ICFR CENTRAL REGIONAL INTEREST GROUP FIELD DAY · Andrea Louw [email protected] Institute for Commercial Forestry Research, PO Box 100281, Scottsville 3209 Introduction

© ICFR 2009 Page 1 ICFR Central Regional Field Day

ICFR CENTRAL REGIONAL INTEREST GROUP FIELD DAY

Date: Thursday 28th May 2009

Venue: Fontana Church Hall, Piet Retief

Time: 08h00 for 08h30

PROGRAMMEPROGRAMMEPROGRAMMEPROGRAMME

08h00 Meet for tea and coffee at the Fontana Church Hall

INDOOR PRESENTATIONSINDOOR PRESENTATIONSINDOOR PRESENTATIONSINDOOR PRESENTATIONS

08h30 Welcome to the field day Rhudolf Muller &

Colin Dyer

Mondi

ICFR

08h40 Update on wattle pests and diseases Izette Greyling FABI

09h00 Genetic improvement in black wattle Andrea Louw ICFR

09h30 Interim results: current ICFR Acacia mearnsii spacing

trials Trevor Morley ICFR

10h00 TEA

10h20 Update on eucalypt pests and diseases Ryan Nadel FABI

10h40 Pulping properties of Eucalyptus benthamii and

improved Eucalyptus macarthurii. Tammy Swain ICFR

FIELD PRESENTATIONSFIELD PRESENTATIONSFIELD PRESENTATIONSFIELD PRESENTATIONS

11h10 Travel to first field stop

11h30

Research to investigate the impact of planting depth,

seedling size and planting method on eucalypts in

summer rainfall region of South Africa

Paul Viero Mondi

12h15 Travel to second field stop (Mr G Stapelberg, Welgekozen)

12h45 In-field discussions on wattle and eucalypt pests and

diseases

Izette Greyling &

Ryan Nadel FABI

13h15 Presentation and discussion on a land preparation

operation, including site preparation and mulching G Stapelberg Private

13h45 LUNCH at the Fontana Hall, Piet Retief


UpdateUpdateUpdateUpdate on wattle pests and diseases on wattle pests and diseases on wattle pests and diseases on wattle pests and diseases

Izette Greyling [email protected]

Tree Protection Co-operative Programme (TPCP), University of Pretoria, Pretoria, South Africa

DiseasesDiseasesDiseasesDiseases •••••••• Ceratocystis wilt – Ceratocystis albifundus

•••••••• Botryosphaeria canker and wilt – Botryoshaeria species

•••••••• Phytopthora root rot – Phytopthora nicotianeae

•••••••• Pink disease – Erythricium salmonicolor

•••••••• Cylindrocladium blight/canker – Cylindrocladium pauciramosum – Nursery & Recent

Transplants

PestsPestsPestsPests •••••••• Bagworm – Chaliopsis junodi

•••••••• Mirid – Lygidolon laevigatum

•••••••• Termites

•••••••• Cutworm

•••••••• White grub

TREEHEALTHNETTREEHEALTHNETTREEHEALTHNETTREEHEALTHNET

An online forum where tree health issues are discussedAn online forum where tree health issues are discussedAn online forum where tree health issues are discussedAn online forum where tree health issues are discussed The TREEHEALTHNET listserver was established to enable fast and effective communication

between scientific and technical staff linked to the Tree Protection Co-operative Programme

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At present the TREEHEALTHNET listserver reaches about 120 subscribers, mainly staff of South

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Genetic improvementGenetic improvementGenetic improvementGenetic improvement in black wattle ( in black wattle ( in black wattle ( in black wattle (Acacia mearnsiiAcacia mearnsiiAcacia mearnsiiAcacia mearnsii))))

Andrea Louw [email protected]

Institute for Commercial Forestry Research, PO Box 100281, Scottsville 3209

IntroductionIntroductionIntroductionIntroduction In the past, the driving force behind the black wattle industry was bark yield, as the bark has a high

tannin content and is economically valuable. Tannin-based products are produced for both tanning

and non-tanning applications. Currently, there is a very high export demand for bark.

Apart from the commercial value of its bark, black wattle timber has, in recent years, become

popular as a source of high quality fibre for pulp and paper production. Subsequently, market

demands for black wattle changed from tannin to wood, and today, timber has taken the leading

role in the industry. However, an acceptable bark quality is still maintained. Today, black wattle

makes up approximately 8.1% of the South African plantation forestry estate, an area of about

103 000 ha.

Black Wattle ImprovementBlack Wattle ImprovementBlack Wattle ImprovementBlack Wattle Improvement Black wattle was introduced into South Africa from Australia in 1864 for use in commercial

plantations. Through adaptation to different environmental sites and climatic conditions, this

material became what is now known as the South African landraces, and this is what constitutes

South Africa’s current commercial plantations.

