nursery guide

8/2/2019 Nursery Guide

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ESTABLISHMENT AND MANAGEMENT OF OIL PALM NURSERIESJANUARY 2010

at

A nursery with compact varieties at BioVale, Para, Brasil

The Amazon (OxG) hybrid at Oleaginosas Salamanca, Tumaco, Colombia

ASD Costa Rica Telfono: (506) 2257 2666 Fax: (506) 2257 [email protected]://www.asd-cr.com


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ESTABLECIMIENTO Y MANEJO DE VIVEROS DE PALMA ACEITERA

Enero 2010 Pgina 2 de 38

CONTENT

GENERAL ASPECTS.......................................................................................................... 3rea and seed requeriments. Error! Bookmark not defined.Site selecction ....................................................................Error! Bookmark not defined.Planning ............................................................................................................................... 4

THEPRENURSERY.......................................................... Error! Bookmark not defined.General aspects ..................................................................Error! Bookmark not defined.Shade ................................................................................................................................... 9Planting ............................................................................................................................. 11

Care after planting ............................................................................................................. 13Weed control and phytosanitary management .................................................................. 13Fertilization ....................................................................................................................... 13Irrigation ............................................................................................................................ 14Culling .............................................................................................................................. 14Trasplanting to the main nursery ....................................................................................... 16Multiple plantlets............................................................................................................... 16Inert substratum ................................................................................................................. 17

MAIN NURSERY ............................................................................................................... 20

Land preparation and soil selection ................................................................................... 20Infraestructure ................................................................................................................... 21Bags .................................................................................................................................. 21Filling and distribution of bags ......................................................................................... 22Preparation and transporting of prenursery plants ............................................................ 24Trasplanting at the main nursery ....................................................................................... 24Irrigation ............................................................................................................................ 26Fertilization ....................................................................................................................... 27Weed control .....................................................................Error! Bookmark not defined.

Phytosanitary management ............................................................................................... 30Culling ............................................................................................................................... 33Plant preparation before field planting .............................................................................. 35ANEX 1: General information on sprinkling irrigation. ................................................... 36

ANEX 2. Expected efficiencies of some activities .38


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GENERAL ASPECTS

An oil palm plantation must begin with the selection of the best planting material available on

the market and an excellent seedling management in the nursery. The planter must obtain itsseeds from a well-known reliable source; that will guarantee the quality and genetic purity of itsvarieties through an ample germplasm base, a well established and recognized breeding program,and by independent official certificates of both genetic purity and high phytosanitary standards.

Only the very best plants from the nursery should be taken to the field. Any false saving at theprenursery or nursery phases may have serious negative economical consequences that may ex-tend throughout the productive life of the plantation (20 or more years). Choosing the best nur-sery plants will allow:

Shortening the period between transplanting in the field and the first harvests (increased pre-cocity)

Increasing the initial accumulated yield, which is very important to improve cash flow during

the first years Reducing initial maintenance costs in the field, particularly weed and pest control

Seed requirements and nursery area

The number of seeds required depends on project size and the percentage of expected losses,which depends on the percentage of emergence and the culling or discarding of abnormal plants.Normally, it is expected to discard around 15-20 % of the plants at the end of the nursery phase;however, this proportion may be larger if agronomical management has been deficient, possiblyleading to loss rates ofup to 25% or more (Table 1).

To estimate the area required for the nursery to house the number of seedlings to be planted in adefined field, two aspects are taken into account: the age of the seedlings when they would beready to be planted in the field, and the spacing between seedlings for each age and variety inparticular. Besides this, some extra space will be necessary to accommodate the infrastructure,such as storage buildings, roads, drains and the irrigation system (approximately 15% of the totalarea).

Usually the seedlings are expected to stays in the prenursery for 2.5-3 months, and in the mainnursery, an additional of nine more months; however, due to unexpected situations in the initia-tion of the project, it may be necessary to plant younger seedlings less than 12 months old orseedlings older than 12 months. Under these circumstances, the spacing between seedlings variesalong with the size of the nursery (Table 1).

Nevertheless, it must be kept in mind that planting too young nursery seedlings (particularly un-der seven months of age) is not advisable, since some of them could develop into abnormalplants, but at such young age they are still undistinguishable from their normal sisters. Besidesthis, when nursery plants are still underdeveloped to be planted in the field, they are more ex-posed to suffer severe damage by some pests like rats, cutting ants and Strategus aloeus. Ratsmay cause severe losses in plants with a thin basal bulb. Finally, weed control have to be initiallymore intensive and expensive, since small plants can suffer more from competition, particularlyfrom tall grasses. On the other hand, taking to the field very large nursery plants (17 or moremonths) may cause severe transplanting shock if no special precautions are taken during plant-ing. In an attempt to facilitate transportation and planting, the grower may severely prune theseplants which is not desirable either.


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Site selection

The area for both the prenursery and main nursery must meet certain requirements:

Nearly flat topography Soil with a top layer rich in organic matter, well structured, preferably sandy loam, loam or

clayed loam Enough space for the number of seedlings needed and the accompanying infrastructure Availability of water year-around Easy access year-around Strategic location with respect to the defined planting areas, particularly for the main nursery

Planning

Some key aspects are:

Timely land preparation (at least three months before the seeds arrive) Reception of the seeds in the appropriate season, so field planting can be done at the begin-

ning of the rainy season Proper estimates of the needs for infrastructure, materials, equipment, transport and other

miscellaneous aspects

In general, the net nursery area can be estimated as follows:

A=N/0.886xS2

Where: A= net area (ha), N=number of plants and S= spacing between bags

I.e.: 1.2 m between bags, will result in 8,000 plants/ha. Placed at 90 cm triangular will be 12,000plants/ha.


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An additional area of around 15% is required for lodging roads, drains and the irrigation system.

