Working Group Minutes / Archives / Soybean Rust Task Team / 25 July 2006
Minutes

Soybean Rust working group

meeting held on Tuesday 25 July 2006 at 09h00 at the University of the Free State, Bloemfontein



  1. Opening

    The chairperson, Mr Scholtemeijer, opened the meeting with prayer.

  2. Welcome

    The chairperson welcomed all present.

  3. Attendance and apologies

    Present

    Mr GJH Scholtemeijer OPOT / AOC (Chairperson)
    Prof AH McDonald ARC-GCI
    Ms M Craven ARC-GCI
    Dr BC Flett ARC-GCI
    Dr K Mashingaidze ARC-GCI
    Dr AJ Liebenberg ARC-GCI
    Mr AJ de Lange ARC-GCI
    Dr J de Kock PRF
    Mr WF van Wyk PRF
    Mr FAS Potgieter GSA
    Mr CJ Louw GSA
    Mr NC van Rij KwaZulu-Natal Department of Agriculture
    Ms S Tweer KwaZulu-Natal Department of Agriculture
    Mr ID Lamprecht Mpumalanga Department of Agriculture
    Ms LC van Jaarsveld University of the Free State
    Prof NW McLaren University of the Free State
    Mr A Jarvie PANNAR
    Ms M Govender PANNAR
    Ms P Kruger ARC-GCI (Secretariat)

    Absent with apologies

    Mr GP de Beer ARC-GCI
    Dr PM Caldwell KwaZulu-Natal University, Pietermaritzburg
    Prof ZA Pretorius University of the Free State
    Dr FJ Kloppers PANNAR
    Ms ED du Preez PANNAR
    Mr LJ Oberholzer Monsanto
    Mr A de Klerk Du Pont
    Mr NGE Hackland BASF
    Mr AG Broeksma BAYER
    Dr GM Swart Syngenta

  4. Personalia

    The chairperson wished a full and speedy recovery to Mr GP de Beer and Prof ZA Pretorius.

  5. Finalisation of agenda

    The agenda was accepted with the addition of item 10: Additional matters.

  6. Minutes of the previous meeting

    1. Corrections and acceptance

      The minutes of the 6th SBR Task Team Meeting held on Tuesday, 26 July 2005 were accepted as a true reflection of the meeting, subject to the following amendments:

      Page 3, item 7.1.1.6, Summary, paragraph 2 (clarification)

      • "Mr Scholtemeijer mentioned that the PRF had had an official request to supply the Crop Estimates Committee with reasons why the actual seed of soybeans reported by SAGIS were higher than the last crop estimate" to read "Mr Scholtemeijer mentioned that the PRF had had an official request to supply the Crops Estimates Committee with reasons why the actual physical crop of soybeans reported by SAGIS was higher than the last crop estimate".

      Page 3, item 7.1.1.6, Summary, paragraph 4 (spelling)

      • "Prof Mc Claren" to read "Prof McLaren.

      Page 4, item 8.2, Comments/Questions/Answers, (clarification, punctuation and sentence structure)

      • "Prof McLaren commented that row spacing, as well as planting dates, are relatively small to be used as a control measure" to read "Prof McLaren commented that the effects of row spacing as well as planting dates, are too small to be used as a control measure".

      Page 8, item 7.12, Breeding Programme, bullet 3 (sentence structure)

      • "Job descriptions for the different breeders to indicate the specific tasks of the breeders" to read "Responsibilities of the different breeders need to be clarified".
    2. Matters arising

      Suggestion / Resolution:

      Most of the items on the agenda were matters arising and would be dealt with as the agenda progressed. No additional matters were raised.

      1. Resistance to fungicides

        Mr Scholtemeijer referred to Mr Hackland's statement as minuted during the previous meeting as to whether the industry should be concerned about resistance to fungicides or not.

        Dr Flett mentioned that it was important that producers be made aware of possible resistance and that fungicides not providing the necessary controls should be reported.

        Resolution:

        1. The producers are to notify GSA immediately if and when resistance to fungicides should occur, so that the chemical companies could be alerted.

        Dr Liebenberg said using different fungicides was one way of preventing such resistance.