When the first black wattle breeding programmes were implemented, seed was collected from

specific families in Australia as well as from the South African commercial plantations, and

research trials were established (Figure 1Figure 1Figure 1Figure 1). From measurements and assessments of the research

trials, the best families and individuals were identified and selected, based on specific

characteristics, such as bark quality, timber yield, cold tolerance and disease tolerance. Seed was

collected from these individuals and further research trials were established. In these trials, the

process was repeated, and further improved seed orchards established. These seed orchards are

now swept and the improved seed supplied to the industry. Companies purchase the improved seed

as seedlings from nurseries, and by purchasing these seedlings they achieve the gains or

improvement made through the breeding strategy.

Figure Figure Figure Figure 1111.... Wattle Improvement at the ICFR

Wattle improvement at the ICFR

SA (Landraces)

Australia

Research trialsCold toleranceTimber yieldBark qualityDisease free

Trials

Best individuals identified

Improved seed

supplied to the industry

Superior trees

Seed Orchards

Seedlings

swept

GAIN

Wattle improvement at the ICFR

SA (Landraces)

Australia

Research trialsCold toleranceTimber yieldBark qualityDisease free

Trials

Best individuals identified

Improved seed

supplied to the industry

Superior trees

Seed Orchards

Seedlings

swept

GAIN


Genetic gain trialsGenetic gain trialsGenetic gain trialsGenetic gain trials In any improvement programme, it is essential that the available improved material is tested

against the unimproved material to assess that improvement is in fact occurring. This is successfully

achieved by planting genetic gain trials. The unimproved seed, used as a control in the research

trials, acts as a baseline in order to determine the degree of improvement made. Currently, in the

wattle breeding programme, genetic gain trials are being used to estimate the performance of the

older seed orchards (established in the early 1970s and ‘80s) relative to the newer seed orchards

(established from the mid 1990s). An expected increase in volume has been estimated from some

of the orchards, which equates to an increased MAI.

Genetic gain trials are of particular importance to the wattle growers using seedlings, in indicating

that the material that they are planting will produce higher yields.

Future Seed OrchardsFuture Seed OrchardsFuture Seed OrchardsFuture Seed Orchards In addition to the current seed orchards supplying the industry with improved seed, a new strategy

was implemented in the wattle breeding programme in 2002, to produce future seed orchards.

These seed orchards will produce individuals with increased volume, whilst still maintaining an

acceptable bark quality, as well as ensuring the continued improvement of the species and the

adequate supply of improved seed to the industry. Figure 2Figure 2Figure 2Figure 2 illustrates these gains (percentage

improvement) in diameter at breast height. Half-rotation measurements show the percentage

improvement of each subpopulation relative to i) the unimproved Natal Tanning Extract (NTE)

material, and ii) one of the older seed orchards (PSOs), currently supplying the industry with

improved seed, when selecting the best families in the population to contribute to improved seed

production. Estimated gains from the new breeding strategy subpopulations ranged from 12.4 to

29.0% increase in dbh (relative to NTE) and from 2.1 to 24.7% (relative to the PSO).

Figure Figure Figure Figure 2222. . . . Percentage improvement in dbh of the top families in the subpopulations relative to unimproved

(NTE) and improved (PSO) material.

0 10 20 30

1

2

3

4

5NTE

PSO

Percentage Improvement in dbh

Su

bp

op

ula

tio

n


Take home pointsTake home pointsTake home pointsTake home points � Results show that the subpopulations, currently representing the main breeding population of

A. mearnsii at the ICFR are performing better than NTE (unimproved seed) and the PSO

material (improved seed).

� Selection would provide potential for further improvement and substantial genetic gains, which will benefit the growers using the seed emanating from this breeding programme.

� Individual selection of superior trees should provide greater gains than family selection. � Growers should always try to obtain the most advanced generation of genetic material for plantation establishment.


Interim results:Interim results:Interim results:Interim results: CCCCurrent ICFR urrent ICFR urrent ICFR urrent ICFR Acacia mearnsiiAcacia mearnsiiAcacia mearnsiiAcacia mearnsii spacing trials spacing trials spacing trials spacing trials

Trevor Morley [email protected]

Institute for Commercial Forestry Research, P O Box 100281, Scottsville, 3209

SummarySummarySummarySummary

IntroductionIntroductionIntroductionIntroduction Since 1948, WRI/ICFR1 research on Acacia mearnsii (black wattle) planting densities reported

primarily on the line sowing method of establishment with subsequent thinning treatments. During

the last two decades, research on genetic improvement and silvicultural practices has led to the

current recommendation that wattle stands be established from seedlings rather than the

traditional methods of line sowing or natural regeneration. While this allows growers to benefit from

the superior genetic quality of the seedlings, the need for the current practice of planting at a

higher density, followed by thinning operations, has been questioned. To address this, an ICFR

spacing trial series was initiated in 2000/1 using improved A. mearnsii seedlings to compare the

effect of planting density (with no thinning) on the rate of growth, survival, form and productivity at

various sites.