Table 1. Estimates of seed quantities and area required (ha) for the main nur-sery according to spacing between seedlings and the project area(15% culling and 2% replanting)

Project size SeedsArea required according to

plant age (months)(ha) Palms/ha required 12

2 143

50 143 8,500 0.7 1.0100 17,200 1.4 2.1500 85,800 6.9 10.3

1,000 171,600 13.8 20.750 160 9,600 0.8 1.2

100 19,200 1.5 2.3500 96,000 7.7 11.6

1,000 192,000 15.5 23.150 170 10,200 0.8 1.2100 20,400 1.6 2.5500 102,000 8.2 12.3

1,000 204,000 16.5 24.62

= 0.9m triangular spacing3

= 1.1m triangular spacing

A percentage of plants (2% or less) may fail after field transplanting due to poor planting tech-niques, diseases, pests, or any other cause. These losses must be anticipated by planting extranursery plants that can be eventually used to fill the vacants. These extra plants will stay in thenursery for at least an extra year, so it is advisable to use more spacing between bags.

The development of large plantations is generally carried out in several phases (years); therefore,nurseries could be established in the same site during several years. On the other hand, the possi-bility of delays in field planting makes it necessary to keep seedlings in the nursery longer thaninitially planned. This means that seedlings to be used in the next phase and those ready fortransplanting in the field may overlap. If this overlapping exceeds the normal prenursery periodof three months it is recommended that sufficient additional area and irrigation capacity be avail-able to accommodate both groups simultaneously. However, it must be kept in mind that main-taining plants of different ages in the same area and using the same site for a nursery during

many years may aggravate some phytosanitary problems. This is the situation observed in siteswere antracnose blight is prevalent, where even prenursery plants could be affected by inoculum(spores) generated in the older seedlings.


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THE PRENURERY

General aspects

ASD only recommends two stage nurseries, where the germinated seeds are first planted in smallpolybags in a prenursery and then transplanted into larger bags at the main nursery after two anda half or three months (3-4 leaves). Planting and selecting the best seedlings at the prenurseryassures that only the best plants are eventually taken to the field at the end of the nursery stage.

The prenursery offers several advantages:

- Less land needs to be prepared initially (bags are smaller and are accommodated togeth-er)

- The initial costs of supervision and maintenance are substantially reduced- Watering is more efficient and less expensive

- There is a substantial saving in large nursery bags and filling with soil of those bags1

- Only the best seedlings will be taken to the main nursery

However, if seedling from the prenursery are not transplanted to the main nursery in a timelyfashion, they will suffer etiolation (abnormal growth due to light competition). This problemcould be even worse when Jiffy pellets or similar small pellets or pots are used to establish theprenursery, since they are very close together. Etiolation is an important factor that reduces ini-tial yields at the field.

Figures 1 and 2 show a general layout of a structure (module) for a prenursery that accommo-dates about 7,200 bags. The structure measures 16x8 meters and holds four beds for placing thebags. Each bed is 15 meter long and holds near 1,800 23x15 cm-bags (12 bags wide). The V in-verted roof has a maximum height of approximately 3.5 m and a minimum of two meters (see

also figure 16).

1 At the end of the prenursery stage, 7-8% of the plants could be discarded, which would be the percentage of largebags which will not be filled with soil and eventually distributed at the main nursery.


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Fig. 1. Distribution of planting beds within a module for a prenursery. The structure holds about7,200 plants. Separation of one meter between beds on both sides allows for transiting with awheelbarrow and placing the bags along the beds (see also figures 2 and 16)

Fig 2. Front view and roof of a module for a prenursery. Clear plastic is used between two layers ofsaran (fiber giving 50% shade). The external layer of saran covers the whole structure down to theground, which also helps to protect the plants from damage caused by intruding animals (see alsofigure 1).

Building these modules individually facilitates personnel distribution, labor assignment, supervi-sion of different activities etc. Besides, groups of plants differing in age, variety or any othercharacteristic can be managed separately. For example, for palms of the same age, shade can beremoved at once.

Clearplastic inbetween

Saran(shade):below

Layer ofsaran:external


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Larger modules can also be built (Fig. 3), but supervision is more difficult, and care has to betaken when doing some tasks, like shade removal, when plants of different ages share the samestructure.

Fig. 3. General layout for a large prenursery. Fencing is done when there is risk of domes-tic or wild animals causing damage. Smaller structures like those pictured in figures 1 and 2are preferred.

Polybags

Black polybags (25 x 20 x 0.01 cm, 20 x 16 x 0.01 cm and 23 x 15 x 0.01 cm) are used at theprenursery. These bags need drainage holes on the sides and at the bottom (about 32 holes fromthe upper third down, plus 8 at the bottom). Smaller bags than those mentioned are not recom-mendable since planting is more difficult, the small volume of soil restrict root development andplants may etiolate if transplanting to the main nursery is delayed

Polybag filling (with soil) and distribution on the beds

Bags are filled with soil a few days before planting (Fig. 4), and should be taken inside the pre-nursery as soon as possible to protect the soil from the direct impact of rain drops. Soils withintermediate textures are preferred (sandy loam, loam, clay loam), free of hard clods, stones,roots and other large pieces of organic matter or foreign materials. The use of clayish textures isassociated with the presence of a larger number of abnormal plantlets. On the other hand, soilswith a large sand content may favor water deficit if the irrigation system fails even for a fewdays. After filling the bags, it is advisable to irrigate for a couple of days to settle the soil. A

Fence Beds withbags

Entrance


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worker may fill between 80 and 100 bags per hour, and near 600 prenursery bags can be filledwith a cubic meter of soil.

If there is some risk of a soil pathogen being present (particularly if organic matter content ishigh), a fungicide like Banrot (1 g/l: 20 ml of the solution/bag) can be used a week before plant-ing.

Bags are normally arranged in blocks (Fig. 5) and placed on a bed made with fine gravel or sand(10 cm height). This facilitate drainage within the bags and prevents the formation of sedimentsbetween them which favor the present of some pests like crickets and make difficult to take outthe bags at the end of the prenursery stage. A worker can accommodate approximately 800 bagsin one hour.

Beds should not be wider than 1.2m to facilitate planting and other activities. Length can vary,but 10-15 meter is normally used (Fig. 10). Enough spacing should be left between blocks, soworkers can move freely along them. In module in figure one, spacing between beds is one me-

ter, which permits transit with a wheelbarrow carrying the bags already filled with soil. Gravel orother kind of material can be put along these alleys to prevent the formation of puddles andgrowth of weeds.

