Research Report 2015/2016
Projects finalised successfuly or that showed progress (Annexures I and II)
Index of projects
- Evaluation of PRF soybean elite lines under South African conditions
- National soybean cultivar trials
- Etiology and population structure of Macrophomina phaseolina (charcoal rot) in sunflower and soybeans in South Africa
- Determining root-knot nematode resistance in soybean genotypes in South Africa
- Studies on Lecanicillium muscarium as a mycoparasite of the soybean rust fungus, Phakopsora pachyrhizi and its use as a biocontrol agent against soybean rust
- Cultivar evaluation of oil and protein seeds in the winter rainfall area
- Chemical manipulation of vegetative growth, reproductive development and grain yield in canola
- Nitrogen top dressings in canola: time of application and rates
- An evaluation of continuous cash crop production (including small grains, canola and other alternative broadleaf crops) under conservation agriculture principles on high potential soils of the Riversdale flats
- Developing a nematode biological control agent for molluscs associated canola (slugs and snails) in South Africa
- Development of protein and phosphorous feed ingredients for the animal feed industry from fish processing waste
- Management strategies for soybean soilborne diseases in South Africa
- Projected protein requirements for animal consumption in South Africa
- Income and cost estimates of soybeans canola and a few competitive crops
- PRF website
Evaluation of PRF soybean elite lines under South African conditions
GP de Beer and WF van Wyk
The PRF soybean Elite trials (2015/16) were planted at the following six (6) localities:
- Stoffberg – Representative of the northern Highveld
- University of Pretoria (Hatfield) – Representative of the southern Highveld
- Brits – Representative of the northern irrigation area
- Potchefstroom – Representative of the western production area
- Bethlehem – Representative of the eastern and northern Free State
- Ukulinga (Pietermaritzburg) – Representative of KwaZulu-Natal (warm area)
The number of controls used in the trials was reduced from five to four local cultivars. Only one of the previous five was retained (LS 6164 R – M.G 6.0). The following four (4) were used:
|LS 6240 R||– M.G. 4.0|
|DM 5953 RSF||– M.G. 5.0|
|LS 6164 R||– M.G. 6.0|
|PAN 1729 R||– M.G. 7.0|
In 2015/16, seventy one (71) lines (genotypes) obtained from seed institutions, mainly from South America (Brazil, Argentina and Uruguay), were planted with the four South African cultivars (controls) at the six mentioned localities. The maturity groups varied from 3.7 to 8.5.
The past season was one of the hottest and driest recorded for some years. The extreme daytime high temperatures caused severe stress for the plants. In spite of supplementary irrigation plants at the Potchefstroom site suffered damage due to the extreme daytime temperatures that often reached 40ºC and caused clear moisture stress in the plants.
A number of the 71 lines showed high yields and therefore have potential to be included in additional local trials that may lead to their possible registration as cultivars in South Africa.
Two of the South African controls showed broad adaptability and were winners or runners-up at most of the localities. Cultivar DM 5953 RSF showed remarkably high yields:
The project creates opportunities for participating seed institutions to consider their material for local registration. Because this project broadens the selection of soybean cultivars in South Africa it should be continued.
National soybean cultivar trials
AS de Beer, L Bronkhorst, HSJ Vermeulen, NN Mogapi, TC Ramatlotlo and S Seutlwadi
A total of 29 commercially available cultivars were evaluated for the 2014/15 season in 22 field trials scattered over the production area representing the cool, moderate and warm areas. Only GMO cultivars were included and Roundup applications were used during the execution of the trials. A randomised complete-block design with three replicates was used for all field trials. Date of flowering (50% flowering), date of harvest maturity, length of growing season, plant height, pod height, green stem, lodging, shattering, 100 seeds mass, undesirable seed, protein- and oil percentage and seed yield were determined and the yield probability of cultivars calculated. Yield probabilities served as the guideline for cultivar selection. The mean number of days from planting to 50% flowering of cultivars for the cool, moderate and warm areas was 74, 59 and 43 respectively. The overall mean oil content for cultivars was 19.8% for the cool, 20.8% for the moderate and 22.1% for the warm areas.
The overall mean protein content was 38.1% (cool), 37.7% (moderate) and 39.8% (warm). The overall mean yield was 2435 kg ha-1 for the cooler areas, 2199 kg ha-1 for the moderate and 3154 kg ha-1 for the warm areas. Cultivars with a high yield probability are important in the selection of cultivars by producers due to the reliability of the expected future yield. Cultivars which had high yield probability over the reporting period were PAN 1454R, LS 6146R and LS 6453R LS 6248R, PAN 1583R, PAN 1500R for the cooler areas, PAN 1583R, LS 6164R, LS 6161R, LS 6261R and PAN 1614R for the moderate area as well as PAN 1664R, LS 6164R and LS 6161R for the warmer areas.
