hand pump while another handles the nozzle. Miscellaneous Tools. Other tools might be mentioned, such as the one-horse cultivator and one-horse marker often used in young orchards, the ''cyclone" and "straight knife" for cutting weeds, the spring-tooth harrow, the reversible disk and share plows for hillside and special needs, the brush cutter for chopping up the prunings to be thrown into the orchard for mulch, the manure spreader, tank wagon, fumigation cart, scrapers and drag-floats for leveling and grading the land, long handled and hand pruning shears, curved saw, grafting wax or, if pre- ferred, thin putty, clippers with curved points. King's soil tester, ladders and other picking equipment, pruning tools, and the many smaller hand tools. But these are either such common ordinary tods that each riian is in a position to enumerate his own needs and select the best obtainable in his community, or they are tools that may be dispensed with altogether except under such conditions as confront the larger orchardist or the orchardist whose needs are exceptional. Single-trees and Double-trees. At all times and in all places in the orchard the .shortest possible double-trees and single-trees should be used, as at best they are a great menace to smooth and low-hanging branches. Leather protections, or guards, over the clips are wise precautions. 34 CALIFORNIA CITRUS CULTURE. PICKING. There are three things which must be carefully observed in picking citrus fruit. First in importance is careful handling. This applies to all kinds of citrus fruit. They must not suffer the least bruise, as any wound forms a seed bed for the ever present blue mold spores, which are terribly fatal to successful shipping; no clipper-cut wound; no thorn-puncture, no bruise from rough handling. The uninjured skin of an orange or lemon is resistant to the common process of decay. Mr. C. C. Chapman called attention to this in his admirable lecture at the Long Beach Seaside Institute about 1904. But until Dr. G. Harold Powell demonstrated the importance of this care thousands of dollars were lost, where there is now hardly any loss. Again, care as to the size is also important. Picking with a ring makes this sure and easy. The orange box, which is 11^ by 11^ by 24 inches, will hold as follows : Number in box Diameter in inches Size of wrapping paper 80 3f inches 3; inches 3^— inches 3^ inches 3g inches 3 inches 2| inches 2§ inches 2§ inches 2* inches 2% inches 2J inches 12 by 12 Ofi 12bvl2 100 12 by 12 112 11 bv 11 lOQ 11 by 11 1.50 11 by 11 17G 10 by 10 200 10 by 10 91(3 9 by 9 2^0 9 by 9 299 8 by 8 324 8 by 8 The lemon box, which is lOf by 13| by 25, wi 11 hold as follows : Number in box Diameter in inches Size of wrapping paper 210 2% inches 2§ inches 21 inches 2h inches 2i inches 2J inches 2-\- inches 2 inches 10 by 10 '>40 - - 9 by 9 270 9 by 9 300 8 by 8 3G0 8 by 8 420 8 by 8 442 7 by 7 490 7 by 7 CALIFORNIA CITRUS CULTURE. 35 ^6 J ^^F' oao L. oao DHOOOD /ao s //Zs uoo OCXX) ooo Fig. 16. — Orange packs. 36 CALIFORNIA CITRUS CULTURE. Z/^./ ^^3/ ^ ^^^^y Fig. 17. — Orange packs. CALIFORNIA CITRUS CULTURE. 37 Z/6 S 3X3 "(^ 4x3-^ Fig. is — Orange packs. 38 CALIFORNIA CITRUS CULTURE. 3Gs zxz-s 3 /ac/erj- ^8J Zxz--^ 6^s zxz-^ Fig. 19 — Grapffruit paok.s. CALIFORNIA CITRUS CULTURE. 39 ZIOJ Fig. 2 0. — Lemon packs. 40 CALIFORNIA CITRUS CULTURE. 3^0 s OoOqOo OnOoOo HoXo^o 3x3-/0 4x3-9 4f^y /■4f7 Fig. 21. — Lemon packs. CALIFORNIA CITRUS CULTURE. 41 A box of oranges will hold from eighty to three hundred and sixty, according to size. The weight will vary with variety, but will average about sixty-six pounds of fruit; the total weight averaging about sev- enty-five pounds. In case of oranges and pomelos, they are not picked until ripe, or should not be, while lemons are better picked green, especially if a desirable size is attained. Lemons picked green and cured in the packing-house will ship better and are the only ones suitable for long shipment. All lemons, except those that ripen on the trees before reaching the desired size, are cured in the packing-house. Oranges and pomelos are usually kept only two or three days until the skin softens by evaporation, when they are more easily packed. Pomelos are some- times held successfully for weeks before shipment. The lemons must color and this takes time. This curing improves the appearance, thick- ness and texture of the lemon peel, giving it a soft kid-glove finish. Lemons are sometimes kept in the packing-house for ten weeks before they are sufficiently cured. It is possible to hold them much longer than this if market conditions require it. The fruit should always be picked by use of curved-pointed clippers and the picking sack, which can be carried and emptied without bruising the fruit, and should be drawn to the packing-house on cars or wagons with good