When soils in the bags settle, it is necessary to refill them to reach the desired level before plant-ing (Fig.6)

Fig. 4. Fillig prenursery bags with soil. A covershade was built with palm leaves for worker com-fort

Fig. 5. Bags are carefully aligned on the beds. Inthis particular case, beds were not raised becausesoil was sandy

Seedling shadeThe use of shade during the first weeks after planting help to maintain a humid environment andprotects the young seedling from high temperatures and direct sunlight which may cause scorch-ing. Shade does not necessarily increases emergence (this depends on other factors), but willimprove plant quality, particularly in places where solar radiation is very high.


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Normally, the structure that holds the shade has a height superior than two meters and is built outof wood, bamboo or metal (Figs. 6 and 7). Synthetic black fiber (saran 50%) is used to providethe shade which is later removed (normally on the sixth week after planting).

Some growers use palm leaves or similar to provide shade, which can be gradually removed bytaken off one leaf at a time every day. However, the use of this type of shade may cause splash-ing unearthing the seedlings, which has to be covered soon after.

Shade should not be removed prematurely to avoid sun scorching. A calm day (without strongwinds), with mild temperatures and not much sun radiation has to be chosen if the shade is goingto be removed at once.

Many of the above problems can be minimized if the prenursery is built fallowing the concept ofmodules (Figs. 1 and 2). The clear plastic used between the two layers of saran, protects theplants from the direct impact of raindrops, helps to better manage moisture in the soil inside thebags and prevents the formation of puddles on the floor. The inverted V shape of the roof avoids

the formation of bags filled with water which weight could rip the plastic and cause damage onthe plants below. The external layer of saran, along with the plastic roof is removed one monthafter planting. The other layer of saran is removed two weeks later.

Fig. 6.Left. Refilling the bags after soil settled. The bags in this prenursery were notput on a raised gravel bed which may negatively affect drainage. Right. Prenurserywith saran shade held with a bamboo structure. Note that beds are too wide difficult-ing planting and other labors

Fig. 7. Detail of the structure (steel wires) holding the shade (saran). On the right the shadewas already removed


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Sowing

It is expected than some time passes between the time the bags are filled with soil and actualplanting. During such time, soil in the bags will settle, some weeds may grow and a compactedsuperficial layer may form. All these make necessary to prepare the bags before sowing theseeds:

Folding down one centimeter the superior border (rim) of the bags Eliminating all weeds and ripping any hard crust on top of the soil. A small metal spatula

(used to scrap off paint from walls) can be used for this purpose Leveling the soil on the bags, leaving about a centimeter clear from the upper rim. This

space could be used later to add a mulch after plant emergencePlanting is a simple procedure but care is needed so the delicate seedlings are not damage.Workers have to be instructed about the importance of the labor, and they have to be closely su-pervised. In most cultures, women normally do a better job, since they handle the seeds delicate-ly.

The normal procedure is as follows:

All documents accompanying the seeds are carefully checked, particularly those that in-dicate seed distribution in each box according to the size of the radicle. Seeds with long-er radicles are planted first. All pertinent information is included in box indentified asnumber one for each shipment

Before planting, keep all seeds in the original packing materials, under the shade in afresh, covered and well ventilated place. Air conditioning can be used at a temperature of20 - 22 oC

Once the planting order is established, open boxes one at a time (Fig. 8). If foam has beenused to protect the seeds in transit, this can be separated by using a fan. This foam is nottoxic, so part of it can remain attached to the roots. Do not open more boxes than neces-sary to keep pace with the planting work. Never expose the germinated seeds to directsunlight for too long (sitting on the soil waiting to be planted).The seeds can also be received inside individual plastic containers, where they are pro-tected with bands of a foamy material (Fig. 8). This packing system better protects theseeds and saves labor (no foam has to be removed) and each individual container can betaken directly to the planting site

If necessary, place the seeds inside a container, such as a plastic bag, a box etc., coverthem with a wet towel and bring them to the planting site. This is not necessary if theseeds already came in individual plastic containers as described above.


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Fig. 8.Left. Traditional packing system used in shipments of germinated seeds. Seeds are protectedwith polyethylene foam. Right. New packing system, where containers can be taken directly to theplanting site. Seeds could be colored to identify varieties

When sowing, the plumule must point upwards and the radicle downwards (Fig. 9). This

is vital, otherwise an inverted seed will not emerge or will generate an abnormal seedling With your fingers make a hole in the soil in the center of the bag. Depth will depend on

the size of the radicle. Place the seed in the hole but do not released it yet (the plumuleshould be between 0.5 and 1.0 cm under the soil surface). A poor plant could be obtainedif the plumule is exposed on the surface or if planted too deep,

Still holding the seed, fill with soil the volume around it. Release the seed, and finishadding soil and gently compact it around. Do not press too hard since the seed could bedamaged. A worker can sow about 200 seeds per hour

Close supervision during and after planting is necessary, checking for uncovered seeds, seeds notplanted or any other abnormal situation. The most common mistakes made during planting are:

Inverted planting (plumule pointing down) Deep or shallow planting Breaking vital structures (plumule or radicle) or separating them from the seed Planting seedling that were mishandled (ie. leaving them under the sun for too long) Using an inadequate substratum (i.e. clayish soils)

Batches in the prenursery should be identified by variety, day of planting and any other impor-tant detail.

Fig. 9.Left. When planting the radicle should point downwards. Center. Seeds being planted fromboth sides of the bed.Right. Bags were improperly accommodated on the bed by pressing again eachother, which compacted the soil and will negatively affects the seedlings.


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Care after plantingRainfall or irrigation water may wash away some of the soil and uncover the seeds (Fig. 10).This problem is common when seeds were planted too shallow and/or palm leaves where used toprovide shade. These seeds so exposed must be covered with soil again immediately.

After plant emerge, some sort of mulch (normally cracked oil palm shells or rice husk: about onecentimeter in depth) can be used to control weeds on the bags, reduce erosion and avoids theformation of a crust on the soil surface that impedes water infiltration and favors the formation ofalgae.

Fig. 10. Prenursery where seeds were plantedtoo shallow and were uncovered by watersplashing

Fig. 11. Shade will be removed soon from thisprenursery.