Etiology and population structure of Macrophomina phaseolina (charcoal rot) in sunflower and soybeans in South Africa
E Jordaan and JE van der Waals
This research aims to answer questions about the Macrophomina phaseolina populations in sunflower and soybean growing regions in South Africa, and whether they could be grouped according to geography, environment and/or cropping practices. More than 100 isolates have been obtained from infected sunflower and soybean plants. Single sclerotia isolations were made. Isolates were stored at -18ºC using the toothpick method. The population will be identified using multiple gene analysis. Isolates are currently being prepared for screening and we hope to complete this by the end of July 2016. In vitro trials focused on growth rate of the pathogen under different temperatures, pH and on Potato Dextrose Agar amended with copper and chlorate (two products known to cause growth inhibition). Some isolates were compared for their pathogenicity and virulence on sunflower and soybean on seed germination. The in vitro results, two pot trials, a grower survey, and prediction modelling will be used to create a holistic picture of charcoal rot on soybeans and sunflower in SA.
A countrywide survey will be conducted to determine growers' perceptions, the occurrence of this disease and the subsequent control practices that are in place, if any, so as to provide a picture of how charcoal rot is affecting production in South Africa. The survey questionnaire has been compiled and we are currently looking at ways to reach the soybean and sunflower producers.
With the use of climate prediction models we will attempt to predict the impact of these changing climatic conditions on disease development in future. Parameters for disease incidence have been compiled and will soon be sent for analyses.
A pot trial to investigate the effect of drought on charcoal rot will also give an indication of the yield reduction caused by charcoal rot. Another pot trial will evaluate nitrogen fertilization to determine the effect of the nitrogen source used and the quantity of nitrogen added to the soil on disease development. Long and short growers for sunflower and soybean will be included in the nitrogen trials. As we have to wait for the growing seasons, these trials will only commence in August 2016.
Future research from this project could be focused on resistance breeding, or screening for tolerant sunflower and soybean cultivars. This research can aid in the forecasting of disease incidence and severity, and to establish control methods. An article on the proposed research has already been published in Oilseeds Focus (June 2016). Upon completion of the project results will be published in peer review articles in scientific journals, articles in local media such as Farmers Weekly and Oilseeds focus, and presented at farmer days.
Determining root-knot nematode resistance in soybean genotypes in South Africa
The purpose of this study is to evaluate soybean cultivars from other countries to determine resistance against the local population of Meliodogyne incognita and M.javanica, compared to South African cultivars as controls, by using one that shows high resistance and one that is severely susceptible.
According to previous data, cultivar LS 5995 was selected as the highly resistant cultivar and LS 6248 R as the highly susceptible cultivar. Twenty one (21) Brazilian lines (genotypes) were evaluated in glass house studies, compared to the two standards.
The evaluation tests were conducted successfully, as LS 6248 R (susceptible control) showed high infestation. However, not one of the 21 lines showed any measure of resistance. Even the resistant cultivar showed Rf values higher than 1, but both evaluations indicated the lowest infestation (Rf values).
Studies on Lecanicillium muscarium as a mycoparasite of the soybean rust fungus, Phakopsora pachyrhizi and its use as a biocontrol agent against soybean rust
In this study, a Isolate N-08, a mycoparasitic fungus, was isolated from Assagay coffee farm, Cato Ridge, KwaZulu-Natal, South Africa, where it was observed parasitizing Hemileia vastatrix, the causal agent of coffee rust. Based on morphological and molecular studies the Isolate N-08 was identified as Lecanicillium muscarium and it was deposited into the National collection of fungi (Accession number PPRI 13715).
Co-inoculation studies of L. muscarium and P. pachyrhizi were done in UKZN Plant Pathology disease garden. The Environmental Scanning Electron Microscope (ESEM) observation of the interactions showed a mycophilic attraction of L. muscarium to P. pachyrhizi urediniospores. Long L. muscarium phialides were observed penetrating and wrapping tightly around P. pachyrhizi urediniospores.
In vitro studies to test the effect of the L. muscarium strain N-08 on P. pachyrhizi, the soybean rust fungus, were done. L. muscarium strain N-08 was observed colonizing P. pachyrhizi under light microscope and ESEM. Laboratory experiments were conducted to assess the effects of different growing conditions (temperatures, artificial growing media, natural substrates and UV radiation) on colony growth and conidia production. Optimization of growing conditions is one of the essential aspects which must be taken into consideration to produce an effective biocontrol agent. L. muscarium strain N-08 grows best at temperatures between 21 to 25ºC. The highest radial growth was observed at 24ºC (46.54mm). V8 juice agar was the best medium for colony growth with the mean value of 42.75mm followed by SDA (Sabouraud dextrose agar) with 37.86mm. When the isolates were exposed to UV light, the results did not show a significant difference between different media on mycelia growth. The highest conidia production occurred on millet cereal (4.2 x 109 conidia/ml) followed by wheat bran (3.2 x 109 conidia/ml) and pearled barley (2.9 x 109 conidia/ml).
The optimal dose level for disease control was assessed in the greenhouse and in field trials. It was found that 106 and 108 conidia/ml were more effective and 106 conidia/ml was chosen as the optimum dose for the field application.
