Post on 23-Apr-2018
transcript
TThhaannkkss aarree eexxtteennddeedd ttoo TTWWKK,, NNTTEE aanndd NNCCTT ffoorr ssppoonnssoorriinngg tthhee ccaatteerriinngg
IICCFFRR CCeenntt rraall RReeggiioonnaall FFiieelldd DDaayy
WWeeddnneessddaayy 2255tthh FFeebbrruuaarryy 22001155
IIsswweeppee CClluubb aanndd MMii ll ll ,, IIsswweeppee,, PPiieett RReett iieeff
ICFR Central Regional Field Day Page | 2 © ICFR 2015
ICFR Central Regional Interest Group Field Day Date: 25th February 2015 Venue: Iswepe Club, Iswepe, Piet Retief Time: 08h00 for 08h30
PROGRAMME
Time Topic Speaker
08h00-08h30 Tea & Coffee
08h30-08h40 Welcome Johan Nel (TWK), Regional Chairperson
Indoor Presentations
08h40-09h05 Opportunities for further improvement in timber and bark yield for the wattle industry Dr Julian Chan (ICFR)
09h05-09h25 An update on pests and diseases of plantation forestry Izette Greyling (FABI)
09h25-09h45 Measuring the impacts of wattle rust on the productivity of black wattle (Acacia mearnsii) in the KwaZulu-Natal Midlands Thobile Mbatha (ICFR)
09h45-10h10 Eucalyptus grandis x Eucalyptus macarthurii hybrids in South African forestry Joel Cele (ICFR)
10h10-10h40 TEA
10h40-11h05 Multisite nutrient depletion trials Dr Steven Dovey (ICFR)
11h05-11h30 Results from long-term wattle fertiliser trial at Bloemendal (6th rotation results) Dr Louis Titshall (ICFR)
11h30-11h55 To grow pine as a long rotation or as a short rotation crop Graham Rusk (FES)
Field Visits
11h55-13h30 Visit to frost tolerant ICFR wattle trials Dr Julian Chan (ICFR)
13h30-14h15 Lunch at Iswepe Club
14h15-15h30 Visit to Iswepe Mill
ICFR Central Regional Field Day Page | 3 © ICFR 2015
Opportunities for further improvement in timber
and bark yield for the wattle industry*
Julian Moreno Chan julian.chan@icfr.ukzn.ac.za
Institute for Commercial Forestry Research, P.O. Box 100281, Scottsville, Pietermaritzburg, 3209
Acacia mearnsii De Wild (black wattle) is an important plantation species for tannin production and
woodchip exports in South Africa. About 45 000 tons of bark extract are produced annually of which the
majority is exported for leather products and wood adhesives. International demand, however, has
remained static over the last two decades due to intense competition from synthetic tannins and the effect
of oil-prices on oil-based adhesives. The species offers important economic advantages for pulp
production (higher wood density and pulp yield, which translate into higher digester productivity and
factory output), as well as superior long-distance stowage in vessels. These factors make A. mearnsii a
sought-after species and have ensured a sustained demand for wattle woodchips in the Japanese
market, and today, continues to attract new customers in emerging markets (China and India). Total black
wattle woodchip exports in 2013 were 800 000 BDMT.
For a number of reasons, efforts are concentrated on increasing productivity from the existing plantation
resource in South Africa:
1) Reductions in land base (20 000 ha of corporate land lost in the period 2003-2013),
2) Changes in species due to risk (frost and new pest and diseases),
3) Current timber yields are below site potential, and
4) Superior timber yields from international competitors.
This presentation discusses the strengths and weaknesses of black wattle in the international woodchip
and pulp markets, the opportunities to increase current yields, and poses the question of whether the
wattle growers are realising the potential of the current improved stock. These issues are discussed in the
context of the A. mearnsii breeding programme, highlighting priorities and what should be done.
