Working Group Minutes / Archives / Soybean Rust Task Team / 12 August 2008
Minutes

Soybean Rust working group

meeting held on Tuesday 12 August 2008 at 09h00 at the University of KwaZulu-Natal



  1. Opening

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

  2. Welcome

    The Chairperson welcomed all present, and thanked Dr Caldwell for organis-ing the facilities and venue for the meeting.

  3. Attendance and apologies

    Present

    Mr GJH Scholtemeijer PRF and OAC (Chairperson)
    Mr P Botha GrainSA
    Dr P Caldwell University of KwaZulu-Natal
    Dr M Craven ARC-GCI
    Mr G de Beer PRF
    Dr J de Kock PRF
    Dr M Griessel PRF
    Mr N Hackland BASF
    Mr A Jarvie PANNAR
    Mr ID Lamprecht Mpumalanga Dept of Agriculture
    Prof N McLaren University of the Free State
    Mr G Odendal Syngenta
    Mr FAS Potgieter PRF
    Mr W Roux Bayer Cropscience
    Ms E Harmse PRF: Secretariat

    Absent with apologies

    Mr A Broeksma Bayer Cropscience
    Mr A de Klerck DuPont
    Ms E Dunlop PANNAR
    Dr BC Flett ARC-GCI
    Dr FJ Kloppers PANNAR
    Dr AJ Liebenberg ARC-GCI
    Dr K Mashingaidze ARC-GCI
    Prof AH McDonald ARC-GCI
    Ms S Tweer PANNAR
    Mr NC van Rij KZN Dept of Agriculture
    Mr W van Wyk PRF
    Prof ZA Pretorius University of the Free State

    By invitation

    Prof C Bezuidenhout University of KwaZulu-Natal
    Ms LM van Niekerk University of KwaZulu-Natal
    Ms D Visser University of KwaZulu-Natal

  4. Personalia

    Prof Pretorius was wished a complete recovery following on his recent surgery. Dr Caldwell was wished good health after her recent surgery, as was Dr Griessel, who had undergone a series of eye operations. Dr Caldwell was wished a happy birthday.

  5. Confirmation of agenda

    The agenda was accepted, after the following discussion items were added:

    • Item 8.2: Report on study tour to the United States and South America; and
    • Item 9.1.8.4: BASF.
  6. Approval of minutes – 14 August 2007

    The minutes of the 8th SBR Task Team Meeting held on 14 August 2007 were accepted as a true and fair reflection of that meeting.

  7. Matters arising

    1. Resistance to fungicides
      (Resolution under item 7.1.1 of minutes)

      The Chairperson asked whether any reports of resistance of soybean rust to fungicides had been received. The meeting noted that no such resistance had been reported. The Chairperson reported that the United States and Brazil likewise had not yet experienced the onset of fungicidal resistance to soybean rust, according to reports he had received during his recent study tour to those countries.

      Resolution:

      1. That no resistance of soybean rust to fungicides had been reported.

        Members

    2. Rust control
      (Resolution under item 7.2.1 of minutes)

      The Chairperson reminded the members that this initiative had originated with GrainSA, as they had expressed concern about producers who did not apply fungicides in the prescribed manner, or did not spray against the disease at all, and had requested advice on possible measures that could be instituted against such producers. He said the matter had been discussed at length at a previous meeting of the Working Group, and that it had been concluded that producers could not be forced to spray, and that it would be difficult to enforce application of chemicals according to the registered dosages, rates, and so forth. He mentioned that the matter was referred back to GrainSA, but that no feedback had been received in this regard. He invited comment form Mr Botha.

      Mr Botha reported that the matter had been discussed at GrainSA, which institution had agreed that there were no practical measures which could be implemented to address the issue. He said that producers had, however, been cautioned against neglecting to spray, and warned about the negative consequences of such actions in GrainSA's weekly newsletter.

      Mr Potgieter reported that producers were not negligent in spraying, and were spraying preventatively against rust in areas where the disease presented a problem.

      The Chairperson ruled that the matter be considered as finalized, as the members had taken cognisance of the fact that producers could not be forced to spray against rust if they did not wish to do so.

  8. Seasonal feedback

    1. Overview / General Discussion
      (Resolution under item 8.1.1 of minutes)

      The Chairperson tabled Appendix B, in which the reports on the occurence of rust during the past season were detailed. He noted that rust had been observed at Winterton, Groblersdal, Normandien, Baynesfield near Richmond, Cedara, Greytown, and in the disease garden at the University of KwaZulu-Natal in Pietermaritzburg, while no rust had been reported at Standerton, Wonderfontein, Delmas and Skandinavia Drift. He called on Mr Jarvie to comment on the list, as reported.

