Reports / Research Reports / 2012/2013 / Projects Finalised

Research Report 2012/2013

6.

 

Projects finalised successfuly or that showed progress (Annexures I and II)


Index of projects

  1. Project titles

    1. Evaluation of PRF-soybean elite lines under South African conditions
    2. National soybean cultivar trials
    3. Increasing soybean production on the Highveld
    4. Establishment of an early warning system for soy­bean rust
    5. Investigating the etiology and incidence of soilborne diseases of soybean in South Africa
    6. Insect biodiversity and abundance in soybeans
    7. Investigating enzyme activity as a new tool to facilitate rapid identification of root-knot nematode resistance in soybean genotypes
    8. Cultivar evaluation of oil and protein seeds in the winter rainfall area
    9. Boron requirements of canola
    10. Plant density of canola: impact on the suppression of weed and yield of canola in the Swartland
    11. Chemical options for weed control in GM-canola
    12. Evaluation of shortened canola production periods and the use of alternative crops on the sustainability of winter grain production under conservation agri­cultural practices in the Riversdale flats
    13. Sulphur (S) and nitrogen (N) requirements of canola
    14. Enhancement of canola as a rotation crop within a conservation system in the dry land areas of the Swartland using a competition between producers
    15. Enhancement of canola as a rotation crop within a conservation system in the dry land areas of the Southern Cape using a competition between pro­ducers
    16. Income and cost estimates for soybeans, canola and certain competitive crops
    17. The effects of dietary crude protein on the fertility of broiler breeder males
    18. PRF web page
    19. Projections of oilcake demand for animal consump­tion in 2015, 2020 and 2025

6.1

 

Evaluation of PRF-soybean elite lines under South African conditions


GP de Beer and WF van Wyk
Contracters, Protein Research Foundation

Trial 1: (INTA)
Three replications of fifteen (15) genotypes, which included maturity groups 4 to 7, were planted in four 45cm rows, 5m in length, on 10/12/2012. Six (6) local cultivars from Pannar and Link Seed were included as controls for each maturity group.

Trial 2: (EMBRAPA)
Three replications of nine (9) genotypes, which included maturity groups 4 to 8, were planted in four 45cm rows 5m in length on 12/11/2012. Six (6) local cultivars from Pannar and Link Seed were included as controls.

Trial 3: (VIÇOSA)
Three replications of ten (10) genotypes, which included maturity groups 4 to 7, were planted in four 45cm rows 5m in length on 12/11/2012. Six (6) local cultivars from Pannar and Link Seed were included as controls.

Trial 4: (EEAOC)
Three replications of 16 genotypes, which included maturity groups 4 to 7, were planted in four 45 cm rows 5 m in length on 2/11/2011. Six (6) local cultivars from Pannar and Link Seed were included as controls.

Trial 4 Ekstra: (EEAOC)
Three replications of fifteen (15) genotypes, which included maturity groups 4 to 8, were planted in four 45cm rows 5m in length on 3/11/2011. Six (6) local cultivars from Pannar and Link Seed were included as controls.

Trial 5: (CHINA)
Three replications of twelve (12) genotypes, which included maturity groups 4 to 8, were planted in four 45cm rows 5m in length on 13/12/2011. Four (4) local cultivars from Pannar and Link Seed were included as controls.

Eighteen (18) different data sets were taken of each of these genotypes before threshing and five (5) after threshing.

The best yields achieved in the different trials were 4307 kg/ha for J102515 in trial 1, 4935 kg/ha for LS 6146 R in trial 2, 4325 kg/ha for CDX 10-105 in trial 3, 4010 kg/ha for MDAT-640-5I in trial 4, 4323 kg/ha for 580-5I in trial 4 (UP-only) and 4168 kg/ha for PAN 1664 R in trial 5. Notice that in two of the six trials our local cultivars had the best yields.


6.2

 

National soybean cultivar trials


Messrs JL Erasmus, NN Mogapi, HSJ Vermeulen and TC Ramatlotlo
ARC-Grain Crops Institute, Potchefstroom

A total of 36 cultivars were evaluated (2007/08 to 2011/12 season) in 146 field trials distributed over the production area representing the cool-, moderate- and warm areas. Conventional as well GM cultivars were included in the trials which were executed in a conventional manner (i.e. no Roundup application). 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 measured and the yield reliability of cultivars calculated. Yield reliabilities serve as guidelines for cultivar selection. The mean number of days from planting to 50% flowering of cultivars for the cool-, moderate and warm areas was respectively 75, 62 and 53 days.

The overall mean yield was 2 302 kg ha-1 for the cooler areas, 2 392 kg ha-1 for the moderate and 3 195 kg ha-1 for the warm areas. Cultivars with a high stability are important in the selection of cultivars by producers due to the reliability of the expected future yield. Cultivars which had high stabilities over the reporting period were PAN 535 R, PAN 737 R and Dundee for the cooler areas, A5409 RG, Heron and LS 6161 R for the moderate areas and, PAN 737 R and LS 6150 R for the warmer areas. Cultivars with an above average reliability at yield targets from 1000 to 4 000 kg ha-1 for three seasons or more can be considered the long-term high performers and deserve special mentioning. These cultivars were PAN 1583 R for the cooler areas, PAN 1666 R, PAN 1454 R, PAN 1583 R , PAN 1664 R and LS 6150 R for the moderate areas as well as LS 6150 R, LS 6161 R, PAN 737 R, PAN 1664 R and Heron for the warmer areas.


6.3

 

Increasing soybean production on the Highveld


Mr WF van Wyk
ARC-Grain Crops Institute, Potchefstroom

Cultivation methods with different rotation systems
Bold printed treatment is the treatment for the prevailing season.

Treatments: Plough (soya, soya, soya, soya) – (soya, maize, soya, maize) – (maize, soya, maize, soya), No-till (soya, soya, soya, soya) – (soya, maize, soya, maize) – (maize, soya, maize, soya), and disc (soya, soya, soya, soya) – (soya, maize, soya, maize) – (maize, soya, maize, soya). In 2009/10 a maize monoculture treatment was added to all three cultivation methods.