Weed and phytosanitary managementWeeds growing on bags should be manually eliminated. As a norm, no herbicides should be usedin the prenursery. A fungicide drench (i.e. Captan or Banrot: 1 g/l: 20-30 ml per bag) can be usedif there is any risk of the presence of a soil-borne pathogen in the substratum. Nevertheless,ASDs seeds have been already treated with fungicides, which normally will protect them duringthe first stages after planting.

Under most conditions, no important phytosanitary problems are expected at the prenursery, butchances can be even lower by supplying a balanced nutrition to the plants and avoiding waterstress (too little or too much water). A basic knowledge of soil fertility and water holding capaci-ty of the substrate will guide fertilization and water supply. This is important, since plants are tooclose from one another, and a favorable environment may form (i.e. high humidity) that favorinfection and dispersal of some pathogens. Agrochemicals (fungicides or insecticides) should notbe applied indiscriminately, but only after a particular problem has been clearly identified andthe right product chosen to help in its control. Regular scouting of the area permits an early iden-tification of a potential problem and taking measures for proper managing.

Fungicides like Benomyl (alone or in mixture with Mancozeb usually), every 10-15 days areused in those places where foliar diseases are expected to occur. It is really important that beforeusing a product or brand for the first time, the product be applied only on a few plants to test fortoxicity.

Fertilization (Manuring)Seedlings may live from seed reserves for approximately two months after planting, howevereven during this time nutrient deficiencies may develop, particularly after removing the shade.


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Such deficiencies are easily avoided by applying a drench of a solution prepared from DAP ferti-lizer (25 g/l: 20-40 ml per plant according to age) using a knapsack sprayer or a small containerproperly calibrated. This treatment can be started about one month after planting and is repeatedweekly. Experience in Costa Rica indicates that DAP can be used directly on the bags (1-2g/plant) according to age.

A formula, high in phosphorus and potassium can also be used, but any solid fertilizer should beused with great care to avoid burning the plants if applied too close to the base (granules shouldbe placed near the border of the bag) or on the leaves. A light irrigation after applying the ferti-lizer will help to wash away any residues from the leaves. An device can easily be constructedusing the upper part of a plastic bottle and PVC (Fig. 12)

Fig. 12.Left. Device made with PVC and a portion of a plastic bottle used to applyfertilizer at the prenursery and reducing the risk of causing toxicity. Right. Sunscorching caused by improper management of shade. This type of burning is similarto that caused by a poor application of a fertilizer.

IrrigationA reliable source of water is essential at both the prenursery and nursery. Normally, micro-sprinkers are used at the prenursery (0.8 l/h) to reduce splashing that may uncover the seeds andcarry soil particles that may bring soil-borne pathogens up to the foliage. Manual irrigation couldbe used, but only in extremes circumstances (failure of the irrigation system), since severe ero-sion can be caused and supply of water will not be uniform to all plants.

CullingCulling of all abnormal plants (off-types) is fundamental to guarantee the success of the futureoil palm plantation. A poor plant taken to the field will be a mistake whose consequences will becarried over for 20 or more years. Final culling at the end of the prenursery normally varies be-tween 7 and 10%, but this depends on the genetic material being used, and above all on agro-

nomic management of the prenursery. In general, the following factors may increase the percen-tage of abnormal plants:

Not using shade or prematurely removing the shade Using heavy (high clay content) or compacted soils in the polybags An inadequate supply of water (too much or too little) Abuse of agrochemicals (herbicides, insecticides etc.) causing toxicity to the plants Extending the prenursery period and causing etiolation (due to light competition) Improper management of pests and diseases


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The most common types of abnormal plants at the end of the prenursery are (Figs 13 and 14):

Very narrow leaves (grassy appearance) Twisted, crinkled, corrugated or rolled leaves

Puckered leaves (collante) Exagerated upright plants

Chimeras (albines)

Underdeveloped plants (dwarfs)

Fig. 13. Normal prenursery plants are shown on the upper left side. The restof pictures show different types of abnormal plants that have to be culled


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Fig. 14.Left. Some of these plants grew abnormally which was associated with the use of aclayish soil. Right. Polybags were pressed against each other causing soil compaction whichaffects seedling emergence and may cause that some plants grow abnormally

The diameter of the basal bulb is a good indicator of plant vigor at the end of the prenursery pe-riod. Normal values for several varieties are:

Table 2. Bulb diameter (mm) in some varieties at the prenursery

Days aftersowing

Deli xAVROS

Deli xGhana

Deli xEkona

Deli xLa M

Deli xYangambi

37 6.3 5.9 5.7 5.1 6.451 6.4 6.0 6.3 5.6 6.663 6.8 6.2 6.6 5.9 6.777 7.1 7.0 6.7 6.2 7.490 8.1 8.4 8.2 8.1 8.8126 12.2 11.6 11.8 12.2 13.1

Trasplanting to the main nursery

Transplanting to the main nursery is done when the plants reach 2.5-3 months of age (3-4 leavesalready formed) in standard prenurseries. When small pots are used (i.e. Jiffy pots) the prenur-sery period has to be shortened to avoid plant etiolation, which seriously limit yield potential inthe field.

Multiple plantsSome germinated seeds may bear two or more germination points giving rise to two or moreseedlings (Fig. 15). The best decision in these cases is to keep the best plant and destroy the otherone. This is normally done just before transplanting to the main nursery or soon before. Howev-er, some growers prefer to make an extra effort and try to save both plants. In this case, it has to


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be remembered that the procedure to separate the plants may cause serious stress to both ofthems, which may severely affect growth and even cause death. To avoid this, special care mustbe taken when separating the plants to reduce stress and speed plant recovery.

The following procedure has been done with some success when separating doubletons:

Let the soil in the bag to lose some water (down to near field capacity). This will makesoil more friable and reduce root damage when separating the plants

Loosen the soil in the bag by gently pressing with your fingers Firmly hold the seed with one hand, and with the other hold the plant that is going to be

separated (the best plant is always left in the original bag) With a quick forward (or backward) movement release the plant from the seed and slowly

take it out the bag trying to cause minimum damage to the roots The plant is then planted in another bag, and kept under shade and well irrigated until it

recovers from the shock To reduce shock, apply a sugar solution (20 g/liter of water). Other products that reduce

stress (i.e. Ergostim) can also be used.

