TEGNIESE TECHNICAL BULLETIN. Creating a progressive, equitable and sustainable table grape industry AUGUST 2018

Transcription

1 TEGNIESE TECHNICAL BULLETIN Creating a progressive, equitable and sustainable table grape industry AUGUST 2018

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3 CONTENTS / INHOUD Uit die kantoor van Willem Bestbier 2 TECHNICAL Sertifisering van tafeldruifplantmateriaal 3 Aanplanting van gesertifiseerde plantmateriaal noodsaaklik 6 Die korrekte hantering, voorbereiding en plant van jong stokke 7 RESEARCH Wingerdvoortplanting: notas vanaf onlangse internasionale konferensie in Duitsland 9 Viruses in South African table grapes 12 Keeping newly-established black table grapes free of grapevine leafroll virus 15 Detection and quantification of soilborne pathogens in grapevine nurseries 19 Going back to our roots: New rootstock trials to identify superior rootstocks 21 INDUSTRY COMMUNICATION Vergelegen - STRENGTH IN NUMBERS 22 For any enquiries, comments and feedback, please contact: Tarryn Wettergreen: Dawie Moelich: Clayton Swart: tarryn@satgi.co.za dawie@satgi.co.za clayton@satgi.co.za

4 UIT DIE KANTOOR VAN WILLEM BESTBIER BEGIN BY DIE BEGIN GOEIE PLANTMATERIAAL Die 2017/2018 seisoen is reeds geskiedenis en die bedryf begin al voorberei vir die volgende groei en produksieseisoen. Met groot dankbaarheid word kennis geneem van goeie vroeë winterreën en is daar n verwagting dat Augustus en September bo-gemiddelde reën sal bring. Daar is hoop dat die uitmergelende 3-jaar droogte minstens gedeeltelik gebreek is en ons bedryf begin voorberei vir n normale en selfs goeie oes. Ons sal nie tafeldruifboere wees indien ons nie optimisties is en aanhou belê in ons wingerde en besighede nie. Een van die belangrikste beleggings is die vestiging van nuwe en die vervanging van ou wingerde. Dit is n noodsaaklikheid van n progressiewe en volhoubare besigheid en die 2018 plantseisoen is juis op hande. Die enjinkamer van ons bedryf wingerde wat geplant is met markgedrewe kultivars en wat oor die vermoë beskik om n winsgewende en volhoubare produksie vir so lank as 20 jaar te lewer. Dit word gedryf deur buitengewoon hoë vestigingskoste en ewe hoë produksiekoste. Dit is nie ongewoon om vandag te verneem dat n goed gevestigde tafeldruiwe wingerd, beskerm met nette, reeds beduidend meer as R per hektaar kos nie. Produksiekoste (verpakking en bemarking uitgesluit) van ongeveer R per hektaar word reeds in sekere gevalle ervaar. Dit is voordat nuwe minimum lone inaggeneem word en verder is dit n realiteit dat tafeldruiwe verbouing sy eie unieke inflasie het, wat ruim hoër is as die nasionale verbruikers- of produksieprysindeks. Ongelukkig is daar te veel wingerde en plantmateriaal wat eenvoudig faal en nie die prestasie lewer wat nodig is om die ekonomie van tafeldruifverbouing te laat klop nie. Hiervoor is daar n legio moontlike redes en oorsake en dit is uiteraard n komplekse aangeleentheid. Teen hierdie agtergrond het SATI onlangs n omvangryke projek ten opsigte van plantmateriaal in ons bedryf geloods. Jacques Ferreira, wat vir 6 jaar die Algemene Bestuurder by Plant SA was, maar tans in SATI se diens is, lei die projek. Die doelwit is om ons deeglik te vergewis van beste internasionale praktyk en tegnologie en n bekostigbare plan te ontwerp wat Suid-Afrikaanse tafeldruif wingerd plantmateriaal en hantering minstens op daardie vlak te bring. Die projek is afgeskop met Jacques wat die 22nd International Geisenheim Conference on Grapevine Propagation in Junie in Duitsland bygewoon het. In hierdie Tegniese Bulletin is n artikel wat terugvoer uit hierdie kongres gee. Die projek word op n multi-dissiplinêre vlak aangepak en verskeie sleutel rolspelers, onder andere produsente, plantverbeteringsorganisasies, tegniese deskundiges en kwekerye, word betrek. Uiteindelik moet die Wingerd Verbeteringskema die bedryf dien om meer kompeterend ten opsigte van kwaliteit plantmateriaal en wingerde te wees. Artikels in hierdie Tegniese Bulletin verskaf enersyds agtergrond oor die huidige tafeldruiwe plantmateriaal sertifiseringskema en andersyds verduidelik dit die voordele van gesertifiseerde plantmateriaal. Dit verdien ook om vermeld te word dat n saak waarvoor SATI hom lank voor beywer het, uiteindelik gerealiseer het met die totstandkoming van n enkel sertifiseringstelsel vir alle wingerd plantmateriaal (tafeldruiwe, wyndruiwe en droogdruiwe). In n ekslusiewe wingerd skema onder leiding van een sertifiseringsliggaam sal dit beter en skerper fokus bewerkstellig. Boomvrugte word voortaan in n eie skema deur n eie sertifiseringsliggaam hanteer. Verdere artikels verskaf inligting oor die toepaslike en skadelike virusse in wingerd plantmateriaal, grond patogene in kwekerye en beskryf n projek wat demonstreer hoe n nuut gevestigde wingerd skoon gehou kan word. Dit lewer bewys dat dit moontlik is deur nougesette goeie landbou praktyke. Heelwat van hierdie inligting bevestig bekende basiese beginsels en reeds verworwe kennis en inligting in ons bedryf. Dit bly belangrik om hierdie beginsels en kennis voortdurend in te skerp en onder spesifieke omstandighede aan te pas. Daarom word die basiese beginsels van die hantering, voorbereiding en plant van jong stokkies in n artikel weergegee. Dikwels oorheers die bo-kultivar (draend) alle aandag ten opsigte van navorsing en tegnologie-oordrag en word n kritiese komponent, naamlik die onderstok, afgeskeep. Daarteen moet gewaak word, veral in Suid-Afrika waar ons bedryf baie afhanklik van n enkele onderstok is. Jarelange onderstok navorsing en evaluering wat deur die LNR met SATI befondsing gedoen is, is onlangs voltooi en n spesiale publikasie wat hierdie omvangryke langtermyn projek in n praktiese handleiding saamvat, sal binnekort die lig sien. Hierdie projek word opgevolg met n nuut ontwerpte SATI onderstok evalueringsprojek wat deur Provar gedoen word en n artikel verskaf meer inligting daaroor. Die SATI Plantmateriaal Projek is n langtermyn projek, maar ons beplan om die quick wins ook te soek en oor te dra. Met die 2018 plantseisoen op hande vertrou ons dat hierdie uitgawe van die SATI Tegniese Bulletin vir elke tafeldruifprodusent tot goeie nut sal wees en dat die reën sal val. Willem Bestbier 2 AUGUST 2018

5 SERTIFISERING VAN TAFELDRUIFMATERIAAL DEEL 1:TYDLYN Die eerste wingerdstokke is reeds in 1652 in Suid-Afrika aangeplant, waarna wingerdaanplantings in groot getalle uitgebrei het. Gedurende die 1880 s het die uitbreek van filloksera in wingerde groot verandering in die destydse wingerdbedryf te weeg gebring. Teen die 1950 s was die Suid- Afrikaanse wingerdbedyf in chaos gedompel (Andrew Teubes Geskiedenis van onderstokke in SA). TECHNICAL 1954: Die Departement van Landbou identifiseer die fisiese- en genetiese status van plantmateriaal as die twee belangrikste faktore om by te dra tot die verhoging van landbouproduksie in Suid-Afrika. 1964: Die Suid-Afrikaanse Plantverbeteringsvereniging word op die been gebring om spesifiek aandag te gee aan hierdie twee aspekte van plantmateriaal vir die wingerd- en sagtevrugtebedrywe. 1974: Die Suid-Afrikaanse Plantverbeteringsorganisasie (SAPO) word deur die Sagtevrugte-, Inmaakvrugte- en Droëvrugte Rade gestig met die doel om verbeterde plantmateriaal (sagtevrugte en tafel- en droogdruiwe) aan die industrie te voorsien. 1976: Die Plantverbeteringswet (Wet nr. 53 van 1976) word goedgekeur met die doel om plantverbeteringsprosesse te reguleer. 1988: Die Departement van Landbou besluit dat hulle nie meer alleen verantwoordelikheid vir die bestuur van plantverbetering kan neem nie. 1992: Die Plantsertifiseringskema vir Wyndruiwe word afgekondig. Die Wyndruifverbeteringsvereniging (WVV) word in plek gestel om die bevoegdhede, die verrigting van werksaamhede en die uitvoering van die pligte wat kragtens die Skema aan die Uitvoerende Raad as gesag verleen, toegewys of opgedra is, uit te oefen. 1993: Die Sagtevrugteplantsertifiseringskema word afgekondig. Die Sagtevrugteplantverbeteringsvereniging (SPV) word in plek gestel om die bevoegdhede, die verrigting van werksaamhede en die uitvoering van die pligte wat kragtens die Skema aan die Uitvoerende Raad as gesag verleen, toegewys of opgedra is, uit te oefen. Die skema maak onder andere voorsiening vir die sertifisering van Tafel-en Droogdruifplantmateriaal. Daar word egter van die begin af onderskeid getref tussen Bome en Tafel-en Droogdruiwe deur twee aparte bylaes binne Skema. 2004: Die twee Rade (SPV en WVV) onderteken op 19 Januarie n ooreenkoms van voorneme om n Artikel 21 maatskappy (Plantverbetering Suid-Afrika) op te rig om die bestuurs- en administratiewe funksies namens die WVV en SPV te verrig. Daar word ook in hierdie ooreenkoms bepaal dat die fasilitering van Een Vitisskema onder die Plantverbeteringswet sal plaasvind. 2017: Na baie jare van onderhandeling en gesprekvoering word die tafel-en droogdruiwe amptelik deel van die WVV wat voortaan bekend staan as die Wingerdverbeteringsvereniging. Die naam van die Skema word ook aangepas om bekend te staan as die Plantsertifiseringskema vir Wingerd. AUGUST