* A good part of information for this presentation was taken from the paper: Moreno Chan, Day, Feely, Thompson, Little, Norris (2015). Acacia mearnsii industry overview: current status, key research and development issues. Southern Forests Journal <in press>
ICFR Central Regional Field Day Page | 4 © ICFR 2015
An update on pests and diseases of plantation forestry
Izette Greyling1, Jolanda Roux, Alistair McTaggert and Brett Hurley 1izette.greyling@fabi.up.ac.za
Tree Protection Co-operative Programme (TPCP), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
The impact that pests and diseases have on the forestry industry has been increasingly evident over the
past year. The appearance of two new insect pests (Ophelimus maskelii and Spondyliaspis plicatuloides),
the outbreak of a rust disease on A. mearnsii, the range expansion of pitch canker of mature trees, and
the Cossid moth (Coryphodema tristis), have contributed to the ever increasing challenge of forest
management. All is not doom and gloom though, as the year also saw the anniversaries (and continued
releases) of Selitrichodes neseri, the biocontrol agent for Leptocybe invasa, and Cleruchoides noackii, the
biocontrol agent for Thaumastocoris peregrinus. In addition, the BiCEP (Biological Control of Eucalyptus
Pests) programme, an international collaboration between FSA (FABI), Australia and Brazil to share
knowledge and biological control agents for major eucalypt pests, continues to evolve. Research into the
use of Psyllaephagus bliteus as a potential biocontol agent for Glycaspis brimblecombei is ongoing in the
FABI Biocontrol Centre at the University of Pretoria.
Management of tree pests and pathogens requires a team effort and participation of the whole industry.
Farmers and foresters are encouraged to report any tree health problems to the TPCP. This will facilitate
the detection of new problems and assist in monitoring established pests and pathogens.
____________________________________________________________________________________
For any pest and/or disease information please contact:
Jolanda Roux (Extension and Diagnostics) – 082 909 3202, jolanda.roux@fabi.up.ac.za
Izette Greyling (Extension and Diagnostics) – 083 269 1983, izette.greyling@fabi.up.ac.za
Darryl Herron (Diagnostic Clinic) – darryl.herron@fabi.up.ac.za
Brett Hurley (Insect Biocontrol) – brett.hurley@fabi.up.ac.za
Jeff Garnas (Entomology) – jeff.garnas@fabi.up.ac.za
____________________________________________________________________________________
We also host a list server where information regarding various aspects related to tree health are shared.
If you would like to subscribe to Treehealthnet, please contact Wilhelm de Beer at
wilhelm.debeer@fabi.up.ac.za or any of the above listed people for assistance.
____________________________________________________________________________________
ICFR Central Regional Field Day Page | 7 © ICFR 2015
Measuring the impacts of wattle rust on the productivity of black wattle
(Acacia mearnsii) in the KwaZulu-Natal Midlands
Thobile Mbatha and Andrew Morris thobile.mbatha@icfr.ukzn.ac.za
Institute for Commercial Forestry Research, P.O. Box 100281, Scottsville, Pietermaritzburg, 3209 A new disease was discovered in the 2012 in the wattle plantations near Eston and has been spreading
in KwaZulu-Natal and infecting trees of all ages. The disease is of Uromycladium rust fungi, and the
species is still under identification by the Forestry and Agricultural Biotechnology Institute, (FABI,
University of Pretoria). These fungi have a complex lifecycle that can involve the formation of up to three
types of fruiting bodies and four spore types. The complexity in the lifecycle of these fungi makes it
challenging to identify the species name and to better understand the pathogen’s biology. A better
understanding of the pathogen’s biology, epidemiology, and impact on productivity will be crucial in
effectively coming up with management strategies for wattle rust. Therefore, a multi-faceted project with
various academic and industry partners, was initiated with the following main aims:
(i) Determine the impact of wattle rust on black wattle growth and productivity;
(ii) Understand the interaction between wattle rust and co-occurring insects and their impact;
(iii) Relate the level of infestations to environmental factors and identify triggers of outbreaks; and
(iv) Provide ground-truthing points for calibration of remote sensing monitoring of the disease
incidence.
