No description available.

No description available.

Dissertation (PhD(Agric))--Stellenbosch University, 2003. / ENGLISH ABSTRACT: The codling moth, Cydia pomonella (L.) has been a major pest of pome fruits since before the turn of the last century. However, despite its high economic profile little is known about the bionomics and . behaviour of this pest in apple orchards in South Africa, information required for the development of a sustainable integrated management programme. In field trials there was contingency between the time of year and the upper and lower half of the tree. First generation moths laid significantly more eggs in the bottom half of the tree while second and third generation moths laid significantly more eggs in the top half of the tree. The preferred oviposition sites on Granny Smith (GS) and Golden Delicious (GD) cultivars, in order of preference, were leaves, fruit and wood. More eggs were laid on the fruit ofGS spurs (35.6 %) than on those ofGD spurs (10.7 %). On fruit spurs there was a significant increase in the number of eggs on GD leaves and GS fruit over the season, whereas the number of eggs on GS leaves and GD fruit remained constant. On branches there was an increase in the number of eggs on GD and GS leaves, but not on the fruit or wood. The preferred oviposition site on the fruit was the fovea of the stalk insertion and the rounded cheek area surrounding the fovea. The distribution within different fruit bearing classes (1 - 4 fruit per spur) was random only for one fruit per spur, while on the other spur classes clustering occurred. In laboratory studies of the embryonic and immature stages there was a linear relationship between rate of development and constant temperatures of 15, 17,20,25 and 30·C ± l·C. The lower threshold temperatures for embryonic, larval and pupal development were 11.1, 7.9, 9.9°C respectively. The degree-days required to complete embryonic, larval and pupal development were 80.5, 345, and 279 respectively. The response of the different stages to constant temperatures was similar to that under fluctuating temperatures. At temperatures below 16°C or abouve 27°C moths did not mate and few eggs were laid. Moth longevity decreased with increasing temperature. There was seasonal variation in longevity and oviposition at constant and fluctuating temperatures. Summer adults produced significantly more eggs than spring adults at constant temperatures. At a constant temperature of2S·C and fluctuating temperatures there were five distinct larval instars. The similarity between the mean head capsule width and ranges for each instar reared on fruit of different stages of development at fluctuating temperatures indicates that fruit development and temperature have little influence on mean head capsule width. From sleeve-cage studies in the orchard there was no significant difference in the fecundity of spring and summer moths. In the beginning of October spring moths produced significantly fewer eggs than in November. Egg mortality increased from 8.2 %in spring to 21.2 %in summer. Failure of 1st instar larvae to penetrate the fruit ranged from 4.9 % to 19.5 %, while mortality oflarvae from egg hatch to emergence from the fruit ranged from 29.7 % to 42.9 %. Mortality of 5th instar larvae after emerging from the apples ranged from 0 % to 8.7 % and pupal mortality from 0 % to 3.5 %. On large 27-year old trees more overwintering larvaewere found on Golden Delicious (13.9) than on Granny Smith trees (5.7), with over 70 % oflarvae being found in pruning wounds on both cultivars. On small 7-year old Golden Delicious and Granny Smith trees the mean number oflarvae was 0.5 and 2.0 per tree. A combined mating disruption and insecticide control programme reduced codling moth resistant populations to levels requiring a minimum to no insecticide intervention for several seasons. The efficacy of a pheromone based strategy, number of pheromone treatments, number of dispenserslha and level of insecticide intervention required are strongly influenced by prevailing weather conditions. Fruit infestation in orchards under a mating disruption programme and under an insecticide programme were greater along the borders compared to the interior. The presence of horticultural mineral oil on the leaves and branches did not have a detrimental effect on oviposition nor was there any significant ovicidal effect. A significant ovicidal effect was obtained when applied after oviposition. In field trials, insecticides with lower levels of efficacy than