Working Group Minutes / Sclerotinia / 23 July 2008
Minutes

Sclerotinia Working Group

Meeting held on 23 July 2008 at 10:00 at the offices of the Oilseeds Industry and the Protein Research Foundation in Rivonia



  1. Opening

    The meeting was opened with a prayer offered by Mr GJH Scholtemeijer.

  2. Welcome

    The Chairperson, Mr GJH Scholtemeijer, welcomed all present, and extended a special word of welcome to Messrs Engelbrecht and Marais, who were both attending a meeting of the Sclerotinia Working Group for the first time.

  3. Attendance

    Present

    Mr GJH Scholtemeijer PRF (Chairperson)
    Mr P Botha GrainSA
    Dr P Caldwell University of KwaZulu-Natal
    Dr J de Kock PRF
    Mr W Engelbrecht Pioneer
    Mr N Hackland BASF
    Mr JS Marais Philagro
    Prof NW McLaren University of the Free State
    Mr FAS Potgieter OAC
    Mr J Potgieter Pannar
    Mr GJ Pretorius OPDT
    Mr H van der Westhuizen Philagro SA
    Mr A van Vuuren NWK
    Mr W van Wyk PRF-Contractor
    Mr GTduT Keun CEO: PRF and OPDT / OAC
    Ms E Harmse Secretariat
    Prof D Berger University of Pretoria
    Dr M Craven ARC-GCI
    Dr BC Flett ARC-GCI
    Dr M Griessel PRF
    Prof AH McDonald ARC-GCI
    Mr B Tollig BASF
    Mr S Venter Syngenta

  4. Personalia

    Dr Caldwell was wished a complete recovery following on her recent surgery. Best wishes were conveyed to Dr Griessel during the recovery period following on a series of eye operations he had undergone. Wishes for complete recovery were conveyed to Prof Sakkie Pretorius. Mr Johan Potgieter's recovery from ill health was acknowledged with gratitude, and he was wished continued good health. Mr Pretorius was wished well after his recent eye surgery. Condolences were conveyed to the family of Ms Bloem from the National Institute of Plant Pro­tection, who had passed away. Dr Caldwell was congratulated on being awarded the distinction of 'Distinguished Teacher' by the University of KwaZulu-Natal.

  5. Confirmation of agenda

    The agenda was accepted as it stood, with the addition of

    Item 7.1 Database of expertise: sclerotinia;
    Item 7.2 Sunflower Symposium 11 September 2008: and,
    Item 7.3 Silicon Congress; and the amendment that
    Item 6.7 Visit to the Americas: is to be reported on after the general overview of sclerotinia occurence during the past season had been concluded.

  6. Approval of minutes

    1. Minutes of 18 July 2007

      Resolved:

      1. That the minutes of the meeting of the Sclerotinia Working Group held on 18 July 2007 be adopted as a true and fair reflection of that meeting, after the following changes had been effected:

        Page 3, Item 6.1, second paragraph, last sentence: 'Mnr Potgieter wys daarop dat daar groot verskille was in dag- en nagtemperature gedurende die afgelope seisoen...' amend the sentence as follows 'Mnr Frans Potgieter wys daarop dat daar groot verskille was in dag- en nagtemperature gedurende die afgelope seisoen...'

        Page 4, Item 6.2, paragraph (ii), first bullet point: 'Ten opsigte van Sumisclex SC saam met 'n benattingsmiddel is daar een suksesvolle proef saam met Break Thru te Winterton gedoen, met die bevinding dat Break Thru bydra tot beheer, en selfs beter presteer as die hoër of volle dosis Sumisclex SC...' amend the sentence as follows 'Ten opsigte van Sumisclex SC saam met 'n benattingsmiddel is daar een suksesvolle proef saam met Break Thru te Winterton gedoen, met die bevinding dat byvoeging van Break Thru bydra tot beheer, en selfs beter presteer as die hoër of volle dosis Sumisclex SC...'

        Page 11, Item 6.8, second paragraph, second sentence: 'Mnr Potgieter dui aan dat die kans so laag as 0,05% is, en dat sonneblomsaad boonop met chemiese middels teen sclerotia behandel kan word' amend the sentence as follows 'Mnr Johan Potgieter dui aan dat die kans so laag as 0,05% is, en dat sonneblomsaad boonop met chemiese middels teen sclerotia behandel kan word', and Page 12, Item 7.2: correct all references to Mr Potgieter by indicating that Mr Johan Potgieter was addressing the issue of research work related to the OxOx-gene.