This presentation will give feedback on the trial in City Forestry. Three exclusion plot trials were
implemented in October 2014 to measure the impact of the pathogen on black wattle growth and
productivity. Fungicide (mixture of azoxystrobin and difenoconazole), insecticide (cypermethrin) or
combination of both, were applied to exclude any pest or pathogen in the trials. iButtons are being used to
measure temperature and relative humidity in the trials. Plant growth parameters (i.e. tree height and
ground line diameter) and weekly disease assessments are being measured in each trial. New spores
were observed after a period of cool and high relative humidity which is common for rust fungi
development. These need to be transported to encounter compatible mating types, in the case of wheat
rust, and are carried by insects (Schumann & Leonard, 2000). The new wattle rust infection was followed
by an increasing number of insects in the trial, most abundantly being the Melolonthinae: Hopliini. Under
similar environmental conditions stem infections were observed. At this stage, there are no significant
differences in terms of tree growth. However, considerable defoliation was observed in the trees which
later will have an impact on growth of the trees. It is therefore, important to continue with the current
observations as they are contributing to our understanding of the pathogen’s biology, epidemiology and
its impact on productivity, support to ultimately developing an integrated management strategy for wattle
rust.
Reference:
Schumann GL, Leonard KJ. 2000. Stem rust of wheat (black rust). The Plant Health Instructor. DOI:
10.1094/PHI-I-2000-0721-01
ICFR Central Regional Field Day Page | 8 © ICFR 2015
Eucalyptus grandis x Eucalyptus macarthurii hybrids
in South African forestry
Joel Cele1 and Tammy Swain 1joel.cele@icfr.ukzn.ac.za
Institute for Commercial Forestry Research, P.O. Box 100281, Scottsville, Pietermaritzburg, 3209
Global predictions for the next 50-100 years foresee an increase in temperature, increase or decrease in
rainfall, and increase in frequency and intensity of extreme events. Therefore, the development of hybrids
that can tolerate these events is a priority. Eucalyptus grandis is a species of major importance for
plantations with approximately 340 000 ha grown in South Africa. The species has vigorous growth,
coppices well and has good rooting ability, stem form and pulping properties, but average to low wood
density and is highly prone to frost damage. Eucalyptus macarthurii is one of the few cold and frost
tolerant eucalypt species commercially planted on colder, high altitude and low productivity sites in South
Africa. Hybrids were developed by crossing E. macarthurii pollen (ex ICFR) onto E. grandis selections (ex
CSIR), and hedges were established in White River. Cuttings were made to establish clone testing trials
at five sites; Panbult, Wyntoun, Potgieterskeus, Piet Retief and Shiselweni (Swaziland).
Growth characteristics (diameter at breast height and height) were evaluated in the E. grandis x
E. macarthurii clones and controls, and basal area calculated. The top performing clones were sampled for
pulp yield and basic density. Results showed that there were clones that performed better than, or equal to,
the pure species controls for diameter, basal area and height at the sites. The basic density of the top
E. grandis x E. macarthurii clones was higher than that of the E. grandis control, at sites where it was
planted. The pulp yield of the selected top clones was higher than that of both E. grandis and E. macarthurii,
but comparable to that of E. nitens and E. dunnii. Twenty clones were selected, based on diameter at breast
height, height and pulp yield, for further testing as having commercial potential for growth on the more
temperate sites of the summer rainfall regions of South Africa.
These clones are currently being rooted in Piet Retief and at the ICFR nursery in Pietermaritzburg for the
establishment of hedges. To date, hedges of 18 of the top 20 performing E. grandis x E. macarthurii clones
have been established at both nurseries.
• Hedges were screened for Leptocybe invasa susceptibility and large variation between the clones
was found. Coppice of the original trials was assessed for the presence of L. invasa three times
during 2014, but there were no signs of damage by the pest.
• Cuttings have been rooted, and two sites chosen, for the establishment of 2nd phase clonal trials
early in 2015.
ICFR Central Regional Field Day Page | 9 © ICFR 2015
Multisite nutrient depletion trials
Steven Dovey steven.dovey@icfr.ukzn.ac.za
Institute for Commercial Forestry Research, P.O. Box 100281, Scottsville, Pietermaritzburg, 3209
Site nutrient supply must be maintained if the productivity of successive rotations is to be sustained.