6 DEEL 2:TENDENSE Daar word sedert die plantjaar rekord gehou van die hoeveelheid plantmateriaal wat deur geregistreerde wingerdkwekerye ge-ent is. In die grafiek hieronder word die getal gesertifiseerde tafeldruifstokke ge-ent teenoor die totale aantal tafeldruifstokke ge-ent vir die ooreenkomstige jaar aangetoon. Die persentasie van gesertifiseerde tafeldruifstokke teenoor die totaal word ook uitgelig. Volgens die tendenslyne kan gesien word dat daar oor die jare n toename in die aantal stokke ge-ent is, terwyl die persentasie gesertifiseerde materiaal oor die laaste 15 jaar n geleidelike afname toon. Grafiek 1: Gesertifiseerde tafeldruifstokke teenoor totale aantal tafeldruifstokke ge-ent 1986/87 tot 2017/18. In die ooreenstemmende tyd het die gesertifiseerde wyndruifstokke op n soortgelyke persentasie koers (65%) begin, maar oor die laaste 15 jaar, in teenstelling met tafeldruiwe, is daar jaarliks gemiddeld 93% gesertifiseerde wyndruifstokke ge-ent. 4 AUGUST 2018

7 DEEL 3: TOEKOMS Die verskuiwing van tafel- en droogdruiwe vanaf die SPV na die WVV is die verwesenliking van n doelwit wat so oud soos die skemas is. Die Wingerdverbeteringsvereniging is die ideale platform vir tafeldruiwe waar die nodige kundigheid gesetel is om werklik waarde toe te voeg tot die verbetering van die plantmateriaal. Beide die WVV Raad sowel as die Tegniese Komitee kan nou uitsluitlik fokus op wingerdsake en die doelwit is om die standaard van tafeldruifplantmateriaal binne die afsienbare tyd tot op dieselfde vlak as die van wyndruiwe te bring. TECHNICAL Beide wyndruif- en tafeldruifstokke word nog al die jare in dieselfde kwekerye verbou, hoewel daar altyd van die kwekers verwag is om by beide die WVV en die SPV te registreer. Alle verslae vir die twee groepe is ook altyd apart hanteer en daar is aan die onderskeie Rade terugvoering gegee rakende die stand van die plantmateriaal. Gevolglik is die tyd van die SPV Raad en Tegniese Komitee altyd verdeel tussen die sagtevrugte-boomsake en die belange van tafeldruiwe. Die eerste daadwerklike poging wat aangewend is om hierdie wanbalans aan te spreek was toe daar besluit is om alle onderstokke binne die WVV te huisves. Met hierdie besluit is die bal aan die rol gesit om die tafeldruiwe binne die WVV te akkommodeer. Hoewel die amptelike afkondiging van die Skemawysigings steeds in proses is, is daar reeds dispensasie toegestaan deur die Registrateur van Plantverbetering om al die wysigings soos deur die Rade aanbeveel, toe te pas. Die WVV Tegniese Komitee is tans besig met n aksieplan om die standaard van die tafeldruifblokke op dieselde vlak as die van wyndruiwe te kry. Die proses sal meebring dat die huidige praktyk om Moederblokke vanaf ander moederblokmateriaal te vestig uitfasseer sal word. Verder sal die fisiese- en fitosanitêre standaarde van gesertifiseerde wingerdmateriaal vir beide wyn- en tafeldruiwe voortaan dieselfde wees. Laastens is dit belangrik om kennis te neem dat die besluit om alle wingerdplantmateriaal binne een Skema te plaas, Suid-Afrika in lyn bring met die res van die wêreld waar daar geen onderskeid getref word tussen tipes wingerdmateriaal op grond van die eindgebruik van die druiwe nie. Selfs in Suid-Afrika word daar nie op die amptelike Variëteitslys onderskei tussen tipes wingerdvariëteite nie. Die toekoms vir tafeldruifplantmateriaal van hoogstaande gehalte lyk belowend en daar word beplan om in samewerking met alle rolspelers, die gebruik van gesertifiseerde plantmateriaal aan te moedig tot voordeel van die bedryf. In die woorde van Maya Angelou: Do the best you can until you know better. Then when you know better, do better. Rachel Kriel GM: Plant SA rachel@plantsa.co.za AUGUST

8 AANPLANTING VAN GESERTIFISEERDE PLANTMATERIAAL NOODSAAKLIK Virus- en bakteriese siektes soos rolblaar en vlamsiekte het n geweldige negatiewe effek op tafeldruif wingerde. Stokke wat met vlamsiekte besmet is gaan agteruit, het laer produksie en sterf later af, wat veroorsaak dat wingerde gouer vervang moet word. Rolblaarinfeksie het nie so n drastiese effek op die stok self soos vlamsiekte nie, maar dit het n direkte effek op die kwaliteit van die vrugte. Die tipiese rolblaar simptoom waar blaarrante na onder rol, en die nerwe asook n klein area langs die nerwe, groen bly is egter nie by alle kultivars sigbaar nie. Soms kom die virus latent voor wat die persepsie kan skep dat die siekte nie teenwoordig is nie, en dat dit daarom nie n probleem is nie. Die virus veroorsaak die afbreek van vaatweefsel en dus n verlies aan fotosintese potensiaal in die blare. Behalwe vir die afbreek van vaatweefsel het dit ook n laer suikerkonsentrasie, vertraagde rypwording en verminderde pigmentasie van korrels tot gevolg. Trosse van rolblaarbesmette stokke is soms kleiner, met kleiner korrels wat oneweredig verkleur. Genoemde faktore is krities vir druifgehalte. Rolblaar se effek neem kummulatief toe met ouderdom, en die ouer wingerde word dus baie meer negatief beinvloed. Rolblaarsimptome op n rooi kultivar Tros vanaf n gesonde Barlinka stok (links) en n tros vanaf n rolblaarbesmette stok (regs) Vlamsiekte kan gedurende snoei oorgedra word, terwyl rolblaar hoofsaaklik deur insekvektore naamlik witluis en dopluis oorgedra word. Beide siektes kan deur geïnfekteerde voortplantingsmateriaal oorgedra word, en daarom is die gebruik van gesertifiseerde plantmateriaal uiters noodsaaklik. Die hoë vervangingswaarde van n hektaar tafeldruiwe (R en meer), noodsaak die gebruik van gesertifiseerde plantmateriaal wat vry is van skadelike virus en bakteriese siektes. Oneweredige verkleuring van korrels kan voorkom by rolblaarbesmette stokke Roleen Carstens SAPO Trust roleen@saplant.co.za 6 AUGUST 2018

9 DIE KORREKTE HANTERING, VOORBEREIDING EN PLANT VAN JONG STOKKE Vestigingskoste van n nuwe wingerd behels kapitale investering van etlike honderde duisende Rande per hektaar. Werklike koste word deur verskeie faktore bepaal, byvoorbeeld keuse van plantdigdheid, besproeiingstelsel, opleisstelsel én die aanbring van oorkoepelende skadunet sisteme. Dit is dus vanselfsprekend dat die basiese beginsels met die vestiging van die jong wingerdstokke korrek sal geskied, aangesien juis dít die fondasie is vir die gelykbreek datum en winsgewendheid van die nuwe wingerd. Die ontnugterende werklikheid is egter dat daar steeds baie basiese foute gemaak word met die vestiging van jong wingerdstokke. Die artikel het ten doel om juis weer hierdie basiese beginsels uit te lig en die belangrikheid daarvan te beklemtoon. Die wortels van n jong wingerdstokkie is uiters sensitief vir uitdroging deur wind asook direkte blootstelling aan warm sonlig. Dit is dus van kritiese belang om jong stokkies ten alle tye te beskerm teen enige moontlike vorm van uitdroging. VERVOER VAN STOKKE TUSSEN KWEKERY EN PLAAS Met laai van stokke by die kwekery moet toegesien word dat stokke se klam wortels so veel as moontlik beskerm word deur dit met ander stokke toe te pak, en uiteindelik die vrag deeglik met n digte plastiek seil toe trek en vas te bind. Die vrag stokke moet so spoedig moontlik by sy eindbestemming aankom. HANTERING VAN STOKKE OP DIE PLAAS VOOR PLANT Met aankoms van die vrag, moet stokke so gou moontlik afgelaai word en in vars water geplaas word, of ingelê word in n voorbereide perseel waar grond diep losgemaak is. Sandgrond is die beste, aangesien dit maklik in spoel tussen stokke. Tydens inlê van stokke, moet die bosse in diep slote gepak word en feitlik toegegooi word met grond ten minste tot bokant die entlaste. Grond moet booor die stokke gegooi en ingewas word met lopende water, om te verseker dat daar geen lug tussen die wortels agterbly nie aangesien dit tot uitdroging kan aanleiding gee. Stokke moet klam gehou word in die inlê perseel totdat dit geplant word. Indien stokke in water gehou word, moet dit verkieslik tot bokant die entlas bedek wees en daagliks vervang word met vars water. PLANT VAN JONG STOKKE Die ideale grond vir plant van jong stokke is klam en breek in drie of meer dele wanneer n hand vol geneem word, dit in n wors gedruk word met toemaak van die hand en dan met die duim stukkend gedruk word. Ideale planttyd is van Julie tot vroeg September hoe vroeër hoe beter. Beskerming teen uitdroging bly die hoogste prioriteit tydens die hantering van stokkies tussen die inlê perseel en die plantgat. Hou stokke deurgaans klam en hanteer jong stokke so ver moontlik in sakke of emmers, waar wortels beskerm word teen sonlig en wind. Plantgate Maak gate verkieslik direk voor stokke geplant word en nie lank voor die tyd nie. Sodoende is die wande van plantgate klam en beskerm dit wortels teen uitdroging. Wande van plantgate moet los wees en nie verdig wees agv die graaf se rugkant nie. Gebruik goeie oordeel soms is dit nodig om gate met vurke te maak, of andersins kan wande met n graaf af gesteek word om die kante lekker los te maak. Plantgate moet diep genoeg gemaak word sodat die stok tot feitlik by die entlas regop in die gat pas, en graafbreedte sodat wortels keëlvormig na onder kan uitsprei (foto 1). Daar moet GEEN produkte hoegenaamd in plantgate toegedien word nie. Wortels kan effens teruggeknip word (foto s 2, 3 en 4), maar nie korter as 25cm (snoeiskêr lengte) onder die basis van die stokkie nie. Sodoende behoort wortels gemaklik keëlvormig na onder in die plantgat te pas soos hierbo beskryf. Die terugknip voorkom ook dat baie lang wortels ombuig in plantgate ( J-rooting ) en selfs soms na plant bo die grondoppervlak uitsteek, of dat die wortels soos n katstert in die gat gedraai word om in te pas. Die stokkie moet in die middel van die plantgat gehou word (foto 5), waarna grond reg rondom die stokkie in die gat gegooi word om wortels te bedek. Dit gee aanleiding tot n goeie, gebalanseerde wortelstelsel wat 360 gebalanseerd kan ontwikkel. n Stokkie TECHNICAL AUGUST