MethodsMethodsMethodsMethods • Three trial sites contrasting in rainfall and temperature were selected at Highflats, Luneburg

and Pietermaritzburg.

• Each trial comprises six treatments, replicated twice, laid out in a randomised blocks

design.

• Plots comprise 144 trees (12 x 12 trees) with the inner 64 trees (8 x 8 trees) measured.

• Plot areas vary according to between- and within-row treatment distance for planting

densities of 1111, 1333, 1667, 1905, 2222 and 2500 trees ha-1.

• Dbh and tree height have been measured annually since establishment, with percentage

mortality and basal area calculated by deduction.

• Trial data were summarised, at approximately age 5 years.

• Site and cross site analyses of variance (ANOVA) were conducted on plot mortality,

quadratic mean dbh (Dq) and height (Hq), and basal area (BA).

• Utilisable volume was estimated to a 5 cm underbark topend diameter.

ResultsResultsResultsResults At approximately five years of age, the trials showed:

Mortality: Mortality: Mortality: Mortality:

No significant differences were detected for mortality between the different treatments at any of

the sites. Bloemendal and Luneburg (15.8 and 13.7%) had higher mortality than Highflats

(10.5%). There are no clear treatment-related trends in terms of mortality within each site, or

between sites, indicating that at this stage mortality may be related to factors other than those

of planting density (eg. windthrow). It is expected that as the trees age, an increase in mortality

will occur in the higher density treatments.

Hq: Hq: Hq: Hq:

This was taller for the lower density treatments at all three trials with treatment differences

significant only at Highflats. Hq is approximately 93% of dominant height at Bloemendal, 95%

at Highflats and 93% at Luneburg.

Dq: Dq: Dq: Dq:

There were significant differences at all three trials in terms of Dq with the lower density

treatments (1111 and 1333 sph) being larger than the higher density treatments (2222 and

2500 sph).

1 Wattle Research Institute (WRI)/ Institute for Commercial Forestry Research (ICFR)


BA: BA: BA: BA:

Similar to Dq and Hq results, there were treatment related differences in BA (which is a

function of stem area and survival), although these were significant only at Highflats and

Luneburg (Table 3 and Figure 1).

Across site analyses showed significant (p < 0.05) site related differences for Ht and Dbh, but not

for mortality, whereas BA was only weakly significant (p < 0.1). No significant interactions were

detected between the three sites and the various treatments, indicating that at this stage treatments

are showing similar trends in terms of the measured growth parameters. Dbh and height was best

at Luneburg and the lower mortality at Highflats gave the highest overall BA treatment (16.95 m2

ha-1 for 2500 sph) (Table 1Table 1Table 1Table 1 and Figure 1Figure 1Figure 1Figure 1). Bloemendal had the lowest average BA (range 9.4 –

12.8 m2 ha-1). Treatment density effects on BA were more apparent at Highflats (larger treatment

differences) than at Luneburg (smaller differences). Growth differences between treatments were

least at Bloemendal whereas statistically significant differences between treatments were

pronounced at Luneburg and especially Highflats (Table 1Table 1Table 1Table 1 and Figure 1Figure 1Figure 1Figure 1). The utilisable volume of

the current stocking densities at about age 5 years, for the sites is illustrated by logarithmic trend

lines in Figure 1Figure 1Figure 1Figure 1.

Figure 1Figure 1Figure 1Figure 1 (top) (top) (top) (top) Development of basal area (m2 ha-1) over time for the Luneburg Acacia mearnsii spacing

trial.

(bottom) (bottom) (bottom) (bottom) Effect of stocking (TPH) on utilisable volume (UVolume) across trial sites.

0

20

40

60

80

100

120

900 1100 1300 1500 1700 1900 2100 2300 2500

TPH at about 5 years

UV

OL

UM

E (

m3 h

a-1)

Luneburg

Highflats

Bloemendal

0

2

4

6

8

10

12

14

16

18

2 3 4 5

Age (Years)

BA

(m

2 h

a-1

)

1111

1333

1667

1905

2222

2500

25001667

1905

11111333

2222

Table 1.Table 1.Table 1.Table 1. Summary of analyses of variance showing the mean squares and treatment means, within sites at approximately five years of age, for three Acacia mearnsii

spacing trials in the summer rainfall region of South Africa.

