New Forests 22: 75–96, 2001.© 2001 Kluwer Academic Publishers. Printed in the Netherlands.

Nursery and field establishment techniques to improveseedling growth of three Costa Rican hardwoods

KEVYN ELIZABETH WIGHTMAN1, TED SHEAR1, BARRYGOLDFARB1 and JEREMY HAGGAR2

1North Carolina State University, Department of Forestry, Raleigh, NC, USA (E-mail:kevyn@ibw.com.ni); 2Organization for Tropical Studies, San Pedro, Costa Rica

Accepted 11 August 2000

Key words: Calophyllum brasiliense, compost, Cordia alliodora, fertilization, herbicide,Hyeronima alchorneoides, native species, reforestation, root trainers, weed control

Abstract. Seedlings of three economically important and ecologically different native hard-woods, Cordia alliodora (Boraginaceae), Hyeronima alchorneoides (Euphorbiaceae), andCalophyllum brasiliense (Clusiaceae), were grown in Rootrainers� (a book-type container),paper pots, and plastic bags filled with either soil, soil with fertilizer, or compost substrates.After transplanting in the field, treatments with and without fertilizer and herbicide wereapplied to all nursery stock types. In the nursery, species responded primarily to substratetype. Cordia grew better in bags of soil with NPK fertilizer and compost than in unamendedsoil, probably responding to higher nitrogen availability. Despite large treatment differences atplanting, there were no significant differences in plant size after one year in the field betweenbook containers and bags. The exception were stump plants that were shorter and had highermortality. Hyeronima grew better in compost than in soil with or without fertilizer, probablyresponding to higher phosphorus availability and lower bulk density of the compost. Plantsproduced in compost were also bigger after one year’s field growth. Plants produced with soilor in paper pots had higher mortality. Calophyllum grew less in compost compared to soil andgrew better when micronutrients were added to the compost and soil. In the field, seedlingproduced in soil or with micronutrients had higher survival or growth, respectively. In general,species grew better with herbicide and fertilizer application after transplanting. However, therewere no interactions with nursery treatments. Responses to field treatments were independentand thus additive to the nursery treatments. Differences in species response can be related tobiomass allocation patterns and ecology of the species.

Introduction

Reforestation in Latin America is an increasingly popular activity due tothe abandonment of unproductive cattle pastures and government incentiveprograms that support tree planting (Schelhas et al. 1997). To promote use ofnative species in forestry plantations and increase profitability for farmers inthe Atlantic Lowlands of Costa Rica, species screening and provenance trials

76

for reforestation were established (Butterfield 1993, 1995; Butterfield andFisher 1994). Currently, farmers in this region are almost exclusively plantingnative species used for furniture and construction wood because of theirdemonstrated fast growth and good form. Rotation periods of 15 years or lesswith one commercial thinning can be achieved. In Costa Rica, small holderfarmers are the primary commercial reforesters, but the seedlings they obtainfrom community nurseries are often of poor quality. While research effortsoften focus on identification of appropriate genotypes for reforestation, moreattention needs to be given to seedling quality.

Despite the enormous diversity of tropical tree species, the majority ofnon-industrial seedlings are produced in the same way, using 500–1500 cm3

perforated plastic (poly) bags with soil. The soil often contains high propor-tions of clay, has poor structure, and is low in plant nutrients. Generally littleor no organic matter is incorporated. Due to poor substrates, plant growth isslow, extending into two nursery seasons, raising costs for the nursery, andinevitably reducing plant growth in the field. Plastic bags are used becausethey are inexpensive and readily available. They can cause root coiling, thespiral growth of roots along the smooth sides and bottom of the bag; this rootdeformation can cause toppling or basal sweep several years after planting,thus greatly lowering the value of the plantation (Mason 1985; Liegel andVenator 1987; Sharma 1987; Josiah and Jones 1992).

Stumps plants (psuedoestacas) are an additional stock type produced inbareroot beds. They are derived from trees usually over 1.5 m tall by trim-ming major portions of the stem and root system (ideally 10 cm shoot and15 cm root remain) after lifting. They are used for several species includingTectona grandis, Gmelina arborea, Bombacopsis quinata (Lamprecht 1986),and Cordia alliodora in the Atlantic lowland region of Costa Rica (Maroto,pers. comm.). They are popular because they require little maintenance in thenursery and are easy for landowners to transport.

Limitations to seedling growth on abandoned pastures or agriculture fieldsin Latin America include weed competition, soil compaction and low fertilitysoils. Weed growth is persistent throughout the year due to favorable environ-mental conditions. Manual weeding with a machete is the most commonvegetation control in plantations and weeding frequency depends on the costand availability of labor (Rheingans 1996). Herbicides and fertilizers are usedby the few landowners who have sufficient economic resources and are morecommonly used in agriculture than in forestry.

Early establishment is important for smallholder landowners in order toreduce weeding costs and possibly reduce time to harvesst. Early plant growthis regulated by the conditions at the planting site, and by the degree to which aplant’s phenotypic characteristics are adapted to a planting site (Burdett et al.

77

1983). High quality seedlings show substantial height growth the first year ofplanting, thus expressing their full genetic potential (Rose et al. 1990). Theycapture the site quicker, therefore allowing fuller expression of site poten-tial (Fry and Poole 1980). In contrast, use of poor planting stock can lowerplantation survival and growth, increase site maintenance costs, and reduceconfidence in reforestation. The use of the most appropriate planting stockcan help overcome site limitations, while early and intensive site managementcan also accelerate seedling growth (Ladrach 1992). Increasing investment innursery stock relative to investment in site preparation can increase financialreturns on overall reforestation investments (South et al. 1993).

In order to capitalize on advances made in reforestation with nativespecies, seedling production techniques should be improved. Assessingoutplanting performance must be an integral part of defining and adjustingtarget seedling characteristics. The objective of this research was todetermine, for three widely planted tropical species with contrasting ecolog-ical characteristics, how different substrates, container types, and containervolumes affect seedling growth in the nursery and early growth in thefield. Weed control and fertilization were also tested to determine if nurseryand field techniques could be integrated to improve seedling growth duringestablishment.

Materials and methods

The nursery was located at the La Selva Biological Research Station of theOrganization for Tropical Studies (OTS) in the Atlantic Lowlands of CostaRica (10◦26′ N, 86◦59′ W). The average annual rainfall and temperature are3900 mm and 24 ◦C, respectively, and elevation averages 40 m amsl (McDadeet al. 1994).

Three rapidly growing native hardwood species that are found throughoutthe neotropics and are commonly planted in the Sarapiquí canton werestudied. Cordia alliodora (R.P.) Cham. (Boraginaceae) is an early succes-sional species occurring on fertile soils; Hyeronima alchorneoides Fr.Allemao (Euphorbiaceae) is a late successional, canopy emergent speciesfound on old alluvial soils; Calophyllum brasiliense Cambess (Clusiaceae)is an old growth, mid-canopy species found on residual soils (Ultisols).

Nursery study

For each species, 11 treatments were replicated in four randomized completeblocks. Treatments were: large (170 cm3) and small (85 cm3) Rootrainers�

with two composts; 500 cm3 bags (10×15 cm) with soil and NPK fertilizer,

78

Table 1. Substrate properties for nursery media.