  7. Matters arising from the minutes of the meeting held on 18 July 2007

    1. General overview

      The members of the Working Group were invited to comment on their observation of the occurence of sclerotinia on sunflower and soybeans during the past season. During the discussion it was noted that:

      • The Crop Estimates Committee conducted an annual survey amongst producers on the occurence of sclerotinia, and that the findings would be made available the following week.
      • Although there had been a relatively limited occurence of sclerotinia in the North West Province, a few severe cases of infection had occurred, with in excess of 90% infection observed on certain fields of sunflower.
      • Sclerotinia infection was observed in the stems of sunflower at an early stage of the season in North West Province.
      • Sclerotinia infection on soybeans in the North West Province was considered to be negligible.
      • Sclerotinia infection on sunflower had for the first time invaded the area to the west of Koster.
      • Charcoal rot (Macrophomina phaseolina), which was unrelated to sclerotinia, was considered to be a serious problem, world wide, and occurred in sandy, high-temperature soils, especially when drought stress conditions were prevalent, resulting in early die-down of the plants. This disease could very well be confused with stem sclerotinia.
      • Stem and root sclerotinia occurred early in the season in Mpumalanga, with as much as 40% to 50% of the plants dying in certain sunflower plantings. High rainfall during the flowering period resulted in sclerotinia head rot. Sclerotinia infection was observed in certain sunflower plantings in Lichtenburg, while sclerotinia infection had not been observed in the Free State.
      • Serious sclerotinia infection was observed on a farm in Kinross, with a 70% to 80% infection measured in certain lands. Sclerotinia infection had previously occurred on this farm.
      • No significant sclerotinia infection was observed at Greytown, Radium and Brits.

      Mr van Wyk reported on the sclerotinia research conducted in South America and in the United States. He said Dr Cláudia Vieira Godoy had informed the group on the development and control of the disease during their visit to the Brazilian Agricultural Research Corporation (Empresa Brasileira de Pesquisa Agropecuária or EMBRAPA). He reported that Dr Vieira Godoy had underlined the importance of using seed free of sclerotia, had recommended that seed treatment was effected by means of Benlate, and that wider rows were to be used when planting. He said research on the use of the trichoderma fungus in the control of sclerotinia sclerotium had indicated that good control of sclerotinia rolfsi or sclerotinia blight could be attained by this means.

      Mr van Wyk reported that Prof Tuneo Sediyama of the University of Viçosa was breeding for grain and seed quality and resistance to diseases. He added that sclerotinia was, however, still considered to be a big problem, and that the research team concentrated their efforts on managing the disease by, for example, breeding cultivars with narrow leaves, for better penetration of fungicides.

      Mr van Wyk continued his reporting, and said a visit was paid to Dr Linda Kull of the University of Illinois during the USA leg of the tour. He said Dr Kull informed the group on the production research undertaken at that institute. He mentioned that an annual publication 'Varietal Information Program for Soybeans' (VIPS) was produced, which contained information on the resistance level of cultivars to diseases such as Phytophthora root rot, sudden death syndrome, soybean mosaic virus, aphid infestation, green stem disorder and soybean cyst nematodes. He noted that sclerotinia had not yet been included in the publication. He mentioned that approximately 600 varieties from some 60 seed companies were screened, and that some twelve conventional public varieties were included in the trials conducted with the view to gathering data for publication in VIPS. He said Dr Kull had noted the importance of screening for sclerotinia throughout the season, and considered sclerotinia to be a tough pathogen.

      Mr van Wyk mentioned that Dr XB Yang, a specialist on soybean rust and sclerotinia, associated with the University of Iowa, had informed the group that single gene resistance in soybean had not yet been identified, but that single gene resistance had, however, been identified in sunflower, although this was complicated by low yield performance. He added that work was currently in progress on identifying multi-gene resistance.

      Mr van Wyk said Dr Yang had divulged information on a biological product Constans WG (water dispersable granules), which is based on the antagonistical fungus Coniothyrium minitans, which attacks and kills the sclerotia in the soil. He reported that the fungus was sprayed onto, and lightly incorporated into, the soil directly after harvesting. He added that the associated costs were high, at approximately R400 / hectare, and that testing of the product was still under way.

