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~- Extension Bulletin No. 4 Ca May 1983 OREE., eg AVOCADO PRODUCTION & MARKETING ry Nw oe } ¥ me _* LP G- wy. Ba 0 17 . a> \-~ i" a ik 6 We oct “a 5 a ® 8./ >) ) 7 Le! As of a> oom) AS wie. ‘ ty Vy ¢ # y , \ ; a oe q Te \ “ . > ay a | => R= ar) “6 S & ¢ s Me : a Line | —— “Ik - os Bee oe COOPERATIVE EXTENSION SERVICE / COLLEGE OF THE VIRGIN ISLANDS THE VI Pain (3) \ 4a J — 1962 AVOCADO PRODUCTION & MARKETING by Chris Ramcharan - Research Horticulturist Clinton George - Extension Horticulturist George Morris - Extension Economist EXTENSION BULLETIN NO. 4 May 1983 Copies of this bulletin available from: COOPERATIVE EXTENSION SERVICE COLLEGE OF THE VIRGIN ISLANDS P.O. Box L, Kingshill, St. Croix, U.S. Virgin Islands 00850 Telephone: (809) 778-0246 CONTENTS FOREWORD. . «i: i cactewewes 5 os ec aseRREas gas ees Page 1 AVOCADO PRODUCTION ...........0 0c eee ee eee 3 IntrOduction....065.5 6 & & & & Keio ees BH % FH NITRO reRIE 3 OPigin. 2. ee ee ee eee eee tte es 3 Description ..........ccsceceeecs reser eerenes 3 Cultiva#ls . ccsueseuecdcsus 63 ¥ EE MSRM & KG EF terrenecess 3 Soils:and GClimaté:ss << i ci 5 cower & & & 6 o gemcorwwaw 4 Propagation ........ 0. cece eee eee eee e eee eees 4 Planting .........cc cece ence sees rece rece eees 6 Weed Control and Cultivation. ..........++eeeees 6 Irrigation .. 6.2... eee eee ee eee eee eee enee 8 Pruning and Training ..........s.cseeeeceeeeee 8 F@rtiHZers « &scoeseu.s as 6 & Sailers 6 oo wo wrereeve® 9 Pollination’ . .. . aciswares « so oo & eeenmwerperers wo 6 vw wiorerETe 9 DISGCASES’. « & & ciate es & os & FO SRI eHG & oo eH HOKE Or 10 Insects and Mites) c-iess ss s & x eiwecewwree ss a ow eve 11 Harvesting ...... ccc cece ese s cee ce cece ee esnes 11 ViGIs.<.c & oF FF ROCIO © EK & & H arerecENDeeens @ 0 6 Hw avarere 1 ECONOMICS OF AVOCADO PRODUCTION ....12 Cash Returns from Production ...........e+ee005 12 Fixed:Gost ¢ < < ssssisseewe's s&s & wi wrerepasanvers wa 0 oe cose 12 Returns from Increased Acreage Density ......... 12 Marketing Possibilities ...........+ee eee eeeees 15 Marketing Arrangements ...........-0+e ee eeees 15 SOME AVOCADO RECIPES*.........00e eee eens 16 TABLES |. Characteristics of Some Recommended Avocado Cultivars for the Virgin Islands.............- 5 ll. Classes of Irrigation Water and Permissible Limits of Constituents ...........0..-eee008 8 lll. Estimated Establishment Cost Per Acre for Avocado Production Using 48 Trees .......... 13 lV. Estimated Cost and Return Per Acre for Avocado Using 48 Trees ........+-ee e+e eee 13 V. Estimated Establishment Cost Per Acre for Avocado Production Using 70 Trees .......... 14 Vl. Estimated Cost and Return Per Acre for Avocado (5-6 Years Old Grafted Trees) ....... 14 Vil. Payback Period from Investment .........-.+-++-- 15 FIGURES 1 Avocado Trees Showing Different Conformations... 2 2 Pyriform (Pear) and Oval (Round) Shape Avocado Fruits: . « sasass.s & 5 & <5 Hwee ase 2 3 WedgeGrafting Avocado .........---e eee eens 7 4 Schematic Longitudinal Section of Avocado Flower .10 *Recipes tested by C.V.I. Home Economics Program and are taken from their publication Native Recipes, Extension Bulletin No. 1. With the phasing out of the sugar cane in- dustry as the island's major cash crop, the past two decades have seen much effort made to di- versify the agricultural sector of the economy te include food crop and livestock production. However, various internal and external factors have hindered this transition. Since the 1960's when the last of the sugar cane crop was har- vested, the people of the Virgin Islands have attempted to develop an appropriate substitute to replace this sugar industry or at least to in- crease self-sufficiency in food production. The people's faith in the basic role which agricul- ture can play in the overall development of our community has been the main contributing fac- tor in rekindling the effort to increase local food production. Water continues to be the major constraint of agricultural production. The other is unavail- ability of land at affordable prices. However, re- cent action by the government to make land and other incentives available to the prospective farmers has helped renew hope for expanding the agriculture industry of the islands. For agriculture to be acceptable, it must be both productive and a preserver of our natural resources. The Cooperative Extension Service with its research capability can help our FOREWORD farmers achieve both of these objectives. To meet the various needs of our part-time and commercial farmers, the Extension Service has published many fact sheets and farmers bulletins. This publication, Avocado Production and Marketing falls in the latter category. This bulletin covers the entire spectrum of production and marketing of avocados. It is written by a team of specialists who possess an excellent background in their areas of exper- tise. | am very pleased that these three capable scientists have joined together to compile this package of information which is so vital to our farming community. Avocado is a popular tropical fruit with great potential for expansion in the Virgin Islands. The climate of the three islands can profitably support avocado orchards. I urge all the Virgin Islands farmers and gardeners to use the information provided in this bulletin. We welcome any comment you feel might assist us in increasing local food production. i { ah adda, Director Land Grant Programs FIGURE 14. iW cas iy ~* pe Bet >> tin ft ' — i - ” a a «x + oy rei ~ mete Pes ‘4 ad A ~ vy ee ¥ a L& ihe wy © len Say - wo eed * Ri ———— Avocado trees showing Sd "dy different conformations hs me ih. Ries ws (a) Low, symmetrical; >) ah Fy ¥ s&s > a “a amy e (b) Low, spreading; oats Sie (c) Large, spreading; A? ~ de a ae Taare y , > bor sy 2 as py * re (d) Tall, upright. SF Bd “er. oF ~ «op endblliryee vt. ~t ree hy Prt TRF +! i Yee th be NS ae wad a 2 it ere ae HN adh! we a ad ‘H - “# Pt tk * ME Va a = afhen cae 3 way ~ n FIGURE 2. Representative of v4 pyriform shaped fruit is ““Lula" on the left; ‘‘Booth iy 7” on the right has a rounded “a shape. AVOCADO PRODUCTION INTRODUCTION Half an avocado and two slices of bread is to many people in the Caribbean a square meal. Although many North Americans consider the avocado an exotic fruit, here in the Virgin Islands it is a popular fresh fruit. It is used to add color, flavor and nutritional appeal to the salads, sandwiches, and many home recipes. The avocado is rich in fruit oil which is relatively unsaturated so that partial substitu- tion of avocado for saturated fat may have a favorable effect in reducing cholesterol level of the blood. The pulp of the avocado contains one to two percent protein, 10 to 17 percent fat, 1.7 percent total sugar and up to 80 percent water. It also contains moderate levels of iron and vitamins A, B, C. D, E, and K. The meals men- tioned above, therefore, are more nutritious than