Bulk density CEC (meq/ P K Ca Mg

Treatment pH (g/cm3) 100 cm3) (ppm) (ppm) (ppm) (ppm)

Soil 5.7 0.99 14 67 338 1,680 40

Soil with NPK fertilizer 5.2 1.02 15 559 934 1,520 44

Compost A∗ 7.2 0.45 53 1,935 8,392 420 120

Compost B∗ 6.5 0.64 75 1,229 12,887 420 243

50% soil with 50% compost A 6.9 0.79 43 973 4,715 446 103

50% soil with 50% compost B 6.3 0.88 36 338 5,247 252 113

CEC = Cation Exchange Capacity∗ with sulfur, 1 g/l

50% compost with 50% soil, 100% compost, or unamended soil; paper potswith two composts; and 250 cm3 bags with compost. Seeds were collectedfrom phenotypically superior trees previously identified by OTS and eachblock contained seed from a single mother tree. Seed was directly sown inthe containers between April and June 1995, depending on species. Eachreplicate of each treatment contained 30 plants: 20 for outplanting, 5 fordestructive harvesting, and 5 for culling. From the three species combined,660 trees were destructively harvested and 2,640 trees were planted.

An alluvial soil was used in this experiment. For the fertilizer treatment, 10grams of 10-30-10 N-P2O5-K2O fertilizer were incorporated into each bag ofsoil before sowing the seed. Compost A, commercially sold for seedling andvegetable production, was a mixture of 50% coconut husk fiber, 25% chickenmanure (containing lime to control flies), 15% sugar cane bagasse and 10%charcoal. Compost B was a mixture of two composted fodder grasses, Pennis-etum purpureum (2 cultivars) and Axonopus scoparius. The pH of compost Awas 7.7 and of compost B was 7.4, which are considered high for producinghardwood seedlings (van den Driessche 1984a). Elemental sulfur powder wasadded at 1 g/l to reduce the pH to 7.2 for compost A and 6.5 for B. Whencomposts were mixed with soil, no sulfur was added. Substrates differed intheir chemical and physical properties (Table 1).

Rootrainers� are plastic containers with grooves that direct roots down-ward to an open end to allow air pruning of the roots. Large and smallRootrainers� , are book-type containers arranged in two halves connectedby a hinge. Small plastic bags were made by cutting the large plastic bagswith a heat sealer. Paper pots were locally produced wax-lined, rectangular,open-ended biodegradable containers and were planted with the trees. Theywere used by an forestry company in southern Costa Rica for productionof Gmelina arborea seedlings. To allow air circulation under plants grownin book containers and paper pots, and retain randomization of treatment

79

order, all containers were placed on chicken wire frames 30 cm above theground. Plastic was placed beneath the bags to avoid air pruning whichnormally would not occur when plants are placed on the ground. Containerswere spaced so that the density of all seedling was equal, approximately 80plants/m2.

For Calophyllum, the addition of micronutrients was tested with twoadditional treatments: slow-release micronutrients were incorporated intolarge book containers with compost and plastic bags with soil. The smallplastic bag with compost was omitted for this species. For Hyeronima andCordia, micronutrients were added to all substrates including unamendedsoil. Micronutrients (Micromax�, Sierra Chem. Co., Milpitas, CA) wereadded at 1 g/l of soil. The fertilizer contained: 15% S, 12% Fe, 2.5% Mn,1% Zn, 0.5% Cu, 0.1% Bo, and 0.005% Mo.

Shoot height and root collar diameter (RCD) were measured on 25 plantsfrom all treatments immediately before planting. Five of these plant weredestructively harvested to measure leaf area of fresh leaves with a LiCor(Li-3000) area meter and root length using the line-intercept method ofTennant (1975). The ratio of these two parameters were chosen instead ofthe commonly reported shoot weight to root weight ratio because the authorsbelieve that they may better reflect the absorptive and evaporative capacityof the plants. Leaves, stems, and roots from these plants were oven-driedseparately at 65 ◦C for 3 days and then weighed. Each tissue was digestedseparately by the method of Parkinson and Allen (1975). Tissue N, P, K,Ca, and Mg were measured on the sulfuric acid/hydrogen peroxide Kjeldahldigests. The N and P concentrations were measured colorimetrically, and K,Ca, and Mg with an atomic absorption spectrophotometer.

Field study

For each species, blocks containing all treatments were planted on the samedate: between July and October 1995 during the rainy season. Seedlings wereage 90 days for Cordia and Hyeronima and 140 days for Calophyllum. Theblocks were located across four sites: La Flaminia, a part of the OTS LaSelva Biological Research Station; two sites on a farm adjacent to La Selva;and a farm 5 km from the station. The soils at all locations were classifiedas Inceptisols, but varied in fertility status due to past use. All sites werepastures either dominated by gramalota (Axonopus micay), a tall grass foundon relatively fertile sites, or ratana (Ischaemum ciliare), a short grass thatforms a heavy thatch, and is probably indicative of site compaction. The farmsites were grazed by cattle immediately prior to this study. The La Flaminiasite had been grazed within the last five years and had been pasture for thelast 40 years.

80

For Cordia, paper pots and bags of soil treatments were not planted dueto poor growth in the nursery and a stump stock type was added. The stumpsoriginated from one-year-old trees (average height 1.6 m) grown in a barerootnursery bed. Shoots and roots were cut to 18 and 17 cm length, respectively,and were planted the same day that they were cut.

A split-split plot field design was used with four blocked replications. Theseedlings were planted in four 0.22 ha monospecific blocks at a spacing of3×3 meters (1,111 trees/ha). Each block was divided into manual weedingand herbicide competition control main plot treatments. Ten trees from eachnursery treatment were planted in each of these two competition treatments.Fertilizer was applied to 5 plants from each nursery treatment within eachcompetition treatment. For the fertilizer treatment, forty grams of 10-30-10N-P2O5-K2O fertilizer were applied once around the base of each tree at 30days after planting.

For the herbicide treatments, plots were kept as weed-free as possible tominimize competition. Herbicide (glyphosate, Roundup�) was applied fourtimes during the first year. A 3 m diameter area was totally cleared of vegeta-tion around the trees to protect them before herbicide was applied. Betweenthe four herbicide applications, vegetation on the entire plot was cut backto a 30 cm height with a machete. On the manually cleaned plots, weedingby machete was done approximately six times per year alternating betweencleaning 2 m around the tree and then whole site clearing (this is the mostcommon vegetation control in the region). More competition occurred onthe manually weeded plots because grasses overgrew the seedlings betweenweedings.

Percent survival, height, and RCD were measured after 1, 2, 3, 6, 9, and12 months. Tree mortality was scored as unexplained, induced by grazing, orby herbicide. Tree mortality due to accidental cattle grazing or herbicide wastreated as missing data.

Data analysis

Treatments were designed to compare a series of a priori established ortho-gonal contrasts. A contrast between Rootrainers� filled with compost andbags of soil was made to compare an alternative technology to the conven-tional method, even though it confounded substrate and container effects(volume differed by 230 cm3). Contrasts were then used to separate specificsubstrate, container, and volume effects. Substrates were tested by comparingthem within the same containers. The two composts (data not shown), werenot significantly different, so treatment means were combined. The containertype was tested by comparing three containers with similar volumes andcontaining the same compost substrate: large book containers, paper pots,

81

and small plastic bags. The volume effect was tested between large and smallbook containers with the same compost substrate.