springs. The rule to be observed, ever and always, "handle all citrus fruits as though they were eggs." 42 CALIFORNIA CITRUS CULTURE. THE PACKING -HOUSE. The packing-house of to-day is a masterpiece of study and skill, and is the result of much thought and experience. The precooling, automatic handling, and easy, gentle working are a surprise to one a stranger to such perfection. A description of the model packing-house of to-day would take much time and space. The only way to become informed is to visit a model house. The lemon house of the Limoneira Company at Santa Paula, where the Teague tents permit easy and ready ventila- tion, and cheap, admirable curing, represents one type ; while the other type with its refrigerator room is well shown in the model house at Pomona. Both types should be visited and thoroughly studied by those contemplating building a packing-house. A lemon must be perfectly clean and bright, and so must be washed. The washer must do its work very gently. We must remember that none but the best is good enough. So much of intelligence is now devoted to citrus culture that he who would succeed must be mindful of every slightest detail. To-day picking gangs under an expert manager are working so carefully and well that deca}' is greatly reduced. Soon all citrus fruit will be picked by skilled pickers. The wrapping and pack- ing is now a work of art, and this is well, as a neat pack will enhance the selling price beyond belief. GRADING. Grading is a matter of great imjiortance. The grading for quality is done hy hand, the sizing is done by machinery. Lemons are usually sized by hand. The ' ' fancy brand" must be bright, smooth and perfect. ' ■ Choice ' ' must be bright, but the skin may be a little rough and thick. "Standards" are less perfect in appearance, but are merchantable. "Culls" take all unmerchantable fruit. These may be plowed under as a source of humus. Oranges before the sugar is developed or when frosted should never be shipped at all. Such fruit is very likely to be sold at a loss, and is very prejudicial to the interests of the industry as a whole. Mr. C. C. Chapman said at the Long Beach Seaside Insti- tute in 1904 that his brand, "Old Mission," was worth as much as the fruit itself. It should be the aim and determination of our citrus growers to establish a brand that would be famed the country over. California citrus culture. 43 PLANT DISEASES. Plant diseas(^s nuiy l)e considered under three heads : Physiological, or plant sickness, fungous and insect attack. There are several ailments that are wholly physiological. The plants or trees are .sick. The most common of these is chlorosis. Chlorosis, Yellow Leaf, Variegated Leaf or Mottled Leaf. This peculiar color is doubtless simply symptomatic. As pallor in man, so chlorosis in plants, denotes disease — something is wrong. As in Fig. 22. — Die-back on orange: A, showing gum pockets; B, cross-section of a Valencia, showing gum at core; C, twig sliowing multiple buds and' dead tips. (After Essig. ) case of all physiological troubles the thing to do is to search for the cause of the ill, and then apply the suggested remedy. In clay soils with poor drainage the earth may be water logged, in which aeration is impossible, and we have a dead soil. This last condition follows from a hard, cemented soil, consequent upon imperfect cultivation. Artificial or natural hardpan will also produce the same condition. Again the plants may be thirsty and suffer from lack of moisture. The soil may be impoverished and the plant cry out for food. Probably the great cause is "malnutrition," including both food and air. The artificial hardpan referred to is a cemented soil, just l>elow the plane of deepest 44 CALIFORNIA CITRUS CULTURE. cultivation, usually eousequent upon the cementing lime carbonate in the water used in irrigntion. Cultivating at different depths will tend to break this up and relieve the trees. Dynamite will break up the deep or natural hardpan. The trio of remedies for physiological ills is right irrigation, cultivation and fertilization. Exanthema— Florida Die-Back. (Fig. 22.) This disease is not well understood. The ends of the branches die; frecjuently tufts of small twigs develop from supernumerary l)uds ; the bark roughens and shows lines of broAvn excrescence ; gum pockets form near the attachment of the leaves ; the fruit is imperfect and often pale yellow and insipid, and gum forms in the fruit close atout the core; dark green leaves appear, which, though they would seem to indicate health, are really the result of the disease. It is claimed that gravelly soils wath coarse gravel for subsoils, or soils underlaid with hardpan promote this disease, as do large applications of stable fertilizer on such soils, especially if the trees have previously lacked plant food. As above advised, good care