      Mr Jarvie said he considered it important to report the absence as well as the presence of rust. The Chairperson added that non-occurence of rust should be reported in areas where rust had occurred before, and not in areas such as Viljoenskroon, in which rust had never been reported. He invited comments on the occurence of rust during the past season.

      Dr Craven reported that rust came in later the further one moved inland, that rust occurred in those areas where it normally presented, but that rust infection was not as severe as the infection experienced during the 2005/2006 season.

      The Chairperson invited comment from Prof McLaren on resolution 8.1.1, minuted during the previous meeting, which stated 'That Prof McLaren discuss the refinement of soybean rust prediction models to make provision for high- and low-risk probability of the occurence of rust, and relating this to the need for preventative spraying, with the Technology Committee of the Protein Research Foundation (PRF)'. Prof McLaren said the issue of the soybean rust prediction model still needed to be investigated and addressed.

      Dr Caldwell reported that Ms van Niekerk's work on management orientated maps of long-term rust-susceptible areas for South Africa, which would be reported on later during the meeting, would be leading to a rust prediction model. She said Ms van Niekerk was using Ms Dunlop's master's degree data and Mr van Rij's weather data in her research. Prof McLaren said there was a lot of data available, which had never been combined into a model.

      The Chairperson ruled that the matter of the refinement of soybean rust prediction models to make provision for high- and low-risk probability of the occurence of rust would be discussed in more detail under discussion item 9.5.

      Resolution:

      1. That the absence as well as the presence of rust be reported in areas where rust had occurred before.

        Members

    2. Report on study tour to the United States and South America

      The Chairperson reported on research and technical support to farmers in Brazil and the USA regarding soybean rust, or Phakopsora pachyrhizi. He said Mr van Wyk, one of the members of the study group, had compiled a brief report of the visit, from which he would mention a few highlights.

      The Chairperson said the climatic conditions that favoured the cultivation of soybeans in the 2006/2007 crop in Brazil, also triggered higher incidences of Asian rust. He said although the rust was highly aggressive in some states, like Rio Grande do Sul and Maranhão, where the first outbreaks took place, damages were not very significant, and that losses amounted to only 2,67 million tons, or 4,5% of the total soybean crop.

      The Chairperson mentioned that the Brazilian agricultural research institution, EMBRAPA, also had an early rust warning system in place, known as the sentinel plots, and had registered 2 980 Asian rust occurences in the entire country during the season mentioned. The states with the most serious incidences were Bahia, Mato Grosso, Paraná and Rio Grande do Sul. He said Dr Godoy, a plant pathologist, had informed them that an Anti-Rust Consortium, that was set up in 2004, currently had more than 100 members, representative of a number of institutions and companies, including some from Paraguay and Argentina. He added that 75 laboratories, where tests were carried out and the disease diagnosed, were also involved in the Consortium. He said the Consortium had its own website (www.consorcioantiferrugem.net) and provided a huge amount of information on the problem of rust infection.

      The Chairperson further quoted from the report, and said an initiative that had contributed towards cushioning the aggressiveness of Asian rust was the so-called sanitary emptiness, which comprised a 90 day period during which the soybean fields remained devoid of any living soy plant. The disease used to be much more devastating, by virtue of winter crops, which acted as 'green bridges' for the fungus, thus triggering the problem in the early stages of the following crop. He said whereas the Brazilians used to plant soybeans throughout the year, the very serious problem presented by the so-called host plants, was addressed by the sanitary emptiness approach. He added that rust needed a live host to survive and propagate, being a biotrophic fungus, and said by resorting to the sanitary emptiness method, the rust inoculum had a reduced incidence on first plantings, and the first outbreaks only took place after the blossoming stage.

      The Chairperson said the disease caused more damage when it initially presented, as there was little knowledge about Asian rust at that stage. He said as knowledge increased, damages decreased at every crop, and that the main losses had been combatted by the use of fungicides, of which 34 have been registered in Brazil to control the problem.