Analyses of variance (GLM procedure) were used to detect significanttreatment differences using contrast statements within the treatment groupsof interest (SAS Institute 1990). Means were calculated across fertilizationand weeding effects because there were no significant interactions betweenthese field treatments and nursery treatments. The PROC MIXED procedurewas used for the field data because it best adjusts for missing data (Wolfingerand Chang 1995). Correlations between response variables were calculatedacross treatments using PROC CORR and are reported as Pearson correlationcoefficients.

Results

Cordia alliodora

Nursery resultsSubstrate effects. Plants grown in book containers were significantly largerthan plants grown in bags of unamended soil. Plants grown in soil with NPKfertilizer obtained the largest mean height, RCD, and total dry weight (Table2). Leaf area and root length were the same for the fertilizer and composttreatments. Plants grown in unamended soil had only 4% and 7% of thebiomass of plants grown with NPK fertilizer and compost, respectively.

Leaf N, P and K concentrations were the same for the four treatmentsin bags. Plants grown in the unamended soil and the compost treatmentshad higher Ca and Mg leaf concentrations than plants grown with NPKfertilizer. Leaf concentrations of N and K did not correlate with any ofthe size variables. Leaf concentrations of P, Ca, and Mg were negativelycorrelated with plant size: P was negatively correlated with total dry weight(r = −0.32), leaf area (r = −0.32) and root length (r = −0.30); Ca wasnegatively correlated with diameter and height (r = −0.26), and Mg wasnegatively correlated with total dry weight (r = −0.29), height (r = −0.33),and diameter (r = −0.31).

Container type and volume. Plants grown in book containers obtained, onaverage, twice the total dry weight and had greater height, diameter, and rootlength as plants grown in paper pots (Table 2). There were no significantdifferences between plants grown in planter books and small plastic bagsdespite the fact that bags were 80 cm3 larger. Seedling size increased withthe larger root trainer volume. Root coiling of tap roots in book containers

82

Tabl

e2.

See

dlin

gm

orph

olog

y,le

afnu

trie

ntco

ncen

trat

ions

and

sign

ifica

nce

leve

lsof

trea

tmen

tcon

tras

tsfo

rC

ordi

aal

liod

ora

afte

r90

days

ofnu

rser

ygr

owth

.

Tre

atm

ents

Hei

ght

RC

DT

DW

TL

eaf

area

Roo

tlen

gth

Lea

fnu

trie

ntco

ncen

trat

ion

(cm

)(m

m)

(g)

(cm

2)

(cm

)L

A:R

L%

N%

P%

K%

Ca

%M

g

500

cm3

bags

Una

men

ded

soil

81.

40.

330

131

0.4

2.2

0.23

3.2

3.3

1.1

Soil

and

NPK

fert

ilize

r61

7.4

7.1

488

565

0.9

2.4

0.16

3.6

2.1

0.8

50%

soil

and

50%

com

post

A43

5.7

4.5

360

650

0.6

2.6

0.18

4.5

2.9

110

0%co

mpo

stA

486

4.2

338

442

0.8

2.3

0.23

3.8

31.

1

Oth

erco

ntai

ners

170

cm3

root

trai

ner,

com

post

A+

B+

253.

31.

211

924

00.

52.

30.

273.

93

1.1

85cm

3ro

ottr

aine

r,co

mpo

stA

+B

+15

2.5

0.7

5219

00.

52.

30.

293.

82.

71

250

cm3

bag

with

com

post

A25

3.7

1.1

111

246

0.5

2.7

0.23

3.8

2.7

114

0cm

3pa

per

potw

ithco

mpo

stA

142.

40.

565

191

0.6

nana

nana

1

Trea

tmen

tcon

tras

tsN

ewvs

.con

vent

iona

ltec

hnol

ogy

Roo

trai

ners

�w

ithco

mpo

stvs

.bag

sw

ithso

il∗∗

∗∗∗

∗∗∗

∗∗∗

∗∗∗

∗ns

∗∗∗

nsns

nsSu

bstr

ate

effe

cts

Una

men

ded

soil

vs.s

oilw

ithfe

rtili

zer

∗∗∗

∗∗∗

∗∗∗

∗∗∗

∗∗∗

∗∗∗

nsns

ns∗∗

∗50

%co

mpo

stvs

.100

%co

mpo

stns

nsns

nsp

=0.

08ns

nsns

nsns

nsU

nam

ende

dso

ilvs

.com

post

∗∗∗

∗∗∗

∗∗∗

∗∗∗

∗∗∗

∗∗∗

nsns

nsns

nsC

ompo

stvs

.soi

lwith

fert

ilize

r∗

∗∗

nsns

nsns

nsns

p=

0.06

∗V

olum

ean

dco

ntai

ner

effe

cts

Lar

gevs

.sm

allR

ootr

aine

rs�

∗∗∗

∗∗∗

∗∗∗∗

∗ns

∗∗ns

nsns

nsns

Smal

lbag

vs.l

arge

Roo

trai

ner�

nsns

nsns

nsns

nsns

nsns

nsPa

per

potv

s.la

rge

Roo

trai

ner�

∗∗∗

∗∗∗

∗∗∗

∗∗∗

nsna

nana

na

Lea

stsq

uare

sm

eans

are

list

ed.R

CD

=ro

otco

llar

diam

eter

;TD

WT

=to

tald

ryw

eigh

t;L

A:R

T=

the

rati

oof

the

leaf

area

toro

otle

ngth

.+

the

mea

nof

the

two

com

post

s,∗∗

∗p

<0.

0001

,∗∗

p<

0.00

1,∗

p<

0.05

,ns

=no

tsig

nifi

cant

,na

=no

tana

lyze

d.

83

was present in 2% of the plants whereas in both the bags and in paper pots9% of the plants had coiled tap roots.

Field resultsEffects of nursery treatments on growth. The significant differences in plantsize persisted through 6 months in the field but were not present (with oneexception) after one year’s field growth (Table 5). Plant height averagedbetween 150–200 cm for all of the treatments, except for stumps. Stumpsremained shorter (102 cm) than all other treatments and had lower diametergrowth. They did not regain their initial height when cut (160 cm) and wereonly 3 mm larger in diameter than when planted.

Effects of weeding and fertilization. There were no interactions betweennursery treatments and weeding or fertilizing. When herbicide was appliedto the plots, tree diameter, but not height, increased significantly (Table 6).There was a significant interaction between weeding and fertilizing for treesize. In plots treated with herbicide, fertilizer increased height and diameterby 19% and 31%, respectively, but there was no response to fertilizer inmanually weeded plots.

Mortality. Survival, not including mortality from grazing or herbicide, wasequally high for all container grown nursery treatments at about 88%. Stumpplants had a significantly lower survival rate of 49%, with most mortalitywithin the first two months after planting (Table 5). Grazing and herbicidecaused an additional 20% mortality. Mortality due to all causes with herbicidedamage probably being the main causes was 30% higher in the herbicidetreated plots than in the manually weeded plots.

Hyeronima alchorneoides

Nursery resultsSubstrate effects. Plants grown in book containers were significantly largerthan plants grown in bags of soil. Plants grown in compost grew best,although leaf area and root length (p = 0.08) were greater in the 50%soil:compost mixture than in pure compost (Table 3). Total dry weight ofplants grown with compost was nearly 4 times greater than plants grown withNPK fertilizer. The addition of fertilizer to soil increased total dry weight by80%, but did not affect height significantly.

Leaf N concentrations were greater in compost than in unamendedsoil. Plants grown in compost or with fertilizer had greater P and K leafconcentrations than plants grown in soil. However, plants grown in composthad lower Ca and Mg concentrations than plants grown in soil with or

84

Tabl

e3.