they first appear. There are many soil-related and climatic fac- tors in the Virgin Islands which make growing avocados a somewhat risky business. The year- ly occurrence of strong winds, unevenly distributed rainfall, rocky shallow calcareous soils, and scarcity of good quality irrigation water are some of these factors. However, avocados are always in demand in the Virgin Islands and command a ready sale. Local pro- duction comprises a small fraction of the total supply, most of which is imported from neighboring islands, and from as far away as Florida. ORIGIN The avocado originated in Guatemala and Mexico, but it is now grown throughout the sub- tropical and tropical world, including the Virgin Islands. The word avocado comes from the Aztec word ‘Ahuacatl."" The Spanish “abogado,”’ and the French ‘‘avocat,’’ and English avocado are all apparently attempts to phonetically reproduce the Aztec name. The ‘‘Alligator Pear’’ name originated because the skin texture of some varieties was equated with that of the alligator. DESCRIPTION The Avocado (Persea americana Mill.) belongs to the family Lauraceae of which other well known members include cinnamon, camphor, and the bay tree. Seedling avocados grow to a height of 50-60 feet, although budded trees are considerably shorter. Mature tree canopy ranges from small and symmetrical to tall, upright and asymmetrical (Figure 1). Leaves are simple, elliptical to oblong shaped, and flowers are small greenish-yellow produced abundantly in loose axillary racemes. The fruit is a berry, pyriform to round or oval in shape, and has a single seed with thick fleshy pulp (Figure 2). CULTIVARS The avocado has been divided into three hor- ticultural groups or ‘races’: The West Indian, Guatemalan, and Mexican. These (races) in- clude hundreds of avocado cultivars and classi- fication is based on several factors including fruit size, shape and quality, season of maturity, and altitude at which plants grow best. The West Indian race is best adapted to low- land tropical conditions—from sea level to 2,500 feet. It is more tolerant of high temperature and humidity, soil salinity, high soil pH, and diseases such as anthracnose, cercospora leaf spot, and scab, than the other two races. Tree and fruit characteristics of the West In- dian race are similar to those of the Guate- malan, but the fruit is generally lower in oil and ripens 5 to 8 months after blossoming. The foliage is slightly lighter in color than the Guatemalan, and is not anise-scented. Fruits are variable in form and size, the skin is thin— rarely thicker than 1/16''—and soft and pliable. The Mexican race originated in highland areas, and is well adapted to cool conditions in the tropics and to subtropical areas with a Mediterranean type climate. It is the most cold- hardy of the races of avocado, but is poorly adapted to conditions of high humidity and temperature, and to fungal diseases which ac- company such a climate. It is intolerant of calcareous soils and high soil salinity. The leaves are anise-scented and fruits are smaller than the other two races. The fruits are smooth and thin-skinned and ripen 6 to 8 months after blossoming. The flavor of its fruits may be good, but their small size and large seed make them undesirable for market. The Guatemalan race of avocado is inter- mediate between the West Indian and the Mex- ican races in adaptation to soil and climate conditions. The foliage is darker green in color than the West Indian race, and when crushed is not anise-scented as in the Mexican. The fruit skin is woody and thick (1/16"' to 1/8"'). In some cultivated cultivars the skin is scarcely thicker than the West Indian race, bul is rarely soft and pliable. The seed is comparatively smooth and the seed coat is thin and adheres closely to the seed. The seed is rarely loose in its cavity within the fruit. The fruit ripens 9 to 12 months after blossoming. The races of avocado hybridize freely, and SOILS AND Although the avocado grows on a wide range of soils, it does best on deep, well drained fer- tile soils of medium texture, with a pH range of 5.5 to 6.5. It prefers a relatively dry climate with an annual rainfall of 50 inches. However, it will thrive under wide rainfall conditions, provided that the distribution is even and the soil is well drained. The plant does not tolerate severe dry seasons, therefore irrigation is necessary under such conditions. It will not thrive on soils with poor drainage or heavy clays, and is short-lived where the water table is less than 3 feet. Rock layers within 3 feet of many of the leading commercial cultivars are hybrids between members of these races. In general, the West Indian and Guatemalan races and crosses between them are more adapted to lowland and middle elevation tropical conditions. Pollock, for example, a large early fruiting cultivar, belongs to the West Indian race and is a popular cultivar in the Caribbean. Introduction and selection of avocado cultivars were done by the USDA in St. Croix during the 1950's. Their objectives were to select better quality cultivars, extend the harvest season, and to encourage more com- mercial plantings. Similar studies on the sur- viving cultivars of the original orchard are now being carried out by the College of the Virgin Islands Agricultural Experiment Station. Table 1 lists characteristics of some of the recommended cultivars for the Virgin Islands. In the Virgin Islands, as in all other Caribbean islands, there are also many avocados grown from seedling trees with excellent fruit charac- teristics. Therefore, there is a continuing need to select and propagate some of these superior local types. CLIMATE the soil surface also impede the growth of the avocado tree and limestone deposits reduce growth and induce leaf chlorosis. Since many of the soils in St. Croix are shallow with an underlying layer of limestone, special care should be taken in choosing a planting site for avocado. Also with the high pH of some local soils, most trees should be treated with chelated minor elements for best growth and performance (see Fertilizers). In St. Croix new plantings should preferably be located on light soils or rocky slopes where drainage is likely to be adequate. PROPAGATION Avocado varieties do not come true from seed and must be propagated vegetatively. Budding, wedge, and side-veneer grafting are methods used to propagate selected avocado cultivars (see Gardeners Factsheets 14, 15). However, propagating one's own avocado tree does re- quire some skill and experience. In budding, a small amount of scion material is used, the chances of the scion drying out are less, and the operation is relatively simple. The TABLE lI. Characteristics of Some Recommended Avocado Cultivars for the Virgin Islands SEASON OF FLOWER _ FRUIT PRODUC- RECOMMENDED ~~ TREE CULTIVAR RACE' MATURITY TYPE _ SIZE (ozs) TION? USE' HABIT FRUIT CHARACTERISTICS Pollock wl July-Sept. B 18-40 M H Small Oblong-pyriform shape, thin Spreading smooth medium green skin, thick dark yellow flesh of good quality. Large loose seed. Simmonds wl July-Sept. A 16-34 M C,H Medium to Pyriform shape, slightly flat- large, tened on one side, very thin spreading skin, medium green, thick medium yellow flesh of good quality. medium-sized seed tight in cavity. Melendez-2. GxWI_ Nov.