      Mr van Wyk mentioned that good results had been attained with the fungicide Topsin, with the active ingredient Thiophanate methyl, which was used to spray plants just before or at the R1 stage, with a resultant 50% decrease in sclerotinia infection. He said herbicides such as Cobra, with the active ingredient Lactofen, which is registered for use on soybeans for broadleaf weeds, was also used in smaller application rates in an effort to control sclerotinia. He added that the herbicide Flexstar with the active ingredient Fomesafen and adjuvants is currently being tested on soybeans.

      Mr van Wyk reported that Dr Yang and his team made use of variety evaluation rather than breeding for resistance. He said Dr Brian Diers, associated with the University of Illinois, focussed his research on identifying partial resistance in variety evaluation, and had published an article 'Evaluation of soybean cultivars for resistance to sclerotinia stem rot under field conditions' (Crop Sci 39: 64-68).

      Mr van Wyk concluded by saying that it seemed as if sclerotinia could be controlled most effectively by following certain practices to manage the disease. He said wider rows, upright varieties, late planting, which could however result in decreased yield, continuous no-till practices and crop rotation with wheat or another non-host crop could be applied to this end. He mentioned that deep ploughing should not be encouraged, as this results in the live sclerotia in the soil being ploughed up.

      With reference to the biological control agent Constans WG, Dr Caldwell said very good results had been obtained by using the bio-control agent EcoT® and Eco77® in the glass house. She said sclerotia disintegrated when Eco77® was applied, and, when inspected under the electron microscope, it was noted that the trichodermia grew round, penetrated the sclerotia, and fed on the sclerotia via some form of chemical reaction. She mentioned that it was difficult for her students to travel to field trials, and offered a few boxes of Eco77® to be applied in the field.

      The Chairperson reported on one of the interesting developments which had impressed him during the study tour to the Americas. He mentioned that the group had visited strip trials of approximately 10 meters x 800 meters, planted on farms in Illinois and Iowa with the view to for example demonstrating cultivars which were more resistant, chemicals with good resistance, and so forth. He said it had been decided in principle that the PRF and the oilseeds industry would explore this avenue further in future research, due partially to the shortage of capacity at the ARC. He mentioned that such trials e.g. could be planted on Stapelberg's farm in Piet Retief, to demonstrate good agricultural practices which could be employed to manage sclerotinia. He said researchers could be contracted to supervise these trials. He suggested that Dr Caldwell's offer could be accomodated by these trials.

      Dr Caldwell reported that she was to present a poster and paper on the use of EcoT® on sclerotia at the International Plant Pathology Congress at Turin later in the year, and said she would report back on this at the next meeting of the Working Group.

      Mr Johan Potgieter mentioned that it was difficult to determine the efficacy of a biological control agent in a period of one year, and said four years would be the preferred time period. He said he had been informed by a Brazilian researcher that burning the residue on fields after harvesting was considered to be one of the best ways to control sclerotia on soybeans.

      Mr Van der Westhuizen reported that Constans WG had been evaluated in South Africa, and had been found not to be very effective. He said the active ingredient of Topsin was one of the degradation products of Benomil, which was an effective seed treatment for sclerotinia. He added that the product was also used in South Africa, and registered on soybeans for the control of sclerotinia. He said Topsin and Benlate are generally considered to be the same molecule, namely carbendizim.

    2. Research: Philagro, Mr Van der Westhuizen


      (Resolutions 6.1.1 to 6.1.6 of the Sclerotinia Working group minutes of 18 July 2007)

      The Chairperson invited Mr Van der Westhuizen to take the floor to introduce this item. Mr Van der Westhuizen reported that two successful soybean field trials had been planted in KwaZulu-Natal, and said infection levels of between 17 and 18% had been established. He said the trial data had not been processed statistically due to a lack of time. In his presentation he referred to the following matters:

      • Registration status Sumisclex SC

        The registration of Sumisclex SC had been amended and approved from the original registration for corrective control of sclerotinia (1,5 liter – 2 liter per hectare), applied by means of a high pressure tractor mounted spray system in a minimum of 500 liter water; to include:

        • The application of Sumisclex through the pivot point.
        • Research undertaken in trials over a period of three years has proved that the application dosage can be reduced to 1,0 liter per hectare Sumisclex, with the addition of the silicon wetting agent Break Thru, at 0,05%. Applications costs are consequently dramatically decreased, to around R230 per hectare.
      • Results of sclerotinia trials