See

dlin

gm

orph

olog

y,le

afnu

trie

ntco

ncen

trat

ions

and

sign

ifica

nce

leve

lsof

trea

tmen

tco

ntra

sts

for

Hye

roni

ma

alch

orne

oide

saf

ter

90da

ysof

nurs

ery

grow

th.

Tre

atm

ents

Hei

ght

RC

DT

DW

TL

eaf

area

Roo

tlen

gth

Lea

fnu

trie

ntco

ncen

trat

ion

(cm

)(m

m)

(g)

(cm

2)

(cm

)L

A:R

L%

N%

P%

K%

Ca

%M

g

500

cm3

bags

Una

men

ded

soil

72.

10.

549

293

c0.

2b

1.1

0.14

1.4

0.7

0.7

Soil

with

NPK

fert

ilize

r11

2.9

0.9

9542

30.

21.

30.

282.

40.

70.

650

%so

ilw

itth

50%

com

post

B24

4.8

3.4

414

714

0.7

1.4

0.25

2.9

0.5

0.4

100%

com

post

B24

4.8

3.2

344

639

0.6

1.6

0.26

2.8

0.4

0.5

Oth

erco

ntai

ners

170

cm3

Roo

trai

ner�

with

com

post

A+

B+

163.

51.

718

053

40.

31.

50.

262.

60.

50.

685

cm3

Roo

trai

ner�

with

com

post

A+

B+

102.

40.

666

315

0.2

1.5

0.26

2.8

0.6

0.7

250

cm3

bag

with

com

post

B15

3.5

1.3

145

441

0.3

1.7

0.26

2.9

0.4

0.5

140

cm3

pape

rpo

twith

com

post

B15

31

146

250

0.7

nana

nana

na

Trea

tmen

tco

ntra

sts

New

vs.c

onve

ntio

nalt

echn

olog

yR

ootr

aine

rs�

w/c

ompo

stvs

.bag

sw

ithso

il∗∗

∗∗∗∗

∗∗p

=0.

06ns

∗∗∗∗

∗∗∗

∗∗∗

Subs

trat

eef

fect

sU

nam

ende

dso

ilvs

.soi

lwith

fert

ilize

rns

∗∗∗

p=

0.06

nsns

ns∗∗

∗∗∗

nsns

50%

com

post

vs.1

00%

com

post

nsns

ns∗∗

nsns

nsns

nsns

nsU

nam

ende

dso

ilvs

.com

post

∗∗∗

∗∗∗

∗∗∗

∗∗∗

∗∗∗

∗∗∗

∗∗∗

∗∗∗

∗∗∗

Com

post

vs.s

oilw

ithfe

rtili

zer

∗∗∗

∗∗∗

∗∗∗

∗∗∗

∗∗∗∗

nsns

ns∗

∗V

olum

ean

dco

ntai

ner

effe

cts

Lar

gevs

.sm

allr

oott

rain

er∗∗

∗∗∗

∗∗∗∗

∗∗∗

nsns

nsns

ns∗

Smal

lbag

vs.l

arge

Roo

trai

ner�

nsns

ns∗

nsns

nsns

nsns

nsPa

per

potv

s.la

rge

Roo

trai

ner�

ns∗∗

ns∗∗

∗∗∗

nana

nana

na

Lea

stsq

uare

sm

eans

are

list

ed.R

CD

=ro

otco

llar

diam

eter

;TD

WT

=to

tald

ryw

eigh

t;L

A:R

T=

the

rati

oof

the

leaf

area

toro

otle

ngth

.+

the

mea

nof

the

two

com

post

s,∗∗

∗p

<0.

0001

,∗∗

p<

0.00

1,∗

p<

0.05

,ns

=no

tsig

nifi

cant

,na

=no

tana

lyze

d.

85

without fertilizer. Leaf P concentrations were positively correlated with totaldry weight (r = 0.36) while Ca concentrations were negatively correlated(r = −0.45).

Container type and volume. Plants grown in small bags and in bookcontainers obtained a greater total dry weight, root length, and diameter thanplants grown in paper pots. Plant height was the same for the three treatments.Plants grown in the large book containers obtained the same size as the plantsin small bags although leaf area was significantly greater, despite the fact thatbags were 80 cm3 larger. Plants grown in large book containers were largerthan those grown in small book containers.

Field resultsEffects of nursery treatments on growth. After one year, plants grown incompost retained their size advantage (Table 5). Plants grown in bookcontainers grew better than plants grown in soil. Plants grown with fertilizerhad greater absolute height growth than plants grown in unamended soil,but final height and diameter were not significantly different. Plants grownin large book containers remained larger in height and diameter thanplants grown in small book containers or in paper pots. Plants grown insmall bags of compost were as large as plants grown in large book containers.

Effects of weeding and fertilization. Plants grew best under intensivemanagement. There were no interactions between nursery main effects andfertilizing or weeding, nor between fertilizer and herbicide. Weed controland fertilization had significant effects on final height and diameter (Table 6).On average, plants were 20% taller and 29% greater in diameter in plots thatreceived herbicide than in manually weeded plots. When fertilized, averageplant height and diameter increased by a smaller but significant amount.

Mortality. The average survival rate of plants grown in soil (85%) and in paperpots (80%) was significantly lower than the survival rates (average 95%)of plants grown in soil with fertilizer, bags of compost or book containers.Grazing increased the total mortality to 25%. Survival was not affected byfertilization or herbicide.

Calophyllum brasiliense

Nursery resultsSubstrate effects. No differences were found in seedling size between plantsgrown in 170 cm3 book containers and those in bags of soil. The addi-tion of NPK fertilizer to the soil did not increase growth, except for leaf

86

area (Table 4). Plants grown in compost were shorter, had smaller total dryweight and leaf area than other treatments. Root lengths did not differ signifi-cantly among the treatments. Plant total dry weight and diameter increasedsignificantly with the addition of micronutrients to soil. The addition ofmicronutrients to compost in book containers increased plant height anddiameter, reduced total root length, but did not affect total dry weight.

Plants grown with compost had higher leaf concentrations of N and Kthan the other substrate treatments. Calcium concentrations were greatestin plants grown with NPK fertilizer and with micronutrients. Plants grownwith NPK fertilizer had higher leaf concentrations of N, P, K and Ca thanplants grown in unamended soil. There was a negative correlation betweentotal dry weight and leaf concentrations of nitrogen (r = −0.56), phosphorus(r = −0.28), potassium (r = −0.28), while calcium was positively correlated(r = 0.47).

Container volume and type. Plant growth was not affected by containervolume, although leaf nutrient concentrations of N and P were smaller in thesmaller containers (Table 4). There were no differences between the plantsgrown in book containers and in paper pots. Root coiling was most prevalentin plants grown in plastic bags. Root coiling of tap root was present in 8% ofthe plants grown in book containers, 15% of those grown in paper pots and23% of those in bags.

Effects of nursery treatments on growth. After one year, plant heights anddiameters were not significantly different for most of the contrasts of interest,despite some initial differences among nursery treatments (Table 5). Theonly significant difference was between the diameters of plants grown inpaper pots (9 mm) and those grown in large book containers (11 mm). Plantsgrown in 100% compost grew less than those grown in soil-based media.Height growth rates of plants grown with micronutrients whether in compostor in soil were greater than those grown in substrates without the addition ofmicronutrients.