      The Chairperson mentioned that the use of early planting cultivars was recommended to help reduce the incidence of Asian rust, with seeding tak-ing place in the early days of the recommended period for every region. He said research on resistant varieties commenced during the 2001/2002 season, when the presence of Asian rust was first detected in the Brazilian soy fields, and added that resistant cultivars were due for release on the market in the near future. He reported that the Embrapa Soy variety, which was created by the institution's Genetic Enhancement programme, was now in the registration phase, and had undergone several tests with regard to productivity, stability, cycle, plant height, and tolerance/resistance to other diseases. He said the multiplication of the basic seed was scheduled for the 2008/2009 season, with commercialization at grower level expected to commence at the 2010/2011 crop.

      The Chairperson reported that he was highly impressed with the University of Viçosa, which he considered to be one of the best agricultural universities he had ever visited. He said work on resistance in host plants was the particular focus of the research on rust resistance and added that over a thousand host plants had already been identified in Brazil, which made research even more complex. Researchers of note associated with this university include Profs Brommonschenkel and Sediyama, a soybean breeder, whose work on Asian rust is based on what he calls a 'slow developing rust', that afforded produc-ers a three week window in which to control the disease. He further reported that Prof Rodrigues of the same university was working on the topic of the use of silicon in the control of Asian soybean rust, which is to be reported on at the international Silicon Congress to be presented during October at the Wild Coast. He said Prof Rodrigues would also address a meeting of the Soy-bean Working Group in Rivonia, to which the members of the Soybean Rust Working Group, among others, would be invited.

      With regard to the American leg of the trip, the Chairperson reported that soybean rust was first detected in the States in November 2004. He said the disease had caused the most significant damage in the Southeast, although it had been detected in a number of soybean-producing states. He mentioned that information is sourced from thousands of sentinel plots, located all over the different states, and reflected on a website, which is updated on a daily basis. (www.sbrusa.net) He considered this to be a very powerful tool for use by producers and other interested authorities.

      The Chairperson mentioned that a visit was also paid to the Monsanto headquarters and research facility, where much research on rust resistant cultivars was done, using one of the biggest germplasm banks in the world. He thanked Dr Caldwell for facilitating the contact made with Prof Hartman at the University of Illinois and others at the University of Iowa. He said Prof Hartman's research focussed on applied and basic research in three areas of soybean pathology that will aid in devising efficient control strategies, viz. the biology and ecology of soybean pathogens with emphasis on pathogenic variation; basic epidemiological concepts related to disease development and spread, and the way in which pathogens and the diseases they cause affect the quality and quantity of soybean yields; and finally, investigation of the existence, nature and genetics of host resistance in soybean germplasm and in other Glycine species. He reported that Prof Hartman was currently involved as project leader on a number of research projects, which included characterization of soybean pathogens and disease management, monitoring airborne transport of SBR spores, fungicide management of soybean rust, and the development of rust-resistant soybean lines and understanding the variability of the soybean rust fungus Phakopsora pachyrhizi.

      The Chairperson mentioned that Prof Yang of the University of Iowa concen-trated his research on partial resistance as well as slowing down disease de-velopment. He concluded his verbal report on the study tour to the United States and Brazil by issuing a strong recommendation that the local soybean interest group should stay abreast of research conducted in countries such as Brazil, and especially in the USA. He invited comment from the members.

      Dr Caldwell raised the issue of single gene resistance, and the pathogen's ability to easily overcome this vertical resistance. She said multiple gene resistance would be far more effective in combatting the disease, although it would be more expensive to produce. She noted her surprise at the success attained with the so called sanitary period, as she had noticed, during a tour of Brazil, that the kudzu vine, a host plant that was extremely invasive and grew very rapidly, did not encroach on the soybean fields. The Chairperson explained that the sanitary period resulted in less damage after the 90 day period, which was considered to be an improvement, but not a solution, to the problem. Mr Jarvie raised the issue of farmers spraying or not spraying, and said the inoculum pressure would determine whether the disease spread or not. Dr Caldwell mentioned that the inoculum pressure related to grey leafspot on maize seemed to be down, because farmers were spraying, and planting tolerant varieties at the correct times to avoid the pathogen. She raised the possibility that soybean rust inoculum pressure had also decreased, as the disease was not as devastating as it had been in 2002. Prof McLaren said the inoculum pressure had probably decreased because farmers were spraying. He mentioned that not much inoculum was needed, with a disease like soybean rust, which had a very short cycle, and produced such a multitude of spores, that it could only be delayed a couple of days by reducing inoculum, as it built up quickly.

      Mr Jarvie reported on a very nice crop just past Seven Oaks he had observed the past season. He said the farmer had sprayed his crop, but that the tractor driver had missed a swathe in his first turn, and missed the swathe again during the second spraying as he was following in his previous tracks. He expressed his amazement at the dramatic effects missing the swathe had.