Figure 1

Maize yield in ton/ha for 2012/2013

Maize yield (ton/ha) for the different cultivation and rotation systems in 2012/13

Figure depicting maize yield for different cultivation and rotation systems

According to Figure 1 above-average yields were achieved with maize in the 2012/13 season. The highest average yield was achieved where maize followed soybeans uisng no-till (13.7 ton/ha) and the lowest yield where maize followed maize using plough cultivation (9.2 ton/ha).

The soybean yields are shown in Figure 2.

Figure 2

Soybean yield in 2012/2013

Soybean yield (kg/ha) for the different cultivation and rotation systems in 2012/13

Figure showing soybean yield for the different cultivation and rotation systems

It is clear from the graph that the yield of soybeans followed by soybeans was lower than when soybeans after maize for all three cultivation methods. With no-till, both soybeans followed by soybeans and maize followed by soybeans had the best yields. Yields were low because this trial is planted under dry land conditions and the rainfall in February was low.

Maximum yield (irrigation)
This trial was not planted this year due to a problem with the irrigation system but will continue in the 2013/14 season.

Planting date trial
Fourteen different cultivars that varied between MG-IV to MG-VII were planted on seven different planting dates in 45 cm rows. The planting dates were respectively 25/9/2012, 5/10/2012, 25/10/2012, 5/11/2012, 20/11/2012 and 30/11/2012.

In Figure 3 the number of days from planting to harvest is shown for the different cultivars for the different planting dates. It is evident that the MG-IV cultivars at all planting dates were ready for harvest in a time frame of between 130 and 148 days while the longer season cultivars were harvested between 136 to 204 days. The variation of the longer season cultivars in terms of harvest readiness is therefore much bigger than with the short season cultivars at different planting dates.

Figure 3 The number of days from planting to harvest of 14 cultivars for 7 planting dates (PD)

Graph showing number of days from planting to harvest of 14 cultivars for 7 planting dates

The yields of the 14 cultivars at 7 different planting dates are given in Figure 4.

Figure 4 Yield (kg/ha) of 14 cultivars for 7 planting dates (PD)

Figure 4 shows yield of 14 cultivars for 7 planting dates

The early planting dates produced better yields in general than the later plantings except for certain determinate growers (PAN 1664R and PAN 535R) where yields were the same or better.

Trials conducted by farmers

Sclerotinia trial at Kinross (Vosstoffel Boerdery)

Six companies entered different products for the control of sclerotinia this past season and are as follows:

  • Philagro: Sumisclex, Sumisclex + BreakThru, Sumisclex + BreakThru as corrective treatment.
  • Plant Health Products: Eco-T on seed followed by Eco-77 spray applications, Eco-T spray applications and Eco-T + Agrisil(K) spray applications and Eco 77 on seed followed by one and two spray applications with Procymidone 250 SC + BreakThru during flowering and 10 days later.
  • Stimuplant: B-Rus on seed followed by spray application during flowering (R1).
  • Green Bio: Chitosan on seed followed by spray application during flowering (R1).
  • Helga Dagitat: Armenius, Sparticus and T-Gro on seed.
  • BASF: Bellis at respectively 600g and 1200g/ha with first flower (R1).

Controls were included between all treatments in such a way that each treatment was bordered by a control at least on one side. A short growth type (LS 6444 R) was included in the trial to "avoid" sclerotinia while a longer growth type (LS 6161 R) was used where the different biological and chemical treatments were tested.

The trial was planted on 20/11/2012 and the different treatments were applied as plants developed. There was no sclerotinia infection this season but the trial was damaged by hail on 11 May and was therefore not harvested.

Planting date and plant density trial at Stoffberg (Piet Prinsloo and Johan Scheepers)

18 cultivars were planted at three different plant densities on the 24/10/2012 and 14/11/2012 respectively at Piet Prinsloo (first planting) and Johan Scheepers (second planting). Flowering and harvesting dates were taken as well as pod heights. The trials were harvested, threshed and all post-harvest data were taken.

In spite of a very dry season, good results were achieved, especially with respect to plant densities. The results demonstrated that some cultivars prefer higher plant densities whilst others do not. These trials were planted under no-till conditions.

It is clear that upright cultivars like LS 6444 R and LS 6146 perform better at a high plant population (520 000) than at a low plant population (400 000). It is also evident that the MG-IV and V cultivars out-yielded the long season growers and this was caused by the drought in February.

The second planting was 65-75% damaged by hail 10 days after emergence but some of the long season cultivars (especially the indeterminate growers) recovered well and therefore out-yielded the early cultivars.

The yields of the second planting date were considerably lower than of the first planting date but when considering the hail damage that occurred, some of the longer growers had reasonable yields.

Mr Marius van Rensburg of the Department of Agriculture at Nooitgedacht, Ermelo (Mpumalanga) was the responsible officer for the trial and he helped with the collection of flowering and harvesting data.


6.4

 

Establishment of an early warning system for soybean rust


Mr GP de Beer
Contractor, Protein Research Foundation

During the 2012/13 season an early warning system was attempted for soybean rust based on trap crop trials, also referred to as indicator trials. Ten localities were identified that represented the major soybean production areas. The PRF and other co-workers such as PANNAR, the KZN Department of Agriculture and a number of soybean producers attempted to create this early warning system. The localities were Kestell (Free State), Cedara, Greytown, Normandien, Vryheid (KwaZulu-Natal), Dirkiesdorp, Morgenzon and Kinross (Mpumalanga), Greylingstad (Gauteng) and Potchefstroom (North West).

As in the past the trap crop trials were planted approximately two weeks before the general soybean planting date in each region. Two Roundup Ready soybean varieties (PAN 1454 R, a MG 4 cultivar and PAN 737 R, a MG 7 cultivar) were planted on an area of 200 m² per site. The producers on whose properties these trials were located were responsible for planting and maintaining the trials, which were visited from the 9 January 2013 on a weekly basis. Strict sanitary protocols were followed in the screening process in order to limit transmission of spores between trials.