        • With regard to the new experimental products, currently referred to as S1 and S2, with Sumisclex SC plus Break Thru used as a control in the trials, it was clearly noticeable that the addition of a wetting agent contributed to control as it directed the active ingredient of the fungicide towards the source of infection on the soil and did not adhere to the leaves.
        • The addition of the silicon wetting agent Break Thru was definitely advisable.
        • Sumisclex SC plus Break Thru was considered to be very effective in the control of sclerotinia.
        • Both experimental products had an effect on the disease, and further trials will be conducted, as there was a strong Japanese interest in these products.
        • The code S1 product performed slightly better at the same amount gram active than the S2.
        • Work on these trials will continue, with two or three soybean trials planned, and the possible inclusion of sunflower trials with Sumisclex SC, the S-code products, and Break Thru.
        • The Eco-biological agents will be included in the soybean trials, with the research protocol to be decided on at a later stage.
        • The trial results will be analysed statistically.
        • The previous year's data have been analysed statistically, and the results will be provided for inclusion in the minutes.
        • Sunflower trials planned for the 2008/2009 trial period include Sumisclex SC and the new S-code Sumitomo products, with application at time of emergence, seed treatment with Benomil, and investigating practical application methods on the farm.

        The Chairperson ruled that the articles 'Sklerotinia peul en stamvrot in sojabone' and 'Hanteer sclerotinia sclerotiorum (kopvrot) by sonneblom só' be referred to the web page for hosting in the public domain. Mr Van der Westhuizen supported the Chairperson's view that producers were ill-informed on the various aspects of sclerotinia, such as the fact that certain weeds served as hosts to the disease. The Chairperson ruled that the matter of the production of colour copies of the two articles and other material to be used as handouts at farmers days and Nampo harvest days be referred to the Technology Committee of the PRF. Dr de Kock reported that ARC planned to update and revise the Soybean Diseases manual.

        Resolutions:

        1. That the matter of the production of colour copies of the two articles and other material to be used as handouts at farmers days and Nampo harvest days be referred to the Technology Committee of the PRF.

          Mr Keun

        2. That the articles 'Sklerotinia peul en stamvrot in sojabone' and 'Hanteer sclerotinia sclerotiorum (kopvrot) by sonneblom só' be referred to the web page for hosting in the public domain.

          Mr Keun


    3. Research: Sunflower: University of KwaZulu-Natal, Dr P Caldwell


      (Resolutions 6.5.1 and 6.5.2 of the Sclerotinia Working Group minutes of 18 July 2007)

      Dr Caldwell reported on the course work done by her student Elungi Konis with regard to the control of rhizoctonia solani and sclero­tinia sclerotiorum to prevent sunflower root diseases and damping-off, using different concentrations and application frequencies of potassium silicate. She said the objective was to investigate the efficiency of silicon for the control of seedling root diseases, and to determine its effect on sunflower seedlings' morphological character viz height, stem diameter and dry weight.

      Dr Caldwell said a lot had been learnt from the trials. She mentioned that prior in vitro trials showed a >90% mycelial growth inhibition of R. solani and S. sclerotiorum using 30ml l-1 Si supplemented agar. She explained that three treatments had been used, with trial one being conducted with the view to determine the effects of pre-treatment on pre-emergence and post-emergence damping-off of sunflower, and trial two, with the view to determine the effects of the treatments on sunflower seeds' morphological character. She added that the plants were inoculated with pathogen growing on barley seed, that all trials were organized as a randomized complete block design with four replicates per treatment, and that pots and plants were kept at optimum conditions of 26 to 28°C, with a relative humidity of 75 to 85% in a glasshouse.

      Dr Caldwell reported that assessment of pre- and post-emergence damping-off was determined at 15 and 30 days after planting, and that plant height was measured at two week intervals, while diameter, number of leaves and plant dry weight were measured seven weeks after planting. She said the trend clearly indicated that the plants' morphological characteristics improved with the addition of silicon, and that the damping-off percentage was much less. In response to Dr de Kock's comment that there was a significant range of variance in the effects of the Si treatments, Dr Caldwell explained that the trial design would be improved so that it could be statistically proved that the improvement in damping-off levels and morphological characteristics resulted from the application of silicon.