the primary insecticide, azinphos-methyl, provided acceptable control when successfully incorporated into a spray programme which followed a policy of alternation of insecticides across generations. The least variation in the number of degree-days between biofix and first egg hatch of the spring flight was when the second trap catch (Biofix 2) was used as the biofix. A biofix based on the first evening when the temperature reached or exceeded 1TC at 18:00 after first trap catch also showed less variation than when the biofix was based on first trap catch. The mean number of degree-days accumulated between Biofix 2 and first egg hatch was found to be 139.1 ° D. The number of degreedays between the first and second flight biofixes varied between 531.2 and 488.87°D with a mean of 508.1°D. / AFRIKAANSE OPSOMMING: Kodlingmot (Cydia pomonella) is reeds sedert die vorige eeu 'n sleutelplaag van kemvrugte. Ten spyte van die hoë ekonomiese profiel, is daar min kennis betreffende die bionomie en gedrag van hierdie plaag in appelboorde in Suid-Afrika. Hierdie inligting is noodsaaklik vir die ontwikkeling van 'n volhoubare geïntegreerde bestuursprogram. Tydens veldproewe is 'n korrelasie tussen die tyd van die jaar en eierlegging in die boonste of onderste helfte van bome gevind. Eerste-generasie motte het betekenisvol meer eiers in die onderste helfte van die bome gelê, terwyl tweede- en derde-generasie motte meer eiers in die boonste helfte van die bome gelê het. In toenemende volgorde was die voorkeur eierleggingsposisies op Granny Smith (GS) en Golden Delicious (GD) appels die blare, vrugte en hout. Meer eiers is op vrugte van GS spore (35.6%) as op dié van GD spore (10.7%) gelê. Op vrugspore was daar 'n betekenisvolle toename in aantal eiers op GD blare en GS vrugte deur die seisoen, terwyl die getal eiers op GS blare en GD vrugte konstant gebly het. Op takke was daar 'n toename in aantal eiers op GD en GS blare, maar nie op vrugte of hout nie. Die voorkeur eierleggingsposisie op vrugte was die fovea van die steelaanhegting en die wang rondom die fovea. Die verspreiding tussen verskillende vrugdraende klasse (1 - 4 vrugte per spoor) was slegs in die een-Vrug-per-spoorklas ewekansig, terwyl daar in die ander spoorklasse groepering voorgekom het. In laboratoriumstudies van embrioniese en onvolwasse stadia is 'n lineêre verband tussen ontwikkelingskoers en konstante temperature van 15, 17,20,25 en 30°C±I°C gevind. Die onderste drempel-temperature vir embrioniese, larwale en papie-ontwikkeling was onderskeidelik II. 1°C, 7.f?C en 9.9°C. Graaddae benodig vir voltooiing van embrioniese, larwale en papie-ontwikkeling was onderskeidelik 80.5,345 en 279. Die respons van verskillende stadia by konstante temperature het ooreengestem met hul respons onder wisselende temperature. Motte het nie gepaar nie en min eiers is gelê by temperature onder 16°C of bo 27°C. Die lewensverwagting van motte het afgeneem met toename in temperatuur. Seisoenale variasie in . lewensverwagting en eierlegging het voorgekom by konstante sowel as wisselende temperature. By konstante temperature het somer-volwassenes betekenisvol meer eiers as lente-volwassenes geproduseer. By 'n konstante temperatuur van 25°C, sowel as by wisselende temperature, het vyf duidelik onderskeibare larwale instars voorgekom. Die ooreenkoms tussen die gemiddelde kopkapsulewydte en wydte-reeks vir elke instar wat op vrugte van verskillende stadiums van ontwikkeling by wisselende temperature geteel is, dui daarop dat vrugontwikkeling en temperatuur weinig invloed op gemiddelde kopkapsule-wydte het. Tydens mou-hok studies in die boord is geen betekenisvolle verskil in die fekunditeit van lente- en somer-motte waargeneem nie. Vroeg in Oktober het lente-motte betekenisvol meer eiers as in November geproduseer. Eiermortaliteit het van 8.2% in die lente tot 21.2% in die somer toegeneem. Faling van 1ste instar larwes om vrugte te penetreer het van 4.9% tot 19.5% gewissel, terwyl mortaliteit van larwes vanaf uitbroei tot uitkoms uit die vrug van 29.7% tot 42.9% gewissel het. Mortaliteit van Sde instar larwes na uitkoms uit die vrug het van 0% tot 8.7% gewissel, en papie-mortaliteit van 0% tot 3.5%. Op groot, 27-jaar oue bome is meer oorwinterende larwes op Golden Delicious (13.9) as op Granny Smith (5.7) gevind, en meer as 70% van die larwes op beide kultivars is op snoeiwonde gevind. Op klein, 7-jaar oue bome was die gemiddelde aantallarwes op Golden Delicious en Granny Smithbome 0.5 en 2.0 onderskeidelik. 