and removing the cause when possible is the only known cure. Gummosis— Gum Disease. Mr. H. S. Fawcett has shown that gum disease is often fungoid. The gum is an incident. Fungoid attack of the bark is the real disease. It affects all kinds of citrus trees, but lemons suffer most. Gum exudes at various places, but in case of lemons, most at the crown near or at the place where the bud was inserted. Injuries, improper irrigation and earth compacted about the spot where the bud was inserted are enough to cause the disease. It is best to have the bud above the earth and avoid running water about the crown. IMr. Fawcett has produced gum disease of the lemon by inoculations Avith the decajdng bark; also from cultures. He finds two distinct forms, both produced by common molds of the packing-house. In one, the brown rot fungus {Pythiacystis citrophthora), the decay of the inner and outer bark is almost coincident, and the diseased bark remains hard, while in the other, gray fungus (Botrytis vulgaris), the outer bark decays before the inner, and all becomes soft. The cure for both is Bordeaux paste. (See Monthly Bulletin, Vol. 2, No. 8, page 601, August, 1913.) Psorosus— Scaly Bark. (Fig. 23.) This trouble, not found in the lemon, is described in its name. The cause may be improper aeration or irrigation. When serious it is often CALIFORNIA CITRUS CULTURE. 45 fatal. When only small areas or branches are attacked, by cutting out and painting with wax a cure may be effected. This, like gummosis, is not contagious, though its nature and cause are not fully known. This and mal di gomma described below may prove to be fungoid. Fig. 23. -California scaly bark or psorosis on orange. (After Pawcett.) Mal di Gomma— Foot Rot. This is only met on water-logged, clay soils, and is often fatal if not speedily treated. There is decay of the roots from the origin down, 46 CALIFORNIA CITRUS CULTURE. which is serious. Removinii' the earth from the main roots, (^^tting out the diseased portion and disinfecting will usually effect a cure. Mr. R. P. Cundiff, of Riverside, California, claims to have used large duantities of gypsum, 50 per cent pure, working it into the earth about the trees with apparently excellent results. Splitting. Here again the name tells the story. Oranges alone are attacked — the oranges split. It is probably caused by spasms of growth caused by irregularities in culture, irrigation or seasons. Navels, especially, suffer. As we should expect, it is much more common some years than others. We can do something, I think, by regularity and punctuality in our care. Of course we can not control the seasoms. Puffing. This is described by the name. The rind of the orange bulges out in sections, is often very rough, and is easily injured in handling. I have seen it very pronounced in case of trees pushed to extremes, by excessive fertilization. The orange loses its flavor and is likely to become worth- less. Soil and season seem to influence in this aft'ection, and, as we should expect, it is more serious some years than others. Improper irrigation may be provocative of this disease. Peteca. In this disease, which is usually seen only in the packing-house on lemons, there is a pitting of the surface of the fruit. It is injurious only in marring the appearance of the lemon. The cause is obscure. Brown Spot. This is a serious affection, more frequent in the navel orange, which marks the rind of the finest fruit, and appears only after the fruit is picked for some days. Often there is no disc^oloration until the fruit is shipped. It is early picked fruit that shows the spot. The cause of this spotting is not certainly discovered. It would seem that some injury to the epidermis of the fruit may be the seat of the trouble. Brown spot is much less common near the coast. I first had samples from San Fernando, then San Dimas, then Redlands, where that first season it injured fifty per cent of the early picked fruit. Fungi, Molds, Etc. Our citrus trees ol'tcii suffer sevei'cly from the attacks of fungi. These very simple organisms are among the lowest of plants. They develop no chlorophyll, do not take oxygen, but depend upon other CALIFORNIA CITRUS CULTURE. 