      Dr Caldwell continued the presentation by saying that results indicated that 100mg/liter of silicon applied weekly would be the most cost effective application, as the effects of the 30ml/liter plus 200mg silicon applied bi-weekly were not significantly different from the 100mg/liter weekly application. She mentioned that future work would include repetition of the trial with Eco-T for seed protection until the silicon comes into effect. She said the trial had to be run for longer, as seven weeks was considered not to be enough to get significant differences between the controls and all the different treatments. She added that she considered it important that potassium had to be included as a control, to determine its effect in potassium silicate, which was the form of silicon applied.

      The Chairperson afforded the members the opportunity to ask questions. Mr van Vuuren said silicon had become increasingly pro­minent in agriculture in recent years, was considered to be an inert element and was normally associated with plant nutrition in compounds such as potassium silicate. He asked what control mechanism in silicon suppressed pathogens such as sclerotinia. Dr Caldwell said silicon was deposited in the leaf hairs (trichomes) of soybeans, which created physical barriers that made it very hard for the fungus to penetrate. She said the silicon also triggered a biochemical pathway, that made the plant resistant to the pathogen via systemic acquired resistance.

      With reference to the resolution that EcoT® would be included in the soybean field trials, and that the time and frequency of appli­cation, as well as the dosage rate would be determined, Dr Caldwell reported that EcoT® had not been included in the previous year's trial, as it could not be put down at planting due to logistical reasons. She confirmed that EcoT® would, however, be included in this year's trials in the glasshouse. Mr Johan Potgieter expressed his concern about this, as he considered the inclusion of EcoT® as a separate trial, as the product would control the sclerotia in the soil, and not the disease itself. The Chairperson said the inclusion of EcoT® in a sclerotinia field trial would be handled by Mr Van der Westhuizen.

      The Chairperson referred the meeting to the paper prepared by Ms Dael Visser, included in the documentation as Annexure C. He asked whether Ms Visser intended continuing her research on sclerotinia stem rot in soybeans. Dr Caldwell said Ms Visser had indicated that she would prefer to do her PhD on soybean rust. In response to a question on the possibility of involving an inter­national silicon researcher in the work, Dr Caldwell indicated that she would prefer to work with Mr Van der Westhuizen. Mr van der Westhuizen said soil application of biological agents did not fall within his area of expertise, but agreed that he could include the foliar applications in his trials. Dr Caldwell pointed out that Eco77® as a foliar application was not as effective as the soil application of EcoT®. The Chairperson ruled that Dr de Kock would follow up on the possibility of including EcoT® in a field trial.

      Resolution:

      1. That the possibility of including EcoT® in a strip demonstration trial be investigated.

        Dr de Kock


    4. Research: Soybeans: University of the Free State, Prof NW McLaren


      (Resolutions 6.6.1 to 6.6.3 of the Sclerotinia Working Group minutes of 18 July 2007)

      Prof McLaren reported that the proposed protocol for 2007 on the effect of weather on disease incidence could not be carried out as planned, and that plots were, instead, treated as individual natural epidemics and combined with historic data, that were included in a model to predict sclerotinia infection. He explained the potentials and pentad data used, and said these were linearized and put in a step down multiple regression analysis which confirmed maximum temperature and maximum relative humidity as the primary variables that were affecting disease severity. He added that natural epidemics could be used to get a fairly decent picture of the conditions under which sclerotinia occurs, and added that this work could serve as a basis for a prediction model which could be extended by using a wider range of epidemics over a wider a range of conditions. He said aspects of the model that the National Institute of Plant Protection (NIPP) developed could be included in the model he developed. The Chairperson confirmed that the CEO would re-send a copy of the NIPP prediction model to Dr Caldwell and Prof McLaren.

      Prof McLaren said a similar study was done by Ms Botha, where the effect of leaf wetness duration and temperature on the develop­ment of sclerotinia stem rot on soybeans was studied, with findings consistent with the study using natural epidemics. He sum­marised Ms Botha's research by saying that she initially did an overview of sclerotinia stem rot on soybean, after which greenhouse inoculation techniques for screening for sclerotinia stem rot were evaluated, and greenhouse work done on the effect of leaf wetness duration and temperature on the development of sclerotinia stem rot on soybeans were done. He added that Ms Botha also did an evaluation of isolate variation and pathogenicity of S sclerotiorum isolates in South Africa, as well as a comparison of selected chemical and biological control strategies for sclerotinia stem rot caused by the pathogen.