Effects of weeding and fertilization. During the first six months, plant heightand diameter increased with fertilization, but this effect did not persist after 9months. Plant height was greater in manually weeded plots (Table 6). Therewas no interaction between weeding and fertilizing.

Mortality. Plants produced in bags of soil or soil amended with fertilizeror micronutrients had an average survival of 93% whereas plants grown incompost had a significantly lower survival rate of 71%. Mortality due to

87

Tabl

e4.

See

dlin

gm

orph

olog

y,le

afnu

trie

ntco

ncen

trat

ions

and

sign

ifica

nce

leve

lsof

trea

tmen

tcon

tras

tsfo

rCal

ophy

llum

bras

ilie

nse

afte

r14

0da

ysof

nurs

ery

grow

th.

Tre

atm

ents

Hei

ght

RC

DT

DW

TL

eaf

area

Roo

tlen

gth

Lea

fnu

trie

ntco

ncen

trat

ion

(cm

)(m

m)

(g)

(cm

2)

(cm

)L

A:R

L%

N%

P%

K%

Ca

%M

g

500

cm3

bags

Una

men

ded

soil

202.

81.

610

327

30.

41.

00.

060.

60.

40.

1So

ilw

ithN

PKfe

rtili

zer

202.

81.

813

024

00.

51.

10.

121

0.5

0.1

50%

soil

with

50%

com

post

A18

2.6

1.3

8126

00.

31.

50.

121.

40.

40.

110

0%co

mpo

stA

182.

61

6017

70.

31.

50.

162.

10.

40.

250

0cm

3ba

gw

ithso

il+

mic

ronu

trie

nts

224.

22.

112

317

10.

71.

00.

060.

60.

50.

1

Oth

erco

ntai

ners

170

cm3

Roo

trai

ner�

with

com

post

A+

B+

202.

61.

510

828

00.

41.

50.

201.

60.

40.

285

cm3

Roo

trai

ner�

with

com

post

A+

B+

202.

61.

390

223

0.4

1.3

0.12

1.3

0.4

0.2

140

cm3

pape

rpo

twith

com

post

A21

2.8

1.4

9822

50.

4na

nana

nana

170

cm3

Roo

trai

ner�

w/c

ompo

stA

+m

icro

nutr

ient

s26

3.5

1.5

119

128

1.1

1.3

0.09

1.5

0.4

0.1

Trea

tmen

tcon

tras

tsN

ewvs

.con

vent

iona

ltec

hnol

ogy

Roo

trai

ners

�w

ithco

mpo

stvs

.bag

sw

ithso

ilns

nsns

nsns

ns∗∗

∗∗∗

∗∗ns

∗∗Su

bstr

ate

effe

cts

Una

men

ded

soil

vs.s

oilw

ithfe

rtili

zer

nsns

nsp

=0.

08ns

∗∗∗

∗∗p

=0.

07∗

ns50

%co

mpo

stvs

.100

%co

mpo

stns

nsns

nsns

nsns

ns∗∗

nsns

Una

men

ded

soil

vs.c

ompo

st∗

ns∗

∗ns

ns∗∗

∗∗

∗∗∗

nsC

ompo

stvs

.soi

lwith

fert

ilize

r∗

ns∗∗

∗∗ns

∗∗∗∗

∗ns

∗∗∗∗

nsSo

ilw

ithm

icro

nutr

ient

svs

.soi

lwith

out

∗∗∗

∗∗

nsns

∗ns

nsns

nsns

Com

post

with

mic

ronu

trie

nts

vs.c

ompo

stw

ithou

t∗

∗ns

ns∗

∗∗∗

nsns

∗p

=0.

08V

olum

ean

dco

ntai

ner

effe

cts

Lar

gevs

.sm

allR

ootr

aine

rs�

nsns

nsns

nsns

∗∗∗

nsp

=0.

06ns

Pape

rpo

tvs.

larg

eR

ootr

aine

r�ns

nsns

nsns

nsna

nana

nana

Lea

stsq

uare

sm

eans

are

list

ed.R

CD

=ro

otco

llar

diam

eter

;TD

WT

=to

tald

ryw

eigh

t;L

A:R

T=

the

rati

oof

the

leaf

area

toro

otle

ngth

.+

the

mea

nof

the

two

com

post

s,∗∗

∗p

<0.

0001

,∗∗

p<

0.00

1,∗

p<

0.05

,ns

=no

tsig

nifi

cant

,na

=no

tana

lyze

d.

88

Tabl

e5.

See

dlin

gsi

ze,g

row

thin

crem

ent,

surv

ival

and

trea

tmen

tcon

tras

tsaf

ter

12m

onth

sof

fiel

dgr

owth

for

thre

eha

rdw

ood

spec

ies.

Cor

dia

alli

odor

aH

yero

nim

aal

chor

neoi

des

Cal

ophy

llum

bras

ilie

nse

Tre

atm

ents

Hei

ght(

cm)

Dia

met

er(m

m)

Sur

viva

lH

eigh

t(cm

)D

iam

eter

(mm

)S

urvi

val

Hei

ght(

cm)

Dia

met

er(m

m)

Sur

viva

l

Fina

lG

row

/day

Fin

alG

row

/day

(%)

Fin

alG

row

/day

Fina

lG

row

/day

(%)

Fina

lG

row

/day

Fin

alG

row

/day

(%)

500

cm3

bags

Soi

lna

nana

nana

79(8

)0.

218

(1)

0.04

285

87(6

)0.

1911

(1)

0.02

295

Soi

lwit

hN

PK

fert

iliz

er19

6(2

1)0.

2539

(5)

0.07

9099

(4)

0.25

23(1

)0.

055

9489

(6)

0.19

12(1

)0.

025

89

50%

soil

,50%

com

post

196

(12)

0.38

40(4

)0.

0990

147

(8)

0.36

32(1

)0.

078

9789

(6)

0.19

11(1

)0.

024

77

100%

com

post

203

(24)

0.37

41(4

)0.

0890

137

(10)

0.33

31(2

)0.

074

9872

(6)

0.15

9(1

)0.

018

65

Soil

wit

hm

icro

nutr

ient

sna

nana

nana

nana

nana

na92

(7)

0.22

10(1

)0.

022

90

Oth

erco

ntai

ners

wit

hco

mpo

st

85cm

3R

ootr

aine

rs�

+16

1(2

3)0.

3333

(7)

0.06

8392

(6)

0.23

22(1

)0.

053

9083

(5)

0.17

10(1

)0.

021

76

170

cm3

Roo

trai

ners

�+

165

(18)

0.31

34(5

)0.

0781

119

(7)

0.31

26(1

)0.

065

9683

(5)

0.17

11(1

)0.

021

83

250

cm3

bag

151

(18)

0.28

29(4

)0.

0689

116

(6)

0.28

25(1

)0.

062

94na

nana

nana

140

cm3

pape

rpo

tsna

nana

nana

84(5

)0.

220

(1)

0.04

980

76(6

)0.

159

(1)

0.01

772

170

cm3

Roo

trai

ners

�+

mic

ronu

trie

nts

nana

nana

nana

nana

nana

100

(7)

0.23

12(1

)0.

027

88

Stum

ps10

2(1

5)0.