      2. Rust control

        Mr Potgieter enquired as to whether there were legal procedures applicable to producers who did not control rust effectively.

        Resolution:

        1. Chemical companies are to be contacted in order to establish whether legal action could be instituted against producers who did not apply fungicides in the prescribed manner.

          Mr Scholtemeijer

  7. Seasonal feedback

    1. Overview / general discussion

      See document distributed at the meeting for more information with regard to the reporting of soybean rust.

      Questions / Answers / Comments

      Mr Scholtemeijer explained that rust which had been detected and confirmed was reported to the secretary. The report would be distributed to the task team members once the chairperson had approved such distribution.

      Mr Potgieter requested that producers be informed immediately when rust was detected in an area.

      Resolution:

      Reports that rust had been detected are to be forwarded to Mr Louw of GSA, who would then distribute the information to the producers.

      Ms P Kruger

      Prof McDonald indicated that it was important to determine the level of infection before alerting producers that rust had been detected.

      Resolution:

      All rust reports are to contain the contact details of the person who detected the rust, so that said person could be contacted by the producers for additional information, should this be required.

      Dr Flett commented that the producers had to participate in the detection of rust. He said that producers had to report any suspicious symptoms and were to desist from depending on the experts only.

      Resolution:

      Experts should be invited to attend farmers' days in order to communicate the particulars with regard to rust.

      GSA, ARC, Chemical Companies

      Prof McLaren expressed his concern that producers were depending on the trap crops to ascertain whether or not crops were at risk, and whether or not preventative spraying should be applied. He said producers should be informed that the trap crops were not the sole indicator of whether or not rust had been detected.

      Ms Van Jaarsveld stated that producers should be alerted to the alternative hosts for soybean rust. Those areas which experienced low levels of rust infection during the present season could show higher levels of infection during the following season due to these hosts.

      Kudzu vine is currently the only known alternative host locally.

      Mr Jarvie mentioned that soybean was cultivated in areas not traditionally regarded as suitable for soybean planting during the past season. He suggested that trap crops be planted in all of the production areas. He noted that rust spreads easily, whether it over-wintered or not.

      Dr Flett mentioned that the spread of rust to areas where it did not previously occur was a cause for concern. The climatic factors which limited the incidence of the disease were to be identified, as climate determined the extent of the epidemic.

      The question was raised as to whether alternative hosts had to be investigated pro-actively.

      Mr Potgieter emphasised that producers were to call on an expert to confirm suspected rust, as samples could not be sent to the experts due to concerns about spreading the rust.

      The issue of experts possibly spreading rust by moving from one area to another was raised. It was stated that a strict sanitary protocol is maintained – 70% bleach (Jik).

  8. Report back and discussion of research projects
    (electronic copies to be forwarded to Ms P Kruger at krugerp@arc.agric.za)

    1. Fungicide trials – Mr NC van Rij

      No departmental fungicide trials were conducted during the past season (2005/06). It was not deemed necessary to conduct trials as no new classes of fungicides have been registered thus far.

      Rust was found on kudzu at Cedara and it was hypothesised that this could act as a "green bridge" for the pathogen to over-winter on. The researchers would attempt to collect leaves at the end of that winter and test spore germination to see whether there were viable spores at the end of the season.

      Questions / Answers / Comments

      A concern was raised as to when fungicide trials became the responsibility of the chemical companies.

    2. An early warning system for soybean rust (trap cropping) – Ms M Craven

      See Annexure of the presentation for more detail.

      Questions / Answers / Comments

      It was suggested that screening should commence only when rust had been reported in KwaZulu-Natal. The suggestion was seconded by Dr Flett and Ms Tweer. The trials at Greytown were to be monitored by PANNAR and the trials at Cedara by the KwaZulu-Natal Department of Agriculture.

      Resolution:

      1. Ms Craven is to take full responsibility for the project with PANNAR and KZN Provincial Department of Agriculture being co-workers only.
      2. Trials are to be planted at Normandien, Winterton, Vryheid and Piet Retief. Trials are to be visited once rust had been reported by KZN. Ms Craven is to commence with the screening should no reports have been submitted by the end of January.
      3. The status quo for visiting Mpumalanga will remain as it is. In order to add localities, certain localities will have to be removed.
      4. The use of only experimental farms is not practical. The status quo for the planting of trials for the current season is to be maintained.
      5. Two cultivars should be used in the trap crop trials.