47 organisnivS for their support. If the supporting organism is dead, we call them saprophj^tes, in which case they do no harm. If living, then they are parasites, and may work us great harm. They often produce myriads of spores, very small seed-like bodies by which they reproduce. JMany put forth minute, thread-like growths, called hyphje, or the tangle, mycelium. These threads which form the common mold, push into the living tissue and sap from it its substance, or, to state it otherwise, feed upon it. The larger and more highly developed are familiar to us in the toadstools and mushrooms, others in the rusts, molds and mildews. Blue Mold (Penicillium italicum) and Green Mold (P. dig-itatum). We are all fainiliar with these molds. The myriad spores give the color, blue or green. They are the common cause of rot in all citrus fruits, and are not unconnnon in many other fruits. They attack almost exclusively injured fruit. This formerly was the cause of millions of dollars loss to citrus growers. The masterly researches of Mr. G. Harold Powell, expert of the United States Department of Agri- culture, demonstrated the cause and remedy for this common rot, so that now the loss from this cause is much lessened. Clipping and handling the fruit so carefully as to produce no injury is a great pre- ventive, and precooling or cooling it off in the cars by icing so that no spores can germinate, has decreased the decay very greatly. The motto of every citrus grower should be, "Handle all fruit as though it were eggs," and never bruise or wound in the least degree. Yet it remains to be said that some fruit, fruit from certain localities and fruit from orchards heavily manured, fails to stand up. There doubtless is sus- ceptible fruit. It may he physiologically weak. The attack is also increased apparently by a continued moist atmosphere. Brown Rot (Pythiacystis citrophthora) . This is a very serious enemy of citrus fruits. The brownish color is very characteristic. It is observed on the fruit, the leaves and lower branches of the tree, in the packing-house and in the packed boxes. It spreads rapidly from fruit to fruit, wherever they touch in boxes or elsewhere. There is a characteristic odor of decomposing oil. It is most common on lemons. The fungus grows and fruits in the soil and in washing the fruit in the packing-house the spores that have blown on the lemons in the grove collect in myriads in the water and play havoc with the fruit, by being carried to every lemon. Professor Ralph E. Smith and H. J. Ramsey, of the University of California (Whittier Experiment Station), in suggesting bluestone (copper sulphate) as a cure, and in working out methods of sanitary treatment in the packing- house, conferred a rare service to the industry and to the State. Blue- stone is placed in the washing water in the packing-house. Straw 48 CALIFORNIA CITRUS CULTURE. placed under the trees, and to a lesser degree a cover crop, lie^ps to keep the spores from reaching the fruit. The usual strength of the bluestone water for brown rot is one and one half pounds to one thousand gallons. This fungus, as we have seen, causes one kind of gum disease of lemon, see page 44. Cottony Mold or White Rot (Sclerotinia libertiana). This is much like the bro\^ai rot, except that it coats the fruit with white. It attacks and often kills the twigs a foot or two from the end. In this mold develop black bodies (sclerotia), another stage in the growth of the fungus. This fungus also develops in the soil, and is more likely to attack lemons that are bruised. It is thought that cover crops, especially vetch, which is also a host plant, favors this fungus. Bluestone will aid in its control, but it must be stronger than for brown rot. Professor Smith suggests that it may not be safe to use it strong enough to be effective on account of injury to the fruit, in which case the remedy must be to destroy it in the field. This fungus has been found recently attacking the orange roots of full grown lemon trees, entirely killing the trees in many instances, at the same time causing more or less gummosis. Gray Mold (Botrytis vulgaris). This is the dark colored decay of lemons in which a gray fungus develops. The fungus in the packing-house is not usually very serious, but as we have seen, it is a cause of gum disease. (See Monthly Bulle- tin, Vol. 2, No. 8, page 601, August, 1913.) Wither-tip (CoUetotrichum gioeosporioides). This fungus kills the twigs at their ends, spots the fruit and leaves, and fells the latter to the ground. Mr. C. C. Teague says that this pest has cost the Limoneira lemon grove more than all injurious insects combined. I saw the plague in Mr. N. W. Blanchard's orange orchard so bad that the foliage looked as if it had been blighted by fire. This disease is becoming more and more common in many orchards, and many are now fighting it with no little success. It seems to be erratic, depend- ing on seasons. Bordeaux mixture and lime-sulphur spray are the specifies to use in its control. Care must be taken in the use of the Bordeaux or injury may result. This is the more true if fumigation follows soon after the spraying. Damping Off (Rhizoctonia and Fusarium). Two fungi seem to be responsible for damping off. The first named fungus attacks the young seedlings at or just above the ground, causing CALIFORNIA CITRUS CULTURE. 