      The Chairperson invited Mr Jarvie to elaborate on the international breeding situation, to which Mr Jarvie responded by saying he would do a presentation on this later during the meeting. Prof McLaren reported that Virginia Tech were not getting good results with their screening proceedings, and were placing much emphasis on biotechnology, as they had access to incredible facilities for biotechnological transformations and so forth, and were going laterally rather that following the traditional approach to breeding.

      The Chairperson ventured the opinion that the various seed companies and institutions were far more advanced than they were prepared to admit, as they were quite prepared to convey the results of progress attained thus far. He had little doubt that gene stacking would be effected, and that it would only be a matter of time before soybean rust resistant cultivars were released.

      Noted:

      1. That the final report of the study tour to Brazil and the United States would be made available to the Soybean Rust Working Group once finalized.

        Members

  9. Report back and discussion of research projects

    1. An early warning system for soybean rust (trap cropping) – Dr M Craven
      (Resolution under item 10.1.1 of minutes)

      See annexure for more detail of the presentation.

      The Chairperson called on Dr Craven to do a presentation on the project 'Establishment of an early warning system for soybean rust'. Dr Craven reported that work on the project had commenced in the 2005/2006 season, with the main aim of establishing a way to warn producers of the occurence of soybean rust. She said planting the trapcrops timeously was experienced as a problem locally, as planting dryland trials had to be delayed, until the first rains fell, as opposed to the sentinel crops planted in countries where the rainy season starts one month ahead of planting time. She said the fact that she had to drive around and do the screening herself, and running the risk of spreading the spores, was also problematic. She mentioned that extension officers were responsible for collecting and mailing samples from sentinel crops for testing to laboratories by post, which she considered to be advantageous to sentinel crops planted in countries such as Brazil. She said the project title indicated that the system was being established, and added that she was always open to new ideas with regard to the protocol, screening, trials and so forth. She announced that the project is to be discontinued at the end of March, and that the ARC would like to get a functional system up and running by that time.

      During the presentation, Dr Craven elaborated on the trial protocol, which included two cultivars, one being a short and one a long season grower. She said although producers were advised to plant the seed by the beginning of October, planting of the trapcrops rarely commenced before the third week of October. She said inconsistency in planting dates resulted in her having to screen one trial for a longer period than the others. She said ten localities had been planted during the past season, of which three trials had been lost due to problems with the collaborators. She indicated that the most important trials would probably be planted under irrigation in the coming season.

      Dr Craven also elaborated on the screening protocol employed in the project. She said trials were screened on a weekly basis starting on 16 January, except if Mr van Rij observed rust at Cedara before this date, in which case screening commenced with immediate effect. She mentioned that the sampled material was left in a sealed bag for two to three days after arrival at Potchefstroom, and re-screened, in the event that rust developed within that period of time.

      In response to a question on the total area per trial, Dr Craven confirmed that the plot size was less than 2 000 m². She said the initial idea of the bigger the better was found to be unrealistic, as only one person carried out the screening. Mr Jarvie said he thought 5 m2 plots would be adequate, as these could be planted in a producer's vegetable garden and watered with watering cans. This could result in more plots, of a more manageable size, being planted. The meeting noted this suggestion. Mr Jarvie suggested that a journal article be published on Dr Craven's work.

      Dr Griessel asked what led to the decision to terminate the project at the end of the 2008/2009 season. The Chairperson said although the project had run for four years, this did not imply that a new project, which would in reality be a continuation of the old project, could not be applied for. Dr Griessel considered the project to be invaluable, and said a lot had been accomplished with the project. The meeting were in agreement that the trapcropping project had to be continued.

      Dr Craven said the ARC could not commit itself to the project for another four years. She said the aim had been to establish a protocol, to identify localities, to set up a screening protocol and so forth. She said the ARC did not have the capacity to carry on with the project, as this implied sending out a person for two days a week over a period of three months to do the screening. She said this meant that she lost any number of days in which she could have done research, and published papers and articles.

      The Chairperson undertook to raise the matter with the top management of the ARC. He ruled that the matter be referred to the Technology Committee, as the members were ad idem that the continuation of the trapcropping trials was essential.

      Resolution:

      1. That the suggestion that the total area per trial planted as part of the project 'Establishment of an early warning system for soybean rust' be reduced to 5m² plots be noted.