10 : Korrekte plantgat 2: Stokkie met lang wortels soos uitgehaal 3: Wortels korrek korter geknip 4: Wortels te kort geknip 5: Stokkie in middel van gat, half vol grond vasgetrap wat teen die wand van die plantgat gehou word (Hoender-voet), veroorsaak dat wortels hoofsaaklik na een kant toe ontwikkel en lei tot swakker stok prestasie. Trap die grond bo-op wortels liggies vas nadat die plantgat half vol grond gemaak is. Maak dan die gat tot bo toe vol met die los grond (wat uit die gat uit gekom het). Stokke moet deeglik natgemaak word direk na plant. Die plantgat moet deurdrenk word met water om sodoende alle moontlike lug rondom die wortels uit te druk en die grond goed in te was rondom die wortels. Indien direk voor n goeie reënbui geplant word (>10mm), sal die reënwater voldoende wees. Terugknip van lote moet verkieslik eers gedoen word nadat die stokkies begin bot het. VERSORGING VAN STOKKIES NA PLANT Grond rondom die wortels van jong stokkies moet gereeld nat gemaak word na plant, om te verseker dat wortels lewendig bly en kan begin groei soos temperature in die lente warmer word en stokke begin bot. Waak teen oorbesproeiing asook onderbesproeiing met die negatiewe gevolge wat beide inhou. Moniteer die effektiwiteit van besproeiings. Lote van jong stokkies kan teruggesnoei word na 2-4 ogies op die sterkste loot nadat goeie uitbot begin het. Behou ten minste een groen lootjie om sapvloei te verseker. Die toediening van bemestingstowwe kan n aanvang neem nadat stokke sterk uitgebot het en begin aktief groei. Wees baie versigtig vir oordosering asook vir die skroei van jong blare, lootjies en wortels. Blaarvoedings speel ook n groot rol in die stimulering van die nuwe groei van jong stokkies. Hou by voorgeskrewe dosisse en resepte wat werk Spuit voorkomend teen swamsiektes. Begin met groenloot ontwikkelling. Onkruidbeheer by jong stokke speel n deurslaggewende rol in die prestasie van jong stokke. Wees uiters versigtig met die keuse en toediening van onkruiddoders rondom jong stokkies. Werk streng op aanbevole dosisse en toedieningsmetodes van landbouchemiese adviseurs. Waak daarteen om die stamme van jong stokkies raak te spuit of selfs tydens hand/ meganiese onkruidbeheer stamme te beseer. Die veiligste is om onkruide wat direk rondom stokkies groei met die hand uit te trek. Dit is n baie goeie en aanbevole praktyk om later in die groeiseisoen die swakker stokkies te identifiseer en spesiale aandag aan hierdie stokke te skenk ten einde die wingerd egalig te probeer ontwikkel. Groeibuise kan van waarde wees, sowel as toediening van addisionele voedingstowwe en water. Die vestiging van nuwe wingerde is n eeue oue proses en daar is slegs n paar basiese beginsels wat die sukses van jong stokkies waarborg, soos hierbo uitgeengesit. Kontak my gerus indien enige verdere navrae: Johan Viljoen of johan@bosmanadama.co.za of ons Kantoor by AUGUST 2018

11 WINGERDVOORTPLANTING: NOTAS VANAF ONLANGSE INTERNASIONALE KONFERENSIE IN DUITSLAND Die 22 ste Internasionale Geisenheim Konferensie vir Wingerdvoortplanting is vroeër vanjaar vanaf 28 tot 30 Junie by die Geisenheim Universiteit in Duitsland in die bekende Rheingau-wynstreek aangebied. Dit was n ideale geleentheid vir kongresgangers om van die wêreld se voorste wingerdkwekers, -navorsers en -telers te ontmoet en eerstehands in drie onderskeie sessies meer te kon hoor van: Tegniese ontwikkelings in die wingerdkwekery-bedryf; Voorsiening van gesonde en produktiewe wingerdkwekerystokke; Teling van siekte-weerstandbiedende kultivars. Hiermee n opsomming en paar blywende indrukke van hierdie afgelope konferensie. TEGNIESE ONTWIKKELINGS IN DIE WINGERDKWEKERY-BEDRYF Toekomstige ontwikkelings in wingerdkwekerymeganisasie is op n gepaste wyse deur Prof Hans-Peter Schwarz van Geisenheim ingelei met n terugblik op die eerste wingerdenting in Dit was in daardie jaar wat die Amerikaanse entomoloog Charles V. Riley filloksera-weerstandbiedende onderstamme (Vitis labrusca) vir Jules E. Planchon van Frankryk gestuur het en so Europese wingerd (Vitis vinifera) van n gewiste ondergang gered het deur die suksesvolle enting van hierdie wingerdspesies met mekaar te illustreer. Wingerdkwekery masjiene. n Wye reeks moderne en doeltreffende plantmasjiene met indrukwekkende laser- en GPS-beheer is vandag beskikaar vir kwekerye wat vinnig en akkuraat wil plant. Brigitte Goutorbe-Wagner van Wagner Plantingenieurswese in Duitsland het n oorsig van hul kwekery-spesifieke produktereeks verskaf. Kwekerye wat hierdie roete wil volg is sekerlik reeds goed bekend met die beskikbare tegnologie, veral op die gebied van entmasjiene en stokkie-uithaal masjienerie. Produksie van geënte wingerdstokke in Kanada en die VSA. Vinetech is gebaseer in Ontario Kanada en is met meer as 3 miljoen stokkies die grootste verspreider van wingerdstokke in Kanada. Met weidverspreide waarneming van Rolblad- (GLRaV) en Red- Blotch (GRBaV)-geassosieerde virusse in Kanada die afgelope paar jaar is streng fitosanitêre maatreëls ingestel, wat insluit die vermeerdering van onderstok-bronmateriaal in potte in grondlose kondisies. Groot en skoon. Dit was die eenvoudige en duidelike boodskap van John Duarte van Duarte Kwekery in die VSA wat wingerdstokke in verskillende groottes in potte bemark, nl. Groot Pot, Magnum en Ubervine TM, met laasgenoemde n 91 cm hoë super-wingerdstok met diep wortels wat vinniger in produksie kom en sodoende opleidingskoste verminder. Eenvoudige skoon-plant-beginsels word by Duarte-Kwekery gevolg waar bekende sowel as onbekende peste as n bedryging hanteer word. Die fitosanitêre risiko wat kwekerye inherent problematies maak word hier nie ligtelik opgeneem nie. Kwekerymateriaal word immers vanaf diverse bronne gesny en ingesamel, dan bewond, naasliggend aan mekaar uitgeplant, en van daar versprei na uiteenlopende landboustreke waar dit tot verdere verspreiding van potensieël besmette materiaal kan lei. Algemene sanitasie in die kwekery en moederblokke is daarom eenvoudig ononderhandelbaar en alle entmateriaal word RESEARCH AUGUST