Effect of L. muscarium against soybean rust was evaluated in the field. Two field experimental trials (2014/2015 and 2015/2016) were run at Ukulinga Research Farm. Compared to the pathogen inoculated control, all the three L. muscarium doses (104, 106, 108 conidia/ml) and the fungicide control (Score) decreased disease severity by 73.3%, 88.2%, 89.1%, and 90% respectively. The Area under the Disease Progress Curve (AUDPC) for the treatments were as follows: 1st trial, Score (172.2 units), 108 conidia/ml (186.2 units), 106 conidia/ml (202.16 units), 104 (457.8 units) and pathogen inoculated control (1716.8 units). 2nd trial, score (259.7 units), 108 (284.9 units), 106 (319.9 units), 104 (462.7 units) and the pathogen inoculated control (1053.5 units). Treated plots showed higher yield increase compared to the pathogen inoculated pathogen. However, dry seed weight did not significantly differ between the L. muscarium strain N-08 treated and score fungicide treated plots.
Cultivar evaluation of oil and protein seeds in the winter rainfall area
PJA Lombard, L Smorenburg and JA Strauss
The Western Cape Department of Agriculture conducted a range of cultivar trials during the 2015 season in the Swartland and Southern Cape. In the Southern Cape eight trials were planted and six data sets were used (bad establishment occurred at Rietpoel and herbicide damage at Roodebloem). In the Swartland eight trials were planted and only one trial was not harvested (insect damage).
The past season in the Swartland was characterized by extremely dry conditions during August and September. The rainy season starts on May 30, there were two months of effective rainfall. In the Swartland the average rainfall for April to September was 45% to 57% of the long-term average. In the Southern Cape above-average rainfall occurred. May was dry in the central and western parts of the Rûens. In the eastern parts trials were planted in April with good soil moisture.
During August and September, the minimum and maximum temperatures at Langgewens were above average. At Rietpoel the maximum temperature for July was 2.5ºC lower than the long term average. The minimum temperature in August and September was however 1ºC warmer than the long term average.
In the Swartland the average yield was 1320 kg ha-1 compared to 2468 kg ha-1 in 2014. Plants in all the trials in the Swartland emerged at the same time after the first rain on May 30.
The new conventional hybrid cultivar Diamond (1721 kg ha-1) was the top performer in the Swartland. Diamond was followed by Tango (1519 kg ha-1) and CB Agamax (1441 kg ha-1). The above cultivars are all early to medium cultivars and were better adapted to the short growing season. The CL-cultivar 44Y89 (1643 kg ha-1) had the 2nd highest yield in the Swartland trials and was significantly higher than other cultivars within the CL group. In the TT group, the hybrid cultivar, Hyola 559 (1273 kg ha-1) was the best performer. The yield of Hyola 559 was not significantly better than CB Atomic and Granite TT.
The yield of the TT-cultivars in the Swartland and Southern Cape was 24% and 18.1% respectively lower than the conventional varieties.
In Rûens the average yield ranged from 1714 kg ha-1 at Witsand to 2121 kg ha-1 in Napier. The conventional cultivar Belinda (2278 kg ha-1) had the highest average yield in the conventional group and was followed by the cultivar Diamond. The CL-cultivar 45Y88 (2346 kg ha-1) was the highest yielding cultivar in the CL group. It was also the variety with the highest yield in the Southern Cape. The cultivar 44Y89 was 2nd in the CL group, its yield was not significantly lower than 45Y88. In the TT group CB Atomic HT (1800 kg ha-1) produced the highest yield followed by Hyola 555 and Granite.
Chemical manipulation of vegetative growth, reproductive development and grain yield in canola
GA Agenbag and E Kempen
Canola (Brassica napus L.) is one of the most important sources of plant oil in the world and is rapidly becoming an important crop in South Africa. Although yield per hectare has increased in recent years due to the introduction of hybrid cultivars and improved production techniques, yield per hectare is still low compared to leading world producers such as Canada.
Lower than expected yields may be the result of several factors such as low and uneven plant populations, insect pests, poor plant nutrition management and weed control as well as harvesting losses. The highest yields in South Africa are achieved with early plantings on high fertility sites, but this practice often produces bulky crops which when combined with high plant populations may result in lodging during pod development.
Research done in Australia showed that shorter plants are much more resistant to lodging than taller plants. By shortening the stem and changing the canopy structure with the use of plant growth regulators (PGR's) an even, compact pod canopy can be produced. As a result, competition for assimilates and light can be reduced, ripening will be more uniform, pod shattering will be reduced and harvesting will be more efficient.
No PGR's are at present registered for use in canola in the RSA, but preliminary research done recently with the PGR's, Primo Maxx® and Moddus® as well as liquid seaweed extract (Kelpak®) showed promising results in both pot and field trails. For this reason field trials were conducted during 2015 at 3 localities in the Swartland (2) and Southern Cape (1) canola producing areas. Three spraying treatments (control, Kelpak® and Moddus®) in combination with four plant densities, 30, 60, 90 and 120 plants m-2 were tested.
Both Kelpak® and Moddus®) resulted in significant increases in grain yield at the higher rainfall localities of Altona and Roodebloem and especially so in plots with higher plant populations. At both localities yield increases of 300-400 kg ha-1 were obtained when compared to the control (unsprayed) plots. Although similar trends were seen at the lower rainfall locality of Langgewens no significant yield increases were recorded.
