ICFR Midlands Field Day · PDF file * @fabi.up.ac.za Tree Protection Co-operative Programme...

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  • ICFR KwaZulu-Natal Midlands Field Day Page | 2 © ICFR 2014

    ICFR KZN Midlands Regional Interest Group Field Day Date: 20th November 2014 Venue: Wartburg Lutheran Church, Wartburg Time: 08h30 for 09h00

    PROGRAMME

    08h30 Meet for tea and coffee Indoor Presentations

    09h00 Welcome Shaun Henderson Masonite

    09h10 Mapping the risk of the myrtle rust Puccinia psidii in South Africa: A bioclimatic approach Ilaria Germishuizen ICFR

    09h35 Update on plantation pests and diseases in South Africa Jolanda Roux FABI

    10h00 The effect of spacing Eucalyptus dunnii seedlings at different ages and densities

    Marnie Light ICFR

    10h25 A comparison between two hybrid breeding strategies employed in the production of Eucalyptus grandis x Eucalyptus urophylla

    Gert van den Berg Mondi

    10h50 TEA

    11h30 The development of time study standards for Southern Africa - the benefit to harvesting and silviculture operations

    Simon Ackerman ICFR

    11h55 Long-term wattle fertiliser trial: Some early 6th rotation results

    Louis Titshall ICFR

    12h20 Community involvement in research and small grower projects

    Terry Everson UKZN

    12h50 LUNCH

    14h00 Field visit to nutrient depletion trial site Steven Dovey ICFR

    15h30 End of Field Day

  • ICFR KwaZulu-Natal Midlands Field Day Page | 3 © ICFR 2014

    Mapping the risk of the myrtle rust Puccinia psidii in South Africa:

    A bioclimatic approach

    Ilaria Germishuizen ilaria.germishuizen@icfr.ukzn.ac.za

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

    The pathogen Puccinia psidii (Myrtle rust) was first detected in South Africa in May 2013 in the KwaZulu-

    Natal South Coast. The Myrtle rust represents potentially a serious threat to Eucalyptus plantations and to

    native species of the family Myrtaceae by causing a rust disease. This presentation focuses on the

    development of a risk model to identify areas where the environmental conditions required for the

    establishment of a viable population of P. psidii in South Africa are met, and it is part of a collaborative

    research project led by Prof Jolanda Roux (FABI) and involving the ICFR (Dr Ilaria Germishuizen and Dr

    Ryan Nadel) and the Department of Agriculture, Forestry and Fisheries (DAFF) of Australia (Dr Jeoff

    Pegg).

    The risk model uses bioclimatic variables as predictors to geographically map the potential distribution of

    P. psidii. Climatic variables and thresholds were defined based on available literature describing the

    climatic requirements of the pathogen where viable populations are established (Blum and Dianese,

    2001; Booth et al., 2000; Glen et al., 2007; Kriticos et al., 2013; Ruiz et al., 1989). Variable predictors

    selected for the model were based on 1 minute by 1 minute historical climatic grids (Schulze 2007).

    Seasonal and annual risk maps were developed showing areas of potential high (RH ≥ 80% and Tmin

    ≥18 and ≤22 °C) and medium (RH ≥70% and Tmin ≥10 °C) risk (Figure 1).

    The potential risk to Eucalyptus plantations was evaluated by overlaying the current areas under forestry

    to the potential geographic range of P. psidii. Most of the areas currently under forestry (about 80%) are

    within the geographic range suitable to P. psidii, indicating a potential threat to the health of Eucalytpus

    plantations in South Africa. The current distribution range of the 4 native species of the family Myrtaceae

    also broadly overlay with P. psidii suitable range, suggesting a potential threat to the regional biodiversity

    asset.

  • ICFR KwaZulu-Natal Midlands Field Day Page | 4 © ICFR 2014

    Figure 1. Potential Puccinia psidii high (RH ≥ 80% and Tmin ≥18 and ≤22 °C) and medium (RH ≥70% and Tmin ≥10 °C) risk areas in South Africa.

    References

    Blum LEB, Dianese JC. 2001. Patterns of urediniospores release and development of rose apple rust.