12 onderwerp aan warmwaterbehandeling (WWB), terwyl kalliswater skoon gehou word met sandand ultraviolet-filters. Soos Duarte dit opsom met n tipiese Amerikaanse aksent: We don t care what pest it is, we don t want it in our nursery. As oorwerk van n gevestigde wingerd met n nuwe kultivar met behulp van lugenting dalk al ooit vir jou n opsie was het Marc Birebent van Worldwide Vineyards, met n koste-vergelyking van laasgenoemde metode met tradisionele bankenting, die kort-termyn voordele verskaf. Sy maatskappy verskaf n diens om wingerd deur middel van T-en Chip-entings oor te werk. Die voordeel: n Vinniger oorskakeling van n bestaande blok na n ander kultivar, terwyl slegs n enkele oes gemis word. Die nadeel natuurlik dat enige virus- of ander oordgraagbare siektes wat oor die jare in die stok en wortelstelsel sou opgebou het vinnig sal versprei van die ou wortelstelsel na die nuwe bostokkultivar. VOORSIENING VAN GESONDE EN PRODUKTIEWE WINGERDSTOKKE Wingerdsiektes oorgedra deur insekvektore. Dr Michael Maixner van die Julius Kühn- Instituut (JKI), Federale Navorsingsinstituut in Duitsland, het risiko s en beheerstrategieë vir potensieël vernietegende insek-oordraagbare wingerdsiektes in Europa bespreek: Flavescense dorée (FD) en Bois noir, fitoplasmas van die astervergeling-groep, Vektore in Europa: Floëem-voedende blaarspringers (Scaphoideus titanus en Hyalesthes obsoletus), Pierce-se-Siekte (Xylella Fastidiosa), n bakteriese siekte wat in die VSA voorkom en n wingerdstok binne slegs twee jaar laat vrek, Vektore in Europa: Xileem-voedende sharshooters (Cicadellidae) en skuimbesies (Cercopidae), ( splittlebugs in Engels) Behalwe vir vektorverspreiding is al hierdie siektes ent-oordraagbaar, en sal gevolglik vinnig versprei in die geval van geïnfekteerde plantmateriaal. Vir n bedryf om te verseker dat gesonde en produktiewe plantmateriaal aan produsente verskaf word, en ook om bio-sekuriteit te bestuur, is n goeie begrip en gepaardgaande voorkomingsmaatreëls noodsaaklik. Al drie bogenoemde wingerdsiektes is nog kwarantynsiektes in SA. WWB is deur Dr Maixner as fitosanitêre maatreël uitgesonder om die risiko van FD verspreiding te beperk en word vir voortplantingsmateriaal in geaffekteerde areas in Frankryk voorgeskryf, asook vir uitvoer van plantmateriaal na sekere ander lande vanaf Europa. Voorskrifte en kondisies vir WWB in Europa word deur die Europese en Meditereense Plantbeskermings Organisasie (EPPO) gelys. Dit bestaan uit onder andere voor- en na- behandelingsprotokolle met streng temperatuurregulasies om die voorgeskrewe 50 C vir 45-minute te handhaaf. Daar is tans meer as twintig gesertifiseerde WWB-toestelle in Frankryk, maar nog geen in Duitsland nie. Plaaslik uit eie bodem. Nico Spreeth, uitvoerende hoof van Vititec, het statistiek oor die S.A wingerdkwekerybedryf verskaf en Vititec se aanslag tot die bestuur van rolbladvirus uiteengesit. Die voorkoming van virus herinfeksies in moederblokke word verkry deur o.a. WWB van entmateriaal, gereelde inspeksies, uitmerk en verwydering van besmette stokke, aanplantings in nie-tradisionele wingerdareas asook die tydige vervanging van ou moederblokke. In n historiese perspektief van kwekerye vóór en ná plantverbetering het hy die waarde van volgehoue virus-eliminering, -toetsing en vermeerdering volgens die klassieke roete van wingerdvoortplantingsmateriaal uitgebeeld. Mikro-organismes in kwekerymateriaal. Helen Waite, bekende navorser van Australië veral vir haar werk op WWB se aanbieding (opgestel in samewerking met Dr Francois Halleen van die LNR), het gefokus op wingerdstamsiektes (WSS), of beter bekend in Engels as GTD (grapevine trunk diseases). Die volgende punte bied n oorsig van haar aanbeiding: WSS, van die mees belangrikste siektes by wingerd, ontstaan gewoonlik weens n kompleks van meer as een organisme. Meer as 130 swamspesies word met WSS verbind. Simptome sluit in: swak entlaste, dooie houtweefsel, vertraagde bot, swak wortelstelsels, swak vestiging en dood van stokke in die wingerd. Bronne van WSS sluit in: swak bestuurde moederblokke, onbehandelde water of water wat gebruik is vir doop van entmateriaal, entmasjiene, kallis-media en verpakkingsmateriaal. Veral tydens die entingsproses word kwekerystokke dikwels aan verskeie infeksies blootgestel. Voorkoming van die verpsreiding van WSS vanaf moederblokke na entlote en kruiskontaminasie in die kwekery is noodsaaklik vir die produksie van gesonde en produktiewe wingerdstokke. Onopgeleide moederblokke is meer vatbaar vir infeksies deur WSS. Die mees effektiefste behandeling van WSS is n kombinasie van WWB en die onderdompeling van entmateriaal in swamdoder. 10 AUGUST 2018

13 TELING VAN SIEKTE-WEERSTANDBIEDENDE KULTIVARS Navorsers uit verskeie lande het n oorsig oor wingerdteling met die fokus op swamweerstandbiedende varieteite gegee. Dr Peter Cousins, wingerdteler en genetikus van Kalifornië het onlangse suksesse in wingerdteling in die VSA gedeel: Seleksies van die onderstok-kultivar, DEMKO 10-17A, is goed bestand teen nematodes soos knopwortelaalwurm, getoets by die Foundation Plant Services (FPS) aan die Universiteit van Kalifornië, en is beskibaar vanaf FPS. n Droogdruif kultivar, Sunpreme, waarvan die druiwekorrels aan die stok verdroog en n feitlik arbeidlose rosyntjie produksie beloof. Meer onlangs is twee kultivars geteel wat goeie weerstandbiedendheid teen Pierce-se- Siekte toon, en benamings word binnekort verwag. Europese regulasies bepaal dat voordat n nuwe kultivar tot hul nasionale lys gevoeg kan word, die kultivar getoets moet word om te bevestig dat die kultivar wel genoegsame waarde vir verbouing het (die sogenaamde VCU, value for cultivation or use ). Hierdie VCU sluit studies oor weerstandbiedendheid teen peste en abiotiese stresse in, en is bo-en behalwe die normale DUS ( distinct, uniform and stable ) vereistes, soorteglyk aan plasing op die plaaslike S.A Variëteitslys. Dit is duidelik dat heelwat werk op swambestande wyndruifkultivars wêreldwyd gedoen is, maar of dit die potensiaal het om die tradisionele kultivars te vervang is onseker. Hierdie navorsing verskaf egter waardevolle inligting vir moderne telingsprogramme en sogenaamde Volgende Generasie Teling ( Next Generations Breeding ) vir tafelduifkultivars om met behulp van merker-geassisteerde-seleksie ( marker assisted selection -MAS) nuwe kultivars te teel wat minder vatbaar vir smamsiektes is. RESEARCH JACQUES FERREIRA Greenhouse Sanitation at Duarte Nursery. After cleaning, benches and floors are treated with an oxidizing chlorine foam to kill any pathogens before the next crop comes in. AUGUST

14 VIRUSES IN SOUTH AFRICAN TABLE GRAPES Importance of certification schemes for virus control in table grapes Virus infections are generally more important in vegetative propagated crops such as, grapes, bananas, potatoes and strawberries, than in crops where the planting material is seed. The process of producing seed is almost a cleansing process in nature with relatively few viruses being able to pass from the mother plant to the progeny via seed. In contrast, progeny of a virusinfected plant, derived from vegetative material, are often also infected with the virus. This is because viruses are often distributed throughout the tissue of the mother plant sometime after the initial infection. For this reason, certification schemes are most often implemented on vegetative propagated crops to ensure planting material of a good phytosanitary status. Grapes, propagated by vegetative means over centuries, have accumulated several viruses. The presence of multiple virus infections in a single vine is not uncommon. Control of these viruses through certification schemes are important for the delivery of plants of good phytosanitary status. HOW DOES THE CERTIFICATION SCHEME WORK FOR TABLE GRAPES? In South Africa, table grape propagation material is prepared via the One Vitis certification scheme. This scheme is a recent amalgamation of the certification schemes that were implemented on Wine and Table grapes separately in the past. In the scheme, Vitis material with desired properties are subjected to process of virus-elimination, generally without prior knowledge of the virus status of the plant. This process generally involves placing Vitis plants at constant elevated temperatures for a lengthy period (most commonly 30 o C for 3 months). The replication and distribution of virus particles through the plant is slowed down for a number of viruses under these conditions. By selecting the uppermost few meristematic cells of the plant, which are not virus infected, and growing these cells in tissue culture to form new plants, plants lacking the virus infection can be derived. As the virus status of plants is seldom determined prior to virus-elimination we do not have good information on exactly which viruses are eliminated in this manner, but the process is known to work extremely well for important viruses such as Grapevine fanleaf virus (GFLV) and Grapevine leafroll associated virus type 3 (GLRaV-3). Based on the presence of some viruses still present after the virus-elimination process, it is known to not work for all viruses. One such example is Grapevine rupestris stem pitting associated virus (GRSPaV) which appears recalcitrant to virus elimination using current methods. Along with tests for genetic trueness to type and some viticultural properties, plants derived from the process of virus elimination, are tested to ensure that they are free of specific viruses included in the certification scheme requirements. If free of these, the plants gain the status of being nuclear plants. Such plants remain susceptible to viruses and do not gain any form of resistance by going through the process of virus-elimination. They must therefore be kept under very stringent conditions in insect-free greenhouses to ensure that they do not get re-infected from an external virus source. From these nuclear plants further propagation takes place to produce Foundation block vines (generally the first generation of plants grown in the field) and from these even larger numbers are propagated in so-called motherblocks which are generally also commercial vineyards. Material from these vineyards are available to nurseries for further sale and distribution. In a certification scheme, stringent measures to ensure the phytosanitary status of the material can generally only be implemented in the early phases (nuclear and foundation plants). With each successive propagation phase, as the number of plants involved increases, fewer and fewer measures can be applied practically. For example, it is feasible to keep only the relatively few nuclear plants under vector-free conditions. Nuclear plants are therefore very important and valuable resources. They are the source of every vine of that clone in industry and should they still be infected with a virus, that virus can potentially be found in thousands of progeny vines. VIRUSES IN GRAPE CERTIFICATION SCHEMES Over 70 viruses have been reported to infect grapevines worldwide and the effect of these viruses on the plant host are generally not known. Furthermore, the geographical distribution and incidence of each virus are also seldom fully determined. All viruses are parasites of their host, hijacking the plant hosts own molecular machinery to replicate themselves. While a number of viruses cause serious diseases in plants, in some instances killing the plant, most virus effects are more subtle, generally reducing yield or quality 12 AUGUST 2018