Nitrogen top dressings in canola: time of application and rates
Previous research projects in the Western Cape showed that application rates of 80-120 kg of N ha-1 and 15-30 kg S ha-1 are needed to produce canola grain yields of more than 2.0 ton ha-1 in soil with low organic C contents. These high fertiliser requirements increase production costs and often make nitrogen and sulphur fertilisation the most costly production factor in canola.
The efficiency of applications is affected by soil properties and climatic conditions and very importantly by time of application. Research done in Canada showed that although the nitrogen uptake by canola is the highest from the 5-leaf to 50% flower (which in the Western Cape is reached at 80-90 d after planting), uptake remains high till 50% podded stage (120-130 d after planting). These results indicate that nitrogen topdressing during the flowering stage may be important in high-yielding canola crops. In order to determine optimum nitrogen application strategies for different soil and climatic conditions, field trials were conducted during 2015 at 3 localities in the Swartland (2) and Southern Cape (1) canola producing areas. Four nitrogen rates namely 60, 90, 120 and 150 kg N ha-1 were tested, with 20 kg N ha-1 applied at planting and the remaining nitrogen applied as a single top dressing 30 d after planting (dap); divided between 30 and 60 dap or divided between 30, 60 and 90 dap (full flowering stage). Control plots did not receive any nitrogen fertiliser.
Although the Western Cape canola producing area experienced very low rainfall and a short rainy season during 2015 which hampered yields especially in the lower rainfall locality of Langgewens, mean grain yields of canola varied between 1682 kg ha-1 at Langgewens, 1890 kg ha-1 at Roodebloem and 3294 kg ha-1 in the high rainfall locality of Altona. At Langgewens the highest grain yield of 1723 kg ha-1 was recorded with an application of 90 kg N ha-1, while at Roodebloem (2013 kg ha-1) and Altona (3363 kg ha-1) highest yields were recorded with 120 kg N ha-1. Due to the generally poor yields and poor response to nitrogen applications under low rainfall conditions at Langgewens, the timing of the topdressings with nitrogen did not affect grain yields. However, at Roodebloem best results were obtained with an application of 20 kg N ha-1 at planting and the remainder applied at 30 dap. At the high rainfall locality of Altona, where grain yields of more than 3000 kg ha-1 were recorded, highest yields were recorded with 20 kg N ha-1 applied at planting and the remainder of the nitrogen application splitted between 30 and 60 days after planting. Because of abnormal rainfall conditions during 2015 it will be important to test the different strategies for at least three years at each locality before any conclusions can be drawn.
An evaluation of continuous cash crop production (including small grains, canola and other alternative broadleaf crops) under conservation agriculture principles on high potential soils of the Riversdale flats
The year 2015 was the 4th year of production on the new trial. Six cash crop systems are tested including shortened canola rotations and cover crops. A total of 60 plots were planted. The 6 systems tested are replicated 3 times and all crops within each system are represented on the field each year. Riversdale received late summer rainfall in the pre-season which resulted in enough available moisture to plant early in April. The rest of the 2015 rainfall during the production season from April to September was higher than the 2014 season but still around 40mm less than the long term average. The rain was well spread throughout the season and a cool September stretched the season which resulted in excellent yields.
The canola cultivar 44Y87 was planted at Riversdale at 3 kg/ha. A total of 53 kg N/ha was applied to each plot (23kg N/ha at planting and 30kg N/ha top-dressings). Canola yields at Riversdale averaged 1420 kg/ha with all plots showing oil yield above 40%. This average yield was 10 kg/ha less than in 2014.
The wheat cultivar SST027 was planted at Riversdale at 74 kg/ha. A total of 53 kg N/ha was applied to each plot (23 kg N/ha at planting and 30 kg N/ha top-dressings). Wheat yields at Riversdale averaged 3598 kg/ha. This was 941 kg/ha more than in 2014.
The barley cultivar Erica was planted at Riversdale at 53 kg/ha. Barley yields at Riversdale averaged 3610 kg/ha. This average yield was 160 kg/ha less than in 2014.
The lupin cultivar Mandelup was not available so a bitter lupin mix was planted at Riversdale at 110 kg/ha. Lupin yields at Riversdale averaged 272 kg/ha.
The oats cultivar Saia and vetch was planted at Riversdale at 29 kg/ha and 42 kg/ha, respectively. No other input cost was incurred during the season except the herbicide cost to kill the cover crop following the information day.
The economic data for 2013, 2014 and 2015 have been captured and will be discussed in this report. A summation of the gross margins of each of the six systems tested at the site over the 3 combined 3-year period has been completed.