      Prof McLaren indicated that the work on S sclerotiorum should be continued. He said eighteen isolates had been collected and studied to establish whether those isolates differed in any way. He mentioned that temperature studies were carried out to this effect, as well as studies on oxalic acid production, as this was supposedly related to the pathogenicity of the organism.

      Prof McLaren outlined his proposal for continuation, and said he would like to further progress the work on weather analysis, based on the regression multivariable approach, to create more diverse epidemics at a range of localities, combined with resistance screening trials. He added that he also wanted to determine the importance of population diversity on disease severity and cultivar response.

      The Chairperson referred to the article 'Evaluation of soybean cultivars for resistance to sclerotinia stalk rot in South Africa' which was co-authored by Prof McLaren, and was included in the documentation of the meeting as Annexure D, and asked whether there was a quick screening method whereby new cultivars could be screened for sclerotinia. Prof McLaren replied in the negative, and added that sclerotinia was considered to be a weak pathogen, as opposed to rust, which was a specialised pathogen. He explained that weather effects and host physiology had a bigger impact on weak pathogens than on specialised pathogens, and added that screening at a single point under one condition was not going to reflect how the host package was going to react under changing conditions. He said the regression method was used to determine the host response over a range of conditions, with the intention to identify a host that gave a smaller area under the disease potential curve, which would then be a lower risk cultivar.

      Dr de Kock asked whether it would be possible to continue the research without the assistance of a student. Prof McLaren said he hoped Mr van Wyk would assist with research in Kinross, and said he thought he could possibly also get assistance from Pannar.

      There was general agreement that it would be desirable to publish a popular article on the research Prof McLaren had reported on.

      Noted:

      1. That Prof McLaren would publish a popular article on the research he had conducted on the conditions under which sclerotinia occured.

        Members


    5. Soybean seed quality monitoring project


      (Resolution 6.8.1 of the Sclerotinia Working Group minutes of 18 July 2007)

      The Chairperson raised the matter of the seed quality monitoring project, and said GrainSA supported the project, whereby the ARC monitored seed for sclerotinia spores, amongst others. Mr Pretorius reported that this was a once-off project, which had been concluded. The Chairperson ruled that the matter be considered as finalised.

    6. Effective management of sclerotinia


      (Resolutions 7.3.1 to 7.3.3 of the Sclerotinia Working Group minutes of 18 July 2007)

      The Chairperson referred to the resolution passed at the previous meeting which related to agronomic trials on the management of sclerotinia, to investigate the effect of row widths, plant density, cultivars and so forth on the disease. He said he had already mentioned that the intention was to plant such trials on selected producers' farms in the coming season.

      Dr de Kock said the resolution that the possibility to undertake research on the relationship between soil biodiversity and sclerotinia be investigated had been referred to and discussed by the Technology Committee. He said a lack of research capacity had somewhat hampered progress thus far, but added that the intention was to discuss the matter with Dr Beukes and Prof Barnard, to determine whether they would be interested in such a project. He said the work could form part of the no till trial which was included in Mr van Wyk's project at the Hatfield experimental farm.

      Prof McLean reported that Prof Swart was currently researching soil biodiversity under different production conditions with pistachio nuts, and said Prof Swart could very well be interested in getting involved in a project on soil biodiversity and sclerotinia. He undertook to follow up on this with Prof Swart.

      Dr de Kock requested that Dr Caldwell, Prof McLaren and Mr Van der Westhuizen submit their research protocols by 30 September. He added that he would appreciate a short project report twice a year, to inform him on the status of the project, the status of sclerotinia at that time, covering both soybean and sunflower, any problems experienced, and so forth. He indicated that he would like to receive these reports on 13 February and 24 April 2009. Mr Keun agreed that he would remind the researchers of the deadlines by email.

      Noted:

      1. That Dr Caldwell, Prof McLaren and Mr van der Westhuizen would submit their research protocols by 30 September, and would submit progress reports on 13 February and 24 April 2009.

        Dr Caldwell
        Prof McLaren
        Mr Van der Westhuizen


    7. Feedback: Study tour to the Americas

      This item was discussed as part of the general overview (see: discussion item 6.1).

    8. Use of unregistered chemicals


      (Resolution 7.2.2.1 of the Soybean Working Group minutes of 6 May 2008)

      Dr de Kock reported that mention had been made at a meeting of the Soybean Working Group that producers in the Ogies area used a mixture of Apron C and Celeste, which were registered for use on dry beans, as seed treatment on soybeans. He said the producers reported excellent results of this mixture as a seed treatment for the control of sclerotinia. He said Benomil, or Benlate, as it was previously known, was the only chemical registered as a seed treatment for soybeans against sclerotinia infection.