Fig. 15. Germinated seeds with two seedlings. Right. Plants were separated at the end of theprenursery phase (the most vigorous plant is left in the original bag). The other plant withsome roots is planted in another bag and kept well irrigated and under the shade

Use of inert substrata at the prenurseryTraditional prenurseries are done using polybags filled with soil. An alternative to this method isto use small plastic pots or Jiffy pellets carrying an inert substratum. This system has severaladvantages, but transplanting time to the main nursery is critical (see below). The plastic pots orJiffy pellets (after being soaked in water) are placed on trays on raised beds (made with metal,wood, bamboo etc., approximately 90 cm height). These beds facilitate planting and other activi-

ties, and help to maintain the floor of the nursery free of puddles (Figs. 16 and 17).


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Fig. 16. General view of a module for a prenursery that can accommodate about 7,200 bags (23 x15 cm) in four gravel beds, 15 m long and 1.20 cm wide (12 bags). Raised beds can also be built(bamboo was used in this case) to place trays with Jiffy pellets or pots with an inert substratum

like peat mosses (see other details on section on shade and figures 1 and 2)

The use of an inert substratum, like Jiffy pellets may have several advantages:

Saves space and infrastructure costs: a module such as in figure 1 can hold up to 16, 128Jiffy pellets compared with 7, 200 prenursery bags filled with soil

Increase plant emergence Better quality plants (less phytosanitary problems) Weed control is easier and less intensive Efficiency of maintenance and supervision activities improves Planting efficiency at the nursery increases with less transplanting shock Culling is facilitated

The volume of the substratum where roots can grow is rather small and also the diameter of thepots and pellets is small. This means that if transplanting to the main nursery is delayed, severeetiolation (light competition) can occur and the roots will grow out the containers, affectinggrowth and originating plants of inferior quality in the nursery. To avoid these problems it isnecessary a careful planning of activities, particularly with respect to transplanting to the mainnursery, that should be done about seven weeks after planting.


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Fig. 17. Prenursery on raised beds where germinated seeds were sown in small plastic pots filled

with peat moss and placed on plastic trays

Sowing the germinated seeds in the Jiffy pellets is facilitated by using a device as illustrated infigure 18. This PVC spoon is used to bore a hole in the substratum down near the bottom toavoid the radicle pushing the seed up and exposing it. Depth of planting is the same as in soil.

In general, most labors in these prenurseries are similar as in standard prenurseries, but foliarfertilization is normally done weekly starting one month after planting. Slow release fertilizersare also very efficient to avoid the appearance of nutrient deficiencies.

When a roof of clear plastic is used on top (and between two layers of saran), this is removedalong with one saran layer one month after planting. The other saran layer is removed one weeklater (Figs. 2 and 16)

Fig. 18. A PVC spoon used to bore a hole in a Jiffy pellet (already soaked in water) where the ger-minated seed is planted. On the right, a plant ready to be transplanted to the main nursery.


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MAIN NURSERY

At the main nursery, the plants from the prenursery are transplanted in larger polybags distributedon the corners of equilateral triangles. The idea is that every plant receives as much sunlight as poss-ible during this phase. At the end of the nursery, the best plants are chosen to be taken to the fieldand make the final plantation. No false saving should be permitted here, and the decision of takenpoor plants to the field will have a negative effect on early yields and even accumulated yields dur-ing the whole life of the plantation.

Land preparation and soil selectionThe nursery site is prepared 2-3 months in advance before placing the bags. If grasses predomi-nate, these have to be eliminated along with their propagules. Polybags should be filled withgood quality soil, normally taken from the surface on site (first 15-20 cm). Soil structure must bestrong (good internal drainage), texture intermediate (sandy loam, loam, clay loam), rich in or-ganic matter and fertile. This soil is scraped from the surface and piled up on strategic places tobe used to fill the bags. Care has to be taken to disturb the soil as little as possible to preserve itsphysical properties. If the soil on site does not meet these criteria, it is advisable to bring it fromsomeplace else and there should be no compromise on this.

Soil piles must be covered with plastic or other material to prevent loses due to erosion. Besides,if the soil is too wet, this will make difficult to fill the bags properly. Stones, roots, debris andother strange materials can be eliminated by sieving the soil before filling the bags (Fig. 19)

Fig. 19. Sieving the soil to be used in the polybags. Stones, roots and any debris should be elimi-nated. On the right, the soil was covered with plastic to protect it from rain (that causes erosionand excessive moisture that will make bags filing and planting difficult).

A compound fertilizer (N-P-K) can be added to a low fertility soil: 2 g per bag. Organic fertilizercan also be added to the soil, but in a proportion lower than 10% v/v, and by mixing homoge-neously. A poor soil (heavy: high clay content) can be mixed with sand to improve physicalproperties. Such a substratum sometimes takes equal parts of soil and sand and then compost(less than 10% v/v), but, as pointed before, it is advisable to choose an excellent soil from thebeginning to avoid these inconveniences. The ideal situation is to use the top soil from the site


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chosen, but if the same site is used for more than one year, it might be necessary to bring top soilfrom someplace else.

InfrastructureLarge nurseries require roads, where the main one runs laterally long the area or it is placed atthe center. Secondary roads (spaced 40-80 meters) are built parallel to this, so bags and plantswill not be carried more than 40 meters (Fig. 20).

Main drains are normally built laterally along the nursery. Secondary drains are built parallel tosecondary roads and between them. Small tertiary drains can be done every 15-30 m, dependingon topography and the presence of standing water. Detailed maps indicating infrastructure built,varieties and planting dates and other details are used as a guide for planning activities and tak-ing and processing relevant information.

.

Fig. 20. General diagram for the main nursery showing roads and drains

PolybagsHigh density black polybags, with no recycled materials, and ultra violet radiation protection (tinu-

vin 622, 2%) are recommended for the main nursery, since these bags must withstand outdoor con-ditions for at least nine months. Bags should have a gusset at the bottom to help sit then on the floor.A normal size is about 40 x 53 x 0.015 cm, with approximately 120 holes for drainage (lateral andon the bottom). These holes are circular (0.5 cm in diameter). A bag this size will hold 18-20 kgof soil with the right moisture (field capacity) (Fig. 21)

Secondarydrainage

Mainroad

Main drainage Secondary roadSuperficialdrainage


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Fig. 21. Nursery polybag showing holes for drainage, mulch on top(cracked nut shell) and manual weeding

A premature deterioration of the bags (Fig. 22) may cause serious problem to plant developmentand increases costs unnecessarily. It would be possible to acquire some additional larger (45 x 55x 0.015 cm) bags (2%) to replace those that may eventually fail, but this is not recommendable,and best quality bags should be bought since the beginning.