Site and age (years)Site and age (years)Site and age (years)Site and age (years) Bloemendal Bloemendal Bloemendal Bloemendal (5.007) HighflatsHighflatsHighflatsHighflats (4.941) LuneburgLuneburgLuneburgLuneburg (5.037)

Source of variationSource of variationSource of variationSource of variation d.fd.fd.fd.f HqHqHqHq

(m)(m)(m)(m)

DqDqDqDq

(cm)(cm)(cm)(cm)

MortalityMortalityMortalityMortality####

(%)(%)(%)(%)

BABABABA

(m(m(m(m2222 ha ha ha ha----1111))))

HqHqHqHq

(m)(m)(m)(m)

DqDqDqDq

(cm)(cm)(cm)(cm)


(%)(%)(%)(%)

BABABABA

(m(m(m(m2222 ha ha ha ha----1111))))

HqHqHqHq

(m)(m)(m)(m)

DqDqDqDq

(cm)(cm)(cm)(cm)


(%)(%)(%)(%)

BABABABA

(m(m(m(m2222 ha ha ha ha----1111))))

Rep 1 0.23 0.52 0.26 4.2 1.42 0.04 0.58 0.42 0.01 0.01 1.28 4.45

Treatments 5 0.36ns 2.13* 0.72ns 3.2ns 0.62* 2.83** 0.60ns 7.54** 0.28ns 2.89** 0.30ns 3.44**

Residual 5 0.77 0.28 0.71 1.5 0.08 0.02 0.18 0.37 0.22 0.5 0.19 0.18

Total 11

Summary of dataSummary of dataSummary of dataSummary of data

(Treatment means)(Treatment means)(Treatment means)(Treatment means)

1. 1111 13.17 11.48a 4.19 (18.0) 9.43 15.05ab 12.20a 4.5 (11.7) 11.46a 15.46 13.21a 4.96 (15.6) 12.85a

2. 1333 13.27 10.99ab 3.18 (10.2) 11.41 15.67a 12.30a 5.4 (20.3) 12.63a 15.40 11.61b 4.19 (8.6) 12.94a

3. 1667 13.57 10.83ab 4.33 (18.8) 12.48 14.76bc 10.96b 4.1 (7.8) 14.49b 15.82 11.42b 4.33 (10.2) 15.35bc

4. 1905 12.90 9.78bc 3.75 (14.1) 12.30 14.67bc 10.50b 4.2 (8.6) 15.08b 14.83 10.72c 4.85 (14.8) 14.62b

5. 2222 12.56 9.09c 3.25 (11.7) 12.76 14.33bc 9.66c 4.1 (8.6) 14.89b 15.08 10.10d 4.85 (14.8) 15.14bc

6. 2500 12.46 9.08c 4.65 (21.9) 12.60 14.09c 9.60c 3.9 (6.2) 16.95c 14.93 9.97d 5.19 (18.0) 16.01c

Grand Mean 12.99 10.21 3.89 (15.8) 11.83 14.76 10.87 4.38 (10.5) 14.25 15.25 11.17 4.73 (13.7) 14.49

Std. error of the difference 0.88 0.53 0.84 (6.31) 1.20 0.29 0.16 0.42 (3.48) 0.61 0.47 0.22 0.44 (4.10) 0.43

CV (%) 6.8 5.2 21.6 (40.0) 10.2 2.0 1.4 9.6 (33.0) 4.3 1.2 2.0 9.2 (30.0) 3.0

NoteNoteNoteNotessss:::: * and ** denote significance at p < 0.05 (F5,5 5.05) and p < 0.01 (F5,5 10.97) respectively and ns denotes non-significance.

Within each column, values followed by the same letter are not significantly different (p < 0.05) according to Student’s t-test. # Square root transformation carried out on Mortality data. Percentage (untransformed means) values are shown in brackets for the readers benefit.


Take Take Take Take hhhhome ome ome ome pointspointspointspoints � Mid-rotation results show initial stand density does not have a substantial effect on the growth of Acacia mearnsii.

� Although volume increased at Highflats and Luneburg with increasing stocking, the difference in doubling the current stocking from 1100 to 2200 TPH was less than 21 m3 ha-1.

� Best growth on the Bloemendal lower productivity site was between 1400 and 1600 TPH but the difference between best and worst stocking was not substantial (6 m3 ha-1).

� Results suggest planting at higher densities (>1800 TPH) without thinning does not necessarily result in consistently better growth.

� The grower will also need to determine whether any increase in volume associated with the higher stand densities offsets initial establishment and harvesting costs, compared to the

lower density treatments.