      Mr Van der Westhuizen said both Apron C and Celeste were Syngenta products, and suggested that Syngenta be approached for comment in this regard. He mentioned the possibility that the mixture was considered to be effective, but that the mixture was actually applied in vain, as sclerotinia pressure varied from year to year and there would not have been sclerotinia infection during that season anyway. He mentioned that sclerotinia was considered to be a big challenge world wide, and said Syngenta most probably would have invested in research on the efficacy of Apron C and Celeste as seed treatment against sclerotinia on soybeans.

      Mr Van der Westhuizen reported that Syngenta had applied for registration of Amistar and Amistar Top for the control of rust on soybeans. He said no formal mention was made of the use of Amistar on sclerotinia, although Amistar had been found to have a suppressive effect on sclerotinia if it was sprayed before the disease commenced.

      Resolution:

      1. That Syngenta be approached for comment on the fact that producers in the Ogies area had succesfully used a mixture of Apron C and Celeste, which were registered for use on dry beans, as seed treatment on soybeans.

        Mr Keun

  8. Additional items

    1. Database of Expertise: subcategory – Sclerotinia research


      (Resolution 6.1.5 of the Sclerotinia working group minutes of 28 June 2006)

      The Chairperson made an appeal to the members to identify specific institutions and researchers with whom close contact could be established and maintained. Mr Johan Potgieter confirmed that he was in close contact with Dr Gulya, who headed a dedicated sclerotinia sunflower research unit at North Dakota.

      The Chairperson asked the members whether they thought the meetings of the Sclerotinia Working Group were of value, and should continue to be convened annually, and if so, whether there were other people the members thought should be invited to the meetings. He invited the members to inform the PRF and oilseeds industry of researchers of international renown who could be invited to address the Working Group.

      Prof Mclaren considered the meetings of the Working Group as a good forum for a diverse group of people to discuss matters of common interest. Mr Johan Potgieter was in agreement with Prof McLaren, while Dr Caldwell and Mr Engelbrecht underlined the value of networking opportunities the meetings offered. Mr Van der Westhuizen considered the meetings to be not only desirable, but also a necessity. The Chairperson thanked the members for their input.

    2. Sunflower Symposium – Post 2008

      The Chairperson informed the members that a sunflower symposium would be presented on 11 September. He said the symposium had been an initiative suggested by Mr Pretorius, and reported that Dr de Kock had been charged with the organisational aspects of the day. He invited Dr de Kock to take the floor.

      Dr de Kock said the keynote address would be delivered by Mr Larry W Kleingartner, executive director of the American National Sunflower Association. He mentioned that topics such as consumer needs, market opportunities, producers' and oil expressers' needs, breeding of cultivars, production matters and so forth would be addressed.

      The Chairperson invited the members to attend the symposium, which will be held in Bothaville, with registration from 8 o'clock in the morning.

    3. Fourth International Silicon in Agriculture Congress, Wild Coast Sun 26 to 31 October 2008

      The Chairperson invited Dr Caldwell to address the meeting on the forthcoming congress. Dr Caldwell said the top international researchers on the use of silicon in agriculture have been invited to address the congress. She reported that field trials have been planted with four different crops on the South Coast, and that a day field trip was planned to visit those. She mentioned that the program will be released the following week, and said it would also be made available on the congress website.

      Dr Caldwell thanked the PRF and oilseeds industry for their generous sponsorship of two international speakers, viz Dr Rodrigues from Brazil and Dr Liang from China, and mentioned that they would also address the Soybean Working Group during their visit to South Africa. The Chairperson proposed that the members of the Sclerotinia Working Group and the Sunflower and Soybean Forum also be invited to the meeting of the Soybean Working Group, which was to be convened on 24 October.

      Resolution:

      1. That the members of the Sclerotinia Working Group and the Sunflower and Soybean Forum be invited to the meeting of the Soybean Working Group, which is to be convened on 24 October.

        Mr Keun

  9. Date of next meeting

    The next meeting of the Sclerotinia Working group was scheduled for 22 July 2009.

  10. Closure

    There being no further matters to discuss, the Chairperson closed the meeting at 13:55, and wished all a safe journey to their respective homes.