15 by various amounts depending on the virus and host. In the case of vegetative propagated crops derived from one or only a few initial infected plants the effects of viruses, even those causing very little effect on individual plants may be economically important because of the sheer number of infections. Such infections may even go unnoticed as there may be no healthy plants with which to compare infected vines. To complicate matters, because plants subjected to virus elimination protocol remain susceptible to viruses, they can become infected again once planted in the field in the presence of a vector and a source of virus. The vectors of some grapevine viruses are known, for example GFLV - is transmitted by various nematode species, Grapevine pinot gris virus is transmitted by a mite, and -GLRaV-3 is transmitted by various mealybugs and scale insects. However, for many viruses of grapevines the vector is unknown and natural spread in the field, if it occurs, is not documented. In some instances, some viruses have lost their ability to be transmitted by vectors because of the centuries that Vitis plants have been propagated vegetatively obviating the evolutionary need of the virus for a vector. An example of this may be Grapevine leafroll associated virus type 2 (GLRaV-2), which even though it is related to viruses which have aphid vectors, is not known to have a vector and no natural spread has been demonstrated for it. Through the stringent application of virus elimination and testing, viruses without vectors can be completely eliminated from the industry served by the specific certification scheme. To ensure healthy grape planting material is distributed throughout the South African Table grape industry, it is obligatory that nuclear plants be tested for GFLV, Grapevine leafroll associated virus type 1 (GLRaV-1, GLRaV-2 and GLRaV-3) in the One Vitis certification Scheme. GFLV and GLRaV-3 are the two most important grapevine viruses worldwide. Within the scheme plant improvement organizations are however encouraged, but not obliged, to test the nuclear plants for other known grapevine viruses. A number of these organisations send nuclear material annually to international diagnostic laboratories to do so. In recent years significant improvements have taken place in the ability to detect viruses. Very sensitive techniques such as (Polymerase chain reaction) PCR and Loop-mediated isothermal amplification (LAMP) are now available to detect specific viruses or viral groups, while a technique such as next generation sequencing makes it possible to detect and identify previously unknown or undetected viruses. This has contributed to the discovery of ever increasing numbers of viruses on grapevines. Some of the viruses now known to occur on grapevines would not have been detected within the certification scheme in past years due to only being recently discovered and concomitant detection methods developed. In view of the importance of viruses in vegetative propagated crops such as grapevines, and the fact that healthy plants can become reinfected in the field if viruses with vectors occur, it is important to determine which viruses are present in table grapes in South Africa, which are the most prevalent viruses and how widely are they distributed in the industry. SURVEY FOR VIRUSES OF TABLE GRAPES The South African Table Grape Industry (SATI) has recently funded a project to gain an insight into which viruses are present in South African table grapes and to gain some measure of incidence and the geographical distribution of these viruses. This will allow the industry to identify deleterious viruses requiring further measures to control them and to mitigate any economic effect they may have. This project was initiated at the beginning of 2017, and is a joint effort between the authors who are at the University of Stellenbosch and SAPO Trust. During the first two seasons of this study, 160 vine samples representing 41 cultivars were collected. Samples were from 38 table grape farms and most were from the greater Paarl/Wellington, Hex River Valley and Vredendal areas, but some samples were also obtained from Kakamas, Upington, Riebeeck- Kasteel, Piketberg and Groblershoop. Samples represented vines planted between 1969 and 2016, and were selected to represent a range of symptoms, cultivars, vineyards and growing areas. Older vineyards were selected as these are most likely to contain viruses which may have been spread by vectors, hence would be the most common and be the most important to control in mother and foundation vineyards. METHOD OF VIRUS DETECTION USED DURING THE SURVEY Samples were tested for a range of viral genera along with some specific viruses, representing 41 known viruses of grapevine. This method was developed during a Winetech- funded project and is based on a suite of PCR systems, generally each of which can detect a number of grapevine viruses simultaneously. This method is described in greater detail in WineLand Technical, January, 2017 ( co.za/latest-sequencing-technology-detection- RESEARCH AUGUST

16 identification-grapevine-viruses/), and basically relies on related viruses having two pieces of their Ribonucleic acid (RNA), quite close to each other being the same, or at least very similar, amongst the related viruses. Millions of copies of this part of the virus is created in the PCR process, making it detectable by a process known as electrophoresis. For the tests capable of detecting multiple viruses the exact virus must be further identified using sequencing. The test allows for the analysis of a relatively large number of samples for many viruses but is unlikely to detect distantly or unrelated viruses or novel viruses present. It therefore will be followed by next generation sequencing (NGS) on some selected samples. This approach, which is not ideal, was selected, as NGS, which ideally should be applied to all samples, is still too expensive for large scale use. In order to do the PCR tests, the RNA from the viruses must first be extracted. As the virus cannot easily be separated from its host plants, the total RNA (virus, host and other organisms inside the plant) is extracted and used for the test. KEY RESULTS At the time of writing RNA extraction was successfully performed on 145 of the samples and PCR tests were performed on most of them for ampeloviruses, grapevine leafroll associated viruses (GLRaV) [GLRaV-1-, GLRaV-2-, and GLRAV-3 specific], tombusviruses 1, marafiviruses 2, maculaviruses 3, nepoviruses B 4,, grapevine redblotch associated virus (GRBaV) and Grapevine cabernet sauvignon virus (GCSV). Of the 145 samples tested thus far, 114 were positive for GLRaV-3 and 46 for GLRaV-2 (often in mixed infections with GLRaV-3). Only five samples contained GLRaV-1 of which four were mixed infections of GLRaV-1, 2 and 3. A number of samples tested positive for Maculaviruses, Tombusviruses or Marafiviruses but the specific viruses involved must still be determined. No instances of grapevine red-blotch associated virus or grapevine cabernet sauvignon virus were obtained. Tests for Viti/Foveaviruses 5, Nepovirus A, or GLRaV-7 have not been conducted yet. Samples have not yet been analysed for unrelated or novel viruses by NGS yet. These tests are planned for the final year of the project on selected samples. PRELIMINARY CONCLUSIONS FROM THE SURVEY GLRaV-3, the virus mainly associated with grapevine leafroll disease, is the most prevalent virus in South African Table grapes. This mirrors the situation in wine grapes in South Africa. An integrated control strategy to prevent the spread of this disease has been developed and implemented in the wine industry where it works very well. The program is being tested on a pilot scale in the table grape industry (refer to the article Keeping newly-established table grape vineyards free of grapevine leafroll in this same publication). GLRaV-2 is surprisingly common in table grapes. The virus has no known vector, has not been demonstrated to spread naturally, and is only transmitted by planting material and grafting. This virus can be eliminated from all new vineyards of the Table grape industry through the judicious use of healthy planting material and by not performing top grafting onto old vineyard rootstocks. The presence of significant numbers of Macula-, Marafi- and Tombusvirus infected samples warrants further investigation into whether these viruses should be included for control in the certification scheme. FOOTNOTE 1 Known grapevine infecting Tombusviruses include 1) Grapevine algerian latent virus (GALV) and 2) Petunia asteroid mosaic virus (PAMV). 2 Known grapevine infected Marafiviruses include 1) Grapevine asteroid mosaic associated virus (GAMaV), 2) Grapevine Syrah virus 1 (GSyV- 1), and 3) Grapevine rupestris vein feathering virus (GRVFV). 3 Known grapevine infecting Maculaviruses include Grapevine fleck virus (GFkV) or Grapevine redglobe virus (GRGV). 4 Known grapevine infecting members of the Nepoviruses B and C clade include Blueberry leaf mottle virus (BBLMV), Cherry leafroll virus (CLRV), Grapevine bulgarian latent virus (GBLV), Grapevine tunisian ringspot virus (GTRSV), Peach rosette mosaic virus (PRMV), Tomato ringspot virus (ToRSV), Grapevine anatolian ringspot virus (GARSV), Artichoke italian latent virus (AILV), Grapevine chrome mosaic virus (GCMV) or Tomato blackring virus (TBRV). 5 Known grapevine infecting Viti- and Foveaviruses include grapevine virus A (GVA), grapevine virus B (GVB), GVD, GVE, GVF, GVH, GVI, GVG and grapevine rupestris stem pitting associated virus. Viruses infecting grapevines belonging to the Nepovirus A and C clade include; Grapevine fanleaf virus (GFLV), Raspberry ringspot virus (RpRSV), Arabis mosaic virus (ArMV), Grapevine deformation virus (GDefV), and Tobacco ringspot virus (TRSV). Gerhard Pietersen (Department of Genetics, Stellenbosch University) and Emcee Gagiano (SAPO Trust) 14 AUGUST 2018