      The following answers were provided to questions raised:

      • Cultivars used in the trials were susceptible to rust.
      • Commercial planting dates are to be used to determine planting dates, and the trap crops should be called indicator crops.
      • Trap crop trials are to be carried out under irrigation due to a lack of rainfall in certain areas, which could result in trials being late.
      • In terms of the protocol for minimising the spread of the rust, it was suggested that Ms Craven should consider working her way from the non-infected areas to the infected areas.
    3. Hypothesis statement for breeding for soybean rust resistance – Mr AJ de Lange

      See Annexure of the presentation for more detail.

      Questions / Answers / Comments

      The question was raised as to whether further work would be conducted on the micro and macro elements, with the response being that the intent was to conduct glasshouse work to determine certain interactions.

      Suggestion:

      1. Copper and molybdenum should be investigated in depth due to the huge difference between the inducing and non-inducing soils. Dr de Kock was erroneously indicated as responsible for the suggested action.

        Dr De Kock

      In response to a question as to why the texture had not been indicated in the presentation, it was indicated that the texture had been analysed, but that all the results had not been received from ARC-ISCW.

      Mr Van Wyk commented that the clay percentage in the soil had an influence on the micro- and macro-elements. He said that the potassium level (163.5) could not be considered high when compared to the calcium and magnesium levels. The ratio between calcium, magnesium and potassium for the inducing soil was not as positive as the ratio for the non-inducing soil. The pH of the inducing soil was ten times more alkaline than the pH of the non-inducing soils.

      Mr De Lange confirmed that he was aware of the pH levels and how to calculate those, and that the balance of the inducing soil was better than that of the non-inducing soil. The non-inducing soil had been infected with a lot of rust, while no rust infection occurred in the inducing soil. The issue of whether the balance was important was referred to Prof Du Preez who collaborated on the project.

      The following answers were provided to questions raised:

      The number of races in South Africa is not known. As far as progress made with regard to resistant and tolerant material concerns, F6 has been identified as the tolerant material, and F5 as the resistant material. Selections could be made from this point forward. At the end of the 2006 planting season, the entries will be used in order to conduct a yield test.

      The intention is to plant 136 F6's during the coming season.

      At the end of the season the best performing F6's should be known and only then could these be selected for further evaluation.

      Although both resistance and tolerance will be studied, resistance is considered to be of temporary duration, and would be a short term answer to the problem whereas tolerance is a long term solution.

      Soil microbiology tests could be conducted with regard to the soil differences, and although soil samples have been taken and the soil organisms looked at, the current intention was to only look at the population.

      To Dr Flett's comment that having the inducing and non-inducing soils sprayed would have been ideal to obtain an optimum yield on both and would give an indication of imbalances, the response was that the research had been conducted on both sprayed and unsprayed replicates, that the results had been obtained, but that those had not yet been analysed.

      Dr Flett mentioned that the rust pathogen would usually infect healthy plants to a greater extent than unhealthy plants. The healthier the plant, the more severe the infection would be. If the implication was that an unhealthy situation was required to reduce the rust, the object of the project would be defeated.

      The dry matter of the plants had been determined. The dry matter of the plants in the inducing soil was double that of the plants in the non-inducing soil.

      Dr Liebenberg confirmed that Mr De Lange had been concentrating on the tolerance aspect due to the fact that resistance was linked to the race and if there was more than one race, a specific resistance would not be applicable to the other races.

      To the question on the number of soil samples which had been taken for analysis, the response was that the first soil sample was a global sample with an initial analysis of the two sites, and that detailed soil samples were taken during the second and third seasons. It had been indicated that there were no significant differences between the two seasons, but there were differences between the two sites, as had been shown in the presentation.

    4. Epidemiology trials at UNP – Dr PM Caldwell

      It was reported that a comprehensive report in the form of a thesis had just been examined and would be made available once finalised.

    5. Feedback from other research trials

      1. Chemical Companies

        1. Du Pont (Mr A de Klerk)

          See Annexure of the e-mail from Mr De Klerk for more information.