    Pesquisa Agropecuaria Brasileira 36; 845–850

    Booth TH, Old KM, Jovanovic T. 2000. A preliminary assessment of high risk areas for Puccinia psidii

    (Eucalyptus rust) in the Neotropics and Australia. Agriculture Ecosystems & Environment 82:

    295–301

    Glen M, Alfenas AC, Zauza EAV, Wingfield MJ, Mohammed C. 2007. Puccinia psidii: a threat to the

    Australian environment and economy – a review. Australasian Plant Pathology 36; 1-16

    Kriticos JD, Morin L, Leriche A, Anderson RC, Caley P. 2013. Combining a climatic niche model of an

    invasive fungus with its host species distributions to identify risks to natural assets: Puccinia

    psidii sensu latu in Australia. Plos 8(5): 13p

    Ruiz RAR, Alfenas AC, Ferreira FA. 1989. Effect of temperature, light and inoculum source on teliospore

    and urediniospore production of Puccinia psidii. Fitopatologia Brasileira 14: 70–73

    Schulze RE. 2007. South African atlas of climatology and agrohydrology. Water Research Commission,

    Pretoria, RSA, WRC Report 1489/1/06

  • ICFR KwaZulu-Natal Midlands Field Day Page | 5 © ICFR 2014

    Update on plantation pests and diseases in South Africa

    Jolanda Roux*, Alistair McTaggart and Brett Hurley

    *jolanda.roux@fabi.up.ac.za Tree Protection Co-operative Programme (TPCP), Forestry and Agricultural Biotechnology Institute (FABI), University

    of Pretoria, Pretoria, South Africa,

    Pest and disease problems continue to challenge the South African forestry industry. In the past year the

    industry has seen the appearance of a number of new insect pests in the country, an outbreak of a rust

    disease of Acacia mearnsii, the appearance of pitch canker disease of Pinus species in the KwaZulu-

    Natal Midlands and Limpopo Province and the cossid moth in the Karkloof area.

    In 2012 some farmers in the KZN Midlands became aware of an unknown disease problem on

    A. mearnsii. This disease (Figure 1) rapidly became a serious concern to the industry, with many farmers

    experiencing epidemics resulting in tree stunting and in some cases death. The cause of the disease has

    been confirmed as being a rust fungus in the genus Uromycladium, most closely related to U. alpinum.

    Research is underway to more accurately identify the fungus to species level in order to gain more

    information on its possible origin. Together with the ICFR and other stakeholders, studies on the

    epidemiology of the pathogen will commence in 2015, so as to more accurately apply chemical treatment

    to reduce the impact of the pathogen.

    Pitch canker of mature Pinus species, caused by the fungus Fusarium circinatum, was first reported from

    the Karkloof area in 2012, from a trial planting of P. greggii. These trees were ten years of age and

    showed typical symptoms of resin exudation (Figure 2e) from the main stems of trees. In 2014 the

    disease was confirmed in a nearby commercial stand of P. greggii. Most recently, pitch canker disease

    was confirmed on four and seventeen year-old P. patula trees in the Limpopo Province.The blue gum

    chalcid, Leptocybe invasa, is continuing to result in significant damage to eucalypt plantings country wide

    (Figures 2a,b). Infestations are leading to tree stunting and in some cases death. In 2012 a biological

    control agent, Selitrichoides neseri, was released at more than 400 sites in South Africa. Monitoring of

    these sites have shown that S. neseri has successfully established at most sites, and have started

    moving naturally to adjacent areas.

    For many years the cossid moth, Coryphodema tristis, was known from Eucalyptus nitens, only from the

    Lothair area. In 2014, this insect was, however, found on E. nitens in the Karkloof. It is specific to

    E. nitens, resulting in wood loss as a result of the tunnelling action of the larvae of the moth. Great

    success has been made in developing a pheromone to attract and trap the moth and this is currently

    being tested extensively under field conditions.

    Two new incursions of important Eucalyptus insect pests were detected in Gauteng in 2014. These are

    the gall wasp Ophelimus maskeli (Figure 2d) and the psyllid Spondyliaspis sp. (Figure 2c). Currently

    these insects are only known from Gauteng, but experience with L. invasa and the red gum lerp psyllid,

  • ICFR KwaZulu-Natal Midlands Field Day Page | 6 © ICFR 2014

    Glycaspis brimblecombii, suggest that they may very rapidly spread countrywide. Through collaborations

    with researchers in other countries, the TPCP has already accessed biological control agents to manage

    some of these pests. These are currently being tested in our laboratories in Pretoria.

    Management of tree pests and diseases requires a team effort and participation by all in the industry. We

    encourage all farmers and foresters to report any unknown/unusual tree health problems to the