-Jan. B 16-24 H H,C Large Oblong shape with a neck; spreading seed large. Semil 43 GxWI_ Nov.-Jan. B 20-30 H H.C Large Elliptic (Egg shape); medium spreading sized seed. Semil 34 GxWI_ Nov.-Feb. A 20-35 H H,C Large Pyriform shape; relatively spreading — thick pale-yellow flesh with excellent quality. Small seed, tight in the seed cavity. Choquette GxWI_ Nov.-Feb. A 24-40 M H,C Large Oval shape: buttery yellow spreading flesh of excellent quality, Medium-sized seed, fairly tight in seed cavity. Utado Nov.-Mar. A 16-26 H H Medium- Pear to ovoid shaped, green sized brittle woody skin, fairly thick spreading light yellow flesh of very good quality. Medium-sized seed in tight cavity. Booth 8 GxWI_ Nov.-Mar. B 9-28 H C,H Large, Rounded obovate, thick woody spreading green skin, thick flesh of fair quality. medium-sized seed in tight cavity. Booth 7 GxWI_ Dec.-Mar. B 10-20 H C.H Large, Rounded obovate shape, thick spreading medium green skin, thick light yellow flesh of fairly good quality, medium large seed tight in cavity. Lula GxM __Dec.-Mar. A 14-24 H ¢c Tall, Pyriform, sometimes with upright neck, smooth light green skin. Hall GxWI _ Dec.-Mar. B 20-30 H C,H Medium- Pear shaped with distinct sized, neck, thin leathery green skin spreading peels easily, thick medium yellow flesh of very good quality, medium-sized seed in tight cavity. Taylor GxWI = Jan.-Mar. A 12-18 i H Tall, Pear shaped, green brittle upright woody skin, thin light yellow flesh of very good quality, large seed tight in cavity. 1. WI: West Indian, G: Guatemalan, M: Mexican 2. L: Light, M: Moderate, H: Heavy 3. H: Home, C: Commercial inverled ‘T’ is used for budding, which should be done as soon as the seedling stock plant is 8 to 12 inches high. Best results have been obtained in the Virgin Islands with the wedge graft (Figure 3) using stock seedlings 2-4 weeks after germination. Freshly cut scions from terminal growth con- taining plump buds and of the same diameter as the seedlings being grafted are preferred. The top of the rootstock is cut off and discarded 3-5 inches above soil level, and the stock is then split 112-2 inches. The scion is trimmed into a 2-sided wedge with long tapering cuts about equal in length to wedge in the rootstock. The scion is then placed into the wedge in the stock and the graft is wrapped securely, leaving the terminal exposed. With the use of these young succulent seedlings, better than 90 percent success can be obtained. Side-veneer grafting can be performed with older seedlings. Cut surfaces of the avocado plant are very susceptible to infection, thus budding and grafting operations should be carried out under very aseptic (sterile) conditions. The scion material should be well protected to pre- vent drying out. Since the West Indian cultivars are more tolerant of high pH soils, vigorous large seeded seedlings of this race are recommended for use as stock plant for pro- pagation in areas such as the Virgin Islands. The seed from a fresh avocado will germinate within a few weeks. Germination may be enhanced by removing the seed coat or by cut- ting off the top half inch of the pointed end of the seed. The seed is planted pointed end up to about half its depth. Established avocado trees of almost any size can be top-worked, or grafted to change cultivars. If the tree is vigorous and healthy, it may be cut off just above ground level, the wound painted, and a side-veneer or wedge graft inserted in a new sprout that will grow out. Follow-up care is important; scions should be shaded and tied to prevent wind damage. PLANTING Like any other tree crop, avocados occupy the ground for a long time so that every effort should be made to lay out and prepare the fields properly before planting large areas. The land should be ploughed and harrowed before laying out cambered beds or tree rows. If possible, organic matter dressings should be turned in while the soil is being prepared. In high rainfall areas cambered beds and drains must be made to remove surplus water. On sloping land, contour drains should be put in. The recommended spacing for grafted avo- cados is 25 to 30 feet (70 to 48 trees/acre, respectively) apart, depending on expected size of the mature tree. Trees planted too close eventually crowd each other, resulting not only in lower yields, but also in more expensive harvesting since most fruit is produced in the upper half of trees. WEED CONTROL Avocado trees are shallow-rooted and in areas of limited soil depth weed control is im- portant particularly during the dry months of the year. Cultivation by disking may be harmful since many roots near the soil surface may be damaged. Frequent mowing or cutlassing is The planting hole should be as deep as the rool ball and about 6 to 8 inches wider. Well- rotted manure or top soil should be mixed with the soil at each planting site. The young plant is placed in the ground so that the top of the root ball is level with the soil surface, and the sides backfilled with top soil and firmly tapped. A big mound is not needed for planting, but the soil level should be slightly raised to ensure that water does not collect around the plant. Care should always be taken to ensure that the graft-union is well above the soil line. Water immediately after planting to provide adequate moisture to the roots and to eliminate air pockets. During the rainy season especially, it is very important to keep water from accumu- lating around the young plant, since this may induce rool rot (see Diseases). AND CULTIVATION perhaps the best means of weed control. The use of herbicides should be avoided around trees in their first year’s growth. The most economical method for weed con- trol in the first three to four years in an avocado grove is by intercropping, provided oe FIGURE 3. ip ih S tte ay in » , ~~ gsi eed a meal ® 7® qf ee, \y ; van < NP ie, Phy ye nw ~ ge fii Be, 4 ry if y ie I g oS iA .