PPPPulping propulping propulping propulping properties of erties of erties of erties of Eucalyptus benthamiiEucalyptus benthamiiEucalyptus benthamiiEucalyptus benthamii and and and and

improvedimprovedimprovedimproved Eucalyptus macarthuriiEucalyptus macarthuriiEucalyptus macarthuriiEucalyptus macarthurii

Tammy Swain

[email protected] Institute for Commercial Forestry Research, P O Box 100281, Scottsville, 3209


Eucalyptus macarthuriiEucalyptus macarthuriiEucalyptus macarthuriiEucalyptus macarthurii Eucalyptus macarthurii is the most frost tolerant of the cold tolerant eucalypts grown commercially

in South Africa, and is often the only eucalypt species that will grow on certain temperate sites.

Tremendous gains have been made in the two generations of breeding that have been completed

by the ICFR - these include increases in growth/yield and improvement in stem form, bark

strippability and snow tolerance.

It has been found that genotype by environment interaction (GEI) exists in the ICFR

E. macarthurii breeding population for various growth characteristics, meaning that certain families

are strongly influenced by environment, and perform better at one site type than at another. The

presence of GEI also indicates that different breeding populations should be developed

independently of each other for different sites.

Pulping studies have indicated that E. macarthurii does not have as favourable pulp yields as

species such as E. smithii and E. nitens. A project was undertaken to select for improved pulp yield

in ICFR’s improved 2nd generation breeding population. Core samples at breast height were taken

of almost 600 selected trees in sub-populations and progeny trials in both KwaZulu-Natal and

Mpumalanga. These cores were then ground into sawdust and scanned using Near Infra Red (NIR)

spectroscopy, using a model developed for this purpose (Ndlovu, 2009).

ResultsResultsResultsResults Total Pulp Yield (TPY) percentages were predicted using NIR for selected trees in the 2nd

generation breeding population. Total Pulp Yield is the percentage Screened Pulp Yield of the

sample plus the rejects, and provides values which can be used for relative ranking of individuals,

rather than absolute pulp yields. This is still very useful in a Tree Improvement programme, where

top individuals can be selected based on ranking. The TPY’s showed the following:

• TPY differed significantly (p ≤ 0.001) according to whether the trees were grown in

KwaZulu-Natal or Mpumalanga i.e. South African provinces influence TPY. In this case,

TPYs were higher in KwaZulu-Natal than in Mpumalanga.

• Within both KwaZulu-Natal and Mpumalanga provinces, there were significant site

differences (p ≤ 0.001) with regards to TPY. However, in both provinces, generally two sites

contributed significantly to this difference ie. in KwaZulu-Natal, sites at Maxwell and

Pinewoods differed from the rest, and in Mpumalanga, sites at The Brook and Dorstbult

differed.

• The 2nd generation families differed significantly (p ≤ 0.001) from each other for TPY. This

indicates that it is possible to select families for improved pulp yield.


Eucalyptus benthamiiEucalyptus benthamiiEucalyptus benthamiiEucalyptus benthamii Due to the many factors affecting growth of some cold tolerant eucalypt species on high altitude,

temperate forestry sites, there was a need to investigate alternate eucalypt species for the

temperate areas. ICFR site-species interaction trials established during the late 1980s and early

1990s showed that E. benthamii was one of the few species which showed commercial potential in

these areas. Tree improvement trials testing a wider range of Australian E. benthamii seedlots and

provenances were established at three sites in South Africa, and showed that provenance

differences exist for growth in this species (Swain and Gardner, 2003), as well as confirming the

potential role of E. benthamii in the South African forestry industry.

Very little is known about the pulping properties of this species, other than the results obtained by

Gardner (2001) from limited samples in two ICFR site–species trials, with no provenance

representation. To gain further knowledge of the pulp yields in this species, wood samples of three

bulked E. benthamii provenances were collected from two of the ICFR provenance progeny trials at

Panbult (Iswepe, Mpumalanga) and Mossbank (Bulwer, KwaZulu-Natal) (see Table 1Table 1Table 1Table 1 for site

details) and pulped by the CSIR for Total Pulp Yield (TPY).

Table 1. Table 1. Table 1. Table 1. Site details of E. benthamii provenance/progeny trials from which wood samples were

collected.

LocalityLocalityLocalityLocality

LatitudeLatitudeLatitudeLatitude

(S)(S)(S)(S)

LongitudeLongitudeLongitudeLongitude

(E)(E)(E)(E)

AltitudeAltitudeAltitudeAltitude

(m)(m)(m)(m)

MAPMAPMAPMAP

(mm)(mm)(mm)(mm)

MATMATMATMAT

((((ooooC)C)C)C)

Soil depthSoil depthSoil depthSoil depth

(mm)(mm)(mm)(mm) Mossbank, Bulwer

29o50'

29o42'

1610

1050

14.4

1200

Leiden, Panbult

26o50'

30o18'

1470

800

15.0

>1200

ResultsResultsResultsResults The TPYs obtained from the E. benthamii and control species wood samples at two sites showed

(Figure 1Figure 1Figure 1Figure 1):

• Site differences were apparent, as with the E. macarthurii study. Total Pulp Yields at the

wetter Mossbank site were higher than at Panbult.