2025

(2)

0.01

49na

nana

nana

nana

nana

na

Trea

tmen

tcon

tras

ts

New

vs.c

onve

ntio

nalt

echn

olog

y

Roo

trai

ners

�vs

.bag

sna

nana

nana

∗ns

p=

0.09

∗ns

nsns

nsns

∗Su

bstr

ate

effe

cts

Una

men

ded

soil

vs.s

oilw

/fer

tili

zer

nsns

nsns

nsns

∗ns

nsns

nsns

nsns

ns50

%co

mpo

stvs

.100

%co

mpo

stns

nsns

nsns

nsns

nsns

nsns

∗ns

nsns

Una

men

ded

soil

vs.c

ompo

stns

nsns

nsns

∗∗∗∗

∗∗∗∗

∗∗

nsns

nsns

∗C

ompo

stvs

.soi

lwit

hfe

rtil

izer

nsns

nsns

ns∗

∗∗∗

∗∗ns

nsns

∗p

=0.

07∗

Soil

wit

hm

icro

nutr

ient

svs

.soi

lwit

hout

nana

nana

nana

nana

nana

ns∗

nsns

nsC

ompo

stw

/mic

ronu

rien

tsvs

.com

post

w/o

nana

nana

nana

nana

nana

ns∗

nsns

ns

Vol

ume

and

cont

aine

ref

fect

s

Lar

gevs

.sm

allR

ootr

aine

rs�

nsns

nsns

ns∗

p=

0.07

∗p

=0.

07ns

nsns

nsns

ns

Sm

allb

agvs

.lar

geR

ootr

aine

rs�

nsns

nsns

nsns

nsns

nsns

nana

nana

na

Pape

rpo

tvs.

larg

eR

ootr

aine

rs�

nsns

nsns

ns∗

∗∗

∗∗∗

nsns

∗∗

ns

Stu

mps

vs.a

lltr

eatm

ents

∗ns

ns∗∗

∗∗na

nana

nana

nana

nana

na

Lea

stsq

uare

sm

eans

are

liste

d.St

d.er

rors

in(

).+

mea

nof

two

com

post

s,∗∗

∗p

<0.

0001

,∗∗

p<

0.00

1,∗

p<

0.05

,ns

=no

tsig

nifi

cant

,na

=no

tana

lyze

d.

89

Table 6. Effects of weeding and fertilization on height and diameter after 12 months of fieldgrowth.

Cordia alliodora Hyeronima alchorneoides Calophyllum brasiliense

Weed control Weed control Weed controlFertilizer Herbicide Manual Mean Herbicide Manual Mean Herbicide Manual Mean

Height (cm)

With 191 (17) x 154 (14) j 172 (11) a 123 (8) 105 (7) 114 (5) a 80 (4) 87 (2) 83 (2) aWithout 158 (16) y 164 (14) j 161 (11) a 115 (7) 94 (5) 105 (5) b 81 (4) 88 (2) 85 (2) aMean 175 (14) a 159 (12) a 119 (5) a 99 (4) b 80 (3) b 88 (2) a

Diameter (mm)

With 44 (4) x 28 (3) j 36 (3) a 29 (1) 23 (1) 26 (1) a 10 (0.4) 10 (0.3) 10 (0.2) aWithout 35 (4) y 29 (3) j 32 (2) b∗ 26 (1) 21 (1) 24 (1) b 11 (1) 10 (0.3) 10 (0.3) aMean 39 (3) a 29 (3) b 27 (1) a 22 (1) b 11 (0.3) a 10 (0.1) a

Treatment main effects are separated using a, b. Treatment interactions when present areseparated using x, y, j.∗ indicates a p value of 0.07.Least squares means are listed. Standard errors are in parenthesis.

unexplained causes averaged 20%. This was equally partitioned between theplots that were manually weeded and those that received herbicide. Mortalitydue to herbicide or grazing was only 1%, with no difference between thevegetation management regimes.

Discussion

Cordia alliodora

Plants grown in both the fertilized substrate and in compost grew quickly and,based upon height and root development, were ready for outplanting after twomonths. In contrast, plants grown in unamended soil were less than 10 cm tallafter five months in the nursery, and thus were not planted in the field.

The negative correlations between P, Ca, and Mg concentrations in theleaves and total dry weight but positive response to fertilizer indicate thatN, K, or both were limiting growth. This may be an example of the carbo-hydrate dilution effect where the increase of one limiting nutrient causesincreased plant growth that results in the decrease in tissue levels of othernon-limiting nutrients. Nitrogen supply was not determined in the substrates,but P and K supply were higher in the compost than in soil with fertilizer.In the compost, N supply may have been lower or N was bound in organiccomplexes rendering it unavailable to plants. This is a common problem withorganic substrates with a high carbon:nitrogen ratio (Rose et al. 1995). Cordia

90

was probably N limited in this experiment, and thus the growth responseswere primarily due to the different N concentrations in the substrates. Leafconcentrations were lower than typically found in leaves of trees growingin plantations in the Atlantic Lowlands of Costa Rica where Cordia isconsidered a N demanding species (Bergmann et al. 1994).

Although plants produced in book containers were smaller at planting,they grew as well as the larger plants produced with NPK fertilizer and in bagsof compost. They also had a lower leaf area to root length ratio than the largerplants grown in bags with fertilizer or compost; but during the first year’sgrowth their relative growth rate was significantly higher than these plants.The relative growth, that is growth proportional to original size, correlatednegatively to the ratio of leaf area to root length (r = −0.59), indicating anadvantage for plants with more roots than leaf area. Plants grown in bookcontainers also grew better and had higher survival than stump plants. Eventhough it was raining almost daily when the study was planted, stumps diedprobably to due to insufficient nutrient reserves to recover and compete withaggressive weeds. The common recommendations to use stump plants (Calvoand Melendez 1999) should be viewed cautiously.

Plants benefited from competition control. The interaction betweenweeding and fertilization clearly demonstrates that there was little benefit tofertilizing plants in weedy plots. When weed competition was high, trees didnot respond to the addition of fertilizer. Reducing weed competition probablyinfluenced nutrient availability to this species. The leaves of the trees in theplots that received herbicide were dark green, whereas trees were less greenin manually-weeded plots. The lack of interaction between nursery treat-ments and weeding and fertilizing indicates that the small plants producedin book containers did not require more intensive field management thanlarger planting stock types, a commonly held belief. They also had fewerroot deformities than plastic bags, a potential long-term advantage (Burdettet al. 1986).

Hyeronima alchorneoides

In the nursery, total dry weight, leaf area, and leaf nutrient concentration ofP and K were greater in plants grown with fertilizer or compost than thosegrown in unamended soil. Availability of P and K were greater in the soil withfertilizer and in compost than in the unamended soil (Table 1). The positivecorrelation between leaf P concentration and plant size and the high totalP content of plants grown in compost suggest that Hyeronima responded tothe P availability in the substrates. Nevertheless, plants produced in compostgrew considerably larger than those produced in soil with fertilizer. Thismay be due to the higher P availability in the compost than in the soil with

91

fertilizer or due to the better biological and physical properties of the compostsubstrate.

In the field, final plant size was largely determined by initial plant size.There were significant positive correlations between the final diameter andinitial plant size (total dry weight, r = 0.37, leaf area, r = 0.51, and root length,r = 0.30). The plants that grew best were those which had been produced inbook containers or in plastic bags with organic substrates. Root mass wasnot significantly correlated to final plant size. The shoot to root ratio waspositively correlated to final height and diameter in the field (r = 0.55). Theplants in plastic bags retained their initial size advantage possibly due to theirlarge leaf area or greater shoot mass.

Hyeronima responded to the fertilizer on both herbicide treated and handweeded plots. The high fine root density of this species may enable it to effec-tively compete with the vegetation for the applied nutrients even in weedyplots.