* a ME , 4 Bey Wedge Grafting Avocado ma X, am. ee (a) Grafting material oc ~~ (b) Prepared scion (c) Prepared stock (d) Insertion of scion into stock (e) Wrapping graft that the intercrops are not allowed to crowd the young plants. In older orchards where the trees shade the ground, weeds are reduced considerably and very little mowing may be necessary. Chemical weed control with contact herbicides such as weed oil or Paraquat may be more feasible and economical in this situa- tion, particularly where mowing is prohibited by steep terrain. These chemicals must be used with extreme caution, as with all other agri- cultural chemicals. IRRIGATION Avocado trees require more frequent irriga- tion than many other fruit trees. Young trees, particularly newly planted ones, need moist soil for vigorous growth. However, the soil should not be allowed to become too wel or saturated. Maintaining adequate soil moisture around older trees helps prevent excessive fruit fall during hot dry periods. The salt con- tent of the irrigation water (see Table II) is critical for many fruit trees. Avocados are very sensitive to high salt water and can tolerate no more than 300 ppm of chlorides in the irriga- tion water. Total salinity does not appear to be as important as accumulation of individual ions such as chloride (Cl ~ ) and sodium (Na * ). TABLE II. Classes of Irrigation Water and Permissible Limits of Constituents Electrical Total Sodium Class of Water Conductance Dissolved Percent of Boron EC x 10° Salts Total Salts ppm at 25° ppm 1. Excellent Less than 25 175 20 33 2. Good 25-75 175-525 20-40 .33 - 67 3. Permissible 75-200 525-1400 40-60 .67 - 1.00 4. Doubtful 200-300 1400-2100 60-80 1.00 - 1.25 5. Unsuitable More than 300 2100 80 1.25 Source: L/V. Wilcox. 1948. The Quality of Water for Irrigation Use. USDA Tech. Bull. 962:p.27. PRUNING AND TRAINING For most avocado cultivars, very little prun- ing is required in the first few years of the young plant. However, for upright growing types such as Booth 7 and Taylor, early train- ing is required. Terminal shoots should be pinched after each flush to promote lateral growth. Such pinching is necessary beginning the second growing season and continues until the tree is properly shaped. This helps give the tree a better, stronger spread. Tree height is therefore restricted without loss of growth and production, and the fruit bearing area main- tained within reach. If upright growing avocado trees are not trained early, they tend to grow too high. After 6 to 8 years, most fruits are produced in the tree's upper half, making picking difficult and expensive. Successful top- ping to reduce height after 6-8 years is not possible without greatly reducing future yields and increasing limb breakage. In the spreading types of avocados, it is desirable to cut back the top of the tree occa- sionally after several years of production. This also makes spraying and harvesting simpler and lessens storm damage. Such pruning should be done as soon as possible after harvesting. For low bearing trees, it is not necessary to prune low branches to prevent fruits from touching the ground, although prop- ping of heavy fruiting branches may be needed to avoid breakage. Avocados are particularly susceptible to in- fection. Pruning, and all other cuts, should be treated with a protective-type pruning paint. FERTILIZERS Generally the major element composition of fertilizers used on avocado should not be high- er than 10% (see Gardeners Factsheet #16). This is a safeguard against ‘salt burning’ since avocados, except when planted in ditched- groves, have the great majority of their roots in the top eight inches of soil. This is particularly applicable in some areas of St. Croix where the top soil is shallow with an underlying caliche layer. Young trees are easily injured by ex- cessive fertilizer applications and leaf burn or defoliation and dieback may result. Nitrogen and potassium are of major signifi- cance in avocado nutrition, but nitrogen is more likely to become deficient than potassium in areas where supplemental fertilization is not used. Phosphorus is essential for young vigorous plants, but its relative importance declines as the tree growth rate slows down. Phosphorus in calcareous soils tends to ac- cumulate, becoming available to the plant very slowly but apparently in adequate amounts. Therefore, the amount of phosphorus needed for avocado trees in production is relatively small. A general fertilizer recommendation would be % Ib of 10-10-10 applied three times per year during the first year’s growth. This should be increased gradually to 1 lb per tree in subse- quent years. Extreme care must be taken in areas where shallow rooting occurs and to app- ly fertilizer evenly to about a foot beyond the dripline area of the tree. For bearing trees, fer- tilizers containing reduced phosphorus such as 10-4-10 are more suitable. Maximum applica- tion should be 4 to 5 lbs per tree per year in 2 or 3 split applications. Chloride-containing fer- tilizers such as Potassium Chloride are con- sidered unsuitable for avocados. Sulphate fer- tilizers, such as Ammonium, Potassium and Iron Sulphate should be used as they help in reducing the pH of the soil. It is highly ad- visable that soil and/or tissue analysis be taken before exact fertilizer recommendations can be made (see Gardeners Factsheet #25). Among the micro-nutrients, zinc and iron are critical since the avocado is very susceptible to their deficiency. The ideal soil pH for avocado trees is 5.5 to 6.5. Trees growing in soils with pH level exceeding 7.0, as occurs in many areas of the Virgin Islands, will become defi- cient in minor elements such as iron, zinc and manganese (see Factsheet #16). In such areas, it is therefore advisable to apply the chelates of iron (preferably Fe 138), zinc, and manganese at the recommended rates even before defici- ency symptoms appear. Slow-to-start plants may also respond well to foliar sprays of these micro-elements. Excess of salts such as chlorides and sodium usually occurs in dry areas where there is insuf- ficient rainfall for leaching and where the ir- rigation water may also contain considerable amounts of salts. The reason that avocados can- not tolerate more than 300 ppm of chloride and sodium is that the plants tend to absorb and ac- cumulate these salts. Damage symptoms are tip and marginal burns of older leaves, ultimately causing defoliation. (This must not be confused with early stages of root rot which exhibit quite similar symptoms). Sodium toxicity symptoms are interveinal leaf burn compounded with twig dieback in extreme situations. Extreme care must be taken when watering avocado plants with potable or well water in the Virgin Islands. Recent work in other dry areas has indicated that of the three races, the West Indian avocados are more tolerant to the toxicity of salts and to iron chlorosis. Consequently, stock seedlings of West Indian cultivars should be used in the Virgin Islands and other similar areas where the above soil and water problems occur. POLLINATION The number of fruits which set and mature is small relative to the number of flowers pro- duced by an avocado tree. Cultivars also differ in productivity and in regularity of bearing, some producing a large crop only every other year. The avocado flower is bisexual, having both male and female organs. However, the flower performs in such a way that self-pollination is highly unlikely within a given tree or even a given cultivar. This is because each flower opens twice and is closed in between; the first time it functions as a female, the second time as a male (Figure 