Developing a nematode biological control agent for molluscs associated canola (slugs and snails) in South Africa
A Pieterse, JL Ross and AP Malan
Invasive European molluscs (slugs and snails) have become significant economic pests in South Africa, especially in the Western Cape where the climate is favourable. One crop that is particularly targeted is Canola (Brassica napus) which is a winter-arable crop that is commercially produced for animal feed protein. Canola is sown between March and May in the Western Cape, with the seedlings being most susceptible to mollusc damage during the first four weeks after planting. The three mollusc species that are particularly pestiferous in Canola are Milax gagates, Deroceras panormitanum and Deroceras reticulatum. All three species of slugs (as opposed to snails) are European exotic invaders. Current methods for controlling the invasive European slugs rely on the use of chemical molluscicide pellets containing metaldehyde and carbaryl, although these are often ineffective and toxic to non-target organisms making it crucial that a method of biological control be identified. The most effective commercial method for the biological control of molluscs in Europe entails the use of the mollusc-parasitic nematode Phasmarhabditis hermaphrodita. The product, which is available in Europe from BASF, is sold under the trade name Nemaslug®. The product provides protection against many terrestrial mollusc families, including Agriolimacidae, Arionidae, Limacidae, Milacidae, and Vagnulidae. To date, Nemaslug® cannot be sold in South Africa due to the legislation (amended Act 18 of 1989, in terms of the Agricultural Pest Act 36 of 1947) that is currently in place, thus an indigenous method of biological control requires development. The project in question aims to identify local indigenous nematode isolates that have the potential to be developed as a biological control agent for molluscs in South Africa.
Several nematode species have been identified through annual surveys conducted in the Western Cape. Of the isolates identified to date using molecular and morphological data, the following species have been identified: Angiostoma margaretae; Angiostoma sp.; Caenorhabditis elegans; mermithid sp.; and Phasmarhabditis spp. Several different nematode species that have shown promise for the control of slugs have been the subject of numerous pathogenicity studies. Currently, the pathogenicity of local isolates is being compared with that of the commercial Nemaslug® product. New species are being named and described for South Africa. Phasmarhabditis sp. is in the process of being cultured in vitro for purposes of mass production. In addition, surveying, aimed at identifying further isolates, is continuous in the province. In conclusion, the project described here is aimed at developing an indigenous biological molluscicide, which should have a significant impact on the agricultural industries in South Africa.
Development of protein and phosphorous feed ingredients for the animal feed industry from fish processing waste
The aim of this research is to develop the technology required to produce high quality protein and phosphorous animal feed ingredients using low value fish processing waste from capture fisheries and aquaculture as feedstock. By establishing suitable technologies to produce higher value animal feed ingredients from waste products, economic incentive can be created to encourage utilisation of these waste materials, simultaneously improving the utilisation of scarce natural resources. The overall investigation will be achieved by way of three separate postgraduate (Masters) projects, each of which forms the basis of a Master's study.
The first two Masters studies have completed the laboratory phase of investigations and reporting (via Masters Theses) is under way. The third project was initiated in 2016 and planning and preparation for the trial is under way. It is anticipated that a growth- and bio-availability study will commence in September 2016.
The first two projects focused on development of technology to recover high-value products from fish processing waste, and the two products specifically targeted were enzymatically hydrolysed proteins and bone minerals (with emphasis on phosphates). The hydrolysed protein recovery process has been optimized at laboratory scale and reaction conditions have been optimized for two industrial enzymes, Alcalase and bromelain. In the phosphate project the bone mineral extraction and phosphate recovery has been optimized at laboratory scale. Additional to the original project aims, gelatin extraction was also investigated and processing of these data is being finalised. For both these projects, it is anticipated that thesis examination will be completed during 2016, and external examiners have already been appointed.
Good progress is being made with the final phase of the investigation which commenced in 2016. During this phase, the hydrolysed protein and bone mineral ingredients will be evaluated for bioavailability in aquaculture feed trials. All diets have been formulated and experimental feed ingredient preparation has commenced. Feed preparation will commence soon, and experimental animals have been ordered to initiate the trials in September 2016. It is anticipated that the trial will run to the end of November 2016, with all experimental and data analysis being completed in 2017. As the project stands currently, it is on track to deliver the required results within the time required.
Management strategies for soybean soilborne diseases in South Africa
YT Tewoldemedhin and SC Lamprecht
In the surveys conducted in South Africa in cultivar trials and farmers' fields, 71 fungal and oomycete species were obtained from soybean crowns, hypocotyls, cotyledons and roots. Of the 71 fungal and oomycete species, Fusarium (F. begoniae, F. graminearum, F. oxysporum, F. solani) were among the root rot causing species, while Pythium spp. and R. solani (P. aphanidermatum, P. heterothallicum, P. irregulare, P. ultimum, R. solani AG-2-2 IIIB and R. solani AG-4 HG-III) caused root rot and/or damping-off. However, Sclerotium rolfsii is reported to cause southern blight and Diaporthe / Phomopsis spp. complex are causal agents of stem blight in South Africa. These soilborne diseases of soybean are reported to cause yield losses of up to 70% and in some cases plant losses and yield reductions of 100% have been reported in highly susceptible soybean cultivars. In other countries it is clear that integrated management strategies that include at least seed treatment, resistance / tolerance and proper crop rotation are essential to sustainably manage soilborne diseases of soybean in South Africa. Although management strategies have been tested in other countries they have not been properly tested and applied in South Africa. For this purpose, three management strategies were evaluated last year under glasshouse conditions. Among the fungicides evaluated, potential fungicides suitable and effective as seed treatment on soybean were identified. Of the screened cultivars those with tolerance / resistance against the most important pathogens of soybean were also identified. Pre-crops (rotation crops) that are either non-hosts or have some degree of tolerance to the soybean pathogens were also identified, which will render them suitable as rotation crops. However, the results of this study need to be verified to be considered reliable. Therefore the aims of the current study were to repeat the glasshouse bioassays to control pre- and/or post-emergence damping off, root rot, southern blight and stem blight of soybean by investigating
- fungicide seed treatments,
- screening commercially available South African soybean cultivars for tolerance / resistance and
- screening pre-crops as rotation crops to reduce disease pressure.