        2. Syngenta (Dr GM Swart)

          Dr Swart reported via e-mail that Syngenta had nothing new to report at this stage.

        3. Bayer (Mr AG Broeksma)

          Mr Broeksma reported via e-mail that Bayer Crop Science had no new or additional information to share or contribute.

      2. Seed Companies

        1. Pannar – Mr A Jarvie

          Mr Jarvie informed the meeting that Pannar held data on four seasons of rust, and were looking at the effect of rust on yield compared to a sprayed control. They have been able to analyse the effect of cultivar maturity and planting date on yield loss and concluded that neither could be used by farmers as a strategy to consistently avoid rust epidemics. This information is to be be published in a scientific journal during the year. The PRF would be advised.

          Pannar had concentrated its research efforts on tolerance to rust and had a number of high yielding varieties which showed a good measure of tolerance. They have been trying to establish what the source of this tolerance was and have done some work on latent periods, but would have to repeat that work during the winter season.

          A small pilot study on the effect of Roundup herbicide on rust had been conducted in response to published articles on the fungicidal effect of the herbicide on soybean rust. Although Roundup applied early in the season had no apparent effect on the levels of rust, it had a visible effect on premature leaf senescence normally associated with rust when applied after flowering, and particularly at the time when or before the rust was observed. It would appear that the effect of Roundup on rust merited further research.

          Request:

          Mr Jarvie was requested to keep the Task Team informed with regard to when and where the information would be published.

          Ms Craven asked whether she was to continue to use Roundup on the trap crops.

          Resolution:

          Ms Craven is to maintain the status quo on the trap crops with regard to the use of Roundup.

          It was noted that all the cultivars used in the trap crops were Roundup Ready.

          Dr Flett clarified that Ms Craven should continue to use the Roundup Ready varieties and that Roundup could be sprayed for weed control, but should not be sprayed from flowering onwards. The spraying of Roundup should be coordinated with the farmers.

          Resolution:

          The use of Roundup is to be referred to the PRF Technical Committee and should be coordinated with the ARC.

      3. University of the Free State – Ms LC van Jaarsveld

        See Annexure of the presentation for more detail.

        Questions / Answers / Comments

        Are the work that you did and the methodologies that you used similar to those used in the mentioned article?
        This was the first experiment that Ms Van Jaarsveld did. The article quoted made use of different techniques in the glasshouse only.

        Was the plant found to be more susceptible during later physiology or only during the presence of the pathogen?
        The problem was that the pathogen presented itself at a very late stage at Cedara. Samples were taken to look at the full life cycle of the plant.

        Was artificial inoculation used early in the season?
        Artificial inoculation was used in the glasshouse, but was not applied in the field trials. Artificial inoculation would be attempted during the next field trial.

        The question was posed whether there was any correlation between the fact that flowering put stress on the plant, which caused the plant to suffer deficiencies, and the onset of rust which occurred at that stage.

        Prof McLaren answered that the whole issue of post-flowering stress related more to issues like stalk and root rot with the transportation of minerals. How this linked up with a parasite like rust was uncertain.

        Prof Mc Donald commented that in terms of nematode parasitism, the symptoms were not visible until flowering.

        Dr Flett emphasised that it was important to realise that the spores were present in the area and that it was the susceptible stage which actually triggered the beginning of the epidemic.

        Ms Van Jaarsveld mentioned that they were planning to look at the structures of the pathogen rust spores that occurred before flowering compared to rust that occurred later.

        Dr Flett commented that it would be interesting to look at glasshouse conditions under the same climatic conditions which would favour fungal infection at various growth stages, and whether the length of the growth season as well as the rate of infection could be measured. This might give one an indication of when rust actually occurred.

        Ms Tweer said six week old soybeans infected with rust had been observed in field situations under high inoculum pressure.

        Prof McLaren indicated that a distinction needed to be made between infection and colonisation.

      4. Report back on kudzu – Mr ID Lamprecht

        Mr Lamprecht said that the kudzu vine was native to Asia, and was considered to be the third biggest invader plant in the United States. Contact had been made with people knowledgeable on invader plants who indicated that they were not aware of this plant and that it did not currently pose a threat. He had contacted a person who confirmed that he was aware of the specific site where rust had been detected on kudzu and although he wanted to monitor the situation, he had more important concerns at that stage.