Fig 22. Left. The bags used in this nursery were of poor quality and deteriorated. Be-sides this, not enough soil was added to the bags. Right. Bags had no drainage holeswhich caused standing water and the formation of a superficial crust where algae grow.

Filling of polybags and aligningIt is recommended to add an inert material (such as cracked nut shells: about 3 cm in depth) be-fore adding the soil to the bags in order to improve internal drainage by separating the bag fromthe floor of the nursery (Fig. 23). Soil is then added up to about 4 cm from the rim: 2 cm will beused to fold it down (to improve resistance during handling) and the other two will hold a mulch.It is normal that soil will settle (due to rain or irrigation) after filling the bags, so more soil has tobe added to complete the desired volume. A worker may fill 40-60 bags per hour.


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Fig. 23. An inert material such as cracked nut shells is put on the bottom of the bagsbefore adding the soil to improve drainage. Right. A custom made PVC tube can beused to facilitate filling of bags by a single worker

If only bags without gusset are available, the tips at the bottom are folded inwards before addingthe soil, which allows broadening the base and reducing the risk of tipping over.

Bags are aligned on the corners of an equilateral triangle, which permits an optimum use ofspace and maximize sunlight exposure to every palm. Bags are line up using wires or metalchains with marks indicating bag spacing (Fig. 24). Normally, rows are set up in a North toSouth direction. Bag spacing depends on the variety (vigorous varieties may easily etiolate) andexpected time of permanence in the nursery (Table 3).

Fig. 24. Line up of polybags at the main nursery. A wire with marks according to bag spacing is

used to get proper aligning

Table 3. Distance between bags (corner of an equilateral triangle) accord-ing to time of permanence at the nursery

Months

Spacing(m)

9 a 11 1.00-1.2012 a 14 1.20-1.35


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Preparation and transportation of the prenursery plantsThis is a delicate labor, since it is very important to preserve the quality of the seedlings. If thedistance between the prenursery site and the main nursery is long, transportation should be doneearly in the morning or in the evening. A light irrigation is given to the plants as a preparationand then they are carefully placed inside an appropriate box, such a those used to transport somevegetables (Fig. 25)

Fig. 25. General view of a prenursery ready to be transplanted to the main nursery. Right.Seedlings were put in plastic boxes to protect them while transporting

Planting at the main nursery

A cylindrical hole is made in the soil at the center of the bag. This operation is betterdone with a auger that would make a hole of a diameter and depth slightly larger than theseedlings bole of earth. A worker can make about 250 of such holes per hour. If Jiffypellets were used at the prenursery, the holes would be necessary smaller (need an appro-

priate auger) and planting efficiency increases (Fig. 26). The planting sequence is as fol-lows:

Fig. 26.Left. Making holes with an auger in the polybags in preparation for planting at the main nursery.Center. Auger. Right. Polybag filled with soil with a hole already prepared to receive the prenurseryseedling


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The prenursery polybag is carefully removed trying not to disturb the bole of soil aroundthe roots

The seedling is placed in the hole keeping the integrity of the bole of earth Free spaces around the bole are filled with soil and gently compacted with the fingers

(Fig. 27) The plants collar should maintain the same level as in the prenursery bag (either deep or

shallow planting negatively affects plant development)

Fig. 27. Sequence illustrating the transplanting procedure (from prenursery to the main nur-

sery). On the lelft, the prenursery polybag is removed by using a sickle-shape knife that facili-tates the operation. The plants collar maintain the same level as in the prenursery bag.

Transplanting work has to be closely supervised, to avoid damage to the plant (foliage androots). Besides this, depth of planting must retain that of the prenursery plant: not too shallowand not to deep, since this affect the quality of the nursery plant (Figs. 27 and 28).

Fig. 28. Deep planting of the prenursery plant. Right. Shallow planting. Both situationshave to be avoided since they negativelly affect plant quality.


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IrrigationNursery plants require a reliable water supply during the whole period, particularly during theearly stages, and when the planting substrate has a low water holding capacity. This makes ne-cessary to take all precautions to make sure the irrigation system is installed and properly work-ing before the plants arrive. In is not wise to rely on rainfall, even during the rainy season, sinceeven short dry spells may cause severe damage to the young seedlings

Sprinkling irrigation (Fig. 29) is normally preferred in oil palm nurseries, since it is efficient, easy tocontrol, allows for a uniform supply of water and requires fewer work forces. There are many op-tions available on the market; but the system normally has a pump, pipes for distribution and forthe sprinklers, coupling elements, valves (pressure and flow), towers and sprinklers. The finaldesign including pumping capacity, size, pipe resistance and other aspects may vary under dif-ferent circumstances, and all these aspects should be considered when buying the system from avendor, who normally includes the pertinent technical assistance as part of the sell (Annex 1).

Fig. 29.Left. Traditional irrigation system with sprinklers. Right. Central pivot appropriate forvery large nurseries (Brazil)

Dripping irrigation (Fig. 30) has also been used in some nurseries. The main advantages are wa-ter economy and the possibility of adding the fertilizer when irrigating. However, it may alsopresent some problems with clogged drippers, and it is a physical obstacle during weed controland other activities.

Fig. 30. Dripping irrigation at the main nursery


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Depending on plant age, soil and weather, water needs at the nursery phase may vary between 4and 10 millimeters per day.

During the early stages of grow, plants explore the volume of soil within the bags, but eventually(7-8 months old) the roots grow through the bottom of the bags and explore the soil beneath. Astandard nursery bag (40 x 50 cm) holds about 18.5 liters of soil with a water holding capacity(available for the plant) of about 2.5-4 liters. A tensiometer in the soil of the bag will help to de-termine water depletion rate and irrigation periods to avoid water stress. All necessary precau-tions should be taken to make sure the irrigation system is on site and properly working by thetime the seedlings arrive. Necessary parts must be available to keep it running, since a failure,even for a short period of time may have highly negative consequences (Fig. 31).