        Dr de Kock

      2. That the matter of the continuation of the trapcropping trials be referred to the Technology Committee of the Protein Research Foundation for urgent attention.

        Mr Keun

    2. Hypothesis statement for breeding for soybean rust resistance – Dr A Liebenberg
      (Resolutions under item 9.2.1 of minutes)

      The Chairperson referred the meeting to resolution 9.2.1 minuted during the previous meeting, which stated 'That the issue of the lack of capacity in the soybean breeding programme be taken up with Dr Moephuli'. He said it had been reported that the soybean breeding programme had been abandoned, as it was felt that progress was not satisfactory, and also because much progress had been made in North and South America.

      The Chairperson confirmed that the breeding programme would be brought to a logical conclusion, with all the promising material from the programme to be evaluated in the coming season. He said the ARC had been instructed to breed for cold tolerance, drought, nematode resistance and rust resistance. He reported that the nematode work would be continued. He said all of the material will be evaluated at the end of the coming season, following which discussions would be had with interested parties with the view to making the material available and developing it further.

      The Chairperson said cultivars were precisely classified per region in America, and that it was hoped that the same type of classification could be established for local application. He considered the cultivar evaluation trials to be valuable to the industry, and said the intention was to also plant strip demonstration trials on selected producers' farms. He said this would be done with the view to promoting soybean production amongst the farming community. He mentioned that it was the intention to involve institutions such as the agricultural research institutions in Argentina and Brazil in identifying suitable international soybean cultivars for local production.

      The Chairperson said the current area of approximately 200 000 hectares planted to soybeans in South Africa did not offer a big seed market to the local companies. He said it was the PRF's intention to vigorously promote the soybean industry, and hoped to significantly expand the area planted to soybeans within the medium term, and was awaiting the final go-ahead of the Coega plant, which would facilitate the processing of a million tons of soybeans. He said there was a huge local market for protein for use in animal feed, for oil and for soy-oilcake, and said the main aim of the PRF was to produce enough protein for animal feed locally to be self-sufficient.

      The Chairperson said although there was not sufficient seed available locally for the proposed expansion of the soybean industry in the coming season, the matter would hopefully be resolved by the following season.

    3. Epidemiology of soybean rust – Dr PM Caldwell
      (Resolutions under item 9.3.1 of minutes)

      The members noted the contents of the abstract of Ms Nunkumar's thesis.

    4. The effect of silicon on the control of Phakopsora pachyrhizi (soybean rust) on soybeans – Dr PM Caldwell
      (Item 9.4 of minutes)

      See annexure for more detail of the presentation.

      Dr Caldwell introduced Ms Visser, and said she was basing her doctoral studies on the effect of silicon on the control of Phakopsora pachyrhizi. During her presentation, Ms Visser explained that silicon was the big buzz word in plant pathology, and that the environmental concerns about the use of herbicides, pesticides and fungicides had given rise to the recent move to organic farming. She said silicon (Si) was regarded as an organic farming product. She gave a short account of current Si-research, and mentioned that minimal research was being done on the use of silicon in soybean production. She proceeded to report on the research work she had done during the previous growing season, giving details of the field trial. She said a hydroponics trial and a drench trial was carried out in order to identify where in the plant and at what concentration Si accumulated, and gave preliminary results for those trials. She mentioned that she also intended to identify the plant defense proteins that are catalysed by Si. She concluded her presentation by detailing the work that had to be completed in 2008 and 2009.

      The Chairperson congratulated Ms Visser on being awarded her Masters degree cum laude. He wished her well with her doctoral studies, and expressed the PRF's delight that she had decided to do ground-breaking research on soybeans. He opened the floor for questions and comments.

      Mr Jarvie said he was surprised that Ms Visser had only tested leaves and stems for Si-accumulation, and had not tested the seed levels of Si. He said accumulation of Si-levels in the seed may support conditioning of the crop for the following season. Dr Caldwell mentioned that Prof Laing had said that it was often not the amount of silicon put down that was important, but rather the frequency with which Si was added that had the effect. She said the intention was to get in early during the next season, to test the validity of Prof Laing's remark. She said multiple applications were costly, and reported that Prof Laing was investigating a slow-release silicon, which would not require as many applications.