Once rust was detected the relevant producer in the affected area was immediately advised to spray the trial with specific fungicides in order to ensure that the trial did not serve as a a source of infection of commercial material in the area. Rust was first found at Cedara (8 February 2013), Vryheid (9 February 2013), Dirkiesdorp and Normandien (4 March 2013). No rust was found at any of the other localities.


6.5

 

Investigating the etiology and incidence of soilborne diseases of soybean in South Africa


Drs YT Tewoldemedhin and SC Lamprecht
ARC-Plant Protection Research Institute

Soybean seedlings and plants are susceptible to a wide range of soilborne pathogens, which complicates research on the etiology and diagnosis of soilborne diseases of the crop. Research in other countries showed that soilborne diseases of soybean can cause significant economic losses in most soybean growing areas of the world. Yield losses of up to 70% and in some cases plant losses and yield reduction of 100% in very susceptible soybean cultivars have been reported. In South Africa, the etiology of soybean soilborne diseases was not studied and documented prior to the study that was conducted over the past two years. It, therefore, is the first extensive survey that has investigated soilborne disease of soybean in South Africa. The study was done in thirteen national cultivar trial sites situated in soybean production localities in six provinces representing three climatic regions. The results of this study indicate that important soilborne pathogens reported in other countries were found to be associated with diseased soybean crowns and roots in soybean production areas of South Africa. The incidences of genera and species recovered were affected by area sampled, time of sampling and climate of the area sampled.

In the previous study it was concluded that the importance of all the species found in soybean production regions of South Africa should be determined on soybean as soilborne pathogens. Furthermore, the previous survey was conducted on national cultivar trial sites and concluded that the incidence and severity of soilborne diseases of soybean should be determined on commercial farmers' fields irrespective of the cultivar planted in order to determine the extent and importance of soilborne diseases in the major soybean production areas of the country. Therefore, the main objectives of the study during 2012/13 were to determine the incidence and severity of soilborne diseases of soybean in commercial farmers' fields irrespective of the cultivar planted in the major soybean production areas of the country; and to investigate the potential of all the fungal species, recovered from the previous study, as soilborne pathogens of soybean by employing pathogenicity tests on soybean seedlings under glasshouse conditions.

The identity of fungi and oomycetes associated with diseased cotyledons, crowns and roots of soybean plants were assessed in a survey con­ducted during the 2012/13 growing season. Soybean plants and rhizosphere soil were collected from all commercial farms that were surveyed. Plants were sampled at three growth stages (two weeks after planting, flowering and physiological maturity or seed pod filling) from twelve soy­bean commercial farms that represent three climatic regions (cool, moderate and warm) in five provinces of South Africa. Diseased cotyledons, hypocotyls / crowns and roots were rated for disease severity and analysed for associated mycoflora using morphological description and sequence analyses of DNA exracted from representative isolates. Soil samples collected from each area were used for glasshouse assays to determine the existence and biological nature of soilborne diseases by pasteurizing half of the soil at 83ºC and planted with soybean seeds. In addition, pathogenicity trials of all the representative species of fungi and oomycete were conducted under glasshouse condition. Pathogenicity and relative virulence of each isolate was determined by assessing the percentage survival of soybean seedlings, plant length and crown and root rot severity three weeks after planting.

From the survey conducted the highest crown and root rot ratings were recorded at Brits, Bothaville and Clocolan, while Brits, Clocolan and Vryheid had the highest cotyledon rot severity. The highest crown rot severities were recorded at the third sampling time. Root rot severity was high at Clocolan throughout the season (all the three sampling times).

A total of 6860 fungal isolates was recovered from cotyledons, crowns and roots. The fungal isolates were from 29 fungal genera. The most frequently isolated fungal genera and species included Alternaria spp., F. equiseti, F. oxysporum, F. solani, Gliocladium spp., Macrophomina spp., Phoma spp., Phomopsis spp., Pythium spp., Rhizoctonia spp., Trichoderma spp. and Sclerotium spp. In addition, Sclerotinia isolates were recovered from diseased soybean stems and crowns. The incidences of genera and species isolated were affected by area sampled, time of sampling and climate of the area sampled.

In this study, close to 60% of all isolates obtained belonged to the genus Fusarium of which Fusarium oxysporum was the dominant species with more than 40% of the isolates recovered belonged to this species. The second most dominant species within the genus Fusarium was F. solani. Fusarium equiseti was also amongst the frequently isolated species within the genus. Fusarium solani isolates recovered in this study do not have 100% sequence similarity with the sudden death syndrome causing species (Fusarium virguliforme formally known as F. solani f. sp. glycines, F. tucumaniae, F. brasiliense and F. crassistipitatum). However, some Fusarium isolates obtained from a farm in Lydenburg (Mpumalanga), with typical sudden death symptoms on the plants, had 99% similarity with Fusarium virguliforme based on one gene area. Further study is being under way to confirm whether these isolates are one of the sudden death causing species.

Glasshouse assays revealed that the survival of soybean seedlings grown in pasteurized field soils collected from all the farms sampled signi­ficantly improved, though with varying degrees at each sampling time. The surveys conducted during the 2012/2013 growing season confirmed that the fungi reported as soilborne disease causing organisms in other countries are found associated with diseased cotyledons, crowns and roots of soybean in South Africa, but some fungi were also reported on soybean for the first time.

Pathogenicity assays using 46 Rhizoctonia isolates, representing the eight anastomosis groups (AGs) and the unidentified multinucleate Rhizoc­tonia, showed that the multinucleates AG-2-2 IIIB, AG-4 HG-III, AG-4 and one unidentified multinucleate Rhizoctonia were pathogenic, since they reduced survival of soybean seedlings and caused significantly more hypocotyl and root rot. Even though R. zeae and a few isolates of AG-Ba did not cause pre-emergence damping-off, they caused significant hypocotyl and root rot compared to the control. This study showed that pathogenic Rhizoctonia species and AGs occur on soybean in all production areas in South Africa. Other pathogenicity trials are being under way and the results will be reported shortly.