'n Gekombineerde paringsontwrigting- en insekdoder beheerprogram het weerstandbiedende kodlingmot-populasies verminder tot 'n vlak waar minimum tot geen insekdoder-toedienings vir verskeie seisoene gemaak is. Die effektiwiteit van 'n feromoon-gebaseerde strategie, aantal feromoonbehandelings, aantal vrystellers/ha en vlak van insekdoder-toediening word sterk deur heersende weersomstandighede beïnvloed. Die rande het hoër vruginfestasie as die middel getoon in boorde onder paringsontwrigting sowel as boorde onder insekdoder-programme. Die teenwoordigheid van minerale olie op blare en takke het geen nadelige effek op eierlegging gehad nie en dit het geen betekenisvolle eierdodende effek gehad nie. Indien die olie ná eierlegging toegedien is, is daar wel 'n betekenisvolle eierdodende effek waargeneem. Tydens veldproewe het insekdoders met laer effektiwiteit as die primêre insekdoder, azinfos-metiel, aanvaarbare beheer verskaf indien dit suksesvol geïnkorporeer is in 'n spuitprogram deur 'n beleid van afwisseling van insekdoders oor generasies. Die kleinste variasie tussen die aantal graaddae tussen biofix en eerste uitbroei van eiers is gevind indien die tweede lokvalvangs as biofix gebruik is. 'n Biofix gebaseer op die eerste aand na die eerste lokval vangste wat die temperatuur 17°Cofhoër was teen 18:00, het ook 'n kleiner variasie getoon as die eerste lokvalvangs. Die aantal graaddae tussen die tweede en derde vlug biofix het tussen 531.2 en 488.87°D gewissel, met 'n gemiddelde van 508.1°D.

No description available.

Glabrous Brassica napus cv Westar and very hairy AtGL3+ B. napus were transformed using Agrobacterium tumefaciens and either a full length trichome regulatory gene BnTTG1 (isoform 1 coding region called O-TTG1) or an RNAi cassette with 260 bp of a conserved region between isoform I and II (called K-TTG1), each driven by the CaMV 35S promoter. Agronomic and trichome phenotypes were observed in the resulting lines. Transformed lines developed in the glabrous Westar background showed no changes in growth or trichome density and transformation efficiency was similar to that of an empty vector control construct. Over-expression of BnTTG1 in the AtGL3+ B. napus background resulted in low transformant survival and poor seed viability, with the only surviving line O-3-7 being taller than non-transformed lines and with a completely glabrous phenotype. The two knock-down lines with the lowest BnTTG1 expression showed a dramatic increase in trichome density, with longer trichomes and expanded trichome density (up to the 12th leaf in the K-5-8 line) compared to the AtGL3+ hairy background line, which showed increased trichome density only on the first three leaves. Moreover, K-5-8 plants were healthy, with both vegetative and reproductive growth similar to that of Westar non-transgenic control plants under both greenhouse and field conditions. The relative expression of five B. napus primary trichome regulatory genes and AtGL3 was measured in three different tissues of B. napus Westar, and the AtGL3+, K-5-8 and O-3-7 transgenic lines. Over-expression of AtGL3 resulted in changes in the expression of BnGL3, BnGL2 and BnTRY. Manipulation of BnTTG1 levels also resulted in changes in expression of these three genes in addition to AtGL3. AtGL3+ plants and O-3-7 also showed increased red pigment accumulation in several above ground vegetative tissues including cotyledons, hypocotyl and leaves, whereas the K-5-8 line (knock down of TTG1) had less anthocyanin in the same tissues. The level of anthocyanin accumulation corresponded to the relative expression of the three primary anthocyanin regulatory genes BnDFR, BnANS and BnGST. In a laboratory bioassay, diamondback moth (DBM) adults (Plutella xylostella) laid more eggs on hairy leaves of K-5-8 than glabrous Westar. However, more feeding damage from young DBM larvae was observed on Westar leaves than K-5-8 in both choice and no-choice feeding assays. In a field test comparing Phyllotreta flea beetle feeding, the hairy K-5-8 leaves showed between a 30-50% reduction in feeding over four ratings on 14 to 28 day old seedlings. Curiously, the glabrous cotyledons of the two hairy lines (AtGL3+ and K-5-8) proved to be more resistant than wild type B. napus Westar cotyledons from Helix XTra® insecticide-treated or non-treated seed. These data support the introduction of AtGL3 and the knockdown of BnTTG1 to induce a dense trichome phenotype, into otherwise glabrous B. napus, resulting in an increased host plant resistance to crucifer insects, without agronomic penalties.