49 a decay of the crown or stem, while the second may produce dead spots at any point. Improper soil (it should be sand, at least on top), over- irrigation and insufficient drainage are favorable to this disease. Fig. 24. — Navel or black rot, Alternaria citri, infecting the navel end. (After Amundsen.) Navel Rot (Alternaria citri). (Fig. 24.) This rot attacks only .the navel orange. It is not a true parasite, and attacks the navel end only when it is injured in growth. It is thought that moisture in the navel cavity may favor the disease, as autumn rains seem to increase the affection. The navel is the finest winter variety for all around use, and its seedlessness adds to its excellence. This rot is cne of its few drawbacks, but it is only occasionally that it becomes of serious importance. Root Rot (Oak-root Fungus, Armillaria mellea). (Fig. 25.) Where orange trees and many others replace oak trees in the foothills and valleys a toadstool -fungus, which previously infested the roots of the oak, may attack and greatly injure the trees. It is common in California, and often serious. Mr. Earl Morris, county horticultural commissioner of Santa Clara County, regards it as the most serious pest in the orchards of his county at the present time. It spreads to other trees from the center of infection. Professor Smith suggests that in case this disease is troublesome other and more resistant trees, like walnuts or cherries, be grown in their stead. I have seen one case of 4 — cc 50 CALIFORNIA CITRUS CULTURE. a serious attack on the walnut. Professor Home finds pears and figs especially resistant to this disease. All interested in citrus culture should possess Bulletin 218, Experi- ment Station, University of California, by Professor Ralph E. Smith and Elizabeth H. Smith. For one who wishes to study more deeply into this intricate subject of fungi, etc., Duggar's Fungous Diseases of Plants will prove admirable. CALIFORNIA CITRUS CULTURE. 51 INJURIOUS CITRUS INSECTS. Insects are not so minute and obscure as are funpi, and their pestif- erous work is much better understood. However, their ravag-es are often alarming. It is stated that by very conservative estimate the amount expended annually in California in insect control reaches the startling Fig. 26. — Adult females and egg masses of the citrus mealy bu^ {Pseudococcus citri) on orange. (Essig, P. C. Jr. Ent. ) sum of one million dollars. Tlie damage wrought by their attack doubt- less far exceeds the million dollar mark. The United States government estimates the damage by the pear thrips alone in California for the last seven years at seven million dollars. CALIFORNIA CITRUS CULTURE. Pig. 27. — Cottony cusliion scale ilcerya nurchasi Mask.) on orange twig. (Cal. Hort. Com.) Fig. 2S. — Soft brown scale (Coccus hesperidwn Linn.) on orange twig. (Essig. P. C. Jr. Ent.) CALIFORNIA CITRUS CULTURE. 53 Fig. 2 9. — Full grown specimens of black scale, Saissetia olew (Bern.), at base of nightshade plant. Many of these were under the surface of the soil. (Essig, P. C. Jr. Ent.) 54 CALIFORNIA CITRUS CULTURE. Fio. 30. — Aspidiotus hederw (Vail.) on lemon a.nd i such cases known as the lemon peel scale. (Essig P. C. Jr. Ent.) Fig. -Red scale, Chrps" on orange. (Essit 1'. o. s aurantii (Mask.), Jr. Ent.) CALIFORNIA CITRUS CULTURE. 55 ^:^^f:-^ Fig. 32. — Yellow or citrus scale, Chrysomphalus ciirinus (Coq. ), on orange leaf. (After Essig. ) CALIFORNIA CITRUS CULTURE. n " '^ •^ Ui a a p. a p- a H- < OS u M fa CS R o «; o — c: ^ a - o J . -o « J3 ■i-i d 03 (M O a> '-< ' ' s a ■J) OJ h S S i2 -^ ^ P5 _ --5 O •^ ^ ., < ttf «^ K <^ 2 t; .^' S •^'- S "5 ^ s '^ a '^ g K " « ;r 03 fa fa O. ^ ^ (D r- r- O M fa C5 fa fa' •fa. fa fa Ji o o P5 fa fa fa.. ^ I fe S i t^ O -s ^ a > (0 S .^s UJ > xK ts m s -—- ^ ^1 - oDC a ^ S UJ S CO .2 t^ ^ 4-. o e'S-l ^ a 5 g I- = 3 a J= O O M ** t^ bi aH (0 a -^ t-.2 (0 C . 2 . ;z -: «-; — b-^ o I a oj K E5 UJ o OS s .52 bt. =■ -I i^S i Pi a^ < -^ O (0 !ft ;0 o CALIFORNIA CITRUS CULTURE. 'Ol ^'^ r:z a u ® <1 < J^ rj > ?? ■r; p -1-. -tJ o fn;< fa fafa ?^ y, fa fafa fa fa -73 « o So s =^ .5 2-3 a; 0) -, ^ „, - 0-' ^ -C J3 y^ IB JJ, OJ J3 7: j= a a a c3 a c3 a rj 03 c3 03 •5 'C -5 'C =s - a ^ o o ®' I* c >- a o o) o3 O $ o s 2 1^ ?^ s 15 0-3 O M fa i'S^S^ a » ^. >■ ■- ofa ^ll x:D: £a| <1 * ; CO M- E^ ft .S O! . o ^ . 1 O) 1-^ _. ■_, IT, m ~— "5 W m 58 CALIFORNIA CITRUS CULTURE. -Purple scale. Leuidosunhes beckii fNewin. ), 1 leaf. (Essig, Bull. 2, C. Pom. CI.) Fig. 34. — Adult citrus white ll.v ( A leyrodes citri R. & H. ) . En- larged fiftee 1 times. After Quayle. Couitesy California Experiment Station. ) CALIFORNIA CITRUS CULTURE. 