This is the first extensive survey on commercial soybean farms to have investigated soilborne diseases and associated pathogens of soybean in South Africa. The survey conducted on commercial farmers' fields during the 2012/2013 season should be repeated during 2013/2014 to confirm results and to ensure that all the fungi and oomycetes associated with diseased cotyledons, crowns and roots of soybean are identified for further studies. This will also determine the focus of future research to develop management strategies against the most important soilborne diseases of soybean in South Africa.


6.6

 

Insect biodiversity and abundance in soybeans (Glycine max)


Ms JM Truter
ARC-Grain Crops Institute, Potchefstroom

The importance of soybeans has increased over the past few growing seasons in South Africa, due to its suitability as a rotation crop with maize. As a result of this production increase it is important to assess arthropod biodiversity in soybean and to determine base line data for future use in assessments of the possible effects of genetically modified soybean or changes in crop production practices on arthropod communities. A better understanding of the species that occur on soybeans may also assist in the development of integrated pest management strategies.

Several arthropod biodiversity studies have been conducted internationally related to biodiversity in soybeans, but a lack of similar information exists in South Africa. Rawat and Kapoor (1968) reported 273 insect species to attack soybeans. In Nigeria 24 insect pest species were recorded (FMARD, 2002), in the tropics 84 insect species caused damage (Jackai et al., 1990) and in India 20 pest species were recorded (Singh & Singh, 1990). From these studies it can be concluded that the complex of insects that inhabit soybeans is large and diverse. It must be accepted that any crop expansion is usually accompanied by increased levels of pests, thus necessitating increased awareness for potential future threats (Van Wyk & Smit, 2010).

The aims of the study were to compile a list of arthropods which occur on soybean plants and to compare the diversity and abundance of arthropods on herbicidetolerant and conventional soybeans. Future pests and possible economically important arthropods were identified from the list through an environmental risk assessment model approach.

In Brits four herbicide-tolerant soybean fields and in Potchefstroom one herbicidetolerant as well as one conventional soybean field was sampled. Conventional fields were not available in the Brits area and therefore no comparative study could be made between the two sites in Potchefstroom and those in Brits. Two methods of collection were used, i.e. pitfall traps and a D-Vac for suction sampling. Both aboveground and ground-dwelling arthropods were sampled. Thirty pitfall traps were placed randomly in each field to sample ground-dwelling arthropods, which was left in the field for one week before collection. The D-Vac method (Kruger et al., 2008) was used to collect the above-ground arthropods. Five replications of 5 m rows were sampled in each field. The D-Vac bags and its contents were placed into a plastic bag and kept for 2 days in a refrigerator. Collection of samples was done once a week for a period of a month (February-March). Growth stage of the soybean was between R5-R6. Species were sorted to morpho-species and identified to at least order and family level. The morpho-species were also grouped into the following functional groups: detritivores, herbivores, predators and parasitoïds. The herbivores and predators were further divided on the basis of feeding strategy into sucking herbivores/predators (piercing-sucking mouthparts) and chewing herbivores/predators (chewing mouthparts). Statistical analyses were done with the total arthropod diversity and for the different functional groups. The Shannon and Margalef indices, the total number of species as well as the total number of individuals were compared between soybean varieties (herbicide-tolerant vs. conventional). The Shannon diversity index (H¹) describes diversity (species richness and evenness), whereas the Margalef richness index (d) describes species richness. The statistical analysis was only done for the Potchefstroom site as no conventional fields were available for the Brits area.

The diversity of arthropods collected during this study was high. A total of 6,175 arthropod individuals, comprising 169 morpho-species were collected during this study. In Brits a total of 4,543 arthropod individuals consisting of 118 morpho-species and in Potchefstroom a total of 1,632 arthropod individuals consisting of 129 morpho-species were collected. The 169 morpho-species consisted of 13 orders. Only 44.3% of these species occurred in both localities. The most abundant arthropods and species found on soybeans and which should be considered in a risk assessment are listed in Table 1.

The diversity indices indicated no differences between herbicide-tolerant and conventional soybeans for total arthropod diversity in Potchef­stroom. There was also no significant difference between number of species, but there was, however, a significant difference for the number of individuals between herbicide-tolerant and conventional soybeans (p=0.01) in the Potchefstroom area.

Initial results indicate that herbicide-tolerant soybeans do not have an effect on arthropod diversity or on the different functional groups. Additional research over various seasons is, however required to confirm this observation. This study provides a baseline in biodiversity of arthropods on soybeans in South Africa and generates a basic checklist of these species that can be used in an integrated pest management system.

Knowledge and understanding of the entire soybean system, not the pests alone, and of the influence of herbicide-tolerant cropping systems on the occurrence, density and behaviour of pest and beneficial arthropods in soybeans must increase if integrated pest management systems for soybeans are to be developed and implemented (Jackai et al., 1990; Jackson & Pitre, 2004).

Table 1
Functional groups and abundance of arthropods that should be considered in an environmental risk assessment of soybeans
Volopste spesie per funksionele groep
Functional group Species per group Order Family Genus / Morpho spp. Total
individuals
Detritivores 18 Diptera Diptera sp. 6 167
Sucking herbivores 34 Hemiptera Cicadellidae Cicadellidae sp. 2 111
Chewing herbivores 38 Coleoptera Chrysomelidae Chrysomelidae sp. 1 66
Sucking predators 15 Hemiptera Miridae Deraeocoris sp. 1 45
Chewing predators 54 Hymenoptera Formicidae Formicidae sp. 1 3 386
Parasitoïds 13 Hymenoptera Hymenoptera sp. 2 49

6.7

 

Investigating enzyme activity as a new tool to facilitate rapid identification of root-knot nematode resistance in soybean genotypes


Prof HA Fourie, Ms C Venter & Mr J Berner
School for Biological Sciences, North-West University, Potchefstroom