• Of the three E. benthamii provenances that were sampled, the Bents Basin material

produced lower TPYs than Kedumba Valley A and B at both sites. Interestingly, this was the

same trend that was found with the dbh measurements in these trials (Swain and Gardner,

2001).

• E. nitens had the highest TPY of all species at Mossbank, followed by E. benthamii

Kedumba Valley A and E. badjensis. The E. benthamii Kedumba Valley A provenance had

a higher TPY than E. macarthurii.

This indicates that E. benthamii may be a suitable alternative to E. macarthurii in terms of

pulp yield, and that variation does exist in the new species to improve pulp yield even

further.


FFFFigure 1. igure 1. igure 1. igure 1. Screened and Total pulp yields (%) of three bulked E. benthamii provenances and controls, at

two different sites.

Take Take Take Take hhhhome ome ome ome ppppoints:oints:oints:oints:

� Improved E. macarthurii families differ significantly from each other for Total Pulp Yield.

� It is therefore possible to select certain E. macarthurii families and individuals which are

already superior in terms of growth and stem form, and to further improve them with

regards to pulp yield.

� However, as genotype by environment interactions exist for growth characteristics as well as pulp yield, it is suggested that two separate populations of E. macarthurii are bred for

commercial deployment in KwaZulu-Natal and Mpumalanga.

� Provenance differences exist for pulp yield in E. benthamii.

� On the one site sampled, the Kedumba Valley A provenance of E. benthamii outperformed

E. macarthurii for Total Pulp Yield.

� Therefore E. benthamii may be a suitable alternative to E. macarthurii in terms of pulp yield

on certain sites.

ReferencesReferencesReferencesReferences Gardner, RAW. 2001. Site-species interaction studies with cold-tolerant eucalypts in South Africa: Final

results of a 1990/1991 - planted high-altitude series. In: Proceedings of IUFRO Working

Group 2.08.03 Conference “Developing the eucalypt of the future”, Valdivia, Chile, 10-14

September, 2001.

Ndlovu, ZTL. 2009. Breeding of advanced generation Eucalyptus macarthurii - growth parameters and

development of a near infrared (NIR) calibration model to predict whole tree pulp yield using

non-destructive cores. MSc thesis. University of KwaZulu-Natal.

Swain, T-L and Gardner, RAW. 2001. New cold tolerant eucalypt species in South Africa – an update on

provenance/progeny trials on E. badjensis and E. benthamii. In: Proceedings of IUFRO

Working Group 2.08.03 Conference “Developing the eucalypt of the future”, Valdivia, Chile,

10-14 September, 2001.

Swain, T-L and Gardner, RAW. 2003. A summary of current knowledge of cold tolerant eucalypt species

(CTE’s) grown in South Africa. ICFR Bulletin Series 03/2003. Institute for Commercial

Forestry Research, Pietermaritzburg, South Africa.

0

10

20

30

40

50

60

Pulp

yie

ld (%

)

E. nitens

E. ben - K

A

E. badje

nsis

E. m

acarthurii

E. dorrig

oensis

E. ben - K

B

Ben - B

B

E. ben - K

B

E. ben - K

A

E. ben - B

B

Mossbank Panbult

% Screened Pulp yield

% Total Pulp Yield

E. benthamiiE. benthamiiE. benthamiiE. benthamii provenances: provenances: provenances: provenances:

KA – Kedumba Valley A

KB – Kedumba Valley B

BB – Bents Basin


Research to investigate the impact of seedling size, planting depth and Research to investigate the impact of seedling size, planting depth and Research to investigate the impact of seedling size, planting depth and Research to investigate the impact of seedling size, planting depth and

planting method on eucalypts in the summer rainfall region of South Africaplanting method on eucalypts in the summer rainfall region of South Africaplanting method on eucalypts in the summer rainfall region of South Africaplanting method on eucalypts in the summer rainfall region of South Africa (a trial series by the ICFR)(a trial series by the ICFR)(a trial series by the ICFR)(a trial series by the ICFR)

Paul Viero [email protected]

Mondi Limited. P O Box 39, Pietermaritzburg 3200

Introduction:Introduction:Introduction:Introduction: The commercial planting of eucalypts in South Africa will typically include operations such as

marking, pit preparation, planting and watering, all of which may impact on the successful re-

establishment of eucalypts. For each of these operations there are a number of factors that vary

according to geographic region, company policy and individual contractor understanding.