4). Nearly all avocado cultivars (and seedlings) fall clearly into 1 of 2 contrasted categories conventionaly designated A and B. A-type cultivars have their first or female opening in the morning. The second or male opening is the afternoon of the following day; the lapse is about 34 hours. B-type cultivars first open in the afternoon. The second opening is the following morning; the lapse is about 24 hours. Therefore, every morning A-pistils can be fer- tilized by B-pollen, while during afternoons B-pistils are ready to receive A-pollen. For good production in large stands of avocados, con- DISEASES Avocado Root Rot - (Phytophthora cinnamomi) Avocado root rot is a serious fungus disease of avocado in areas with poorly drained soils or a high water table. Leaves become pale green, wilted and branches may die back. A new sys- temic fungicide still being tested experimentally seems to control this disease by killing the organism on the tree. This treatment is mainly for non-fruiting trees. For bearing trees, fruits must be discarded within 12 months after treat- ment. The best preventive measure is to plant in well-drained sites. Anthracnose - (Colletotrichum gloeosporoides Penz.) Anthracnose is commonly found on maturing avocado fruit and is the most frequently ob- served rot of avocados in the market. The first sign of the disease is small light brown to black nearly circular discolorations on the skin of the fruit. As the fruit matures the spots enlarge and the fungus enters the flesh of the fruit causing decay. Anthracnose can be controlled by sprays of benomy! or copper fungicides. Avocado Scab - (Sphaceloma perseae Jenk.) The disease occurs on leaves as purplish to dark brown spots visible on both sides of the leaf. The centers of the spots may fall out, leav- ing small irregular holes. On the fruits, spots are raised, dark brown to purplish-brown and cor- ky. Scab disease is confined to the outer fruit surface and the flesh is not affected. However, the disease reduces the marketability of fruits and scab-infected fruits are also more suscepti- 10 sideration should therefore be given not only to planting early, mid-season, and late maturing cultivars, but also to the inclusion of cultivars of different flower types that bloom during the same season, Wind alone cannot be relied upon to trans- port pollen because avocado pollen is relatively heavy and drops to the ground. Several con- clusive studies have shown the need for the presence of relatively large insects to obtain regular fruit set. The honey bee is probably the chief pollinator but wasps and flies may play an important role. It is very important, therefore, to reduce spraying when pollinators are active. FIGURE 4. Stigma receptive Anther not dehisced Stigma no longer receptive Anther dehisced Schematic longitudinal section of avocado flower. (a) Female stage, with stigma receplive, bul stamens bent outward and anthers not dehisced. (b) Male stage, with stigma no longer receplive, but stamens upright and anthers dehisced. (Reproduced from McGregor, S.E. 1976. Insect pollination of cultivated crop plants. U.S.D.A. Agr. Hdbk. 496. p.95). ble to anthracnose which can increase prehar- vest fruit drop. Cultivars vary in susceptibility to scab. Generally, the West Indian x Guate- malan hybrids such as Booth 7 and 8 are moder- ately susceptible, and the West Indian cultivars such as Pollock and Simmonds are least suscep- tible. Scab is controlled with monthly sprays of finely divided copper or Benlate. A sticker solu- tion should be added to the spray for more effec- tive coverage. INSECTS AND MITES Many insect pests attack avocados but they do not limit fruit production significantly. In- sect infestations are not predictable and con- trol measures are justified only when large populations build up. The most important pests of avocado in the Virgin Islands are mites, scales, stem borers, and thrips. The avocado rust mite and scale insects can sometimes build up to large proportions. Keeping trees in good healthy condition can very often be sufficient to offset these pests. For young trees sulphur or Malathion can be used to control mites, and Malathion or Diazinon with or without oil for scales and thrips. Care must be taken to see that oil sprays are not used with sulphur or ap- plied to trees that have recently been treated with sulphur. Termites can often allack dead- wood in trees and may penetrate to the heart- wood. They should be controlled at an early stage by spray application of Diazinon into the nest after it is chopped open. The adult weevil of the sugar cane root stalk borer (Diaprepes abbreviatus) is sometimes found feeding on leaves and roots. The grub may feed on the roots, especially in potted seedlings. Sevin can be used to control the weevil adults, and Diazinon the grubs, but attacks are seldom of sufficient severity to warrant control measures and Sevin is extremely toxic to pollinating bees. Further information on diseases and pests and their control measures can be obtained from the Cooperative Extension Service Pest and Pesticide Management Program. HARVESTING Avocados do not ripen on the tree and fruits picked when immature are of inferior quality. Some experience is required to determine when an avocado is sufficiently mature for har- vesting. Generally the skin color becomes more yellowish-green and the surface shine becomes dull in appearance. In certain areas of the tropics, fruit maturity is determined by weight and diameter. Recent research alt the CVI Agricultural Experiment Station involves detec- ting the fruit maturity and subsequent harvest dates by employing an ethylene gas detector. This method has been fully developed for temperate fruits such as apples and pears, and similar technology is now being adapted for some tropical fruits including the avocado. Usually a quick twist will detach mature fruits and the stem can then be clipped to give a clean cut. Fruits should always be hand picked and never knocked off the tree to the ground. Picking poles with bags attached to their ends or ladders can be used for harvesting fruits out of arm's reach. Of all production practices, harvesting is the single most expensive opera- tion and requires labor of certain ability and ex- perience. Field containers should be of 40 lb capacity and market containers no more than 25 lb capa- city. They should be padded so as to reduce squeezing and bouncing of fruits. Avocado ripen best al about 60° F to 75° F. Cold storage delays ripening and avocados can be cold-stored at no lower than 45° F for a month or two. YIELD Avocado yields tend to be irregular from year to year. With proper management, grafted trees should start bearing about the third or fourth year, reaching their maximum potential be- tween 13-15 years, with an average production 11 of 5-6 bushels (250-300 lbs) per fruit tree each year. At this rate an average annual production of 6.5 and 9.5 tons per acre (48 