Root-knot nematode resistance levels of local soybean cultivars that continuously enter the market must be available to producers. The use of host plant resistance is currently one of the few cost-effective and environmentally-friendly management strategies to minimize yield losses since no nematicides (synthetic and/or biological) are currently registered locally for use on the crop. Classical assays to determine the host suitability of soybean cultivars to Meloidogyne spp. are elaborate, laborious, time-consuming and strongly influenced by environmental conditions and nematode genetic variability. This project thus focusses on the use of biochemical markers, which include the most recent deoxyribonucleic acid (DNA) technology, to enable identification of root-knot nematode resistance in soybean. These include phenotypic markers based on proteins and/or enzymes associated with the resistance status or response to nematode infection, viz. catalase (CAT), lipoxygenase (LOX) and peroxidase (POD). Results obtained as a result of screening trials that were conducted with M. incognita showed that substantial variation existed among the 24 cultivars with regard to their host status to this root-knot nematode species. Gall rating indices obtained 30 days after inoculation (DAI) indicated that the resistant standard LS5995 as well as cultivar PHB95Y20 had similar and significantly lower index values compared to the other 22 cultivars screened. Although significant differences were evident among the latter 22 cultivars they all exhibited high gall rating indices with PAN1666R having the highest, followed by Sonop and A5409RG. Furthermore, all nematode parameters that were determined indicated that cultivar LS5995 was the poorest host to M. incognita with an Rf value of <1, indicating resistance. In contrast cultivar LS6248R was the most susceptible, followed by Dundee and LS6164R. For the traditional screening techniques used, results obtained thus far indicate that gall ratings do not correspond with egg and second-stage juvenile (J2) counts/root system and per g of root and also not with Rf values that were determined. The traditional method of using gall ratings at an early growth stage of soybean plants therefore is not an option to use in order to accurately identify poor hosts of M. incognita. In terms of enzyme activity measured, CAT results were highly variable and do not warrant further discussion. Initial results with LOD and POD on the other hand showed a 40% and 20% increase in activity for the respective enzymes for M. incognita-infected LS5995 plants compared to uninfected plants.


6.8

 

Cultivar evaluation of oil and protein seeds in the winter rainfall area


Mr PJA Lombard
Department of Agriculture: Western Cape

The Western Cape Department of Agriculture conducted a range of cultivar trials during the 2012 season in the Western and Southern Cape (Rûens). In the Southern Cape eight trials were planted and the data sets of five trials were used. Three trials were lost due to bird damage (wildemakoue), fall over because of blackleg and too wet conditions at Tygerhoek. In the Swartland seven trials were planted at six locations and six sets of data were used (wildemakou damage at Grasrug).

The past season was characterized by very good moisture conditions in both the Swartland and Rûens. At both areas, above average rainfall occurred during the spring which caused an extended growing season (by a few days). The exception was Pools in the Swartland with below average rainfall.

In the Swartland, the average yield was significantly higher in 2012 (2300 kg ha-1) than in 2010 and 2011 (1840 kg ha-1 and 1923 kg ha-1). The trial result from Pools differed significantly. The TT cultivars had a very low yield while four cultivars yielded over 2000 kg ha-1. The trial average (despite the low TT yields) was 1344 kg ha-1.

The mean trial yields varied between 1344 kg ha-1 (Pools) and 3124 kg ha-1 (Langgewens 1st planting on the 9th of May). The yield of 1st planting at Langgewens was 4% higher than the 2nd planting (23 May). The small difference can be attributed to favourable climatic conditions during seed fill stage.

Hyola 50 (2948 kg ha-1) was on average the best conventional cultivar and Hyola 575 CL (2850 kg ha-1) the best CL cultivar. The CL cultivar, 46Y83 (2755 kg ha-1) has the 3rd highest seed yield, however significantly lower than Hyola 50. The seed yield of Agamax, Hyola 571CL and 45Y86 returns were significantly lower than those of Hyola 575 CL.

In the TT group, the two hybrids Hyola 555 TT (2392 kg ha-1) and Tumby HT (2177 kg ha-1) gave the highest yield (all the trials). The seed yield of Hyola 555 TT was significantly better than the other cultivars in the TT group. The yield of the TT cultivars (1969 kg ha-1) was on average 25.6% lower than the conventional cultivars (2647 kg ha-1) (24.6 in 2011 and 25.26% in 2010). The average yields of the CL cultivars were 7.1% lower than that of the conventional cultivars.

In the Rûens the average yield per trial ranged from 3062 kg ha-1 at Klipdale to 1855 kg ha-1 at Tygerhoek 1. The data from the Tygerhoek trial (early planting) are included; the yield was less than expected due to very wet conditions. The average yield of TT cultivars was 17.5% (22.1% in 2010 and 11% in 2011) lower than the average of the conventional cultivars. The seed yield of the Cl group was only 0.2% better than the conventional group (10% in 2011).

The CL cultivar 46Y83 (3194 kg ha-1) and the conventional cultivar Hyola 50 (3.193 kg ha-1) had the highest average yield in Rûens. In the TT group, the two hybrids Hyola 555 TT (2553 kg ha-1) and CB Jardee HT (2518 kg ha-1) gave the highest seed yield.


6.9

 

Boron requirements of canola


Prof GA Agenbag and Mr E Kempen
Stellenbosch University

Boron is one of the eight essential micronutrients required for normal growth and development of most plants. Deficiency of boron can cause reductions in crop yield, impair crop quality or have both effects, due to its role in various metabolic processes and pollination. Boron deficiencies may result in sterility or low germination of pollen. Like all its relatives in the Brassica family, canola has a very high boron requirement and needs more boron through all growth stages (vegetative and reproductive) than most other crops. However, high levels of boron may be toxic to plants, and crops differ with regard to sensitivity. Little research has been done previously in the Western Cape on boron requirements of canola and although some canola producers do apply boron, recommendations are based on research done on cereal and vegetable crops and have not been verified for canola.

Field trials were conducted during 2012 at Altona and Langgewens Research Farm in the Swartland and Roodebloem in the Southern Cape on soil with deficient (< 0.30 mg kg-1) or low (0.30-0.50 mg kg-1) boron contents. Boron, at rates of 0, 0.5, 1.0 and 1.5 kg Solubor ha-1 were applied 40 days after planting (DAP), 60 DAP or 40 and 60 DAP. Due to a long rainy season and generally cool climatic conditions during the grain filing stages, high grain yields of more than 2000 kg ha-1 were obtained at Altona and Roodebloem. Smaller grain kernels (lower thousand grain weight) at Langgewens indicated less favourable conditions during grain filling which resulted in lower grain yields and lower oil and protein contents. Solubor (boron) applications resulted in significantly higher grain yields in all localities. Optimum application rates differed between localities and seem to correlate with boron content of the soil, while application rates of 2-3 kg Solubor ha-1 showed reduced yields (toxic effects) at all localities. No significant differences were obtained between Solubor applications at 40 or 60 days after planting in 2012. It was however clear that splitting the application between 40 and 60 days after planting did not result in higher grain yields. Solubor (boron) applications had very little effect on oil or protein content of the grain.