Fig. 31. Left. Uneven water distribution caused serious damage (water deficit) to some palms.Right. Poor nursery: plants were taken late from the prenursery (severely etiolated), suffered waterstress due to inefficient water supply and low water holding capacity of this sandy soil. An additionalproblem of this nursery is that bag spacing is too short and plants may suffer severe etiolation if fieldplanting is delayed.

FertilizationCommonly, only nitrogen, potassium, phosphorus, magnesium and boron are applied during thenursery phase. Only on particular sites, other elements like copper, zinc and sulphur are also ap-plied.

Total amount of fertilizer applied during the entire nursery phase is usually less than half a kilo-gram. The response depends then, not much on the amount applied, but the frequency of the ap-plications, which should be every 8-10 days. The fertilizer is placed carefully around the stem ofthe plant but without touching it (close to the rim of the bag). Direct contact with the foliagemust be avoided, particularly when wet

Special containers (scoops) can be made from PVC that hold the right amount of fertilizer to beapplied per palm. A scale ( 0.5-grams) is needed to previously calibrate the containers (Figs. 32and 33).


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Fig. 32. Applying the right amount of fertilizer per plant by using a calibrated cup

made out of PVC.Right. A device is used to apply the fertilizer and reduce the risk oftouching the foliage and causing toxicity.

Fig. 33. Manual manuring: this is not recommended since there is no control on doses appliedand there is more risk of causing toxicity. Right. The plant on the left was severely damage by aimproper application of fertilizer.

A popular program used in nurseries in Malaysia is as follows:


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Table 4. Fertilization program used in some nurseries in Malaysia

Plant age(Months)

No. of applica-tions per month

Grams of formulaper plant

14:13:9:2.5 12:12:17:2

4 2 14 -5 2 - 286 2 28 -7 2 - 428 2 42 -9 2 - 5610 3 56 -

11 1 - 7012 1 70 -13 1 - 8414 1 84 -

294 280

In Costa Rica, alluvial soils predominate, with medium textures, slight acidity, but with highcontents of calcium. For this type of soil the fertilization program is similar to that in Table 5.

Table 5. Fertilization program commonly used in nurseries inCosta Rica

Plant age

(Month)

Grams of formula 14:12:20:6

/plant/month3 124 205 246 307 338 369 4010 4511 5012 6013 6014 60

* Weekly applications.The program is normally supplemented with K-Mag (Sulphomag)applied on weeks 16, 24, 32, 40 and 48 (5, 8, 10, 15 and 20g/plant).This extra application of K is associated with a better as-pect of plants and reduced incidence of foliar diseases, and evenless attack by the whorl worm


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Weed controlBags should be maintained free of weeds all the time (on top and on the sides; since some weedstend to grow out the lateral drainage holes). This labor is done manually. Weed control on thenursery floor should be selective, since some plants are not necessarily harmful. The use of pre-emergence herbicides after land preparation will help to reduce the weed problem later.

Growth of weeds on the nursery floor should be controlled to a point where they do not shade thepalms and do not interfere with normal activities. In general, grasses should be completely elimi-nated inside and around nursery site.

Manual weeding is preferred on the nursery floor, but some herbicides can also be used taken thenecessary precautions to avoid toxicity. Applications should be stopped under windy conditionsand it is always necessary to use a bell or shield around anti-drift nozzles (Fig. 34). Some herbi-cides used in nurseries are Paraquat, Diuron, Oxyfluorfen and Pendimethalin. Selective herbi-cides, such as Fluasifop-buthyl, Haloxyfop methyl and Oxyflourfen are highly effective to con-trol grasses.

Fig. 34. Spraying herbicides on the nursery floor. Note the use of a shield (bell) to reduce drift-ing and the safe equipment used by the worker. On the right, an excessive weed control on thenursery floor which is not necessarily desirable.

Weed growth on the nursery floor can also be reduced by using an inert material, such as crackednut shells or gravel.

Phytosanitary management2Most sanitary problems at the nursery phase are caused by fungi attacking roots and leaves main-ly. These problems are normally controlled by applying fungicides, or most commonly followinga preventive program of applications (Fig. 35).

2 Products and doses mentioned are only used for illustration purposes. Always read the label. When a product,formulation or vendor is going to be used for the first time, the product should be tested on a reduced group of plantsto check for toxicity


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Fig. 35. Spraying equipment and proper indumentary for the worker

The most common phytosanitary problems at the nursery and some suggestion for managementare:

i. Anthracnose (mainly Colletotrichum gloeosporioides) Correct any nutritional unbalance (in particular high N with low K) Avoid water stress: excess or deficit (particularly if the substrate used has a low water

holding capacity) When possible, cut off infected tissue and take it away from the nursery area Weekly sprays of a fungicide such as Mancozeb (2.5-4 g/l c.p.3) or Maneb F (3.5 cc/l

c.p.) alone or mixed with Mertect (Thiabendazole), 0.1% a.i.4 or Benomyl (1-1.5 g/lc.p.), plus coayuvants. Other fungicides like Busamart 30 AC (TCMTB), 1-2 ml/l c.p.,

Cuproxat 35.2% FW (copper sulphate), 3 ml/l c.p., and Phyton 27 (copper sulphate), 1ml/l c.p., may also be used, but may be toxic if not properly used

ii. Curvularia sp., Helminthosporium sp. and related fungi Correct nutritional unbalances (particularly high N in presence of low K) Avoid water deficit Eliminate all grasses in and around the nursery area If possible, cut off and take away from the nursery the infected tissue Weekly sprays of Maneb F (3.5 cc/l c.p.) or Thiram (0.2% i.a.) with Benomyl (1-1.5 g/l

c.p.)

iii. Rhizoctonia sp. (normally during the prenursery)

Use ofmulch on the bags reduces rain splashinf that carries inoculum from the soil tothe foliage

Evoid excessive shade and irrigation Eliminate severely infected palms Sprays with Thiabendazole (0.1% a.i.) or Benomyl (1 g/l c.p.) mixed with Mancozeb

or Maneb Early transplanting to the main nursery

3 Commercial product4 Active ingredient


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iv. Phytophtora spot (blight) Avoid excessive humidity and shade Eliminate infected tissue Weekly sprays with Metalaxyl (3-5 g/l c.p.) or Fosetyl -Al (6-8 g/l c.p.)