Calophyllum brasiliense

Calophyllum did not increase growth with the addition of NPK fertilizerto the soil and grew significantly worse with compost. Although nutrientavailability was high in the compost, and the bulk density was lower thanin the soil substrates, the pH may have been too high, causing a micronutrientdeficiency. This is suggested by the addition of micronutrients to the soil (pH5.7) that resulted in increased total dry weight while the addition to compostdid not (pH 6.5). Organic matter can complex metallic cations such as Fe, Mn,and Zn, rendering them unavailable to plants, or can produce molecules thatchelate micronutrients (van den Dreissche 1984a). The new leaves of manyplants grown without micronutrients were chlorotic, possibly indicating anFe deficiency.

There were weak positive correlations between final height and bothdiameter and leaf area (r = 0.28, 0.34, p = 0.07, respectively). Plants withmicronutrients had significantly greater leaf area:root length ratios. The effectof relieving micronutrient deficiencies seemed to cause a change in allocationbetween roots and leaves and, in turn, may have increased growth.

Species comparisons

The three species exhibited a range of responses underlining the importanceof unique nursery management for each. Substrate quality and containertype greatly influenced seedling growth. The same substrates are not recom-mended for the three species because nutrient demands and biomass alloca-tion appear to be different among them.

92

Cordia displayed the largest differences in seedling development. Theresponses were primarily attributed to nutrient availability because fertilizerdramatically improved growth in soil. Cordia grew best in N rich substrates(compost and soil with NPK fertilizer) and seemed unaffected by the physicalcharacteristics of the substrate. Hyeronima grew best in compost and onlyslightly better in soil with fertilizer than in soil without fertilizer. Nutrientavailability possibly played a secondary role to the better physical and biolog-ical characteristics of the compost substrate which enhanced root growth.Both species grew significantly better in nutrient rich substrates than in soilalone.

The responses of Calophyllum to the treatments were totally differentthan those of Cordia and Hyeronima. Plant size did not significantly increasewith the addition of fertilizer to soil. In the compost and soil with fertilizersubstrates, tissue concentrations of nutrients increased, but plant growth didnot increase. The plants may have been affected by the high pH of thecompost. Plants had greater total dry weight and N concentrations in the leaftissues when micronutrients were added to the soil.

In the nursery, container type influenced plant development. Through airpruning, plants in book containers had higher root densities and fewer rootdeformities than plants in bags. Lateral root development has been demon-strated to be related to seedling growth (Kormanik 1986). For Cordia, atap-rooted species, root density (as root length per volume (cm/cm3)) was1.4 in large book containers and 1 in small bags. For Hyeronima, a branchyrooted species, root density was 3.3 in large book containers and 1.8 in smallbags. For Calophyllum, also a tap-rooted species, root density was 1.5 inbook containers and 0.3 in large bags of compost, and 0.5 in bags of soil.A clear effect of container design on final plant size is difficult to discern.The fast relative growth of Cordia in book containers may be due to the airpruning effect. Hyeronima in book containers attained the same final heightas plants in small plastic bags. Air pruning may not be as important as forbranchy root species like Hyeronima as for the strongly tap-rooted Cordia orCalophyllum.

For both Hyeronima and Cordia, paper pots did not promote good plantdevelopment. Despite the inner wax lining, the inner walls had deterioratedafter one month. Roots of adjacent seedlings grew together and had to becut apart for measuring and planting. Disintegration may have been accel-erated by the compost substrate. When growing Gmelina arborea seedlingsin paper pots, the forestry company Ston Forestal in Costa Rica used a soilsubstrate and kept the plants in the nursery for only 30 days. Field manage-ment did not interact with nursery treatments. Field and nursery treatmentswere independent and their effects were additive. Different management was

93

not necessary for small plants. Cordia and Hyeronima responded positivelyto increasing intensity of field management. For Calophyllum, fertilizer andherbicide effects only lasted six months, but after 12 months, plants hadgrown better in manually weeded plots.

Planting stock characteristics as well as weeding regimes and fertiliza-tion influenced plant size and plant growth of the three species during the12-month period. The unique responses may reflect ecological differencesamong species. Cordia is a pioneer species with fast initial growth thatrequires sites with high nutrient availability and good drainage (Bergmannet al. 1994). Cordia is used as a shade overstory in intensively managedcacao and coffee plantations in Costa Rica where it probably benefits fromfertilizer application and is reported to be damaged by herbicide (Beer 1979).Low specific leaf area allows rapid canopy growth, but low investment inroots make it sensitive to below-ground competition (Haggar and Ewel 1995,1997). Smaller seedlings with lower leaf area:root length ratios (i.e. moreroots) may have been able to obtain the same size as larger seedlings withhigher leaf area:root length ratios (i.e. more investment in leaves) due to beingless susceptible to competition.

Hyeronima is a late secondary, canopy emergent species (Clark and Clark1992). Further, this species is characterized by its low specific leaf area(fresh leaf area/oven dry mass of leaves) and high fine root density (Haggarand Ewel 1995). Canopy expansion is slower than for Cordia, but it is notcompetition sensitive. Large seedlings with a high leaf area when plantedcan capture more light without having to make additional leaves, and thuscompared to small plants, they may have an advantage in early establish-ment. As fine root densities were inherently higher than for Cordia, there mayhave been little disadvantage to the higher above- to below-ground biomassallocation found in large plants. This may explain why above-ground biomassallocation is more important for growth and final size than below-groundbiomass in contrast to Cordia. Calophyllum has a large geographical distri-bution in the neotropics and occurs in primary forests. Although it generallyhas slow initial growth in plantations (Butterfield and Espinoza 1995), it hasgood form and is valued for its wood properties which are similar to thoseof Cedrela odorata (ACEN 1992). Calophyllum is a slow growing, shadetolerant, mid-canopy species commonly found on highly weathered soils. Itis used for restoration of degraded sites in Puerto Rico (Little and Wadsworth1964; Jordon and Farnworth 1982) and may be competitively viable on poorsoils. The lack of seedling response to NPK fertilizer in the nursery as well asin the field may indicate that the species is well-adapted to nutrient-poor soils.Micronutrients added to soil improved growth in the nursery and subsequentgrowth through increasing leaf area relative to root length. It appears that

94

for this slow growing, low-nutrient tolerant species, growth rates were corre-lated to above ground biomass allocation and leaf area similar to Hyeronima.Calophyllum, in contrast to Cordia or Hyeronima, did not respond positivelyto the addition of compost, indicating organic substrates should not be usedalone. The influence of container type may have diminished because of thepoor response to the compost substrate. Although it is adapted to poor siteconditions, a stronger response than what was seen to nutrient availability inthe nursery was expected because many plants use resources when available.

Conclusions

Substrate quality was the dominant factor for plant growth for all species.Although responses were species specific, they can be interpreted with respectto the ecology of the species. Moreover, some general conclusions can bemade. When plant growth was good in compost, book containers increasedroot mass and length. Plants grown in book containers had smaller leafarea:root length ratios than plants grown in bags of compost or soil withfertilizer; in some species this was an advantage (e.g., Cordia) in others not(e.g., Hyeronima). Book containers may control root spiraling problems fortap-rooted species (Cordia and Calophyllum). With a high quality substrate,small volume containers can be used. The lack of interactions betweennursery treatments and field management indicates that field managementdoes not need to be tailored to nursery stock type. Species of early to midsuccession responded positively to better weed control and fertilization.