6.10

 

Plant density of canola: impact on the suppression of weed and yield of canola in the Swartland


Dr PJ Pieterse
Stellenbosch University

The aims of the study are 1) to study the effect of plant density on the suppression of weeds (biomass) by different canola cultivars in the Swartland and Southern Cape and 2) to study the effect of plant density on the development (flowering date, physiological ripening date), growth (biomass of reproductive versus vegetative components), plant length, yield and quality of different canola cultivars in the Swartland and Southern Cape canola production areas. Field trials were planted on the Roodebloem experimental farm (Southern Cape) and the Langgewens experimental farm (Swartland) respectively. In one set of experiments at each locality the recommended weed control programs were followed to create a weedfree environment. In the second set of experiments no weed control (except for nonselective herbicides before planting) were carried out to determine the weed suppressive effects of the different canola cultivars. The treatments were as follows: a) 4 cultivars (1 open pollinated and 1 hybrid cultivars each of the TT and Clearfield types) (CB Jardee, Bravo, 43c80 and 45y82) were planted and b) sowing densities were manipulated with the aim of achieving 4 plant densities (30, 60, 90 and 120 plants m-2). Plant samples (canola and weeds) were taken about 60 and 90 days after establishment and the dry mass was determined. Yield and physiological ripening date of the canola seed were determined as well as crude protein and crude fat content. Preliminary results showed, as expected, that the weed infested trials had a much lower plant density as well as biomass production of canola plants. There are however, no clear trends in terms of the effect of cultivar or plant density on weed suppression or yield. There are however still results that need to be statistically analyzed and these results may clarify the picture. The research will be continued in 2013 and 2014.


6.11

 

Chemical options for weed control in GM-canola


Dr PJ Pieterse
Stellenbosch University

The aims of the project are:   1) to determine the effect of applying different doses of glufosinate ammonium (Basta®) to ryegrass and wild radish (ramenas) seedlings at different growth stages in order to investigate the possible use of more economic but effective dosage rates and   2) to determine the efficacy of glyphosate, glufosinate ammonium, atrazine and imazamox (Cysure®) and mixtures of these herbicides with the pre-emergence herbicide propyzamide (Kerb®) that can be applied after establishment of canola in terms of immediate as well as residual weed control. The four herbicides were selected because canola cultivars resistant to atrazine and imazamox are already available in South Africa and it is expected that GM-canola cultivars resistant to glyphosate (Roundup Ready® cultivars) and glufosinate ammonium (Liberty Link® cultivars) will be released in South Africa in the not too distant future. Glasshouse trials on ryegrass (a commercial pasture cultivar as well as a weedy accession from the field) showed that satisfactory control (>90%) could be obtained with 2.5 L ha-1 of glufosinate ammonium on plants ranging in age (size) from 2 weeks to 10 weeks. Therefore the statement from literature that weed size plays an important role in glufosinate ammonium efficiency could not be confirmed for ryegrass. Likewise the need to apply 5 to 7.5 L ha-1 of glufosinate ammonium (the registered dose in South Africa) to control ryegrass was also not confirmed. However it must be taken into consideration that these trials were carried out under favorable conditions in a greenhouse and should be tested in the field. Field trials showed that the best results in terms of weed control were obtained by applying glyphosate at 1.5 L ha-1, followed by atrazine at 2.5 L ha-1, glufosinate ammonium at 7.5 L ha-1 and imazamox at 1.2 L ha-1. Addition of propyzamide did not have any effect on the efficiency of the herbicides. The trials will be repeated in 2013 and 2014.


6.12

 

Evaluation of shortened canola production periods and the use of alternative crops on the sustainability of winter grain production under conservation agricultural practices in the Riversdale flats


Dr JA Strauss and Mr W Langenhoven
Department of Agriculture: Western Cape

2012 was the first 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. All trial areas were planted and managed according to the planned protocols (including appropriate weed, disease and insect control measures).

Riversdale received adequate rainfall during the season, which resulted in above average canola yields. No other cash crop was harvested due to a management decision to kill off the growth of wheat, barley and lupin in mid September to control a possible serious weed issue.

Canola production – Canola (AGAMax) was planted at Riversdale at 2.7 kg/ha.

A total of 58 kg N/ha was applied to each plot (20 kg N/ha at planting and 38 kg N/ha top-dressings). Canola yields at Riversdale averaged 1804 kg/ha with all plots showing oil yield above 40%.

Economics – Crop production data from the Riversdale site has not been captured at the writing of this report. Since the decision to kill the other cash crops was a drastic measure to ensure a weed-free trial site (a decision no farmer will do on his whole farm), an economist will be advising us how to handle the economics for each cash crop to be able to compare the systems with each other.


6.13

 

Sulphur (S) and nitrogen (N) requirements of canola


Prof GA Agenbag and Mr E Kempen
Stellenbosch University

It is generally known that in comparison to wheat, canola needs approximately double the amount of nitrogen (N), phosphorus and potassium and more than three times the amount of sulphur (S) to produce a tonne of grain. For this reason the application of sulphur fertiliser to canola is very important to ensure high yielding crops. Research started during 2012 at three localities in the Western Cape aiming at the establishment of optimum nitrogen and sulphur application rates, optimum application times and the evaluation of different sources of nitrogen and sulphur.