      The Chairperson remarked that the principles had to be established in the first instance, following on which the fine-tuning could be effected. Dr de Kock said silicon was regarded as a friendly element, and that he doubted whether applying too much silicon would have a negative effect on the crop the following year. Dr Griessel asked why the plants, to which 2 000 ppm silicon had been applied, looked sick and weak, compared to the plants to which silicon had been applied in weaker concentrations. He said there had to be some form of interaction between the various macro- and micro nutrients if soil contained too high a level of a particular element in the soil. He asked whether an explanation was provided in the relevant literature on the physiological reasons why silicon was considered to offer solutions to the problem of combating the various fungal diseases.

      Dr Caldwell said silicon triggered the defense response known as systemic acquired resistance. She added that it had been established, by means of electron microscopy, that the silicon was deposited in the lower epidermis of the plant, and formed a defensive barrier through which the fungus would have to penetrate.

      Mr Hackland said he found the reference to organic farming misleading, as silicon was not an organic molecule at all.

      The Chairperson concluded that this was a novel and exciting approach to soybean rust, and wished Ms Visser well with her research.

    5. Generating management-orientated maps of long-term soybean rust-susceptible areas for South Africa – Dr PM Caldwell
      (Item 9.5 of minutes)

      See annexure for more detail of the presentation.

      Dr Caldwell reported that Ms Lauren van Niekerk was currently studying towards obtaining her Masters degree, with Prof Bezuidenhout as supervisor and herself as co-supervisor. She said the work that Ms Nunkumar had done in the dew chamber on the epidemiology of soybean rust, together with Mr van Rij's work on the automatic weather stations, and Ms Dunlop's data on chemical control of soybean rust, would be put into the model, so as to generate maps of long-term soybean rust-susceptible areas for South Africa.

      In her presentation, Ms van Niekerk explained the aim and objectives of the project. She reported that she had completed the literature review, had done a principle component analysis course and a course on agrometeorological principles, and had identified, and was working on, algorithms.

      The Chairperson opened the presentation for questions. Mr Jarvie said he had seen a world map, detailing areas that would be prone to soybean rust infection regardless of whether inoculum was present or not. He considered the South African coverage to be rather coarse, and said Ms van Niekerk's proposed model would be more acceptable. He reported that the world map indicated that the whole of the South African eastern seaboard, from Kosi Bay to Cape Town, was considered to be susceptible to soybean rust.

      In response to a question by Dr de Kock, Ms van Niekerk said she doubted whether the maps would replace the soybean rust indicator trials, but that she thought the maps would prove to be very useful as a general indicator. Prof Bezuidenhout was in agreement on this. He said Ms van Niekerk's work would serve as a blueprint to establish an early warning system. He explained that half of the data Mr van Rij had collected for the detailed climate record would be used to build the model, while the other half would probably be used for verification.

      The Chairman thanked Mrs van Niekerk for her presentation and Prof Bezuidenhout for attending the meeting.

    6. Determining the epidemiological value of resistance to rust caused by Phakopsora pachyrhizi in soybean lines – Prof N McLaren
      (Resolutions under item 9.6.1 of minutes)

      See annexure for more detail of the presentation.

      Prof McLaren reported that the emphasis of his research over the past year had been to identify resistance and the components of resistance. He said the three principal studies had been identifying components of the epidemic which contributed to disease development and concomitant yield loss, components of resistance in cultivars, and components of resistance in lines.

      Prof McLaren said he had undertaken a crop loss analysis, using some of the old data, and had measured factors such as date of first detection of the disease, the affected leaf area, the rate of development and so forth. He said he had reached the conclusion that area under disease progress curve (AUDPC) is an integrated function of relative life time at disease onset, rate of disease development, and premature defoliation, while yield loss was a function of AUDPC, and measurement of yield loss was a function of spray efficiency.

      Prof McLaren summarised the reaction of South African cultivars to rust caused by Phakopsora pachyrhizi by saying that although differences in disease severity were recorded between the cultivars, none of the cultivars were sufficiently resistant to be of economic value and to avoid the need for chemical control, but that results confirmed the importance of time of disease onset, defoliation and apparent infection rate as the main factors in rust severity and yield loss.

      With reference to future research, Prof McLaren said he intended to screen sources for potential rust reducing characteristics, in both the greenhouse and the field. He said he also intended to study the epidemiological impact of resistance, and to do a rust collection, looking at races and differentials. In addition, he intended studying the mechanisms of resistance, and various interactions between planting data, weather and onset of disease.