and 70 trees/ acre, respectively) could be anticipated. Like most fruit crop production, avocado car- ries with it a heavy initial investment in both the establishment and maintenance of the fruit or- chard. Profitable returns from avocado produc- tion depend to a considerable extent on its an- nual yield per acre. However, since yields of commercial significance would not be realized in the first four years, intercropping is advisable as a means of securing a cash flow. The density of trees per acre is a significant factor influencing high yields as well as higher returns per acre during the early years of pro- duction (Tables IV and VI). Table III depicts cost set at $785.04 (48 trees/acre). This figure was calculated on the basis of all the necessary ECONOMICS OF AVOCADO PRODUCTION recommended inputs except water. The table further suggests that the highest component of the initial investment is that of the young grafted plants and labor. The yield in Table IV shows an average of 7,200 lbs of avocado per acre. An average wholesale price of 50¢ per lb was used, thus a gross receipt of $3,600.00 per acre was realized. During the maintenance of the orchard, signi- ficant increases in cost over the five-year period only occurred as a result of increases in fer- tilizer usage. These increases caused main- tenance cost to rise in the second, third and fourth year of production. CASH RETURNS FROM PRODUCTION Variable cost in Table IV (the cost which oc- curs with the onset of production) tends to be quite low ($474.63) when compared with income generated from this expenditure. Returns above variable cost were estimated at $3,125.37 with the highest cost component being that of labor. Irrigation was introduced in the year after establishment as a repair expense. However, water requirement was not included due to the fact that annual quantities per tree were not determined. FIXED COST In most production operations a fixed cost occurs during the short run as a result of pro- ducers’ inability to expand their operation dur- ing this period. Therefore, some costs are con- sidered fixed irrespective of production. With respect to fixed cost as stated in Tables IV and VI, equipment was assumed as a basket of items containing shovel, hoe, fork, rake and RETURNS FROM Table V illustrates the density of avocado plants per acre when planted with 70 trees, at a unit cost of $10.00 per tree. The value of total trees planted was calculated at $700.00 per acre, compared to $480.00 in the less densely planted acreage of 48 trees. Another high com- ponent cost indicated in Table V was that of labor, which was calculated at $126.48 per acre. (This did not include pruning.) The reduction in these components may be possible if plants were to be grafted locally as opposed to importing grafted plants. It may also be possible to reduce labor if mechanical hole diggers are available for rent. Total 12 hole digger. These items were then depreciated in order to arrive at an annual depreciation cost. The item stated as “‘other’’ under fixed cost was calculated as spraying equipment. By subtracting total cost from gross receipt in Table IV, net returns per acre were estimated at $2,860.54. INCREASED ACREAGE DENSITY establishment cost was set at $1,083.36 per acre compared to the less densely planted acreage of 48 trees with total establishment cost of $785.04 as shown in Table III. Gross receipts as illustrated in Table VI, were calculated at $5,250.00 from an acreage yield of 10,500 lbs of avocados per annum. Both income above variable cost ($4,404.61) and net return ($4,139.80) per acre appear economical- ly attractive. However, with densely populated plants the per acre labor cost will rise as a result of the need for additional pruning, as will the cost of utilizing more mulching materials. TABLE III. Estimated Establishment Cost Per Acre For Avocado Production Using 48 Trees Items Input Used Unit Cost/Unit($) Value($) Land Clearing 1.00 Acre 20.00 45.00 Plow & Disk Harrow 1.00 Acre 40.00 30.00 Grafted 48.00 Tree 10.00 480.00 Labor 33.00 Hrs. 3:17 104.61 Manure 50.00 Hrs. -—-— —— Mulching 48.00 Bale 1.00 48.00 Fertilizer 100.00 Lb. 0.20 20.00 Benlate 1.00 Lb. 12.00 12.00 Malathion 1.50 Gal. 25.00 37.50 Pruning 2.50 Hrs. 3:17 7.93 Total Betablishment: Costs cs is: sccicscciies us a sie wrerswtarsin woe He we SH DEERE! ane wre BoM Aw erOLe $785.04 TABLE IV. Estimated Cost and Return Per Acre For Avocado Production Using 48 Trees Items Yield Unit Cost/Unit($) Value($) Avocado 7,200 Lb. 0.50 3,600.00 Gross Receipts 3,600.00 Variable Cost Input Used Fertilizer 240.00 Lb. 0.20 48.00 Malathion 0.75 Gal. 25.00 18.75 Benlate 1.75 Lb. 12.00 21.00 Spreader Sticker 0.75 Pt. 2.00 1.50 Mulching 48.00 Bales 1.00 48.00 Pruning 9.60 Hrs. 3.17 30.43 Mowing 1.00 Acre 20.00 20.00 Irrigation Repairs 1.00 Acre 50.00 50.00 Labor 33.12 Hrs. 3.17 104.99 Interest on Op. Capital 3.17 Dol. 10.00 31.70 Subtotal Preharvest $ 374.37 Harvest Cost Picking & Storing 12.00 Hrs. 3.17 38.04 Marketing Cost 2.00 Trip 31.11 62.22 Subtotal 100.26 Total Variable Cost $ 474.63 Income Above Variable Cost $3,125.37 Fixed Cost Equipment 1.00 Acre 15.00 15.00 Irrigation 1.00 Acre 243.75 243.75 Other 1.00 Acre 6.08 6.08 Total Fixed Cost Acre 264.83 Total Cost Acre 739.46 Net Return $2,860.54 13 TABLE V. Estimated Establishment Cost Per Acre For Avocado Production Using 70 Trees Items Input Used Unit Cost/Unit($) Value($) Land Clearing 1.00 Acre 20.00 45.00 Plow & Disk Harrow 1.00 Acre 40.00 30.00 Grafted 70.00 Tree 10.00 700.00 Labor 39.90 Hrs. 3.17 126.48 Manure 105.00 Lb. — os Mulching 70.00 Bale 1.00 70.00 Fertilizer 175.00 Lb. 0.20 35.00 Benlate 1.50 Lb. 12.00 18,00 Malathion 2.00 Gal. 25.00 50.00 Pruning 2.80 Hrs. 3.17 8.88 Total Establishment Cost .............-- 0. cece eee ee ee renee eee teen eens $1,083.36 TABLE VI. Estimated Cost and Return Per Acre For Avocado (5-6 Year Old Grafted Tree) Items Yield Unit Cost/Unit($) Value($) Avocado 10,500 Lb. 0.50 5,250.00 Gross Receipts 5,250.00 Variable Cost Input Used Fertilizer 3.50 Lb. 0.20 70.00 Malathion 1,00 Gal. 25.00 25.00 Benlate 2.00 Lb. 12.00 24.00 Spreader Sticker 1.00 Pt. 2.00 2.00 Mulching 210.00 Bales 1.00 210.00 Pruning 15.00 Hrs. 3.17 47.55 Mowing 1.00 Acre 20.00 20.00 Irrigation Repairs 1.00 Dol. 50.00 50.00 Labor 40.50 Hrs. 3.17 128.39 Interest on Op. Capital 6.25 Dol. 7.00 43.75 Subtotal Preharvest $ 620.69 Harvest Cost Picking & Storing 12.00 Hrs. 3.17 38.04 Marketing Cost 6.00 Trip 31.11 186.66 Subtolal 224.70 Total Variable Cost $ 845.39 Income Above Variable Cost $4,404.61 Fixed Cost Equipment 1.00 Acre 15.00 15.00 Irrigation 1.00 Acre 243.75 243.75 Other 1,00 Acre 6.08 6.08 Total Fixed Cost Acre 264.83 Total Cost Acre 1,110.20 Net Return $4,139.80 14 TABLE VII. Payback Period from Investment Maintenance Maintenance Expense (Using Establishment Expense (Using Establishment Year 70 Trees) Cost Year 48 Trees) Cost 1 $1,083.36 1 $ 785.04 2 $ 840.50 2 $ 610.58 