Due to the growth conditions in 2012 which favoured high yielding crops, grain yields increased significantly due to increased nitrogen application rates (0, 40, 80, 120 and 160 kg N ha-1, applied as LAN) at all localities. Yield responses to nitrogen were however increased when sulphur (0, 30 and 60 kg S ha-1, applied as gypsum) was applied as well. For this reason, highest yields of 2573 kg ha-1 at Altona, 2173 kg ha-1 at Roodebloem and 1938 kg ha-1 at Langgewens were obtained with rates of 120-160 kg N and 30-60 kg S ha-1. In general, yields obtained with 30 and 60 kg S ha-1 did not differ significantly.

In a second trial, three S rates (0, 30 and 60 kg S ha-1, applied at planting or divided between planting, 30 and 60 days after planting) were evaluated in combination with three N rates (0, 80 and 160 kg N ha-1). In contrast to Langgewens, grain yields at Altona and Roodebloem were generally increased by splitting the sulphur application between planting, 30 and 60 days after planting. According to literature, sulphur may yield good results when applied as a top dressing during the growing season of canola. Because Langgewens received less rain compared to the other localities, poor results at Langgewens may be due to the poor solubility and as a result slow reaction time of gypsum (which was used as a source of sulphur). This conclusion was however not supported by the results of an experiment where different sources of nitrogen and sulphur were compared, because no differences in yield with Urea-S compared to gypsum (plus LAN) as sources of sulphur were recorded at any locality during 2012.

To determine the effect of different growing seasons, the trials will be repeated during 2013.


6.14

 

Enhancement of canola as a rotation crop within a conservation system in the dry land areas of the Swartland using a competition between producers


Mr IF Slabbert
Department of Agriculture: Western Cape

Fourteen producers entered and all were evaluated. The entrants included four participants in the Malmesbury area, three in the Moorreesburg area, three in the Piketberg area, three in the Hermon area and one near Durbanville. It was an outstanding season. Rainfall distribution was very good. Initially very little rain fell, but as the plants grew, more rain fell in all areas. It remained relatively cool during the main flowering time in August.

No special group events were convened, but at the September SKOG day, demonstration and cultivar trials were viewed. Visits were arranged to various farms where canola had been planted, to provide advice to the farmers.

The average 2012 yield was 1,81 tonnes per hectare. In 2011 the average yield was 1,64 tonnes per hectare. This means that the average yield was 0,17 tonnes more than that of the previous year and was the highest yield recorded since inception of the competition in 2001.

The highest yield, of 2,46 tonnes per hectare, was achieved by Mr AJ Louw of Malmesbury. The second highest yield was recorded by Mr Boet Le Roux, at 2,247 tonnes per hectare. Mr AJ Louw also achieved the highest gross margin of R6 996 per hectare, while Mr Boet Le Roux achieved the second highest gross margin of R4 779 per hectare. Mr Isak Smit, farming in the Eendekuil area achieved the best yield of 9,19 kg/mm rainfall during the season.


6.15

 

Enhancement of canola as a rotation crop within a conservation system in the dry land areas of the Southern Cape using a competition between producers


Mr JG Loubser
Contractor, Protein Research Foundation

Thirty producers entered the Southern Cape Canola competition in 2012. The information from all the entrants was processed and included in the report. The results were released and discussed on 26 February 2013 at the annual Overberg Agri Pre-planting Information Day held at Rietpoel near Caledon.

The results were individually discussed with each participant after the Information Day.

The rainfall distributions (mm) for five weather stations were discussed. The weather stations are Voorstekop (Heidelberg), Shildskloof (Rietpoel), Napky (Swellendam), Uitkyk (Riversdal) and Dunghye Park (Caledon).

The rainfall for March and April was above the long-term average. The rainfall was well distributed. The Canola seeds which were sown sprouted after 7 to 10 days.

For the month of May the rainfall was above the long-term average at Voorstekop but below average at the other four stations.The rainfall for June was above average for Voorstekop, Rietpoel and Uitkyk but below the average at Dunghye Park and Napky.

In July the rainfall changed and was above average in Rietpoel, Napky and Uitkyk and below the average in Voorstekop and Dunghye Park.

Only at Dunghye Park was the rainfall below average in August with all other stations recording above-average rainfall, and in September the above-average rainfall continued at all stations other than Voorstekop. Temperatures in August and September were relatively low which softened the effect of the low rainfall on seed forming.

The average canola producers' price was R4,392 per ton and the average yield was 2.17 ton per hectare. The average gross margin was R5 634 per hectare.

Agri Dwala (Pty) Ltd of the farm Jafters Krantz near Napier was the participant with the highest yield (3.345 tons/ha) and the best gross margin (R10,169 /ha).

Agri Dwala (Pty) Ltd of Napier was the participant who managed rainfall most effectively with a yield of 9,114 kg seed per millimetre of rain.


6.16

 

Income and cost estimates for soybeans, canola and certain competitive crops


Messrs JSG Joubert and SG Ferreira
Protein Research Foundation and Agriconcep

During the year under review income and cost estimates for selected crops and respective regions within the summer and winter rainfall areas were calculated as had been done in previous reporting years. Apart from the income and cost aspects, the information includes costs to produce a crop, but also the relative profitability of certain competitive crops in terms of gross margin (gross income less variable costs). The estimates are prepared to keep the PRF informed of the relative profitability of promoted crops to achieve the PRF vision and mission. The information is also available to producers for calculating comprehensive farm and cash flow planning. In addition, the information may be used to calculate credit requirements for the farming enterprise. Advisers and contractors/consultants may use the available information in the broader advisory environment and actions. The respective areas and crops included in the summer and winter rainfall calculations are shown in Tables 1 and 2.