Fig. 36. Anthracnose.Right. Foliar blight caused byRhizoctonia sp.

v. Chlorotic ring spot (viral) Nursery should be set up away from low areas (away from rivers, ponds etc., where

tall grasses may grow) The nursery area and surroundings have to be kept free of weeds, particularly grasses Eradicate all infected palms with the very first symptoms and burn Fast knocking action insecticides may be applied in the nursery and on weeds around

the area Use a repellent mulch such as rice husk and yellow colored traps with a sticking agent

to trap visiting insects

Other fungi attacking roots and the basal bulb may be controlled with fungicides like Captan andBanrot (1 g/10 l).

Fig. 37. Chlorotic ring spot. On the right a detail of symptoms giving the name to the disease


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There are also many pests that can attack the young palms. Some of the most common are:

i. Grasshoppers and other defoliators: Deltamethrin (1 g a.i./10 l), Fenitrothion (15 g a.i./10l) or Diazinon (6 g i.a./10 l)

ii. Cutting worms and similar: Carbaryl (12 g a.i./10 l), Methomyl (10 g a.i./10 l) or Cyper-methrin (2 g a.i./10 l). Granular formulations of Carbofuran and Aldicarb (2-4 g/plant) arealso effective

iii. Mites: micronized sulphur (5-8 g/10 l), Binapacryl (5-6 g a.i./10 l), Monocrotophos (4 ga.i./10 l) or Cyhexatin (Plictran). Applications of boron and sprinkling irrigation also help toreduce mite attack

Some products may cause toxicity when used at inappropriate doses (too high) or under some

environmental conditions (high temperatures). Any new product, formulation, or source shouldbe tested first on a reduced number of plants.

Applications should be done when the foliage is dry, trying to get a good coverage of leaves(sometimes, it would be necessary to direct the application toward the lower part of the leaves).By using a 18-20 liter-knapsack sprayer it would be possible to spray 800-1,000 plants (4-5leaves present) or 100-150 plants (10-12 leaves present).

iv. Rats: rodents may cause serious damage if not controlled. Some important preventivemeasures are:

Keep clean of weeds and debris (piles) an area of at least 25 m around the prenurseryand nursery areas

Keep all drainages clean and properly working Use poisoned baits wisely

CullingOff-type (abnormal) nursery plants should never be taken to the field, and there must be no com-promise on this. Final culling rate partially depends on the genetic material used, but agronomicmanagement is also crucial to improve plant quality. In general terms, the factors that are asso-ciated with an increase in the percentage of abnormal plants at the end of the nursery period arethe same as mentioned for prenursery palms, excluding of course the shade effect. Under normalcircumstances, culling rate for the nursery phase is 7-15%, which added to prenursery discardinggives a final culling rate of 15-25%.

Final culling is done just before the plants abandon the nursery. The following are examples of

plants that should not be taken to the field (Figs. 38, 39 and 40): Under developed palms (dwarfs), particularly with a thin basal bulb Abnormal leaves (leaflets): rolled, twisted, too short, long or narrow, etc. Short young leaves, given the palm a flat appearance Acute leaf insertion angle, given the plant a rigid and up right appearance Juvenile character: leaflets do not differentiate


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Fig. 38.Left. Plants with good appearance and ready to be taken to the field. Right. Abnormal plantswith up right appearance.

Fig 39. Etiolated plants that were kept for too long at the nursery. Plants were severely prunedin an attempt to solve the problem but damage was already done and these sort of plants will giverise to plantation with suboptimum yields.Center. Juvenil leaves.Left. Up right growth, with verynarrow leaflets.

Fig. 40. Corrugated leaves. Center. Off-type plant.Left. A nurserhy plant that was prematurellytaken to the field.


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Preparing the plants for field planting and initial careTransplanting from the nursery to the field always causes stress to the plants, so every efforthave to be done to reduce it. Pruning half of the root system sticking out from the bottom of thebags two weeks prior to transplanting is sometimes done in an attempt to reduce transplantingshock. However, this is not necessarily advisable, since plant may tip over and suffer even more.

Two weeks before transplanting, plants are prepared by given a last fertilization, and just beforetaking them out the nursery they receive the last irrigation to wet the soil. All the effort to obtainthe best nursery plants may go down the drain if plants are not carefully handled during transpor-tation and planting. A poor selection (culling), a careless transport (Fig. 41) and inappropriateplanting techniques and management during the unproductive period may severely reduce yieldpotential of a plantation.

Fig. 41. Unproductive palm: should have been culled while at the nursery. Center. Poor trans-

porting for nursery palms: all efforts to get good quality plants at the nursery may end here. Left.Poor planting technique and post planting care.


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Coverage as indicated by the vendors is only achieved under conditions without wind and withsprayers placed at a certain height to get a discharge superior to certain value.

The maximum separation between sprinklers based on coverage varies according to wind speed:

Mean wind speed(km/h)

Spacing

15 30% between sprinklers 50% between laterals


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ANNEX 2. Expected efficiencies of several activities at the prenursery andnursery

UnitsActivity* Prenursery NurseryFilling of bags with soil 600 350Refilling of bags after soil settles 8,000 1,700Bags distribution on the beds 5,000 1,200Distribution of the prenursery plants** 1,000Boring of holes on the soil of the nursery bags 1,250Planting 1,350 1,200Aplication of mulch 3,000Manual weeding 4,000 2,500Spraying of foliar fertilizer 40,000Granular fertilization 8,000Rouging of abnormal plants 25,000

Spraying of agrochemicals (fungicides, insecti-cides)

40,000 10,000-8,000-5,000***

* Average efficiency during a normal working day of 8 hours in standard prenurse-ries and nurseries. When Jiffy pellets or similar planting pellets are used, efficiencyof most labor improves

** At the end of the prenursery period, the plants have to be taken to the main nur-sery and placed on the side of the nursery bag where they will be planted

***When plants have 5, 8 and 11 leaves respectively

nursery guide

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