3 829.50 3 601.06 o 885.50 4 639.20 5 885.50 Total 5 639.20 Total $3,444.00 + $1,083.36 = $4,527.36 $2,490.04 + $ 785.04 = $3,275.08 Payback Period = Net Cash Investment Payback Period = Net Cash Investment Estimated annual cash inflows Estimated annual cash inflows Payback Period = $4,527.36 1.09 years Payback Period = $3,275.08 1.14 years $4,139.80 $2,806.54 The economics of increasing the density of plants from 48 trees using an investment of $3,275.08 to that of 70 trees using an investment of $4,527.36 demonstrates a marginal profitabil- ity of 99¢ for every additional dollar of invest- ment expenditure beyond $3,275.08 (Table VII). It is important to state that in the short run the yields from the most densely planted MARKETING The demand for fresh fruits and vegetables in the Virgin Islands is quite stable. Present pro- duction levels for most fruits, including avocado, are considerably lower than demand. A recent marketing survey sponsored by the Cooperative acreage (70 trees per acre) would certainly be greater than those of the 48 trees per acre, as will revenue from these crops. In the leng run (13-15 years) yields from the less densely populated acreage will tend to surpass that of 70 trees per acre. This is due to the fact that the densely planted acreage will have less space for growth and expansion in later years. POSSIBILITIES Extension Services suggests that 91.8% of all avocados consumed on the islands are imported. These figurs clearly imply a favorable local market demand for avocados. MARKETING ARRANGEMENTS Marketing arrangements can be made with several existing marketing channel outlets on all three islands. Currently the bulk of avocado sales are primarily concentrated in the major supermarkets in both St. Croix and St. Thomas. Specialty markets such as local hotels and res- taurants are good marketing outlets for local producers. However, special care must be taken to determine the cultivars and seasonal quali- ties demanded from this market. Since the heaviest supply of avocados cur- rently occurs between mid-August to Mid-Sep- tember, producers should look at earlier and later maturing varieties in order to capitalize on higher prices when supplies are low. With the absence of a public marketing board or govern- 15 ment related agency, all grading, sorting, and packing are usually conducted by wholesalers or retailers. Local buyers suggest the following guidelines for producers: (a) Avocados should be fresh and har- vested at a mature stage (not when they are ripe). This is done primarily to avoid spoilage and at the same time allow a longer shelf life. (b) Particular care must be taken to avoid bruising while picking and storing fruit. (c) If storage is necessary on the farm, tem- peratures of 65-75 degrees are recommended. On the other hand, if storage capacity and facilities are inadequate then arrangement could be made with wholesalers to transport the fruits during the time of harvest. Most buyers are willing to provide transportation of fruits from the farm to the place of market should producers have difficulties acquiring transpor- tation. However, when transporting crops to place of market, producers must take care to avoid direct sunlight on the fruit. Air must be allowed to circulate in the container while traveling to destination point, and sprinkling of fruits before travel may also be helpful. Shipment between islands should be sent on refrigerated vessels to avoid spoilage. Apart from the above arrangement, buyers tend to search for a constant supply of avocados in order to satisfy consumer demand. Some buyers further suggest a farming contract ar- rangement as a means of securing a constant supply. It is therefore important that quantities be determined not only on an annual basis but moreover in terms of quantities available on a monthly as well as a weekly basis. This infor- mation will provide buyers with adequate time to contact other producers before supplies end. Retailing of avocados may be economically attractive to some producers, due to high retail prices. It must be noted that the risks associ- ated with retail selling are also pronounced. That is to say, the costs of storage, packing, grading, sizing and other marketing facilities rest squarely on the shoulders of the pro- ducers. Hence, good economic planning should precede all investment. SOME AVOCADO RECIP In selecting avocados, hold the fruit and press gently. If the avocado ‘‘gives’’ a little, it is soft enough for same-day serving. For serving two or three days later, choose firm fruit and keep in a relatively cool place. To ripen the fruit quickly, place in a brown paper bag and check for ripeness each day. Avocados are versatile food, teaming up well with many combinations. Salads are a favorite way of using avocados and the rich flavor goes well with vinegar and other seasonings. Because of the high fat content, the avocado ES combines best with acid fruits and vegetables such as pineapple, orange, grapefruit and tomato. Chicken and seafood are good com- bined with avocado cubes or slices or used as filling in half an avocado. The avocado contains a tannin which causes it to become very bitter when cooked; conse- quently, no successful method of canning has been found. While whole or sliced avocados do not freeze well, avocados may be frozen in a puree form to be used later in molded salads, sandwich fillings, ices and dips. Avocado Sandwich Fill Mash scooped-out meat of medium-size avoca- do. Season with salt and lime juice. Add celery, chives, chopped green pepper, or crumbled crisp bacon if desired. Spread on bread that has been lightly buttered. Whole wheat or other dark breads are very good with this fill- ing. Avocado Appetizer Mash avocado, add cream-thinned Philadel- phia cheese, minced onion or chives. Heap into pieces of celery. Deviled Dip Scoop meat from ¥% large ripe avocado, leaving shell intact. Mash avocado meat, blend in 1 family-size can deviled ham, 13-ounce cake 16 cream cheese, minced parsley and seasoning to taste. Mix smooth and pile in reserved shell. Serve surrounded with crisp fresh vegetable pieces, potato chips, small crackers. Barbecue Spread Delicious on hamburger slices or hot meat loaf. Stir in 1 cup sieved or mashed avocado, 3 tablespoons mayonnaise, 2 tablespoons tomato catsup, 1 tablespoon lime juice, and salt, tabasco sauce, chopped green chili peppers and onion to taste. Avocado Medley Salad (serves 6) 2 medium avocados diced 2 medium tomatoes diced 1 tablespoon minced onion 2 tablespoons diced celery (continued) (continued) % cup diced cucumber 1 tablespoon diced green pepper % cup mayonnaise Lettuce Peel and dice all vegetables. Dice avocado last and toss all together lightly. Add mayonnaise and toss to coat. Pile in lettuce cups and chill until serving time. Frozen Avocado Puree (serves 6) 4 ripe avocados of medium size % cup lime juice Halve avocados, remove peel or with a spoon scoop pulp from