59 Fig. 35. — Larvae and pupse of the citrus white Hy. {Aleiirodes citri R. & H.) on the under side of an orange leaf. Enlargfd three times. (After Essig. ) 60 CALIFORNIA CITRUS CULTIlti:. PREDACEOUS INSECTS PREYING UPON CITRUS PESTS. Pest preyed upon LACEWINGS. lirowii lacewing- (Si/iiipJicrdhiii.s (hkjiih- titu Bks.) Green lacfvving {Chnifiopa (■iilifoniird Coq.) Tfctncrohiiis pncificus Bks _ LADYBIRD BEETLES. /lippodaniid ( oiirfrr/cii'^ Oner Two-stabbed ladybird bemle (Chiloco- rus iivulnerus Muls.) Sleel-bliie ladybird (Oiciis (■]i(iI:/hciiN Boisd.) A.rion plaf/iotii-^ Oliv Axion pilatil Mnls. E:fochomiis californieiis Casey Vryptogonus orbiculus Schon f'ryptohnniis moniroiizieri Muls Hyperaspis lateralis Muls *S'c// */(////*• sardidns Horn ><(!/minis gittfiilatus Lee Scj/'miiiis iichulosus Lee )S'c///n«HS MarginicolUs Manu l^tetJtorus vagans Blackb Vedalia {Novius cardinalis Muls.) Novius kfrhrlei, Olliff Black ladybird {Rhizohiiis vcntralis Er.) SYRPHID FLIES. Large syrphid (Lnsioplifliiciis pyrnsiyi Linn. ) American syrphid {Ryrplnia aiiicricnna Wied.) Small syrphid (Allograpta ohliqua Say) M(\-ily bigs, mites. Mealy bugs, jilant lice, mites. Mites. Plant lice, young scale insects. Scale insects. Scale insects. Scale insects. Scale insects. Scale insects, plant lice. Mealy bugs. Mealy bugs. Mealy "bugs and other scale insects. Plant lic<', nieal.^' brgs, young armored scales. INIealy bugs. Mealy bugs, plant lice. Scale insects and plant lice. Mites. Cottony cushion scale. Cottony cushion scale. Black scale, mealy bugs. Plant lice. I'lant lice. Plant lice. CALIFORNIA CITRUS CULTURE. 61 Fin. 36. — Adult female of Crvptohnnus Fig. 37. — The two-stabbed ladybird montrouzicri Muls. (Essig, P. C. Jr. beetle, Chilocorus bivulnerus MuLs. Bnt.) 'ii:. 3N. — Tlie vedalia, Novius cdrdiidlis Muls. Fig. 39. — The green lacewing (Chrysopa calif ornica Coq.). A, larva; B, eggs on the slender stalks; C, cocoon opened; D, cocoon closed; E and F, adult females. (Essig, p. C. Jr. Ent) 62 CALIFORNIA CITRUS CULTURE. Fio. 40. — Soft brown scale (Cnccus hpsi)eri(lvii\ Linn.), sliowing exit holes of true parasites. (After Quayle. Courtesy Cal. Exp. Sta.) Fig. 41. — Mumniii'il l.i.li.^ ..r ii,- riims niiliid rr,,j,,ntir, 63. Cover crops, 12, 13, 25, 27. plowing, 25, 30. seeding, 32. vetch, 12. Cowpeas, 25. Crop in orchard, 25. beans, 25. Cryptochwtum icerycr, 63. Cryptogonus orbiculus, 60. Cryptolamus montrousieri, 60, 61. Cucumber beetle, 57. Culbertson, J. D., 3. Culls, brand, 42. Cultivation, 23, 28, 30. Cultivator, 31. Culture, citrus, range, 7, 8. Cundiff, R. P., 3, 46. Curing lemons, 41, 42. Cut-offs, acid, 77. Cuttings, 97. Cutworm, 57, 69. Cyanide, 69, 74, 75, 76, 77, 78, 79. potassium, 69, 77-79. ' sodium, 77-79. Damping off, 4 8-49. Dancy tangerine, 93. figure, 92, Decadence in citrus groves, 82. how prevented, 82. not necessary, 82. Diahrotica soror, 57. Die-back, 44. Dipping fumigating tents, 72. Dipterous parasites, 63. Disk drill, 32. Distillate for orchard heating. 11. Dosage, fumigating, 73, 76, 77. 79, 81. black scale, 79. mealy bug, 79. purple scale, 79. red scale, 79. schedule, SO, 81. yellow scale, 79. Doubletrees, 33. Drained soils, 27. Drills, 32. Duggar, B. M., 50. Dusts, sprays, 68-69. Dynamite for hardpan, 44. Elms, 23. Encyrtus flavus, 63. Eriophyes olcivorus, 56. Essig, E. O., 3. Enlecanium j)ruinosum, 57. Eupelmus mirahiUs, 63. Eureka lemon, 97-99. figure, 99. Euthrips citri, 56. Exanthema, 44. Exchange, California fruit gi-owers", 103-104. Exochomus calif amicus, 60. INDEX. 117 Fancy brand, 42. Farmers' clubs, 102-103. Institutes, 102. Fawcett, H. S., 44. Fertilization, 25-28. Fertilizer, 13, 23. drilling, commercial, 32. Firing-, 10. Flies, syrphid, 60. Florida die-back, 44. Flowers of sulphur, 68. Foot rot, 45-46. Frost, 10, 16, 97. lessons taught, 11. prevention, 10—12. Frosted scale, 57, 63. Frozen fruit, determining, 11. alcohol method, 11. Chase method, 11. marketing, 12. trees, pruning, 12. Fruit, frozen, 11-12. growers' exchange, 103-104. Fuller's rose beetle (weevil), 21, 57, 69. Fumigation, 65. block, 82. Bordeaux mixture, 48, 81. buying materials, 81-82. chemicals, 77. dosage, 79. schedules, 76. exposure, 80. insect pests, 56-57. methods, 69-70. procedure, 79. temperature, 81. tents, 70-73. time, SO. wagons, 73-75. Fungi, 46. Fungous diseases, 43. Furrower, 32. Fusarium, 48-49. Gas, hydrocyanic acid, 69. Generators, acid, 75. Gloves, rubber, 77. Glover's scale, 57. Gold dust to remove soot, 11. Grading, 13, 42. lemons, 42. oranges, 42. Graduates, fumigation, 74. Grafting, 21. Grapefruit, Marsh's seedless, 95. pack, 38. triumph, 95. Gravelly soils, 8. Gray mold, 48. producing gummosis, 44. Greedy scale, 57. Greenhouse thrips, 56. Green, citrus louse, 56. lacewing, 60, 61. mold, 47. peach aphid, 56. Growth of industry, 5. Gum disease, 44. Gummosis, 44. Gypsum, 27, 46. Hampton, Mr., 30. Handling young trees, 14, 16. Hardpan, 9. tree troubles, 43-44. Harrows, 31. Heading trees, high, 24. figure, 23. low, 24. figure, 24. Heliothrips hwmorrhoidalis, 56. Hemerohius pacificus, 60. Hemispherical scale, 57, 63. Hexagonal system, 14-16. Hilgard, E. W., 25, 26. Hippodamia convergens, 