Examples of this include the choice of pitting instrument (hoe, pick or mechanical pitting head); pit

dimensions (depth and width, usually a function of the choice of implement and company

specifications), method of planting and size of the plants used (robustness/sturdiness). Some

companies advocate a “no water” planting policy, others will always plant with water, or will

schedule watering only at times when planting conditions are considered poor (i.e. hot and dry

conditions). Numerous trials worldwide have indicated that larger seedlings (in terms of root collar

diameter and root-plug volume) will survive better than smaller seedlings, thus the impact of

seedling size also needs to be determined for various methods of regeneration, including the depth

at which seedlings are planted, and whether water is used in the process or not.

Most forestry companies in South Africa will agree that the placing of the root plug deeper when

planting (as opposed to shallow) is beneficial to initial seedling/plant survival and growth. However,

the depth at which one is able to plant will often be determined by the size of the seedling that is to

be used with differences based primarily on morphology and age. With a wide range of planting

practices and plant qualities in use across the many land holdings in South Africa, it is often

difficult to understand the function of these different methods as well as to determine which

combination of operations is effective and which is not.

To address these questions the Regeneration Research Project of the ICFR has implemented a

series of three trials focused on increasing understanding of how seedling size (as determined by

root plug volume), planting depth (normal and deeper planting methods) and planting method

(water versus dry planting) will affect survival and early growth in eucalypts. The trials were

implemented in three different physiographic/climatic regions, using species best matched to each

site.

Trial design and treatmentsTrial design and treatmentsTrial design and treatmentsTrial design and treatments • The trial is a 2 x 2 x 2 factorial with one additional control, all of which were replicated four

times. The additional control was duplicated twice within each replicate = total of 10

treatment plots x 4 reps = 40 plots in total.

• Each treatment plot will consist of 8 rows and 8 trees within each row = 64 trees per plot.

• Only the inner 6 x 6 trees will be measured.

• Details for the treatment factors and levels, and their motivation, are given in Tables 1Tables 1Tables 1Tables 1 and

2.2.2.2.


Table 1. Table 1. Table 1. Table 1. Description of the treatment factors and levels, and additional controls, to be implemented for the

proposed trial series

FactorFactorFactorFactor LevelLevelLevelLevel DescriptionDescriptionDescriptionDescription QuestionQuestionQuestionQuestion

Standard 128 cavity tray = 36 cm3

cavity-1

Size of root plugSize of root plugSize of root plugSize of root plug

(Seedling size)

Large 72 cavity tray = 103 cm3

cavity-1

Can early plant survival and growth be

enhanced through using plug volume,

with a corresponding increase in

seedling size?

Standard Top of root plug 5cm below

soil surface.

Depth of planting Depth of planting Depth of planting Depth of planting

Deep Top of root plug 15cm below

soil surface

Compared to the standard depth of

planting, does planting deeper

significantly enhance plant survival and

initial growth (root plug in cooler,

moister zone)? Is planting depth a

function of plant size?

Dry plant No water used in the

planting operation Method of plantingMethod of plantingMethod of plantingMethod of planting

Water plant One litre water applied prior

to planting

Does planting with water significantly

improve survival over that of dry

planting? Is there an interaction with

seedling size and depth of planting?

Additional controlAdditional controlAdditional controlAdditional control

Hydrogel Optimum rate of Hydrogel

applied to planting hole.

Does a hydrogel provide for better

survival over dry or water planting?

Table 2. List of treatments.Table 2. List of treatments.Table 2. List of treatments.Table 2. List of treatments.

Treatment Treatment Treatment Treatment

NoNoNoNo Plug sizePlug sizePlug sizePlug size

Depth of Depth of Depth of Depth of

plantingplantingplantingplanting

Method of Method of Method of Method of

plantingplantingplantingplanting

Additional Additional Additional Additional

ControlsControlsControlsControls

1 Standard Standard Dry -

2 Standard Standard Water -

3 Standard Deeper Dry -

4 Standard Deeper Water -

5 Large Standard Dry -

6 Large Standard Water -

7 Large Deeper Dry -

8 Large Deeper Water -

9 Standard Standard - Hydrogel

10 Standard Standard - Hydrogel

Take home pointsTake home pointsTake home pointsTake home points::::

This trial series has been implemented to help further understanding as to the impact that various

selected re-establishment practices may have on plant survival and growth (initial and at rotation

end).

These re-establishment practices include the following:

� Plant quality, looking at two different plant sizes based on different size plug volumes,

namely:

� a standard plug derived from a 128 deep cavity tray and

� a large plug derived from a 72 cavity tray,

� Different planting depths (standard versus deeper plantings),

� Different planting methods (with or without water), and

� The interaction (if any) between plant size, planting depth and method of planting.