shell into a bowl. Sprinkle with the lime juice. Mash or blend until smooth. Pack into glass jars leaving 1 inch head space. Seal airtight and freeze at O°F. To use, remove from freezer and allow to thaw in refrigerator in container. This will take about 24 hours. Keep tightly covered until used. Cream of Avocado Soup (serves 6) 3 avocados (or 2% cups frozen puree) 2 cups chicken broth 1 cup heavy cream Whipped cream Salt White pepper Mash two avocados with silver fork and press through a fine sieve or puree in a blender. Place in top of a double boiler. Add chicken broth which has been lightly seasoned. Heat, stirring occasionally, until soup comes to a boil. Stir in heavy cream. Cover, keep hot over boil- ing water. When ready to serve stir in the re- maining avocado cut in %-inch cubes. Season to taste with salt and white pepper. Serve with a tablespoon of lightly salted whipped cream on each serving. Avocado Fruit Salad (serves 6) 1 avocado Ye cup coconut, '% cup halved seeded shredded and grapes toasted 2 cups grapefruit Lettuce section French dressing, red or green cherries minted Cut avocados in half but do not peel. Scoop out halves with French ball cutter or teaspoon. Combine with grapes and grapefruit. Marinate in French dressing which has been seasoned with chopped mint leaves. Pile into scooped out shells. Arrange on lettuce. Serve individual servings from shells, or arrange fruits on beds of lettuce in individual servings. Sprinkle with toasted coconut. Garnish with cherries. 17 Seafood Avocado Salad (serves 6) 1 cup cooked lobster meat 2 cups cooked crabmeat 2 cups cooked shrimp (or your own favor- ite seafood combination) 3 avocados 1 tablespoon cut Y% cup mayonnaise chives '% cup sour cream French dressing Remove any bits of shell from lobster and crabmeat. Break into bite-size pieces. Remove a few chunks of lobster and a few whole shrimp for garnish. Cut remaining shrimp into pieces. Combine lobster, crabmeat and shrimp. Add just enough French dressing to coat generous- ly. Chill. Just before serving, cut avocados in halves, remove pit and fill with seafood mix- ture. Combine mayonnaise, sour cream and chives for dressing. Top each avocado with a generous spoonful. Garnish with whole shrimp and lobster chunks. Baked Stuffed Avocado (serves 6) 3 avocados Dash of pepper Y% cup lime juice Dash of cayenne 1 cup flaked 1 teaspoon minced crabmeat onion 1 cup cream sauce 1 cup grated cheese Dash of salt Cut avocados in halves lengthwise. Remove pits. Sprinkle avocado with lime juice and salt. Combine crabmeat and cream sauce. Season to taste with salt, pepper, a pinch of cayenne and onion. Fill avocados with mixture. Sprinkle with grated cheese. Arrange avocados in bak- ing pan with half an inch of water in the bot- tom. Bake in a moderate (350°F) oven 15 minutes or until cheese melts and avocado is heated through. Guacamole Make thin paste of 1 cup mashed avocado, 1 small finely chopped onion, 1 clove finely chop- ped garlic, a dash of Worcestershire sauce, ¥2 teaspoon olive oil, a dash of paprika, and a lit- tle lime juice, salt and pepper to taste. Blend to a smooth consistency in electric blender and serve on crisp crackers or with potato chips, as a dip. Avocado Refresher Heap balled or diced avocado in sherbet glasses and chill. Season with salt lightly and cover with Thousand Island dressing or with tomato catsup seasoned with lime juice, salt and pepper. REFERENCES Aponte, E.C. 1977. Cultivo de Aguacates en Puerto Rico. Extension Bulletin, College of Agriculture, Uni- versity of Puerto Rico. Frederiksen, A. L. and A. Krochmal. 1963. New Avocado Varieties for the U.S. Virgin Islands. Reprint from Caribbean Agriculture, Vol. 1, No. 4. Fruit and Vegetable Facts and Pointers— Avocados. Report from United Fresh Fruit and Vegetable Associ- ation, 777 14th St., N.W., Washington, DC, January 1970. Malo, S. E. 1968. Commercial Avocado Varieties and Production Practices in Florida. Proc. Caribbean Region. Amer. Soc. Hort: Sc., Vol. 12: pp.201-208. Malo, S. E. and C. W. Campbell. 1974. The Avocado. Fruit Crops Fact Sheet FC-74-3. IFAS. University of Florida. McGregor, S. E. 1976. Insect Pollination of Cultivated Crop Plants. U.S.D.A. Agriculture Handbook. 496: p.95. Proceedings of the First International Tropical Fruit Short Course — The Avocado. 1976. Fruit Crops Dept. IFAS University of Florida, Gainesville. Wilcox, L. V. 1948. The Quality of Water for Irrigation Use. U.S.D.A. Tech. Bull. 962: p.27. EXTENSION GARDENING PUBLICATIONS Okra, A Beloved Virgin. Farmers Bulletin No. 1 Sorghum in the Virgin Islands. Farmers Bulletin No. 2 Vegetable Planting and Harvest Guide—Gardeners Factsheet No. 1 ’ Seeding Vegetable Crops—Gardeners Factsheet No. 2 Growing Vegetable Slips—Gardeners Factsheet No. 3 Transplanting Vegetable Crops—Gardeners Factsheet No. 4 Mulch for Your Garden—Gardeners Factsheet No. 5 How to Prepare Your Own Compost—Gardeners Factsheet No. 6 Staking and Training Tomato Plants—Gardeners Factsheet No.7 ,, Growing Spinach in the Virgin Islands—Gardeners Factsheet No. 10 Controlling Nematodes in the Vegetable Garden—Gardeners Factsheet No. 11 Propagation of Fruit and Ornamental Plants by Layering—Gardeners Factsheet No. 12 Propagation of Fruit and Ornamental Plants by Cutting—Gardeners Factsheet No. 13 Propagation of Fruit and Ornamental Plants by Grafting—Gardeners Factsheet No. 14 Propagation of Fruit and Ornamental Plants by Budding—Gardeners Factsheet No 15 Fertilizing Your Garden for Optimum Yields—Gardeners Factsheet No. 16 How Many Teaspoons is 5 Pounds Per Acre?—(Weights and Measures)—Gardeners Factsheet No. 17 Organic Gardening - Soil Fertility—Gardeners Factsheet No. 18 Organic Gardening - Pest Control—Gardeners Factsheet No. 19 A Simple Home Drip Irrigation System—Gardeners Factsheet No. 20 Growing Mangoes—Gardeners Factsheet No. 21 Growing Citrus—Gardeners Factsheet No. 22 Saving Vegetable Seeds for the Home Garden—Gardeners Factsheet No. 23 Growing Mesples (Sapodillas)—Gardeners Factsheet No. 24 Testing Soil for Better Yields (Part I}—Gardeners Factsheet No. 25 Interpreting Your Soil Testing Results (Part II)—Gardeners Factsheet No. 26 Editor Liz Wilson Products and suppliers mentioned by name in this publication are used as examples and in no way imply endorsement or recommendation of these products or suppliers. Issued in furtherance of Cooperative Extension work, acts of Congress of May 8 and June 30, 1914 (as amended), in cooperation with the U.S. Department of Agriculture, D.S. Padda, Director, College of the Virgin Islands Cooperative Ex- tension Service. The College of the Virgin Islands Cooperative Extension Service is an Equal Opportunity/A ffirmative Ac- tion organization, providing educational services in the fields of agriculture, home economics, rural development, 4-H youth development and related subjects to all persons regardless of race, color, religion, sex or national origin. 18 THE VIRG <Vy ri ES CP Ng, 1962