Apron XL (a.i. mefenoxam), Celest XL (a. i. fludioxonil + mefenoxam), DynastyCST (a. i. azoxystrobin + fludioxonil + mefenoxam), Maxim Quatro (a. i. thiabendazole + azoxystrobin + fludioxonil + mefenoxam), EverGol Energy (a. i. penflufen + prothioconazole + metalaxyl) and mixture of Apron XL (a. i. mefenoxam) + Celest XL (a. i. fludioxonil + mefenoxam) fungicides were evaluated as seed treatments for their effects on survival, growth and root rot of seedlings in soil infested with Fusarium spp. (F. begoniae, F. graminearum, F. negundis, F. oxysporum, F. solani), Pythium spp. (P. aphanidermatum, P. heterothallicum, P. irregulare, P. ultimum), and Rhizoctonia solani (AG-2-2 IIIB and AG-4 HG-III). Results of the effect of fungicide seed treatment on survival of soybean seedlings grown in soil infested with important soilborne pathogens showed that pre- and post-emergence damping-off of soybean caused by important soilborne pathogens of soybean can be effectively controlled by Evergol, DynastyCST, Maxim Quatro and a mixture of ApronXL and CelestXL. However, Evergol and Maxim Quatro are more effective against Fusarium spp. Although seed treatment with Apron XL (a.i. mefenoxam) was effective in reducing damage caused by Pythium species, it was not effective against other soilborne diseases of soybean causing species. However, Celest XL was effective in reducing damage caused by R. solani AG-2-2IIIB and AG-4 HGIII, and although, it reduced damping-off of soybeans caused by Pythium species, in most cases it was not as effective as the mixture of Apron XL and Celest XL. It was surprising that DynastyCST and Maxim Quatro were not performing as effective as the mixture of Apron XL and Celest XL, since the active ingredients also contained fludioxil and mefenoxam. However, during the visit to the Argentinian seed treatment facility, Dr M. Scandiani pointed out that the active ingredient azoxystrobin found in both DynastyCST and Maxim Quatro affect seed germination negatively. Therefore, in Argentina they are using a product called Maxim Evolution which contains the same three active ingredients included in Maxim Quatro, but without the azoxystrobin, and reported Maxim Evolution to be much more effective than Maxim Quatro. Our effort to import a sample of Maxim Evolution from Argentina for research purposes was unfortunately not successful. Twenty-seven soybean cultivars were evaluated against important soilborne disease of soybean causing pathogens (Diaporthe phaseolorum var. meridionale, Phomopsis longicolla, F. begoniae, F. graminearum, F. negundis, F. oxysporum, F. solani, F. virguliforme, P. aphanidermatum, P. heterothallicum, P. irregulare, P. ultimum), R. solani AG-2-2 IIIB and R. solani AG-4 HG-III, Sclerotinia sclerotiorum and Sclerotium rolfsii) under glasshouse conditions in order to determine resistance / tolerance in South African commercially available cultivars. From the results obtained in the cultivar screening bioassay, it was clear that there are differences in cultivar tolerance / resistance against the soilborne pathogens of soybean included in this study. Cultivar soy8 was one of the most susceptible cultivars to F. solani, S. rolfsii and all species of Pythium and Rhizoctonia. In addition, cultivars differ in their reaction against different species. For instance, cultivar soy13 had the highest resistance against all Fusarium spp., most of Pythium spp. and R. solani AG-2-2IIIB, but was highly susceptible to R. solani AG-4 HGIII and moderately susceptible to Sclerotium rolfsii. In the cultivar screening bioassay conducted with P. longicolla and D. phaseolorum var. meridionale, it was found that there are different degrees of tolerance / resistance in the cultivars. All of the cultivars evaluated appears to be susceptible to Fusarium virguliforme, M. phaseolina and S. sclerotiorum. Therefore, selecting a cultivar, with tolerance / resistance against soilborne diseases to plant in a field with a known soilborne disease problem, knowledge of the most important pathogen/s is essential. This is necessary, since most of the cultivars tend to have different reactions to different species of soilborne disease causing pathogens.
In order to investigate whether soilborne pathogens of soybean (F. begoniae, F. graminearum, F. negundis, F. oxysporum, F. solani, P. aphanidermatum, P. heterothallicum, P. irregulare, P. ultimum), R. solani AG-2-2 IIIB and R. solani AG-4 HGIII) can affect the pre-soybean (rotation) crops that are used as rotation crops with soybean, six crops were identified and evaluated under glasshouse bioassays. The result of this study revealed that dry bean is affected by only two Pythium spp. (P. aphanidermatum and P. heterothallicum) and two R. solani AGs (AG- 2-2IIIB and AG-4 HGIII). In addition, sunflower, sorghum, and wheat are also affected by Pythium and R. solani. The pathogens caused significant damping-off and root rot on these crops. An interesting observation was that most of the pathogens included in the study induced significant damping-off on yellow maize. However, survival of white maize was not affected by the presence of these pathogens in the soil except by R. solani AG-2-2IIIB. Therefore, in the absence of other management strategies it is important to rotate soybean crops with white maize in order to reduce the inoculum pressure for the following soybean crop without significantly compromising the production of the preseason crop.