Nutrients are supplied to trees from soil reserves that are at risk of becoming depleted through continuous
nutrient removals associated with harvesting and residue management. The ability of forestry soils to
resist and recover from nutrient loss is poorly understood. There is no link between laboratory-determined
nutrient pool size estimates, soil supply potential and the ability of trees to take up and efficiently utilise
nutrients. The ability of sites to naturally recover or be ameliorated is also poorly understood.
A research project was initiated in 2013 that aims to develop knowledge on the nutrient loss that key soils
can withstand until tree growth becomes nutrient limited. Nutrient removal is carried out through intensive
biomass removal. The aim is to induce nutrient-related growth decline in the tree crop on soils derived
from six major parent materials and to relate the decline to laboratory based indicators of soil nutrient
supply. A second phase of this project will be to test the ability for soils to recover naturally or through
fertilisation.
Six research trials were initiated between 2012 and 2014. These are situated on soils with properties to
create a range in risk of soil fertility decline (Table 1 ). The studies utilise a combination of high density
planting, heavy coppicing and annual harvesting and complete residue/litter (forest floor) removal to
induce rapid soil nutrient loss. Nutrient removal through complete tree and residue removal is compared
with treatments that retain or replace nutrients (namely residue retention and fertilisation). After the lower
nutrient supply limits have been detected or identified, the field trials will be operationally re-planted at
conventional spacing to test the ability of each site and soil to recover from nutrient depletion naturally or
through fertilisation.
A treatment-related growth response has already been detected at the first site (NDS2-Windyhill) after
two harvest cycles. A reduction in tree growth and depression of top-soil nutrient status has occurred with
residue and litter removal. Fertilisation and residue retention has maintained tree growth rates.
ICFR Central Regional Field Day Page | 10 © ICFR 2015
Table 1: General site and 0 - 20 cm soil information for the six nutrient depletion study (NDS) sites
Trial NDS1 NDS2 NDS3 NDS4 NDS5 NDS6
Planted 2013 2012 2014 2015 2015 2015
Lithology Aeolian sand
Natal Group sandstone
Aeolian sand Gabbro Granite Shale
Site Dukuduku Windyhill Kwambo (SQF) Glen Eland
Glen Eland Clan
Region Zululand Midlands Zululand Central Central Midlands
Species Egxu Egxu Egxu Egxn Egxn Egxu
MAP (mm) 919 840 1260 884 926 1015
MAT (°C) 21.8 18 21.9 14.8 14.8 18.1
Altitude (m) 47 800 24 1472 1481 788
Silt % 3.0 28.1 3.3 20.4 12.3 nd
Clay % 4.1 17.3 5.9 31.5 21.5 nd
Sand % 92.9 54.7 90.9 48.1 66.2 nd
pH (KCl) 4.4 4.0 3.8 4.1 3.9 3.6
pH(H2O) 5.2 4.8 4.4 4.1 4.8 3.9
N % 0.08 0.40 nd 0.22 0.17 0.51
P (ppm) 3.88 25.39 2.52 2.83 3.71 6.51
K+ cmolc kg-1 0.05 0.19 0.04 0.09 0.15 0.20
Ca2+ cmolc kg-1 0.90 2.27 0.26 0.46 0.88 0.60
Mg2+ cmolc kg-1 0.27 0.94 0.17 0.09 0.23 0.27
Na+ cmolc kg-1 0.04 0.11 0.05 0.04 0.02 0.06
S-value cmolc kg-1 1.26 3.50 0.52 0.59 1.29 1.14
OC (WB) % 0.47 4.65 1.03 3.20 2.28 8.35
Ex.Acid cmolc kg-1 0.20 1.50 0.52 1.48 0.93 7.16
nd = no data (awaiting lab results)
ICFR Central Regional Field Day Page | 11 © ICFR 2015
Results from long-term wattle fertiliser trial at Bloemendal (6th rotation results)
Louis Titshall louis.titshall@icfr.ukzn.ac.za
Institute for Commercial Forestry Research, P.O. Box 100281, Scottsville, Pietermaritzburg, 3209 Project Team: Greg Fuller, Michael Buthelezi, Nkosinathi Kaptein
Introduction
In the late 1940’s a number of factorial fertiliser experiments were implemented to help develop and refine
fertiliser application recommendations for wattle production. In most cases combinations of nitrogen,
phosphorus, potassium and lime were tested. One of the trials (C2 at Bloemendal) was reimplemented for
a further five rotations. The 6th rotation was felled in early 2014 and this presentation provides some of
the early results of various growth parameters assessed.