60. History of citrus, 7. Holes for trees, 16. Homosassa orange, 92. Hopkins, C. G., 25, 26, 30. Hop tree, 83. Hume, H. H., 93. Humus, 8, 12, 23, 25, 26. Hydrocyanic acid gas, 69. Hymenopterous parasites, 63. Hyperaspis lateralis, 60. Icerya purchasi, 52, 56. Imperial lime, 100. Implements, cultivating, 30, 31. Insects, attacks, 43. control, 56-57. illustrations, 51-64. black scale, 53. lacewing, 61. ladybird beetles, 61. chalcid flies, 63-64. lemon peel scale, 54. mealy bug, 51. parasitized aphids, 62. scale, 62. purple scale, 58. red scale, 54. soft brown scale, 62. white fly, 58-59. yellow scale, 55. injurious, 51-59. parasitic, 62-64. predaceous, 60. Irrigation, 9, 17, 19, 23, 28-29. after planting, 17, 18. basin, 23. deep, 23, 28. furrow, 23, 28-29. Italy, 97, 101. Ivy scale, 54, 57. Jaffa orange, 92. figure, 90. Katydid, 56, 63. Kerosene to remove soot, 11. 118 INDEX. King, F. H., 26. soil tester, 9, 28. Koethen, E. L., 3. Kumquat, 95. Lacewings, 60. brown, 60. green, 60. Ladybird beetles, 60-61. JLasiophthicus pyrastri, 60. Layering, 21. Lead arsenate, 67. Leghorn, 101. Legumes, cover crops, 25. Lelong, B. M., 3, 7, 84. Lemon, box, 34. candied peel, 101. frost resistance, 10. grading, 41, 42. oil of, 100. packing, 41. peteca, 46. propagation, 9 7. pruning, 29-30. salted, 101. varieties, 97—98. Eureka, 97, 99. Lisbon, 97, 98. Villa Franca, 97. Lepidosaphes beckii, 57, 58. gloverii, 57. Leucopis hella, 63. Lime, 26, 65. and sulphur, 60. -sulphur, 4S, 67. Lime juice, 100. Limes, 95, 99-100. citrate, 100. Imperial, 100. juice, 100. Mexican, 100. Tahiti, 100. Limestone, 26. Lime-sulphur, commercial, 67. for withertip, 48. Limoneira Companj', packing-house, Lisbon lemon, 97, 98. figure, 98. Loam, 8. Localities to grow citrus, 8, 9, 11. Long- tailed mealy bug, 56. Longulus scale, 57. Macrosiphum citrifolii, 56. Mal-di-gomma, 45-46. Mandarin orange, 93, 95. Manure, 13, 23, 26. Marker, 32. Marking fumigating tents, 73. Marsh's seedless grapefruit, 95. Materials, buying, 81. fumigating tents, 71-72. McFadden, C. E., 77, 78. Mealy bug, 51, 56. dosage, 79. enemies of, 60, 63. 42. Mediterranean sweet orange,»92. Melon aphis, 56. Mexican lime, 100. Microcentrum laurifoUum, 56. Mission Fathers, 7. Mites, citrus red spider, 56. enemies of, 60. silver, 56. six-spotted, 56. Mold, 46. blue, 47. cottony, 48. gray, 48. green, 47. Morrill, A. W., 70. system, 70. Morris, Earl, 49. Moths, 57. Mottled leaf, 43. Mulch under trees, 29. Myzus persicw, 56. Navel orange, 85. figure, 86. rot, 49. figure, 49. Thompson's improved, 89. Washington, 86-87. Nitrate of soda, 26, 27. Nitrogen, 25-27. Novius cardinalis, 60, 61. kabelei, 60. Number of fumigating tents to outfit, Nursery stock, growing, 14, 18-19. Oak-root fungus, 49-50. Oil, kerosene to remove soot, 11. of lemons, 100-101. pots, 10, 11, 12. Orange, bitter, 84-85. blood, 92. chionaspis, 57. diagram of packs, 35, 36, 37. frost resistance, 10. grading, 42. Homosassa, 92. Jaffa, 92. Mandarin, 93. Mediterranean sweet, 92. number in box, 34. paper rind St. Michael, 92. packs, 35-37. picking, 34. puffing, 46. pruning, 29-30. splitting, 46. sweet, 85-92. Thompson's navel, 89-90. tortrix, 57. trifoliate, 84. Valencia, 88-89. Washington navel, 86-87. Orcus chalybeus, 60. Old Mission brand, 42. INDEX. 119- Orchard. 14. care of young, 23. contouring, 28. figure of, 6. planting, 13. preparation of soil, 13. procuring trees, 13. terracing, 28. trees, hexagonal' setting, 14, 15. quincunx, 15, 16. squares, 14, 15. triangular, 14, 15. young trees for, 12. Packing, fruit packs, 35-40. house, 42. Pomona, 42. Teague, 42. grading, 4 2. Packs, grapefruit, 38. lemon, 39-40. orange, 35-37. Palmer, F. K, 27. Paper rind St. Michael, 92. Papilio zoUcaon, 57. Parasites, dipterous, 63. hymenopterous, 63. Parlatoria pergandli, 57. Pear thrips, 51. Peas. Canadian field, 25. cow, 25. Pedigreed stock, 19. PenicilUum cligitatum, 47. italicum, 47. Peridroma margaritosa saucia, 57. Pests, control, 56-57, 60, 63. Peteca of lemons, 46. Phosphates, 26. bone, 26. rock, 26. Phosphoric acid, 27. Physiological troubles, 43. Picking, clippers, 41. expert work, 42. lemons, 41. oranges, 41. pomelos, 41. ring, 34. sack, 41. Plant diseases, 43-50. blue mold, 47. brown rot, 47. brown spot, 46. cottony mold, 48. damping-off, 48. exanthema, 44. fungi, 46. gray mold, 48. gummosis, 44. mal-di-gomma, 45. navel rot, 49. peteca, 46. psorosus, 44. puffing, 46. root-rot, 49. Plant diseases — Continued. spitting. 46. withertip, 4 8. Plant lice, 56, 60. Planting, cover crops, 12, 13. trees, 12-17. time, 13, 16. Plowing, 30-31. cover crop, 25, 30. Plows, 31. Pomelo packs, 38. picking, 41, 93, 94. Potash, 26. sulphate, 27. Potassium cyanide, 77. Powell, G. H., 3, 7, 34, 47. Predators, 60. lacewings, 60. ladybird beetles, 60. syrphid flies, 60. Prickly ash, 83. Propagating citrus trees, 17-19. Prospaltella aurantii, 63. Protective league, citrus, 104. Pruning, 12, 16, 21, 23, 24, 29-30. Pseudococcus citri, 51, 56. longispinus, 56. Psorosis, 44. Puffing, 46. Purchasing trees, 13. Purple scale, 57, 58, 63, 79, 80. Pythiacystis citrophora, 44, 47-48 Quincunx system. 