Three management strategies were evaluated. In the two years' study, among the fungicides evaluated, potential fungicides suitable and effective as seed treatment on soybean were identified. Cultivars with tolerance / resistance against important soilborne pathogens of soybean were also identified, as well as pre-crops (rotation crops) that are either non-host or have some degree of tolerance / resistance to the soybean pathogens evaluated. The ideal practice in combating the soilborne diseases of soybean is to combine the best of the three strategies. This will ensure the sustainability of the management practice with considerably lower input cost. However, the results of this study need to be verified under field condition to be considered reliable. For this purpose, commercially available fungicides that were evaluated under glasshouse conditions will be used to test their ability to control soilborne diseases of soybean under field conditions. Three representative sites, one each in cool, moderate and warm soybean production area, will be selected. In each site seeds of three soybean cultivars will be treated with four fungicides, which will have three replicates.
Projected protein requirements for animal consumption in South Africa
D Strydom¹, W de Jager¹ and E Briedenhann²
Across the globe, the world population is rising at a drastic rate, higher income opportunities in urban areas attract more people to cities, and coupled therewith is the higher income that these people have at their disposal. Higher income streams increase the demand for protein-rich and high-value foods. Furthermore, humans are faced with the huge challenge of producing the same amount of food that was produced in the last 8 000 years, but only in the next 40 years.
South Africa is currently experiencing the same challenges and there is an important drive to supply the human demand for animal-source protein and to reach self-sufficiency in protein supply. Critical linkages exist between the human demand for animal-source protein, the number of animals to be slaughtered to supply this demand, and the animal feeds required to feed the animals. South Africa requires a decision support tool to aid decision making, to provide accurate and relevant results, and to measure self-sufficiency in protein supply.
In this study, dynamic data generated by the BFAP model is integrated into the APR model. Thereafter, the APR_OPT model is able to determine least-cost animal feeds to satisfy the nutrient requirements of all animal categories. This study aims to quantify, manage, and forecast the linkages between these industries. The specific objectives are to replicate and update the APR model, to generate and forecast baseline results for the period 2015 to 2024 with integrated BFAP data, and to determine self-sufficiency of protein for animal feed in the future.Table
|Percentage growth required for local protein production to reach certain targets by 2024|
|Projected total protein
|Required annual growth rate for
local production from 1 190 917 tonnes
|Oilcake quantity||Percentage of projected consumption|
|2 805 516||0.67%||1 262 482||45%|
|2 805 516||4.59%||1 683 310||60%|
|2 805 516||8.52%||2 104 137||75%|
|2 805 516||12.45%||2 524 964||90%|
|2 805 516||15.05%||2 805 516||100%|
|Local growth at forecasted total protein growth|
|2 805 516||9.57%||2 216 358||79%|
Animal feed consumption is expected to increase by an average of 2.54% annually to 14.6 million tonnes by 2024 (Table). Total protein usage for animal feeds is expected to increase from 1.98 million tonnes in 2015 to 2.81 million tonnes by 2024, with a 4.63% average increase per year. South Africa's self-sufficiency in protein supply for animal feeds is expected to increase from 60% in 2015 to 79% by 2024.Figure
Total protein versus imported protein
Income and cost estimates of soybeans canola and a few competitive crops
The main objectives of the Protein Research Foundation (PRF) are to replace imported protein for animal consumption with locally produced protein; and the improved utilisation protein. These objectives are promoted by funding research and technology transfer.
The PRF currently concentrates on two crops, soybeans and canola. It is very important to achieve relative profitability for these and competitive crops.
Income / cost estimates are very useful as they are important information and management tools. It is also possible to use the estimates for strategic planning and policy purposes.
Previously crop income/cost estimates were obtainable easily from the Departments of Agriculture and certain agri businesses. Most government departments no longer conduct the studies regularly and the information they have is mostly dated.
As a result, the PRF requested Agriconcept (Edms.) Bpk. to calculate income / cost estimates for selected grain crops in the summer rainfall areas on a continuous basis.
Field of study and source of information
Regions and sources of information are shown in the table below:Table 1
|North West province|
|Piet Retief||X||Group Discussion|
|Loskop irrigation scheme||X||MGK|
|Bergville / Winterton||X||Group discussion|
|Northern Cape province|
At the moment the PRF enjoys the co-operation of agri businesses within the summer rainfall area. MGK, NWK, GWK and VKB prepare annual income / cost budgets for various crops produced within their service areas. The objective of the budgets is to serve planning instrument and assist with credit applications. They also provide, annually at about August, income/cost crop estimates for the purposes of this study. Agriconcept evaluates the information, does the necessary adjustments where necessary and repackages the information to present the information on a comparable basis. To present the income/cost estimates in a standard format, in a comparable way, every attempt is made to obtain detailed information from agribusinesses. The information is presented in summarised format without making available any detailed information. The PRF tries to reflect a typical medium to long-term situation. As such seasonal variations are not taken into consideration.Table 2
|North West province|
|Piet Retief||X||Group Discussion|
|Loskop irrigation scheme||X||MGK|
|Bergville / Winterton||X||Group discussion|
|Northern Cape province|
Agri businesses in some areas do not offer agricultural economical services. The PRF obtains information in those areas by conducting group discussions. A small group of farmers are involved to obtain the information. The information obtained is processed to produce income / cost estimates. The information is adjusted annually, according to the latest prices or by using price indices. Every attempt is made to conduct group sessions every three years, because of possible structural changes within the industry.