      The Chairperson opened Prof McLaren's presentation for discussion. In response to a question by Dr Caldwell, Prof McLaren confirmed that he could not yet recommend a specific variety for planting in a specific area, and would advise farmers to plant those varieties with stronger plants which had the better yield. He agreed that spray efficiency could vary, depending on the type of application utilised, such as aerial application versus a high volume type of application. Mr Hackland suggested that timing of application relative to level of infection could also be an important factor with regard to spray efficiency.

      Dr de Kock asked whether plant breeders would be interested in the screening of the material, as Prof McLaren had previously stated that his work would be supplementary to a breeding programme. He said in view of the fact that the PRF had decided to withdraw from the breeding programme, another home would have to be found for Prof McLaren's material. Mr Jarvie said he would certainly be interested, as his approach to breeding was not in terms of resistance but in terms of tolerance. Dr Griessel referred to Prof McLaren's remark that this was a numbers game. He said the variations were, however, not big enough to do selections. Prof McLaren said the lines had been included on the basis that they may yield some levels of resistance. Dr de Kock asked whether it would be worthwhile continuing with the project.

      The Chairperson referred to the resolution minuted during the previous meeting, which stated 'that Prof McLaren look into the possibility of providing some quick methods which could be applied to select for actual resistance, especially with regard to horizontal resistance'. He said it was clear research had to be undertaken with the view to future practical application in the soy industry. He said Prof McLaren knew where he was heading, and what he planned to achieve, and invited comment from Prof McLaren.

      Prof McLaren reiterated that the project was a numbers game, with no guarantees that promising material would be found. He said if one did not look, however, one would not find. Dr Griessel said he found Dr de Kock's remark to be very valid, and asked if the major international seed companies would not have a better chance of success with such a project.

      The Chairperson said the breeding programme would be run to its logical conclusion, and that more still needed to be done on the project. He suggested that Prof McLaren carry on with his research, but that a decision be made the following year on whether the level of progress achieved thus far, and the results attained, would be of benefit to the soybean industry.

      Resolution:

      1. That the project 'Determining the epidemiological value of resis-tance to rust caused by Phakopsora pachyrhizi in soybean lines' be revisited the following year, in order to decide whether the level of progress achieved thus far and the results attained would be to the benefit of the soybean industry.

        Prof McLaren
        Members

    7. University of the Free State, Ms LC van Jaarsveld
      (Item 9.7 of minutes)

      Prof McLaren reported that the final report on Ms van Jaarsveld's project would be made available as soon as Prof Pretorius had returned to the office.

      Noted:

      1. That the final report on Ms van Jaarsveld's project would be made available as soon as Prof Pretorius had returned to the office.

        Members
        Mr Keun

    8. Feedback from other research trials

      1. Chemical Companies

        1. Du Pont

          No feedback had been received.

        2. Syngenta (Mr G Odendal)

          Mr Odendal said research was in the pipeline, but that he had nothing new to report on. He noted that the Office of the Registrar caused endless problems by not tending to registration applications timeously.

          Resolved:

          1. That the issue of delays at the Office of the Registrar would be followed up.

            Mr Keun

        3. Bayer (Mr W Roux)

          Nothing new to report on.

        4. BASF (Mr N Hackland)

          The Chairperson called on Mr Hackland to handle this agenda item, as he had stated earlier that he had an announcement to make. Mr Hackland reported that a new product, Abacus, had been registered on soybeans for the control of Phakopsora pachyrhizi, to be sprayed preventatively at 1,0 lt/ha, before the first signs of disease development is noticed (normally at onset of flowering) and repeated 21 to 28 days later. He said the shorter interval of 21days was to be applied when high disease pressure is expected due to weather conditions that favour disease development. He announced that this programme application would also reduce the incidence of Sclerotinia sclerotiorum. Mr Hackland said Abacus could be applied as a ground application, as a full cover spray in 300 to 500 liters of water per hectare, or as an aerial application, as for the preceding recommendations, in 30 to 40 liters of water per hectare.

          The Chairperson expressed his delight at the announcement. He said the registration of Abacus against soybean rust would be announced on the PRF's website. He suggested that Dr de Kock consult with Mr Hackland on the possibility of running a few sclerotinia demonstration trials, using Abacus.

          Resolved:

          1. That the registration of Abacus against soybean rust, and the fact that this programme application would also reduce the incidence of Sclerotinia sclerotiorum on soybeans would be announced on the PRF's website.

            Mr Keun

          2. That Mr Hackland be consulted on the possibility of running a few sclerotinia demonstration trials, using Abacus.

            Dr de Kock

      2. Seed Companies

        1. Pannar – Mr A Jarvie

          See annexure for more details of presentation.