Experimental overview
34 factorial arranged in a quasi-latin square confounded in nine rows by nine columns. Table 1 presents a
summary of historical fertiliser regimes used.
Table 1: Overview of fertiliser regimes used for each rotation of the long-term wattle fertiliser trial at Bloemendal.
Rotation 1 to 3 Rotation 4 Rotation 5 Rotation 6
kg ha -1 (g tree -1) Nitrogen (as Ammonium sulphate)
0, 25, 50 (0, 10.5, 21) None
Phosphorus (as Single Super Phosphate)
0, 20, 40 (0, 8, 16) None
Potassium (as KCl) 0, 60, 120 (0, 12.5, 25) 0, 30, 60 (0, 6, 12) None
Lime 0, 5.6, 11.2 (as agricultural lime)
0, 5.6, 11.2 (as dolomitic lime)
None None
Planting notes Line sowing, thinned to ± 1400
Seedling planted in pits, thinned to ± 1500
Seedling planted in pits, never thinned (± 2400)
Dates R1: 1951 to 1961 R2: 1961 to 1971 R3:1971 to 1982
1982 - 1992 1992 - 2003 2003 - 2014
Variates assessed
• DBH (converted to basal area), total height, volume, stocking, wet bark yield
• Soil samples and bark samples for analysis also collected but not reported here
ICFR Central Regional Field Day Page | 12 © ICFR 2015
Results
• No significant residual interaction effects (p > 0.05)
• No significant main effects of N or K (p > 0.05)
• Some significant main effects of P and Lime (p < 0.05)
o Positive P responses for BA, height, volume
o Negative lime response for BA, volume, stocking and wet bark yield
Some Preliminary Thoughts
• Liming negatively affects production for extended periods – Do not lime wattle plantations.
• Evidence of residual P – may offer opportunity to lower P fertilisation rates in the future.
• Past and current results do not indicate any benefit to nitrogen fertiliser.
• Re-application of potassium may be necessary to main nutrient balance.
Acknowledgements
SAWGU for funding,
Gary Behn and staff for land and operational assistance, past and current ICFR staff involved with trial.
ICFR Central Regional Field Day Page | 13 © ICFR 2015
To grow pine as a long rotation or as a short rotation crop
Graham Rusk grahamr@forec.co.za
Forestry Economics Services
Few of us can plant pine trees to grow on a long rotation of 25 to 30 years and see the results of our
efforts by clearfelling the crop. For many of us that pleasure will be left to our sons and daughters who
inherit the farms, just as we have benefitted from the planting of these long rotation crops by our fathers.
Why plant pine to be managed on a long rotation? Why not plant pine on a short rotation and get our
money back after 15 years? Most of us would see that day. The only problem is that you will probably
only get back the money put into the crop those many years ago with nothing to contribute to your wealth.
This situation has shown up consistently for many years in our monitoring of short rotation pine crops.
The prices for pulpwood do not support the usually high transport costs to distant mills. Pulp prices have
improved slightly quicker over the past few years in order to combat the emerging competition from the
boxwood market but it is still insufficient to encourage investing in a short rotation pine crop.
It appears that the major consumers of pine pulpwood; Sappi and Mondi, are changing their processing
plants to take in less pine and more gum. This will almost demolish the short rotation pine market (about
93% of the crop sold as pulpwood) and it will also create problems for the pine sawlog producers (about
8.5% of the crop sold as pulpwood).
The following table shows the Financial Analysis of both long and short rotations of pine in this Highveld
area for the two years; 2011 and 2012. This Financial Analysis represents a plantation in cycle with one
25th (long rotation) or one 15th (short rotation) of the area being clearfelled and replanted each year. Then
only could all the income for the year be added and all the expenses subtracted to give a profit or loss for
the year like a crop farmer.