14-16. Ramsey, H. J., 47. Red scale, 54, 57, 63, 79, SO. Florida, 57. spider, 56, 69. Reed, Fred, 3. Reed, J. H., 3, 102. Resin wash, 65, 67. Rhisobius ventralis, 60. Rliizoctonia, 48-49. Ring, picking, 34. Roots, 23. position in planting, 16-17. Root-rot, 49. Rose beetle, Fuller's, 21, 57, 69. Rot, brown, 47. foot, 45. navel, 49. root, 49-50. white, 48. Rubber gloves, 77. tubing, 77. Rutacew, 83. Saissetia heinisphwrica, 57. olew, 53, 57. Salted lemons, 101. Sandy soils, 8, 29. Scales, fumigating, 77. Scale insects, 51-58. black, 57. chaff, 57. 120 INDEX. Scale insects — Continued. cottony cushion, 56. enemies of, 60-64. Florida red, 57. Glover's, 57. greedy, 57. hemispherical, '57. ivy, 57. purple, 57. red, 57. soft brown, 57. Scaly bark, 44-45. Schedule, fumigating, 56-57. Sclerotinia Uhertiana, 48. Scutellista cyanea, 63, 64. Scymnus ffuttulatus, 60. marginicollis, 60. nebulossHs, 60. sordidjis, 60. Seeds, large, 17. planting, 12, 13, 17-19. Seed bed stock, 19. Seeding cover crops, 32. Seedlings, 18. figure, 18. handling, 18. orange, 91. Selecting buds, 13, 19-20. trees, 12, 13. Setting trees. 13, 16-17. Shaddock, 94-95. figure, 94. Shamel, A. D., 13, 19. Sicily, 8, 97. Signiphora occidentalis, 63. Silver mite, 56. Singletree, 33. Six-spotted mite. 56. Sizing fruits, 42. Slips, 21. Smith, E. H., 50. R. E.. 47, 48, 50. Smoke, 11. Sodium, carbonate, 26. cyanide, 77. nitrate, 26. Soft brown scale, 52, 57, 62, 63. Soils, adobe. 8. arid, 8. around young trees, 16-17. clay, 8, 12. 28. gravelly, 8. loam, 8. preparation, 12. sandy, 8, 28. Sicily, 8. tester. King's, 9, 28. Soot, removing from fruit, 11. Sour orange, 84. figure, 85. stock, 12, 13, 17, 97. Species of citrus trees, 83-100. Splitting of fruit, 46. Spot, brown, 46. Spraying, 65-67. formulfe, 65-67. outfit, 33. Sprays, 65-67. ^ Bordeau.x; mixture, 65. carbolic acid emulsion, 65. contact, 65. formulae, 65-67. resin wash, 65. Spray wagon, 66. figure, 66. Square system, 14-15.' Stable fertilizer, 13, 23, 26. Standard brand, 42. Steel blue ladybird beetle, 60. Stethorus vagans, 60. St. Michael, 92. figure, 91. Stock, nursery, 19. seed bed, 19. sour, 12, 13, 17. Straw as fertilizer, 26. Subsoiler, 32. Sub-varieties of orange, blood, 92. Homosassa, 92. other varieties, 91. Mediterranean sweet, 92. paper rind St. Michael, 92. figure, 91. seedlings, 91. Thompson's improved navel, 89. figure, 89. Valencia, 88. figure, 88. "Washington navel, 87. figure, 86. Suckers, pruning, 29. Sulphate of potash, 27. Sulphur, and lime, 69. flowers, 68. lime-sulphiir, 48, 67. Sulphuric acid, 73, 74, 75, 78, 79. Sweet clover, 12. Sympherobius angustus, 60. Syrphid flies, 60. American, 60. large, 60. small, 60. Syrplms aviericaniis, 60. Tangerine, Dancy, 92, 93. Tanglefoot bands. 69. Tannin tent dip, 7 3. Tape line, 76. Tariff, citrus, 6. Teague, C. C, 3, 48, 97. Teague, R. M., 3, 17, 19. Temperature, fumigating 80-81. Tents, care, 73. dipping, 72-73. figure of, 70, 71. fumigating, 70-73. hoist, 72. marking, 73. measuring, 76. number for outfit, 73. size, 70. Teague lemon curing, '42. Termes lucifugus, 56. Termite, 56. INDEX. 121 Terracing for irrigation, 28. Tetranychus himaculatus, 56, 69. mytilaspidis, 56, 69. Thermometer, 77. ' Thompson's Improved navel, 89-90. figure, 89. Thrips, 56. clti'us, 56. greenhouse, 56. Thomomys sps., 101. Tobacco extracts, 66. Tomocera californica, 63. Tools, orchard, 31-33. cultivator, 31. drills, 32. harrows, 31. marker, 32. miscellaneous, 33. plows, 31. singletrees and doubletrees, 33. spraying outfit, 33. subsoiler, 32. figure, 32. wagon, 31. Tortrix citrana, 57. Toxoptera aurantiw, 56, 62. Trees, arrangement, 14-16. budded, 13, 19-21. cost of young, 13. digging, 14. planting, 13, 14, 16, 17. procuring, 13. propagating, 17-19. shipping. 14. young, 12. Triangular system, planting, 14-15. Triumph grapefruit, 95. Tuscany, 101. Two-stabbed ladybird beetle, 60, 61. Valencia late orange, 88-S9. figure, 88. Variegated cut worm, 57. leaf, 43. Varieties of trees, 83-100. Vedalia, 60, 61. Vetch, 12, 25. Villa Franca lemon, 97. Wagon, 31, 41. chemical, 73-77. "Washington navel orange, 86-87. figure, 86. Water, fumigating, 78. increased, 9. tank, fumigating, 74. underground, 9. sprouts, pruning, 29. Webber, H. J., 84. Weevil, Fuller's rose, 21, 57, 69. Western 12-spotted cucumber beetle, 57. White ant, 56. fly, 57-59. rot, 48. Withertip, 48. Woglum, R. S., 70, 78, 79. Woolly citrus aphid, 56. Wrapping, 42. Yellow leaf, 43. mite, 69. scale, 55, 57, 63, 64, 79, 80. Young trees, 12. balling, 13, 14. open roots, 13, 14. selecting, 12. 9 — cc LIBRARY OF CONGRESS aDDmi774SD