        Mr De Lange mentioned that the kudzu vine had been imported to control the erosion of sandy soils in Georgia. During the early 1980's the kudzu vine was already growing in the Barberton and Nelspruit areas. At that stage it was already known as a weed – the current status was unknown.

        Mr Lamprech informed the meeting that the specific site in the lowveld was not far from Lydenburg. Although Lydenburg was not specifically monitored for rust, rust had not been reported.

        Resolution:

        Kudzu vine is to be dealt with as and when required.

  9. General

    1. Strategies

      1. Project Continuations

        1. Fungicide trials – Mr NC van Rij

          Suggestion / Resolution:

          • No fungicide trials had been planned for this coming season.
          • KZN PDA had volunteered to assist in assessing the trap crops in Winterton. This would assist Ms Craven with her long round trips.
        2. An early warning system for soybean rust – Ms M Craven

          Suggestion / Resolution:

          • The cultivars PAN 421 RR and PAN 520 RR are to be used.
          • The total area per trial is to be approximately 500 m².
          • Trial – Producers are to be responsible for planting, maintenance and trial termination.
          • The trial is to be planted at the beginning of October 2006.
          • The localities have not been finalized. The proposed localities were: Eastern Free State – Kestell, KwaZulu-Natal – Winterton (KZN Department of Agriculture), Greytown (Pannar), Normandien, Vryheid and Mpumalanga – Piet Retief, Morgenzon and Kinross.
          • Screening – trials are to be screened on a weekly basis once Cedara had reported rust or from the middle/end of January.
          • Leaf material collected at each locality – laboratory analysis (stereo microscope).
          • The strict sanitary protocol is to be maintained – 70% Jik.
        3. Hypothesis statement for breeding for soybean rust resistance – Mr AJ de Lange

          Suggestion / Resolution:

          • Find levels, interactions and elements involved with the induced soybean rust resistance with trials conducted in the glasshouse. If combinations could be established in the glasshouse, the results are to be reproduced under field conditions.
          • Continue with the breeding programme for rust resistance. Select the best material and start yield testing.
          • Test the tolerant lines at Cedara and select the best 16-25 entries. Commence yield testing.
        4. Other research trials

          University of the Free State – Ms LC van Jaarsveld

          Suggestion / Resolution:

          • Final field trial, as well as greenhouse trial, to determine changes in PR-proteins, phenolics (detailed analysis using HPLC) and total soluble carbohydrates as related to host-physiological changes – to be planted 2006 (November and December at Kenilworth and Cedara) – varieties LS 678 and Stork are to be included in the two planting dates at each location.
          • Optimisation of the settling tower method to screen cultivars.
          • Histological investigation of the effect of glyphosphate on soybean rust and host plants, in the field (Greytown) and in the greenhouse.
          PANNAR – Mr A Jarvie

          Suggestion / Resolution:

          • The work on cultivar evaluation for tolerance is to continue, as well as the work on measuring the latent periods.
          • A rust trap crop is to be planted and Ms Craven is to be advised when the first symptoms have appeared.
          • Interact with the University of the Free State regarding the follow-up trials on Roundup.
      2. New proposals

        1. The use of silicon for the control of soybean rust – Dr PM Caldwell

          See document distributed during the meeting for more detail.

          Dr De Kock explained that Dr Caldwell will start off by doing work in the glasshouse to determine the correct formulation and quantity of silicon, followed by field trials which will be conducted for the different rates of silicon to confirm the results from the glasshouse trials. The intention was to extend this research to sclerotinia on sunflower and groundnuts.