Update on eucalypts pestsUpdate on eucalypts pestsUpdate on eucalypts pestsUpdate on eucalypts pests; ; ; ; Leptocybe invasa, Thaumastocoris peregrinus and Gonipterus scutellatusLeptocybe invasa, Thaumastocoris peregrinus and Gonipterus scutellatusLeptocybe invasa, Thaumastocoris peregrinus and Gonipterus scutellatusLeptocybe invasa, Thaumastocoris peregrinus and Gonipterus scutellatus

Ryan Nadel [email protected]; 012 420 3938/9

Tree Protection Co-operative Programme (TPCP), University of Pretoria, Pretoria, South Africa


Leptocybe invasaLeptocybe invasaLeptocybe invasaLeptocybe invasa In 2007 the Eucalyptus gall wasp, Leptocybe invasa, was found in the Pretoria area. The discovery

was made by Dr. Stefan Neser in June 2007 during his regular insect surveys on Eucalyptus in the

area. At that point, the wasp was only known from a few trees in a limited area. Follow-up surveys

later in 2007 by members of the TPCP have found galls on Eucalyptus plants a few kilometres

away, showing that the introduction must have happened well before June 2007 and was

spreading.

Leptocybe has spread incredibly fast throughout other countries where it was introduced, and this

seems to indeed also be the case in South Africa. Early in 2008 the first infestations were noticed in

the FABI nursery at the University of Pretoria experimental farm, some distance from the initial

detection sites. Subsequently, infested plants have also been found in more than one location

around Johannesburg. Heavily infested Eucalyptus was also recently discovered in the Brits area by

members of the Plant Protection Research Institute (PPRI) and even in the Upington area! More

recently this year heavily infected trees was found outside Bela Bela (Warmbad) and Nylstroom in

the Limpopo Province.

It is of utmost importance that every forester assists to monitor the spread of the Eucalyptus gall

wasp. This is especially important for NURSERY MANAGERS. Sending infested plants to the field is

one of the fastest routes to spread this damaging wasp. Please note the photographs below with

typical galls or swellings on the midrib of the leaves, or young twigs. More images are available on

the TPCP website (www.fabinet.up.ac.za/tpcp).

If you suspect that you have the Eucalyptus gall wasp, please contact us to organise a visit to the

site, or send a picture of the observed symptoms. Do not package and send these galls to us. The

wasps are very small and could easily escape from packaged material and spread to new areas.


Thaumastocoris peregrinusThaumastocoris peregrinusThaumastocoris peregrinusThaumastocoris peregrinus Thaumastocoris peregrinus is a serious pest in all Eucalyptus growing regions of South Africa.

Intensive countrywide surveys of this pest have revealed that 26 Eucalyptus species, including three

commercial hybrids, are susceptible to infestation by T. peregrinus. In addition the difficulty in

accurately determining the size of the populations involved in infestation progression or reduction

was revealed.

A monitoring trial to elucidate the effects of a range of environmental variables on

T. peregrinus populations was established in February 2007. Six trial sites were established, located

across northern and eastern parts of South Africa, representing different Eucalyptus growing and

climatic regions. At each site, yellow sticky traps were monitored and changed weekly and together

with daily measurements of temperature, humidity and rainfall.

Populations fluctuated greatly over the study period, revealing unique patterns of build-up and

decline at the various sites. Both temperature and humidity were found to affect the population

dynamics of T. peregrinus at the test sites. Data emerging from this trial will now be used to

develop population models and to direct control strategies such as biological control that appears

to be the only viable option to manage this pest.

Gonipterus scutellatusGonipterus scutellatusGonipterus scutellatusGonipterus scutellatus The Eucalyptus Snout Beetle, Gonipterus scutellatus, is a defoliator of Eucalyptus trees, often

resulting in severe damage. Originating in Australia, G. scutellatus was first recorded in South

Africa in 1916, in Newlands, Cape Town. Gonipterus scutellatus spread rapidly and by 1929 was

present in the majority of South Africa’s Eucalyptus growing areas. The spread of Gonipterus is also

evident on a global scale, as it has spread to every continent, except Antarctica.

In 1926 the egg parasitoid, Anaphes nitens, was introduced from Australia into South Africa as a

biological control agent for G. scutellatus. This wasp was highly successful in controlling G.

scutellatus in the low altitude sites. However, higher altitude, marginal sites still experience

outbreaks of G. scutellatus, often resulting in considerable damage. The cold and dry winters of

these sites are thought to hinder the activity of the wasp. Chemicals are often used to control

outbreaks of G. scutellatus. Although temporary control may be established, chemical control

should be used with caution, as the biological control agent is also negatively affected by the use of

chemicals. If G. scutellatus becomes re-established, it could cause severe and unhindered damage.


Visit to Visit to Visit to Visit to land preparation operationland preparation operationland preparation operationland preparation operation

G Stapelberg

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ICFR CENTRAL REGIONAL INTEREST GROUP FIELD DAY · Andrea Louw [email protected] Institute for Commercial Forestry Research, PO Box 100281, Scottsville 3209 Introduction