17 KEEPING NEWLY-ESTABLISHED TABLE GRAPE VINEYARDS FREE OF GRAPEVINE LEAFROLL REASON FOR LEAFROLL CONTROL Leafroll disease affects all cultivars of table grapes, black, red or white, and result in a delay in the ripening of berries, have unevenly ripening berry clusters, reduced sugar build-up, and reduced berry colour in the case of black or red grapes (Figure 1), all making it difficult to harvest vineyards in which infected and healthy plants are found simultaneously. The vines also have reduced yield and berry sizes, and result in such reduced levels of production. THE VIRUS INVOLVED IS GLRaV-3 While a number of viruses have been associated with grapevine leafroll disease internationally, it is caused predominantly by grapevine leafroll associated virus 3 (GLRaV-3) in South Africa, a fact long known in wine grapes, but also confirmed for table grapes recently during a survey of viruses in this crop (refer to article on Viruses in South African Table grapes on page of this publication). Figure 1: Image from the literature, showing the difference between leafroll infected and healthy black grape bunches. It is the most important virus disease of grapevines locally, and if untreated roughly doubles in incidence in a vineyard annually, until it can no longer double due to the large number of infected vines already present. Once the disease reaches an incidence above about 20% infection in a vineyard block, it is no longer feasible to try to control the disease in that block and the aim should then just be to control mealybug numbers and their dispersal in that block in order to minimize them spreading the disease to the new vineyards. However, control of leafroll in newly established vineyards is imminently feasible. It must be kept in mind that; a) plants derived from certification scheme, while free of certifiable viruses, are still susceptible to virus infection, b) that grapevine leafroll associated viruses are the most prevalent viruses found during the survey of viruses in table grapes, and c) that this virus has a very efficient vector (mealybugs) in South Africa which helps it spread to newly planted vineyards (See the article on Viruses in South African Table grapes on page of this publication). This means that it is important that this virus be controlled on site in newly established local table grape vineyards in order to further the advantages of having planted certified planting material. BIOLOGICAL PROPERTIES OF GLRaV-3 GLRaV-3 does not have any known natural host other than Vitis spp. but was recently experimentally transmitted to Nicotiana benthamiana (a tobacco related plant) at low efficiency. It is commonly accepted however that only Vitis plants play a role in the epidemiology of leafroll disease. It is therefore not necessary to be concerned that the virus may occur on weeds, other crops, or indigenous plants in or around the vineyard. The virus is not mechanically transmissible. This means that the sap from an infected plant on secateurs cannot infect a healthy plant, and therefore no special precautions need to be taken during pruning for this virus. Other pathogens, e.g. fungi involved in trunk disease may however be spread in this manner. While a number of mealybug species and scale insects can transmit GLRaV-3 from an infected to a healthy vine, it is spread primarily by Planococcus ficus (vine mealybug) in South Africa. This transmission takes place in a socalled semi-persistent manner. This means that the virus is restricted to the mouthparts of the mealybug and that it does not transmit the virus to its offspring. Furthermore because of its restriction to the mouthparts it probably also loses the virus every time it moults. These properties simplify the control of spread of this virus. GLRaV-3 is very strongly associated with the easily observable leafroll symptoms observed on black, and some red berried cultivars but it often does not display symptoms on white cultivars or on rootstocks. Therefore to identify GLRaV-3 infected vines in white cultivars for control, laboratory tests must be conducted, making it a costly exercise. RESEARCH AUGUST

18 EPIDEMIOLOGY OF GLRaV-3 In view of the biological properties of GLRaV-3 discussed above, the following is evident. The presence of a GLRaV-3 infected vine in a new vineyard can only occur as a consequence of; a) planting of a vine already infected with the virus, or b) through such a vine being infected by a virus-carrying, or so-called viruliferous mealybug or scale insect which had acquired the virus from a GLRaV-3 infected grapevine, and been dispersed to the new vine where it fed (Figure 2). The mealybug or scale insect can only acquire the virus from a GLRaV-3 infected vine as there are no other known natural plant hosts of this virus. This infected vine can be either in the same, young vineyard, or from another vineyard which may be adjoining, or more distant. The mealybug can be dispersed to the new plant through its own motility over relatively short distances or on workers clothing and implements, and even possibly by wind over longer distances. Figure 2: Epidemiology of GLRaVG-3 CONTROL OF GLRaV-3 To control the disease, each of the means that the plant has of becoming infected has to be addressed. Hence, control of the disease is by using an integrated strategy which includes planting leafroll free certified material, roguing infected vines, mealybug control, sanitary measures to prevent mealybug dispersal from adjoining vineyards, and sanitary measures to reduce virus inoculum between old infected vineyards and their replacements on the same site. In view of the fact that the disease can only be easily detected visually in the black and some red cultivars, and that white cultivars need laboratory tests to detect the virus, means that control is only feasible currently in black and those red cultivars where the disease can be observed. Each of the components are briefly discussed below. Because it takes a while before a newly GLRaV-3 infected plant shows symptoms or reaches levels where the virus can be detected by laboratory tests, planting material from motherblocks maintained in leafroll affected areas may have some infected material as the Plant Improvement organisations would not be able to detect the virus during this latent phase. These infected vines must be removed as quickly as possible from newly infected vineyards before they serve as sources from where the virus spreads to surrounding plants. When relying on visual assessment of this disease this is only feasible once the plant shows symptoms. This may only occur in the second or third season, hence to prevent spread of the virus by mealybugs in the meantime, it is important to treat such plants with a systemic insecticide. Spread to surrounding plants, known as secondary spread, is the largest 16 AUGUST 2018

19 cause of newly infected vines in the industry and therefore the most critical aspect to control. To achieve this, throughout the lifetime of the vineyard mealybug levels should be monitored and controlled (either by systemic insecticides or by biological control through the release of mealybug parasitoids or predators) and infected plants should be removed. The aim should be to keep GLRaV-3 infection levels below about 1% over the long term. Infected volunteer plants ( opslag ) from a previous vineyard must also be controlled by removing them. The number of volunteer plants can be reduced through the use of a fallow period between successive vineyards to remove as much infected material as possible in the interim. Mealybugs can also spread the disease to a healthy vineyard from leafroll infected vineyards adjoining, or in the vicinity of the healthy vineyard. They can be dispersed over short distances by their own motility or over longer distances on workers clothing, on farm implements and through wind. It is thus important to control mealybug numbers in these vineyards too, along with preventing their dispersal to the healthy vineyard. This is done by first working in the healthy vineyard and then only entering infected vineyards. If this is not possible, then implements used in infected vineyards must be washed with a weak detergent to remove any mealybugs before entering the healthy vineyard. The integrated control strategy employing the above principles has been successfully implemented at a number of wine estates in South Africa, New Zealand and Israel. It is likely that control of leafroll in the table grape industry will be even more striking as these producers have a history of good mealybug control. It is also anticipated that the benefits of leafroll control will also be more marked as the berries are likely to ripen more uniformly with regards to berry colour, size and sugar levels throughout a vineyard. In some instances too the earlier ripening of healthy vines may be advantageous with regards to prices obtained. AN EXAMPLE OF LEAFROLL CONTROL IN THE SOUTH AFRICAN TABLE GRAPE INDUSTRY We are aware of at least one producer applying some of these principles on newly planted vineyards. Mr. Anton Viljoen of Boplaas owner of Villion Farms in the Hex River Valley planted several Crimson Seedless foundation block vineyards from Vititec between 2012 and The planting material was derived from the progeny of a Crimson Seedless nuclear plant which had been subjected to virus-elimination by Vititec (See the article on Viruses in South African Table grapes on page of this publication), and was planted on the same site where old vineyards were removed. As per the norm in the industry for old vineyards, these would have been close to 100% leafroll infected, but were not specifically tested or monitored for this. The producer did not apply a fallow period but ensured the thorough removal of vine material from the old vineyard. The newly planted vineyards were in close proximity to existing, highly leafroll infected vineyards (See Figure 3). RESEARCH Figure 3: New Crimson Seedless Vititec foundation vineyards planted on Boplaas since AUGUST

20 During the first season, and every year subsequently these vines were treated with a systemic insecticide. During the last season mealybug parasitoids were also released. The virus status of the plants were either determined visually or by ELISAs done by Vititec, and infected plants removed annually. The incidence of leafroll in these vineyard have not exceeded 1.4% in the six year lifetime of the oldest vineyard or in any of the younger vineyards. Figure 4 shows a map of the GLRaV-3 infections over a number of seasons in the oldest vineyard. Figure 4: Plot of annual leafroll infections of Crimson Seedless Block 2 (2012 to 2017). In this particular case, it is evident that the infection is coming mainly from the immediately adjoining infected plants of the old half of the vineyard. Furthermore, the fact that the infection is primarily within only one of the corners, rather than all along the entire adjoining border with the infected vineyard, suggests that it is due, not to own dispersal of the mealybugs between vine rows, but by dispersal of virus-carrying (viruliferous) mealybugs carried on workers and implements coming into the new vineyard in that corner. FURTHER READING IGWS leafroll fact sheets are available at: igws.co.za/content/fact-sheets/leafroll Gerhard Pietersen Department of Genetics, Stellenbosch University 18 AUGUST 2018