          Questions / Answers / Comments

          Prof McDonald mentioned a few concerns with regard to the proposal: 1) the project title did not promote comprehension of the content of the proposal, 2) paragraph 3 of 'Aim and methodology' – references should be quoted more comprehensively and the initial glasshouse studies did not provide sufficient information, 3) the first aim of optimum quantity and formulation of silicon per hectare in glasshouse studies was contradictory, 4) the extension of the work to sunflower and groundnuts (see the 3rd aim) under point 1 under methodology was confusing and it was not clear how and at what stage the inoculation and assessment would be undertaken in the glasshouse, 5) develop a slow-release formulation of potassium silicate – the methodology was not clearly indicated, 6) point 3 under methodology – how would the field inoculation be done, 7) point 4 under methodology – indicate how the economic assessment would be conducted, 8) point 1 under results envisaged – if silicon controlled pathogenic fungi, what about beneficial species and the effect on the environment, 9) point 2 under value to the industry was an assumption, 10) point 3 under value to the industry was also an assumption – how would the reduced risk of resistance be determined, 11) point 1 under limitations – it was not clear what is meant with the relevance of this information in the larger context to the producers, 12) the proposal should have contained more detail for the less informed, 13) the information generated from the proposal would only be useful to the industry after it had been published scientifically – scientific publications were the key to credibility and 14) ending the project during December in the middle of the growing season, did not make sense.

          Mr Scholtemeijer explained that the agreement with the researchers was that they had to submit a summary of innovative proposed projects. Once it had been determined that the proposal was indeed feasible, a detailed proposal had to be submitted.

          The question was raised whether the concept as such merited calling for a detailed project application. Prof McDonald commented that he was not convinced that the proposal merited a comprehensive study based on what he had read. He said he would have preferred to be presented with some initial data on which he could have based a decision on the feasibility of the project.

          Dr Liebenberg commented that the proposal was not clear on whether the silicon would be applied to the soil or to the leaves. He said the silicon would remain soluble if it was applied to the soil. The proposal indicated that a potassium silicone was to be applied, and it had to be taken into account that the potassium would contribute to the plant cell walls. Some other form of silicon would have to be applied in that instance to rule out the contribution of potassium.

          Prof McLaren commented that references to what had already been reported on in the literature, should have been added to the proposal. He requested that a brief review of the standings in the literature on the subject be made available before a comprehensive proposal was drafted.

          Resolution:

          Comments and suggestions made with regard to the proposal are to be discussed by the PRF Technology Committee.

          Dr De Kock

        2. Generating management-oriented maps of long-term soybean rust-susceptible trends for South Africa – Dr PM Caldwell

          See document distributed during the meeting for more detail.

          Questions / Answers / Comments

          Would this model provide more information than the current indicator trials or to such an extent that the indicator trials could be terminated?

          No. The indicator trials would be retained.

          Prof McLaren emphasised that working with only three or four temperatures would provide an extremely narrow data range. He asked to what extent this data would be checked and repeated in field trials. He suggested that the data should be used to run regressions. Too much data still have to be generated to fill the gaps – the data should be real-time data and not greenhouse data.

          Mr Van Rij explained that the proposed research was not specifically innovative technology research and the gaps would not be filled. Data currently available would be used to determine whether forecasting was possible or not. If the historical data could be used to indicate that historical epidemics had occurred, it should be possible to forecast future epidemics. Should the historical epidemic experiences not be identified by using the historical data, it would be an indication that the proposal was not worth pursuing.

          Mr Jarvie indicated that the data generated during that year in terms of the trap crops, could be used for the model as the trap crop trials provided first class data.

          Dr Flett explained that forecasting models always had problems. Certain diseases were easier to forecast than others. However, whether a model was established or not, some explanation with regard to epidemiology would be provided. He supported the proposal in principle.

          Prof McDonald mentioned a few concerns with regard to the proposal: 1) the proposal should have had a title which made it easier to understand what the proposal concerned itself with, 2) point 1A under 'Aim and methodology' – static long-term information should have been defined, 3) point 2A under 'Aim and methodology' – other countries for the reviewing of literature and knowledge should have been named, 4) point 4A under 'Aim and methodology' – did the spatial (1' x 1') resolutions refer to inches and if so, it should have read (1" x 1") and it should have been stated whether the 50 years of historical data for South Africa covered the incidence of rust, 5) point 5B under 'Aim and methodology' – evidence to be provided with regard to the extremely successful system presently used, 6) point 7B under 'Aim and methodology' – how were the producers going to apply the results generated from the information, 7) point 2 under 'limitations' was of crucial importance, 8) the information generated from the proposal would only be useful to the industry after it had been published scientifically – scientific publications were the key to credibility and 9) ending the project during December in the middle of the growing season, did not make sense.