Acknowledgments

This research was supported by the Organization for Tropical Studies (OTS),Foundation for the Development of the Central Volcanic Mountain Range(FUNDECOR), and North Carolina State University (NCSU), Departmentof Forestry. Additional support of materials was provided by Ston Forestal,Costa Rica, and Spencer-Lemaire Industries, Edmonton-Alberta, Canada.Advice and encouragement from Norman Jones of The World Bank, FroylanCastañeda of FUNDECOR, and Cavell Brownie of the NCSU StatisticsDepartment were greatly appreciated. Ricardo Murillo and Pedro Rojaskindly allowed us to conduct this research on their farms.

95

References

ACEN. 1994. Memoria [Proceedings]. Segundo encuentro regional sobre especies fore-stales nativas de la zona norte y atlantica de Costa Rica. Estacion biologica La Selva,Organizacion para Estudios Tropicales, Costa Rica. 24–25 Sept. 1992. 87 p.

Amorini, E. and Fabbio, G. 1992. The ISSA system for production of container tree seedlings.Tree Planters’ Notes 43(4): 146–149.

Beer, J. 1979. The UNU-CATIE “La Suiza” agroforestry case study, pp. 188–192. In: Salas,G. (Ed.) Workshop. Agro-forestry systems in Latin America. Turrialba, Costa Rica, March26–30. Proceedings.

Bergmann, C., Stuhrmann, M. and Zech, W. 1994. Site factors, foliar nutrient levels, andgrowth of Cordia alliodora plantations in the humid lowlands of Northern Costa Rica.Plant and Soil 166: 193–202.

Burdett, A., Coates, H., Eremka and Martin, P. 1986. Toppling in British Columbia’s lodgepolepine plantations: Significance, cause and prevention. Forestry Chronicle (Oct): 433–439.

Burdett, A., Simpson, D.G. and Thompson, C.F. 1983. Root development and plantationestablishment. Plant and Soil 71: 103–110.

Butterfield, R. 1993. Tropical Timber Species Growth in the Atlantic Lowlands of Costa Ricaand Wood Variation of Two Native Species. Ph.D. dissertation, North Carolina State Univ.Raleigh, 76 p.

Butterfield, R. and Fisher, R. 1994. Untapped potential. Native species for reforestation. J. ofForestry 92(6): 37–40.

Butterfield, R. 1995. Promoting biodiversity: Advances in evaluating native species forreforestation. Forest Ecology and Management 75: 111–121.

Butterfield, R. and Espinoza, M. 1995. Screening trial of 14 tropical hardwoods with anemphasis on species native to Costa Rica: Fourth year results. New Forests 9: 135–145.

Calvo, G. and Melendez, L. 1999. Pseudoestacas de laurel para el enriquecimiento decacaotales. Agroforesteria en las Américas 6(22): 25–27.

Clark, D.A. and Clark, D.B. 1992. Life history diversity of canopy and emergent trees in aneotropical rain forest. Ecological Monographs 62(3): 315–344.

Fry, G. and Poole, B. 1980. Evaluation of planting stock quality several years after planting (adiscussion). New Zealand J. of Forestry Science 10: 299–300.

Haggar, J. and Ewel, J. 1995. Establishment, resource acquisition, and early biomass allocationpatterns of three tropical tree species. Forest Science 41: 689–708.

Haggar, J. and Ewel, J. 1997. Primary productivity and resource partitioning in model tropicalecosystems. Ecology 78(4): 1211–1221.

Jordon, C.F. and Farnworth, E.G. 1982. Natural vs. plantation forests: a case study of landreclamation strategies for the humid tropics. Environmental-Management 6(6): 485–492.

Josiah, S. and Jones, N., 1992. Root Trainers in Seedling Production Systems for TropicalForestry and Agroforestry. Land Resources Series No. 4. The World Bank Asia TechnicalDepartment. 40 pp.

Kormanik, P. 1986. Lateral root morphology as an expression of sweetgum seedling quality.Forest Science 32(3): 95–604.

Ladrach, W., 1992. Plantation establishment techniques in tropical America. Tree Planter’sNotes 43(4): 125–132.

Lamprecht, H., 1986. Silviculture in the Tropics. GTZ, Eschborn. 296 pp.Liegel, L. and Venator, C., 1987. A Technical Guide for Forest Nursery Management in the

Caribbean and Latin America. USDA, Puerto Rico. 156 pp.

96

Little, E. and Wadsworth, F. 1964. Common Trees of Puerto Rico and Virgin Islands. USDA.Agriculture Handbook No. 249.

Morato, Oscar, technical advisor for Sarapiqui Agriculture Center. Personal communication,1996.

Mason, E.T. 1985. Causes of juvenile instability of Pinus radiata in New Zealand. NewZealand J. of Forestry Science 15(3): 263–280.

McDade, L.A., Bawa, K.S., Hespenheide, H. and Hartshorn, G. (Eds.). 1994. La Selva.Ecology and Natural History of a Neotropical Rain Forest. Univ. of Chicago Press. 486 pp.

Parkinson, J. and Allen, S. 1975. A wet oxidation procedure suitable for the determination ofnitrogen and mineral nutrients in biological material. Commun. Soil Sci. Plant Anal. 6(1):1–11.

Rheingans, R. 1996. The Ecological, Economic and Political Effects of Tree Plantation Inter-cropping on Small Farm Forestry in the Atlantic Lowlands of Costa Rica. Ph.D. diss., YaleUniv. 195 pp.

Rose, R., Carlson, W. and Morgan, P., 1990. The target seedling concept, pp. 1–8. In: Rose, R.,Campbell, S. and Landis, T. (Eds.) Target Seedling Symposium: Proceedings, CombinedMeeting of the Western Forest Nursery Associations. Aug. 13–17.

Rose, R., Haase, D. and Boyer, D. 1995. Organic Matter Management in Forest Nurs-eries: Theory and Practice. Nursery Technology Cooperative, Oregon State University,Corvallis, OR, 65 p.

SAS Institute. 1990. SAS Procedures Guide, Version 6. SAS Institute, Cary, NC. 724 pp.Shelhas, J., Jantzi T., Kleppner, C., O’Connor, K. and Thatcher, T. 1997. Meeting farmers’

need through forest stewardship. J. of Forestry (2): 33–38.Sharma, R.D. 1987. Some observations on coiling of roots in nursery raised plants. J. of

Tropical Forestry 3: 207–212.South, D., Mitchell, R., Zutter, B., Balneaves, J., Barber, B., Nelson, D. and Zwolinski, J. 1993.

Integration of nursery practices and vegetation management: Economic and biologicalpotential for improving regeneration. Can. J. For. Res. 23: 2038–2092.

Tennant, D. 1975. A test of a modified line intersect method of estimating root length. J. ofEcology 63: 995–1001.

van den Driessche, R. 1984a. Soil fertility in forest nurseries, pp. 63–74. In: Duryea, M.and Landis, T. (Eds.) Forest Nursery Manual: Production of Bareroot Seedlings. MartinusNijhoff/Dr. W. Junk Publishers.

van den Driessche, R. 1984b. Relationship between spacing and nitrogen fertilization of seed-lings in the nursery, seedling mineral nutrition and outplanting performance. Can. J. For.Research 14: 431–436.

Wolfinger, R. and Chang, M. 1995. Comparing SAS GLM and MIXED Procedures forRepeated Measures. SAS Institute, Cary, NC.