Do we ever reach such a perfect stage in reality with fires, expansion and other situations putting
plantations out of cycle? No, or very seldom. So how do we know whether a long-term project such as
timber growing is profitable? This Financial Analysis page puts together the prices received for the
different products sold in 2011 or 2012 and the current annualised costs of performing the various forestry
operations in 2011 or 2012, then multiplies this by the sustainable, marketable MAI (cubic
metres/ha/year) to provide an annual profit per hectare of plantation before tax, bond interest, loan
repayments, capital expenditure and income tax.
The annualised profit potential of the long and short rotation crops is shown in line 2.22 of the Financial
Analysis. This tells its own story and should make one hesitant to invest in a pine crop to be grown and
managed on a short rotation.
ICFR Central Regional Field Day Page | 14 © ICFR 2015
FORESTRY ECONOMICS SERVICES
MPUMALANGA SOUTHPINE FINANCIAL ANALYSES
LONG ROTATION SHORT ROTATION
2011 2012 2011 2012
1.0 PLANTATION DETAILS
1.1 AVERAGE PLANNED ROTATION AGE Years 25.9 26.3 16.4 16.0
1.2 ACTUAL AGE AT CLEARFELLING Years 26.7 25.6 16.8 16.5
1.3 AVERAGE PLANTATION AGE Years 11.6 12.1 6.9 7.1
1.4 ACTUAL TONS SOLD tons 554 921 559 427 463 045 350 845
2.0 ANNUAL SUSTAINABLE PROFIT PER HECTARE IF M.A.I. IS FELLED AND SOLD
2.1 Timber delivered to Buyer R/ton 455.81 514.34 287.55 314.98
2.2 Timber sold Free on Rail or Depot R/ton 480.74 263.05 - 218.78
2.3 AVERAGE PRICE RECEIVED R/ton 458.97 513.80 287.55 314.93
2.4 Less : Transport costs R/ton 62.21 64.68 130.99 170.02
2.5 NET PRICE ON ROADSIDE R/ton 396.76 449.12 156.56 144.91
2.6 Timber sold on roadside R/ton 487.61 510.08 384.26 405.42
2.7 AVERAGE PRICE ON ROADSIDE R/ton 431.83 479.22 169.14 163.96
2.8 Less : Harvesting costs R/ton 76.26 76.09 65.89 74.22
2.9 NET STANDING PRICE R/ton 355.57 403.13 103.25 89.74
2.10 Standing sales R/ton - - 121.12 108.44
2.11 AVERAGE STANDING PRICE PER TON R/ton 355.57 403.13 103.40 89.94
2.12 Divided by : Conversion Ratio m³/ton 0.94610 0.94224 0.99613 0.99563
2.13 AVERAGE STANDING PRICE PER M³ R/m³ 375.83 427.84 103.80 90.33
2.14 Multiplied by : Sustainable M.A.I. m³/ha/yr 14.71 14.69 14.88 14.88
2.15 ANNUAL STANDING INCOME R/ha 5 526.58 6 284.97 1 544.54 1 344.11
2.16 Add : Sales of other forest products R/ha 8.83 4.43 2.77 3.51
2.17 Less: Establishment costs R/ha 170.45 178.53 204.80 211.92
2.18 Tending costs R/ha 226.03 277.35 160.19 166.56
2.19 Forest Protection costs R/ha 358.56 502.71 358.56 502.71
2.20 GROSS MARGIN R/ha 4 780.37 5 330.81 823.76 466.43
2.21 Less: Overhead costs R/ha 815.46 933.26 815.46 933.26
2.22 ANNUAL PROFIT POTENTIAL IF M.A.I. IS SOLD R/ha 3 964.91 4 397.55 8.30 (466.83)
3.0 EXTENT OF UNDERFELLING (OR OVERFELLING) THI S YEAR RELATIVE TO M.A.I.
3.1 MEAN ANNUAL INCREMENT m³/ha/yr 14.71 14.69 14.88 14.88
3.2 Less : Total Sales this Year m³/ha 10.87 9.81 10.47 10.05
3.3 RELATIVE UNDERFELLING (OVERFELLING) m³/ha 3.83 4.88 4.41 4.83