The budget is prepared as follows:
- Gross income
The expected yield per crop, as well as the gross price, is used as the basis for calculating gross income. SAFEX listed prices are used to calculate the gross income for soybeans, maize, wheat and sunflower. SOILL estimates are used for canola prices to calculate budgets. GWK prepared a groundnut price. Gross prices on 06.11.2014 for futures contracts were as follows:
Crop Source Futures contract for delivery during Futures contract price (R/tonne) Soybeans SAFEX May 2016 5 380 Maize SAFEX July 2016 2 946 Wheat SAFEX December 2016 4 650 Sunflower SAFEX July 2016 5 880
Canola and groundnut prices were as follows:
Crop Source Delivery during Estimated price (R/tonne) Groundnuts GWK April/May 2016 10 930 Canola SOILL November/December 2016 4 550
- Net price at farm gate
The net price per tonne at the farm gate represents the gross price less marketing costs. Marketing costs include the following items:
- Transport differential (obtained from SAFEX)
- Grade discount for wheat (SAFEX formula)
- Handling fee
- Broking fee or marketing commission
- Hedging costs
- Drying costs
- Statutory wheat levy
Transport costs from farm to silo were estimated by Agriconcept, taking into account distance between farm and silo.
It was assumed that products are delivered immediately after harvest, allowing no estimate for storage costs.
- Costs prior to harvest and harvesting costs
Costs prior to harvest are set out in the attached budgets and do not require much explanation. Harvesting costs include only fuel and repair costs. Where producers use contractors' services, the costs were used as cost.
Depreciation is not included as a cost item. Mechanisation costs include only fuel and repair costs.
- Comparable yields
A comparison between yields for various regions is shown in Table 6.2 and Table 6.3.Table 6.2
Comparison of grain yields for the various regions, irrigation Region Soybeans Maize Wheat Groundnuts Canola Soybeans as percentage of maize Tonnes per ha % North West province MGK area (Brits) 4.00 12.00 5.50 - - 33% Mpumalanga province Loskop irrigation scheme 4.00 12.00 5.50 - - 33% KwaZulu-Natal Bergville 4.00 12.00 6.00 - - 33% Northern Cape province GWK area 4.00 13.50 7.50 3.00 3.50 30% Comparison of grain yields for the various regions, dryland Area / Product Soybeans Maize Sunflower Wheat Soybeans as percentage of maize Tonnes per ha % North West province NWK area Koster (area 1) 2.00 3.50 2.00 - 57% Lichtenburg (area 2) 1.50 3.50 1.50 - 43% Mpumalanga province Trichardt (precision) 2.50 8.90 - - 28% Piet Retief 2.50 6.50 - - 38% KwaZulu-Natal Bloedrivier 2.00 4.50 - - 44% Free State Reitz area 2.00 5.00 2.25 2.50 40%
The assumption obtained in tables 6.2 and 6.3, indicates a relatively constant ratio, with the exception of Koster and Kinross, between soybean and maize yields for the respective regions.
GJH Scholtemeijer, M du Preez and Y Papadimitropoulos
The Marketing Committee has paid significant attention to the website over the past few years. The POEMS software system ("PRF/OPDT Electronic Management System") deserves special attention. POEMS enables the administration to use a single programme to control finalised projects, handle project and bursary applications, administer approved bursaries and projects, as well as managing the funding and the central list of contacts. POEMS also offers a search function that allows users to search for general information and news items on the PRF website and on the POEMS project database. Certain information is not available on the public domain and may be accessed only via the PRF database. The Board is grateful to Mrs Du Preez and the staff involved in maintaining the website.
One of the measures to determine the value of the website to users is the number of visitors and time spent on the site, including the number of pages read. The statistics below indicate the number of visitors per reporting year, since the inception of the website.
|Reporting year||Unique visitors
Raw values *
|Visitors||Pages||Pages per visit|
|2007||5 404||3 041||10 838||2.79|
|2008||11 104||5 274||18 829||2.82|
|2009||10 194||6 610||27 341||3.18|
|2010||11 812||6 054||23 347||2.98|
|2011||12 357||5 511||24 258||3.29|
|2012||16 306||6 909||28 206||3.12|
|2013||54 739||8 767||34 284||2.97|
|2014||54 590||10 189||39 363||3.03|
|2015||35 653||12 519||45 078||3.60|
* Raw values indicate total interactions measured by the web server, while Google values only measure the visitors that link to the web site using a web browser. Visitors that link to the web site again, using the same browser are not counted again.