          The Chairperson called on Mr Jarvie to report on progress with regard to breeding for tolerance to soybean rust. Mr Jarvie said most of the soybean rust research around the world was focussed on resistance. He added that every single source of resistance exposed commercially to date has been defeated, and that even combinations of two or more stacked genes have a high risk of failure. He said Pannar had decided to rather look at tolerance as opposed to resistance.

          Mr Jarvie outlined the objectives of the research, and explained how the material was selected and what methods were followed. He said it had been concluded from the research that little or no progress would be made if % yield loss were to be used as a criterium. He quoted Glen Hartman's statement 'What we are looking for are high yielding lines that have stable yields under rust pressure', and said this directed Pannar's search for parameters that would quantify the yield loss and put a value on yield stability. He reported that two measures were used, viz. the Lin and Binns superiority measure, and the ecovalence stability measure. He concluded his presentation by saying that applying the stability statistics was very simple, and said yield loss was relative to the best adapted variety in the area, which is then sprayed to achieve this maximum potential.

          The Chairperson thanked Mr Jarvie for a stimulating presentation. In response to a question raised by the Chairperson, Mr Jarvie confirmed that the research did not involve genetic manipulation.

        2. Monsanto

          The members noted the content of the report on the Monsanto pot trials conducted at the University of KwaZulu-Natal, Pietermaritzburg, included as Annexure H.

  10. General

    1. Strategy for coming season – various research projects

      1. Project Continuations

        • The use of silicon for the control of soybean rust, Dr PM Caldwell: project to be reported on the following year;
        • Generating management-orientated maps of long-term soybean rust-susceptible trends for South Africa, Dr PM Caldwell: project to be reported on the following year;
        • Determining the epidemiological value of resistance or tolerance to rust caused by Phakopsora phakhyrhizi in soybean lines, Prof N McLaren: project to be reported on the following year;
        • The link between plant physiology and rust pathology in soybean, Ms LC van Jaarsveld: final report to be compiled and presented at next meeting;
        • An early warning system for soybean rust, Dr M Craven: to continue for the following season. Project continuation to be investigated.
      2. Other research trials

        None reported.

      3. New research proposals

        None received.

    2. Control strategy

      1. SBR pamphlet

        The Chairperson reminded the members that there had been a debate on certain changes and amendments to the soybean rust pamphlet at the previous meeting. He said these related to the dosage rates, that were not indicated on the table, and Ms Tweer's contact details, that had changed. He remarked that the registration of Abacus also had to be added to the pamphlet, and suggested that the issue of the proposed changes and amendments to the SBR pamphlet be referred to the Technology Committee of the PRF, to be attended to before January 2009.

        Resolved:

        1. That the issue of the proposed changes, amendments and additions to the SBR pamphlet viz. the inclusion of dosage rates, changes to Ms Tweer's contact details, and the announcement of the registration of Abacus, be referred to the Technology Committee of the PRF, to be attended to before January 2009.

          Mr Keun
          Technology Committee

    3. Media strategy

      The Chairperson said any newsworthy information on soybean rust would continue to be released via GrainSA, via SMS, and electronic mails. The members were in agreement that the status quo on the media strategy should be maintained.

  11. Additional matters

    1. Soybean Rust Working Group: the way forward

      The Chairperson tabled a letter he had received from Dr Liebenberg, in which he had apologized for not attending the meeting of the Soybean Rust Working Group that day. He said Dr Liebenberg was apparently of the opinion that it served no purpose to attend the meeting in view of the fact that the soybean breeding programme had been terminated. He remarked that the members of the working group represented a wide spectrum of interest groups, and asked whether the members wished to continue meeting as a working group on an annual basis, and opened the matter for discussion.

      Mr Jarvie said a soybean industry of 500 000 hectares could not be supported if there were to be no local expertise. He ventured the opinion that local expertise was incredibly important and that it was essential for this to be developed. Prof McLaren considered the working group to be a very good forum, also because it allowed academics to be exposed to the commercial world. Dr Caldwell said she considered the meetings very worthwhile.

      The Chairperson said every effort was made not to let the soybean industry slide, also by retaining the services of retired academics and bringing knowledgeable persons, who had left the research institutions' service, back into the fold.

  12. Date and venue of next meeting

    The date of the next meeting was scheduled for 17 August 2009, at the University of KwaZulu-Natal at 08:30 for 09:00.

  13. Adjournment

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