21 DETECTION AND QUANTIFICATION OF SOILBORNE PATHOGENS IN GRAPEVINE NURSERIES INTRODUCTION Grapevine decline is a disease complex that affects young vines in all grape growing regions of the world and leads to a lower survival rate for young vines. A major contributing factor to grapevine decline is black foot disease (BFD) and crown and root rot (CRR). Studies in South Africa has shown that pathogens of BFD and CRR are present in nursery vines. Black foot disease of grapevines is a serious soilborne disease occurring mainly in nurseries and young vineyards and are more often encountered at disease clinics (Department of Plant Pathology, SU and Infruitec-Nietvoorbij ARC) than CRR. Black foot disease of grapevines is caused by species of the genera Dactylonectria (previously known as Cylindrocarpon), Ilyonectria (previously Cylindrocarpon), Campylocarpon, Cylindrocladiella and Thelonectria. The BFD species are soil inhabitants and are regarded as saprobes and weak pathogens and infect roots through wounds and natural openings. In nurseries, the most visible symptoms include plants with reduced vigour, shortened trunks and internodes, sparse foliage and interveinal chlorosis. Upon dissection of the roots and basal ends of rootstocks, black discolouration, gum inclusions of the xylem vessels and brown vascular streaking can be observed. A reduction in root biomass and root hairs, and sunken necrotic root lesions may also be observed on afflicted plants. In young vines (less than 5 years old) death can occur rapidly. All BFD pathogens except Campylocarpon species can produce thickwalled chlamydospores which would allow these pathogens to persist in the soil for long periods. Crown and root rot is caused by species belonging to the genera Phytophthora, Pythium and Phytopythium. Root and crown rot symptoms include black to brown root necrosis, while the above ground plant parts show typical decline symptoms such as stunted growth, leaf chlorosis, wilting, die-back, poor fruit-set and shoot growth. It has been reported that some Phytophthora spp. may even infect the crowns and cause cankers which may girdle grapevine trunks. This girdling may then lead to plant collapse. The infected vines may be isolated or occur in small groups. CRR pathogens can produce sexual oospores that can persist in the soil. Nursery soils are known as a major inoculum source for BFD and CRR pathogens. In South Africa, the treatment of BFD is limited to cultural practices such as hot water treatment, as there are no fungicides registered against this disease. However, the treatment for CRR involves cultural practices as well as the use of phosphonate fungicides. The extent to which BFD and CRR pathogens are present in nursery soils is not known. Also the influence of rotation crops on the occurrence of BFD and CRR has not been investigated and could hold potential in an integrated control strategy. AIM AND OBJECTIVES The aim of the study was to evaluate the effect of different rotation crops used by nurseries by detecting and quantifying BFD and CRR pathogens in nursery plants and soil. The objectives were: To adapt a method for directly quantifying BFD and CRR pathogen DNA in grapevine nursery soils over a 3-year period and, To isolate these pathogens from grapevines, weeds and rotation crops in these nurseries over the same 3-year period. METHODOLOGY AND RESULTS In 2013, soil and grafted grapevine cuttings were collected from five nurseries. In 2014, rotation crops and weeds were collected from the same nurseries at approximately the same sites within the nursery. In 2015, soil and grapevine samples were collected again from the five nurseries. The soil samples were taken at two depths (0-30 cm and cm), 10 cm away from the grapevines that were sampled (Figure 1). Soil analyses were conducted on the soil sampled. Figure 1. Soil samples were taken with an auger. Nursery soils were different as can be seen from a dryer soil (a) versus a more waterlogged soil (b). OBJECTIVE 1: QUANTIFY BFD AND CRR PATHOGEN DNA IN GRAPEVINE NURSERY SOILS Total DNA extractions were done on the soil samples. The pathogen DNA in these total soil DNA samples were then quantified using optimised Quantitative Real-Time Polymerase Chain Reaction (qpcr) protocols for the detection of Phytophthora species, Pythium irregulare, and Dactylonectria and Ilyonectria species. qpcr is a molecular technique used to detect and quantify target DNA in a sample (soil), while the DNA amplification can be viewed in real-time. Dactylonectria and Ilyonectria species, Py. irregulare and Phytophthora DNA was successfully detected and quantified from grapevine nursery soil. The Dactylonectria and Ilyonectria DNA was detected in all nursery soil samples, except for one RESEARCH AUGUST

22 site in one nursery, and ranged from 0.04 pg.μl -1 to pg.μl -1. The Py. irregulare DNA concentration in the soil ranged from 0.01 pg.μl -1 to 3.77 pg.μl -1. The Phytophthora DNA concentrations ranged from 0.01 pg.μl -1 to pg.μl -1. Phytophthora DNA was detected in all nurseries except for three sites in one nursery in Pathogen DNA concentrations increased over the three years for four of the nurseries. OBJECTIVE 2: ISOLATE BFD AND CCR PATHOGENS FROM GRAPEVINES, WEEDS AND ROTATION CROPS FROM NURSERIES Pathogen (fungal and Oomycete) isolations were done from the grapevine cuttings, weeds and rotation crops. Isolations were made from the roots and vascular tissue of the grapevines onto potato dextrose agar and Pythium and Phytophthora selective media. The fungal and Oomycete cultures were identified using Polymerase Chain Reaction (PCR) and sequencing of two gene regions (ITS-rDNA and histone H3). A total of 176 BFD and 108 CRR pathogen isolates were obtained. The predominant BFD pathogens isolated from grapevines in these nurseries were Dactylonectria macrodidyma, Campylocarpon pseudofasciculare and Ca. fasciculare. Symptoms associated with BFD could be seen on the vines isolated from (Figure 2). Figure 2. Isolations were made from visually healthy vines. A longitudinal cut through the base of the vine clearly show the typical brown discolouration due to infection of black foot pathogens (a). A tranverse cut through the rootstock shows brown water soaked discolouration associated with black foot. The predominant CRR pathogens were Pythium irregulare followed by Pp. vexans. Other BFD pathogens such as D. novozelandica, D. toressensis, D. alcacerensis, D. pauciseptata and I. liriodendra were isolated as well. The other CRR pathogens isolated included Pythium irregulare, Py. sylvaticum, Py. ultimum, Py. heterothallicum, Py. rostratum, Pp. vexans, and Ph. niederhauserii. The rotation crops sampled include Canola, white mustard, forage radish, Triticale and lupins. The weeds sampled included Johnson grass, rye grass, winter grass, Cape marigold and Corn spurry. No pathogens were isolated from Canola, white mustard and lupins. Of the different rotation crops Triticale had the greatest diversity of pathogens isolated from. Four isolates of Py. Irregular, 2 isolates of Py. ultimum, D. pauciceptata, D. novozelandica and one isolate of D. macrodidyma were obtained from Triticale roots. One isolate of Py. irregulare was obtained from forage radish. Of the weeds corn spurry, Cape marigold, rye grass, winter grass and Johnson grass, harboured pathogens. One isolate of D. macrodidyma was obtained from the weed, Corn spurry, while one and two isolates of Py. irregulare were obtained from the weeds, winter grass and rye grass, respectively. Two Py. ultimum isolates were also obtained from rye grass and Cape marigold. No correlations could be made between DNA concentrations and occurrence of pathogens in vines or rotation crop. However, one nursery had no pathogens present in the vines isolated from and the concentration of the Dactylonectria and Ilyonectria DNA was significantly less than two other nurseries for all three years. This nursery is situated on the slopes of a hill and makes use of ridging as a method to improve soil drainage. Other factors that could also contribute to this could be that it does not have a long history of grapevine nursery cultivation as well as the 3-year rotation system. CONCLUSIONS This is the first study in South Africa to detect BFD and CCR pathogen DNA from the soil. DNA extraction and qpcr protocols were optimised for soil samples. BFD and CCR pathogen DNA were detected from soil of all five nurseries investigated. From four of the nurseries these pathogens were also isolated from nursery vines collected in year 1 and year 3. Of the rotation crops, only Triticale and forage radish harboured black foot and crown and root rot pathogens, whereas no pathogens were isolated from Canola, white mustard and lupins. The latter rotation crops would be recommended. The weeds: corn spurry, Cape marigold, rye grass, winter grass and Johnson grass, harboured pathogens and may serve as an alternative host in the absence of grapevines (during crop rotation and fallow periods). Weed control would aid in lessening the carry over of pathogens from one vine cropping year to another. The biofumigation effect of the Brassica crops were not directly assessed. Also the potential of lupins with the secretion of the phytochemicals saponins should be further investigated. Therefore, studies should be conducted to test specific rotation crops over several years for their ability to aid in controlling BFD and CRR pathogens in the soil. Since nursery vines get infected from BFD and CCR pathogens present in nursery soils, the most viable solution is hot water treatment of nursery vines. Shaun D. Langenhoven, Francois Halleen, Chris Spies & Lizel Mostert 20 AUGUST 2018

23 GOING BACK TO OUR ROOTS New rootstock trials to identify superior rootstocks In view of replacement expenses of old cultivars in vineyards and to ensure economic and environmentally sustainable table and raisin grape production, appropriate rootstock and cultivar choice has become a critical factor to take into consideration during planning of new plantings. Because of the variation in SA soil and climatic conditions, vine rootstocks need to fit specific requirements depending on the area of production, i.e., suitability for different soil conditions (high ph, salinity, soil texture, waterlogging and drought conditions) and resistance to pests such as phylloxera, margarodes and plant-parasitic nematodes. Each rootstock has its own characteristics and adapts differently in varying soil types and growth areas. Therefore, new rootstocks should be categorized according to their adaptability to a specific soil and growing condition. Since berry quality and harvest time are factors influenced by the vigour and vegetative cycle of the rootstock, the growth potential of the rootstock has a significant effect on the type of trellis and management of the scion cultivar. Other traits, such as yield and compatibility, are also influenced by rootstock choice. A new rootstock project, jointly funded by the South African Table Grape Industry (SATI) and Dried Fruit Technical Services (DFTS), started in This new project will be rolled out by Provar, an independent cultivar and rootstock evaluation company, to seven table grape and raisin production sites including Hex River, Orange River, Vredendal and Porterville. The principle upon which this new rootstock project is based, is the industry s accessibility to view rootstock performance in as many of the table grape regions as possible and to have regular access to the most recent information. The main objective of this project is the evaluation of adaptability of new rootstocks in different soil and growing conditions to enable identification of superior rootstocks for specific planting areas. The first planting will take place in 2019 and a second planting is planned for 2021 when new rootstock additions will become available from nurseries. During 2019, the following rootstocks will be planted as part of a comparative study: Harmony, a medium vigour rootstock with resistance against some nematodes, well adapted to high potential soils; RS-3, a medium vigour rootstock for high potential soils, with resistance against a wide spectrum of nematodes and phylloxera, but sensitive to soil wetness and salinity; RS-9, with resistance to phylloxera and nematodes, but lower in vigour compared to RS-3 and suited to high potential soils; 143 B Mgt, well adapted to heavy, wet soils and with vigorous growth habit; Ruggeri 140 with good adaption to limestone soils, has high drought resistance and suited to limestone, dry, lean, superficial and stony soils; SO4 with high resistance against phylloxera and nematodes. Older rootstock genotypes are included in each planting to serve as controls in the trial, i.e. Ramsey, Richter 110 and Paulsen In 2021 latest releases Minotaur, Kingfisher, GRN-1, GRN-2, GRN-3, VR and Freedom will be planted. These rootstock trials will be performed in preidentified commercial vineyards where normal onfarm practices are applied. The Provar evaluation protocol will focus on viticulture characteristics with commercial impact such as yield and berry quality, and the adaptability of the rootstock x scion combinations exposed to different climatic conditions. Data will be collected on characteristics associated with growth and vigour, fertility and yield, as well as berry and bunch quality. A renewed approach to evaluation is taken to make sure that producers are included in the process, i.e., from identification of the relevant sites, and the choice of scion cultivars and planting of the trial sites. Provar aims towards a transparent process and protocol, where an open discussion platform will be available on a web-based Rootstock Discussion Forum. Provar, in association with these producers, will manage access to the trial sites. The value of the project to the industry lies in independent and objective data collection to supply unbiased information and to recommend the best rootstock for the various planting areas and planting conditions that exist in the South African grape production regions. Iwan Labuschagne iwan@provar.co.za RESEARCH AUGUST