A THESIS PRESENTED TO CAPE PENINSULA UNIVERSITY OF TECHNOLOGY IN FULFILMENT OF THE REQUIREMENTS FOR THE MASTERS OF TECHNOLOGY DEGREE IN HORTICULTURE. IN THE FACULTY OF APPLIED SCIENCES 2014 / Codling moth ([Cydia pomonella (Lepidoptera: Tortricidae]) infest pomes resulting in high production losses to fruit farmers in South Africa and globally. Many farmers are adopting biocontrol methods including the use of entomopathogens as alternatives to synthetic insecticides for sustainable management of Arthropod pests. Research activities on screening and application of entomopathogenic fungi (EPF) have intensified in recent years. This study was carried out to isolate and identify virulent indigenous entomopathogenic fungal strains from soils of selected locations in the Western Cape region of South Africa that are pathogenic against codling moth (Cydia pomonella (Linn) [Lepidoptera: Totricidae]) and to evaluate the possiblility of combining semiochemicals and fungal inoculums in a simulated attract-and-fungus contamination system for codling moth control. Soil samples were collected from 10 locations in the Western Cape, South Africa for the isolation of entomopathogenic fungi (EPF) by baiting the soil samples with 5th instar larvae of codling moths. Fungal strains were identified and characterized using light microscopy and DNA analysis (internal transcribed spacer region) and elongation factor 1-α (EF 1-α) genes of fungal cultures. Thirty-nine (39) isolates belonging to six species were obtained; Purpureocillium lilacinum (8 isolates), Fusarium oxysporum (five isolates), Fusarium polyphialidicum (two isolates), Beauveria pseudo-bassiana (one isolate), Aspergillus flavus (three isolates) and Metarhizium robertii (20 isolates). Generally, M. robertsii was the most frequently encountered species representing 51% of the total number of isolates collected from the soil samples. This is the first report of the isolation of M. robertsii in southern Africa. A screening test to identify the most virulent fungal strains against codling moth was carried out on 39 isolates by immersing 5th instar larvae of C. pomonella into aqueous spore suspension 1 x 108 conidia ml-1. Mortality data from the immersion bioassay indicated that the 39 fungal isolates were pathogenic against fifth instar larvae of codling moth inducing 47-85% insect mortality at an infective concentration of 1 x108 spores’ ml-1, 5 days post-treatment. Two fungal strains MTL151 and GW461 induced over 85% larval mortality and were selected for further evaluations. The effect of MTL151 and GW461 on egg hatchability of 0-day old eggs was evaluated by exposing freshly laid eggs on wax papers that were pre-treated with fungal spores ranging from 103 -108 spores/ml. Egg hatchability reduced significantly from 93-71% (GW461) and 95-66% (MTL151) as spore concentration increases from1 x 103 to 1 x 108 spores ml-1, respectively. The highest spore concentration significantly inhibited egg hatchability resulting in lower egg hatchability compared to that obtained with the cypermethrin containing commercial insecticide (Fruitfly [registered by Kombat (PTY) Ltd] ) tested at the recommended dose of 0.25 ml/250 ml of water. The potential of the two M. robertsii strains to protect apples from infestation by codling moth neonates was assessed in an apple fruit bioassay under laboratory and field bioassay. Codling moth neonates were exposed to apples that were sprayed topically with varied conidia concentrations (103 - 108 sporesml-1). The mean number of participating apple fruits having developing/developed larvae in the core/flesh significantly reduced from 5.3 to 1 and 7.6 to 1 for MTL151 and GW461, respectively as spore concentrations increased from 1 x103 to 1x 108 spores/ml-1. A concurrent decrease in apple fruit rot as conidia concentration increased was observed. Up to 90% of apples treated with 1 x 108 spores/ml-1 had no larva present in their cores and this result compared favourably with the commercial pesticide (Fruitfly) used at a recommended dose of 0.25g/250 ml of water. No significant difference was found between the EC50 values of 1.2 x 103 (CI=1.2 x 102 -1 x 105) (MTL151) and 1.1 x 105 (CI =7 x103 – 5.6x105) (GW461) spores ml-1. However, neither the two M. robertsii strains nor the insecticide deterred the neonates from feeding on the surface of the fruits. The attraction responses of male and female adult codling moths to butyl hexanoate and codlemone blend; butyl hexanoate (0.025 mg / ml of hexane) and codlemone (0.1 mg / ml of hexane) in a ratio of 1:1 (0.5 ml: 0.5 ml from both solutions) were assessed in a one-choice wind tunnel olfactory bioassay