Table 1
Cost and income estimates within the summer rainfall area according to crop and region
Gebied Irrigation / Dry land Maize Soybeans Wheat Canola Groundnuts Sunflowers
GWK Area
Central irrigation regions Irrigation X X X X X  
KwaZulu-Natal
Bloedrivier Dry land X X        
Winterton Irrigation X X X      
Magaliesberg Grain Co-operation
Brits Irrigation X X X      
Mpumalanga
Piet Retief Dry land X X        
Middelburg Dry land X X        
Loskop Irrigation X X X      
North West Co-operation
Koster Dry land X X       X
Lichtenburg Dry land X X       X
Vrystaat Koöperasie
Reitz Dry land X X X     X
Frankfort Dry land X X        
Table 2
Cost and income estimates within the winter rainfall area according to crop and region
Area Wheat Barley Canola
Cape Agri Area
Malmesbury X   X
Porterville X   X
Eendekuil X   X
MKB Area
Moorreesburg X   X
Overberg Agri Area
Caledon X X X
Bredasdorp X X X
Central South Co-operation Area
Swellendam / Heidelberg X X X

Information required to prepare income/cost estimates was obtained, where possible, from agribusinesses. Where information was not available for specific regions, group discussions were held with producers to obtain the information. Due to structural changes within the industry the group discussions are repeated at approximately three yearly intervals. For interim periods assumptions of cost/income estimates are adjusted according to the latest available prices.

Estimates are based on typical and/or recommended practices in the respective areas, or on study group information obtained. The sources of information are indicated by footnotes shown below estimates.

Sources of information are summarised in tables 3 and 4.

Table 3
Sources of information, summer rainfall area
Area Dry land / Irrigation Source
Central irrigation regions Irrigation GWK estimates
Bloedrivier Dry land Group discussions
Winterton Irrigation Group discussions
Loskop Irrigation Scheme Irrigation MGK estimates
Brits Irrigation MGK estimates
Piet Retief Dry land Group discussions
Middelburg Dry land Group discussions
Koster Dry land NWK estimates
Lichtenburg Dry land NWK estimates
Reitz Dry land VKB estimates
Frankfort Dry land VKB estimates
Table 4
Sources of information, winter rainfall area
Area Source
Malmesbury Cape Agri estimates
Porterville Cape Agri estimates
Eendekuil Cape Agri estimates
Moorreesburg MBK estimates
Caledon Overberg estimates
Bredasdorp Overberg estimates
Swellendam / Heidelberg SSK estimates

6.17

 

The effects of dietary crude protein on the fertility of broiler breeder males


Dr NC Tyler
University of KwaZulu-Natal

The response of broiler breeder females to dietary crude protein (CP) for egg production has been studied in the past, but less literature is avail­able on the response in male fertility. Since males are often given the same feed as the females, but do not have the same requirements for protein, it may be possible to save on the cost of protein in male rations, if it were worth feeding the sexes separately. To test this, broiler breeder males (either in natural mating pens, with all females on a commercial ration, or in individual cages) were provided with a fixed daily feed allocation resulting in intakes of 10.4, 12.4, 14.2, 17.8, 19.3 and 20.1g CP/bird d. Birds eating <14.2g CP/d lost weight, while those eating above this gained weight. Hatch percentage was not affected by CP intake and was high across all treatments. Predictions of sperm fertility by counting the sperm trapped in the outer perivitelline membrane of oviposited eggs also did not differ between CP treatments. Diets were formulated to be iso-energetic, but subsequent analysis showed a range of 10 to 11.5 MJ ME/kg and it is possible that this could have caused the decrease in body weight on the low protein (and low energy) feeds, but this did not detract from the important finding that fertility was not compromised even at the lowest intake of protein. Recommendations from breeding companies range from about 14g CP to over 16g CP for male breeders, but the results here demonstrate that as little as 10.4g CP could be fed without compromising fertility. As long as sufficient energy is supplied to prevent males from losing weight, there is an opportunity to reduce feed costs and save at least 4g protein/bird d by providing males with a separately formulated diet, without compromising fertility.


6.18

 

PRF web page


Mr JSG Joubert
Protein Research Foundation

The PRF web page remains a source of essential information and plays an important role in communicating such information to all interested parties. It is apparent when viewing the web page that the PRF is committed to making the web page as user friendly as possible, particularly to keep up with, and adapt to trends in this regard. During the year under review, the photo gallery was introduced to allow visitors to view images of items described in the text.

The online function for income and cost estimates is now fully functional. Demonstrations of the function and applications were presented at various events during the year. Management summaries of projects, study reports (dissertation papers) and articles, not available previously, are now included as part of the web site. Links to other institutions remain important and a number of new links to agricultural or related local and international institutions have been set up.

Board members were introduced to the new web site formats, and the functions were demonstrated to the members to keep them informed of new developments and progress relating to the web site.

The statistics below show the number of visitors to the site per reporting year since the inception of the web site.

Reporting year Number of visitors
2004 1 691
2005 3 285
2006 4 552
2007 5 402
2008 11 104
2009 8 484
2010 7 313
2011 7 830
2012 9 252

During the year under review the number of visitors increased by 18,2%, compared to the previous year. It is encouraging to note that the total number of pages viewed and the number of pages viewed per visit increases continuously.


6.19

 

Projections of oilcake demand for animal consumption in 2015, 2020 and 2025


Drs DB Strydom, E Briedenhann and Mr JSG Joubert

These projections are prepared annually and are based on the actual oilcake consumption shown in the AFMA Annual Report. The method of preparation remains unchanged, only the variables change. The AFMA Annual Reports do not show the oilcake consumption per animal species. This requires the use of an APR model and that model was used, as in the past, to show the division of oilcake consumption per animal species for each basis year. This calculation is an essential element for projections, as the future demand for oilcake required for animal consumption is derived from future demand for animal products such as meat, egg, dairy products etc. for a growing population. The Nieuwoudt/McGuigan model is used to determine the future demand for animal products and to prepare the projections for future oilcake demand.

Variables that are important for projections include estimates relating to population growth according to race. For these projections it is particularly important to distinguish between urban and rural areas in terms of the Black population.

Expected income growth is also considered according to race. Income growth is shown for low and high income scenarios. These estimates also require a differentiation relating to urban and rural Black populations to determine income growth. Another variable taken into account is the income elasticity for various animal products consumed per population group. Protective rates that apply to the respective animal products are incorporated in the model.

When the project was initiated some time ago, projections were prepared for the 2010 year. Now it is possible to determine the accuracy of those projections. The actual oilcake consumption for 2010/2011, compared to the projected consumptions calculated in the past, showed no significant deviations. This confirms the reliability of the models. Results for the oilcake projections for 2015, 2020 and 2025 are discussed in section 4.2.5 of the Research Report.