24 VERGELEGEN: STRENGTH IN NUMBERS From left: Logan von Willingh, Cindy Bosman and Hendrik Davids are part of the team being groomed to take over full management of the business by STRENGTH IN NUMBERS A farm worker empowerment business, Vergelegen Packing, is showing what can be done when land reform beneficiaries are serious about business not running a project and are linked with the right commercial partners. It is one thing to grow up on a farm and come from a line of people who have worked the land, but another, altogether, to become a successful farmer. This is something the 282 farm worker shareholders of the Vergelegen Packing business were fully aware off, when they in 2009 each received R in LRAD grants (a Government grant) to buy the farms Vergelegen and Quickstep near Robertson in the Breede River Valley. The business is owned by seven trusts, with trustees who worked for either AJ Reyneke or De Villiers Graaff in the Hex River Valley when the group applied for grants. It would have been futile to think that our years of experience as farm workers would prepare us for managing a farming operation. We looked at what was happening with other farm worker empowerment projects and realised our strength laid in unity and having strong partnerships with other agricultural roleplayers, said Hendrik Davids, managing director of Imdawo Ekhuhle, the company under which the business is registered. Some of the beneficiaries still work on the farms they worked when the business was initiated, while others have been transferred to Vergelegen. I think one of our greatest strengths, is that group members basically share the same background, with most of us growing up in the Hex River Valley, coming from farm worker families and working on farms when the business was initiated. We, in effect, have very much the same expectations from the business, Davids said. In addition to this, there is no distinction between workers who are part of the trust and those employed from outside. Everybody, working at the business, are treated equally, according to Davids. All the beneficiaries are also aware of what is happening in the business, with the farm management team being directly accountable to the directors of each trust. All management decisions and long-term operations have to be approved by the directors, who communicate the decisions to the trustees, Davids said. 22 AUGUST 2018

25 The management team meets with the directors once every three months, while the directors regularly communicate information to the trustees. An annual general meeting is held once a year. Bonuses have been paid to beneficiaries over the past three years, but beneficiaries understand that the business cannot pay dividends yet, as all the profits have to be reinvested to improve the farm s sustainability or to pay off debt. Ideally, we would like to have a 100 ha under table grapes by 2020 and expand our pack house capacity to cartons, Davids said. Government had a huge stake in the group s success. Without LRAD funding we would never have gotten a farm in the first place and without CASP funding, received two years ago to fix a leaking dam, upgrade our packing infrastructure and plant 18,5 ha of new varieties, some of our production expansions would not have been possible, Davids said. The South African Table Grape Industry (SATI) and Culdevco supported the renewals and expansions by supplying all the planting material for these new developments and renewals from 2013 to 2017, improved their viability, competitiveness, sustainability and ultimately profitability recounts Davids. The group has also been assisted by some very successful commercial farmers. If it wasn t for our mentors, Reyneke, Graaff and the Karsten Group, the farm might have turned into a poverty trap. Imagine having your dream of owning a farm come true and then not having the means to maintain and turn it into a money-making asset. These individuals and/or organisations are more than mentors, they had to become the financiers and marketing agents of our produce due to the incomplete support system provided by government at the time Davids said. A DREAM COME TRUE Our business has significantly changed many people s lives. We have gone from owning hardly anything to being shareholders of a farm. Becoming the managing director of the business also resulted in a lot of career growth and experience, that might have taken much longer to generate, if I was working for another company, Davids said. He added that the business has a strong focus on training and upliftment to equip workers with the necessary skills to fulfil their career potential. Davids daughter, Cindy Bosman, is also a beneficiary in the project. She said the project has been a great inspiration for her to give her best: I am doing everything I can to make our farm as successful as possible, because it is not only a great asset to us, but also our children and potentially their children s children. The business has also resulted in career advancement for her. I started out as a secretary at De Hoop, from where I was promoted to financial clerk. Last year, I was transferred to Vergelegen Packing as assistant accountant. I am happy and satisfied with my present position, but there would be a lot of support if I decided that I actually wanted to become an accountant, she said. Logon von Willingh, junior production manager at the business, also come from a family of farm workers in the Hex River Valley. I wanted to follow in the footsteps of my parents, so did an Agricultural Diploma at Boland College after school, followed by a Certificate Programme hosted by PPECB. I was fortunate to do my internship at De Hoop at the time that Davids and the other beneficiaries started talking to Graaff about having their own farm. The internship turned into full-time employment, which allowed me to also become a beneficiary, Von Willingh said. The business not only realised Von Willingh s dream of having his own farm, but also gave him an opportunity to live out his passion for making a difference in other people s lives. We get many young people and first-time employees on the farm. My objective is to equip them with skills to not only do a good job, but to increase their career prospects. It is a difficult job, as many of the temporary workers do not realise the great opportunities in the industry and in effect come and go, he said. The business has been doing a lot to try and improve the livelihoods of their labourers and people who live on the farm. One of our challenges is that the farm is quite far from towns, Von Willingh said. In addition to building on new rooms, we have been trying to improve the living quality by supplying warm water geysers and DSTV dishes, so people have access to good television programmes when they are not working. He said the business has accelerated his personal growth: Davids has been a great mentor, by teaching me almost all the tricks of the trade, giving me enough space to do my own thing and learn from my mistakes. Along with all the courses I have done up until now, Davids has equipped me with enough knowledge to take the farm over from him if necessary. I would most probably not have been in this position today, if I worked for someone else. INDUSTRY COMMUNICATION AUGUST

26 COMMERCIAL PARTNERS Davids said that Graaff primarily helped to take the group forward by helping them get their vineyards in order, while Karsten Group significantly boosted their profitability by allowing them to market their grapes through the group. Supplying grapes via the Karsten Group is a huge benefit, because they are responsible for their own marketing and sales, which helps to take out third party costs. Our exports have grown from to cartons, since Karsten took over from Graaff around 2013, Davids said. One of the greatest advantages of having a strong industry player on your side, according to Davids, is that it gives you a direct line to someone when you need advice. It is extremely overwhelming for a new entrant to choose reliable service providers from the multitude of available consultants out there. When you have a mentor, you automatically gain access to the service providers that have helped the mentor become successful, Davids said. Another advantage, is that they are not as emotionally involved in the business as the beneficiaries and have years of experience in running a business. This makes it easier for them to offer objective advice. You get mentors who directly interfere and does everything for the group. Ours understand the importance of having the group make its own decisions. They might nudge the group in a direction, but ultimately let the group have the final say, Davids said. One of the group s dilemmas, was that government wanted first option to buy the farm if the group decided to sell the land. We have had a terrible time trying to source production loans from banks, because of this clause. Graaff in the end came to our aid with a R15 million loan, of which we still only owe R3,5 million, Davids said. The loan, along with funding provided through CASP (Department of Agriculture: Western Cape), SATI and Culdevco, was used to plant better table grape varieties and expand production. The Department of Agriculture: Western Cape supported us with the restoration of the packing facility and therefore we have the capacity to pack all our grapes on farm. This adds to our profitability. Vergelegen had 46 ha under table grapes when the farm was bought, but the majority of the vines were old or no longer in demand. No table grapes have been planted at Quickstep, yet, but there is room to plant roughly 66 ha of vines. The group has since replaced all the Dauphine, La Rochelle, Regal, Red Globe and Victoria vines at Vergelegen, with varieties that were better suited to their production conditions and the market. These include Crimson Seedless, Flame Seedless, Derali Seedless, Tawny Seedless, Scarlotta and Joybells. With any empowerment scheme there should always be an exit strategy a point where the group is left to fully manage their own business. We are already functioning quite independently as it is, with Karsten Group only giving inputs when absolutely necessary. The target is for Karsten Group to exit the co-management in the years to come. A lot of time and money is invested in training and education, to ensure the management team is up for this transition, Davids said. The exit strategy, however, does not imply the end of a relationship. Our group would most probably always maintain close ties with the Karsten Group, because of everything the Karsten s has to offer us and have done for us, Davids said. For more information contact Hendrik Davids at hendrik@karsten.co.za GLENNEIS KRIEL From left: Martheleen Olivier, Jane Winnaar, Patricia Hansen and Lia Dempers are line managers in the packhouse. Freek Sas is picking Crimson Seedless grapes. Photos by Glenneis Kriel 24 AUGUST 2018

27 THE SATI TEAM WILLEM BESTBIER CEO EUNICE AVENANT Training Manager LINDI BENIC Trade/Market Access Affairs Manager WILTON SEPTEMBER Transformation Manager CLAYTON SWART Communications Manager STEPHEN TERBLANCHE Accountant THURIA LEVY Office Administrator JOSEPH LOMBARDT Information and Knowledge Manager JACQUES FERREIRA Project Manager: Technical DAWIE MOELICH Technical and Market Access Manager TARRYN WETTERGREEN Research and Technology Transfer VALENCIA WATTS Receptionist