during scoto-phase in the absence of fungal spores. The blend attracted more females (69%) than males (66.7%), however these responses were not significantly different (P > 0.5). The prospect of integrated use of entomopathogenic fungal conidia and semiochemical blend for control of C. pomonella adults was assessed in a wind tunnel containing the combo lure and M. robertsii (MTL151) spores formulated as a powder (250 mg) or aqueous spore suspension (3.1 x 108 spores m-1 ± 7 x 102 sporesml-1). Insect attraction, mean number of spores picked per insect and insect mortality was assessed. No significant difference (P > 0.5) was observed in the number of inoculi picked by unsexed adult moths in the two conidial formulations tested; spore powder (3.1 x 103 ± 1 x 103 spores ml-1) and aqueous spore suspension (3.1 x 103 ± 7 x 102 spores ml-1). No mortality was recorded among fungus or control-treated moths. Both M. robertsii (MTL151) spore formulations did not significantly (P > 0.05) affect the attraction responses of the insects to the combo lure; powder (73.3 ± 3.3%) and aqueous (68.6 ± 2.9%) compared to the control treatment (without the fungal spores) (70 ± 0.5 %). These results suggest that the fungus did not inhibit the attraction of moths by semiochemicals. Despite the successful autoinoculation of moths with fungal spores, the level of contamination was too low to induce mortality among adult moths. This study opens up opportunities for research in attract-and-fungus contamination delivery systems. This is the first report of the occurrence of M. robertsii in the southern Africa. Further, results from this study indicates that C. pomonella is susceptible to indigenous South African entomopathogenic fungi and 2 indigenous M. anisopliae strains, MTL151 and GW461 provided adequate protections against codling moth larval infestations of apple fruits. Future research endeavours to improve adherence of conidia to adult moth cuticle is recommended. Key words: Entomopathogenic fungi (EPF), codling moth, B. pseudobassiana, M. robertsii, larvae, pathogenicity and biological control, coddlemone, butyl hexanoate, attraction, semiochemicals.

No description available.

Thesis (M. Environmental Science))--North-West University, Potchefstroom Campus, 2007.

Cruciferous crops comprise one of the major crop divisions and contribute significantly to global crop production. Insect pests associated with cruciferous crops have the potential to destroy harvests. The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae) and cabbage aphids, Brevicoryne brassicae (L.) and Lipaphis erysimi (Kaltenbach) (Homoptera: Aphididae) are considered the most important cabbage pests in South Africa. Pest control in cabbage is still heavily reliant on use of insecticides even though insecticide application usually result in increased pest status of P. xylostella. Use of integrated pest management (IPM) strategies may yet prove invaluable as a means of suppressing the more serious cabbage pests. Global interest in cultural control strategies, that includes intercropping of unrelated crop plants, has been rekindled because of problems experienced with pesticide use. A study that involved the planting of two field trials with cabbage and carrot plants in different ratios, as a substitutive intercropping system, was undertaken during the 2002/03 and 2003/04 planting seasons. Field trials had five treatments viz. control (cabbage monoculture sprayed with mercaptothion), cabbage monoculture (without chemical application), 1:1 intercropping (cabbage:carrots), 1:3 intercropping and 1:5 intercropping, replicated six times in a randomized block design. Insects were sampled weekly by removing the third-youngest open leaf, from one plant per plot (six plants per treatment). Feeding damage to cabbage leaves was assessed visually by rating 14 plants per plot according to a numeric scale based on damage severity. P. xylostella and aphid parasitism levels were determined. Prominence values were calculated for P. xylostella larvae and aphids for each treatment per sampling date. P. xylostella infestations and parasitism levels were significantly (P ≤ 0.05) lower in control treatments. Intercropping ratio did not have a significant impact on pest infestations. P. xylostella infestations and parasitism on intercropping treatments did not differ significantly (P > 0.05) from that on monoculture plots (except for 1:5 intercropping during the 2003/04 season). Cotesia plutellae (Hymenoptera: Braconidae) was the dominant parasitoid and parasitism levels were significantly correlated with P. xylostella infestation levels. Prominence values showed a decline