          Resolution:

          Comments and suggestions made with regard to the proposal are to be discussed at the PRF Technology Committee.

          Dr De Kock

        3. Determining the epidemiological value of resistance or tolerance to rust caused by Phakopsora pachyrhizi in soybean lines – Prof NW McLaren

          Prof McLaren reported that screening of local soybean cultivars had indicated that, despite some variation in rust resistance, all were susceptible to the disease and had no value in disease management programmes. Similarly, tolerance, i.e. yield stability despite rust infection, had not been identified in any of the commercial germplasm. This indicated that rust control in soybean production was totally dependent on chemical control. Although some lines, purportedly with resistance / tolerance to the disease have been imported, mainly from the USA, and evaluated locally, these evaluations have not yielded data of significant epidemiological value nor sources that could add significant value to the soybean breeding program. Most sources of resistance reported on in the literature had one or more of four major genes for resistance, with limited stability when deployed in different environments with various races of the pathogen. There were few reports of rate-reducing resistance. The latter sources of resistance needed to be identified and exploited for rust management. Rate-reducing resistance hampered the rate of disease development and had the advantage of being effective against most races of the pathogen. Concern had been expressed about the potential of resistance within the pathogen population to the widely used triazole-group fungicides and this emphasized the need for the identification and deployment of stable resistance.

          The primary goal of the study was to collect germplasm from the world collection, identify potential sources of resistance to soybean rust and quantify the epidemiological value of the resistance in terms of yield stability under favourable rust conditions. Identified sources of resistance would be fed into the local soybean breeding programme.

          Questions / Answers / Comments

          Dr Liebenberg confirmed that a breeder needed to be familiar with the best sources of resistance. Single gene resistance should not be overly emphasised.

    2. Control strategy

      1. SBR pamphlet 2006

        See the 2006 pamphlet distributed for current information.

        Questions / Answers / Comments

        Was it necessary to update the pamphlet annually?
        One of the purposes of the Task Team was to provide input with regard to current information and to then advise whether it was necessary to revise the pamphlet or not.

        Resolutions:

        • This item is to remain on the agenda in order for the Task Team to determine whether the SBR pamphlet should be revised or not.

        Ms Kruger

        • The information in the pamphlet needed to be revised.
        • Acknowledgement to the persons responsible for updating the pamphlet should be indicated on the pamphlet.
        • ARC contact details to be added to the pamphlet.

        Proff Pretorius and McLaren

        • Electronic copy of the pamphlet to be distributed to Mr Louw of GSA and to be published in SA Grain.

        Ms Kruger

        Suggestion:

        • The pamphlet should indicate the danger of soybean rust and it should be stated that rust could result in yield losses of up to 70%. Mr Lamprecht was erroneously indicated as responsible for the suggested action.

        Mr Lamprecht

      2. Funding of pamphlet

        Ms Kruger informed the meeting that the reason for featuring the ARC logo on the pamphlet was because the pamphlet had been fully funded by the ARC.

        Resolution:

        1. Agreed in principle that the PRF would make a 50% contribution towards the pamphlet expenses.

          Mr Scholtemeijer

        2. The funders, and the fact that the pamphlet was an initiative of the Soybean Rust Task Team, should be indicated on the pamphlet.

          Ms Kruger

    3. Media strategy

      Resolution:

      1. Maintain status quo. Reports to be communicated to Ms Kruger, who will then distribute the report to the SBR Task Team after obtaining approval from the Chairperson.
      2. Media releases should clearly acknowledge the person who submitted the report – credit to be given where due.
      3. Media releases are to be communicated to the Chairperson, who is to be responsible for finalising the media release.
  10. Additional matters

    The new project proposals from Dr Caldwell and Prof Mc Laren was discussed in detail under items 9.1.2.1 to 9.1.2.3.

  11. Date of next meeting

    The date of the next meeting was scheduled for Tuesday, 14 August 2007, KwaZulu-Natal Department of Agriculture & Environmental Affairs, Cedara at 08:30 for 09:00.

  12. Adjournment

    The meeting was adjourned at 13:30 after the Chairperson had thanked everyone for their active participation in the discussions.