in P. xylostella infestations on intercropping treatments towards the last sampling date during both seasons. Feeding damage severity was lowest on the control treatment but similar for other treatments for both seasons. Aphid infestations were significantly (P ≤ 0.05) lower on the control treatment, but did not differ significantly between intercropping treatments. Aphid prominence values indicated possible suppression of infestations at low population levels during the early part of the season. Aphid parasitism was low during both seasons. It seems more likely that the reduction in insect infestation levels reported from the literature are related more to spatial arrangement of plants than cropping ratios. The observed suppression of aphid infestation levels on intercropped plots early in the season may be valuable in reducing the need for early chemical applications. The limiting of early insecticide application against aphids may result in a reduced pest status of P. xylostella, due to the conservation of C. plutellae populations. / Thesis (M. Environmental Science))--North-West University, Potchefstroom Campus, 2007.

Cruciferous crops comprise one of the major crop divisions and contribute significantly to global crop production. Insect pests associated with cruciferous crops have the potential to destroy harvests. The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae) and cabbage aphids, Brevicoryne brassicae (L.) and Lipaphis erysimi (Kaltenbach) (Homoptera: Aphididae) are considered the most important cabbage pests in South Africa. Pest control in cabbage is still heavily reliant on use of insecticides even though insecticide application usually result in increased pest status of P. xylostella. Use of integrated pest management (IPM) strategies may yet prove invaluable as a means of suppressing the more serious cabbage pests. Global interest in cultural control strategies, that includes intercropping of unrelated crop plants, has been rekindled because of problems experienced with pesticide use. A study that involved the planting of two field trials with cabbage and carrot plants in different ratios, as a substitutive intercropping system, was undertaken during the 2002/03 and 2003/04 planting seasons. Field trials had five treatments viz. control (cabbage monoculture sprayed with mercaptothion), cabbage monoculture (without chemical application), 1:1 intercropping (cabbage:carrots), 1:3 intercropping and 1:5 intercropping, replicated six times in a randomized block design. Insects were sampled weekly by removing the third-youngest open leaf, from one plant per plot (six plants per treatment). Feeding damage to cabbage leaves was assessed visually by rating 14 plants per plot according to a numeric scale based on damage severity. P. xylostella and aphid parasitism levels were determined. Prominence values were calculated for P. xylostella larvae and aphids for each treatment per sampling date. P. xylostella infestations and parasitism levels were significantly (P ≤ 0.05) lower in control treatments. Intercropping ratio did not have a significant impact on pest infestations. P. xylostella infestations and parasitism on intercropping treatments did not differ significantly (P > 0.05) from that on monoculture plots (except for 1:5 intercropping during the 2003/04 season). Cotesia plutellae (Hymenoptera: Braconidae) was the dominant parasitoid and parasitism levels were significantly correlated with P. xylostella infestation levels. Prominence values showed a decline in P. xylostella infestations on intercropping treatments towards the last sampling date during both seasons. Feeding damage severity was lowest on the control treatment but similar for other treatments for both seasons. Aphid infestations were significantly (P ≤ 0.05) lower on the control treatment, but did not differ significantly between intercropping treatments. Aphid prominence values indicated possible suppression of infestations at low population levels during the early part of the season. Aphid parasitism was low during both seasons. It seems more likely that the reduction in insect infestation levels reported from the literature are related more to spatial arrangement of plants than cropping ratios. The observed suppression of aphid infestation levels on intercropped plots early in the season may be valuable in reducing the need for early chemical applications. The limiting of early insecticide application against aphids may result in a reduced pest status of P. xylostella, due to the conservation of C. plutellae populations. / Thesis (M. Environmental Science))--North-West University, Potchefstroom Campus, 2007.