Vegetables November/December 2019

SINCE 1988

NOVEMBER • DECEMBER 2019

Avokado’s en kersies volgende vir China R40,00

(BTW ingesluit) ander lande uitgesluit (Including VAT) other countries excluded

No 192

Kry meer as net gewasbeskerming

insekbeheer aangedryf deur aktiewe bestanddeel

Dis ‘n uitdaging om konsekwent aan verbruikers se vraag na hoë gehalte en esteties aantreklike groente te voldoen. Deur Benevia® insekbeheer vroeg in die seisoen te gebruik, help dit jou om hul behoeftes te bevredig deur jou gewasse ‘n voorsprong te gee tydens die mees kritiese stadium van plantontwikkeling.

Benevia® bevat siaantraniliprool (antraniliese diamied) (Cyazypyr®) Reg. Nr. L10390 Wet Nr 36 van 1947, versigtig.

FMC Chemicals (Edms) Bpk, Posbus 44, Postnet Menlyn, Waterkloof Glen, 0081, Republiek van Suid-Afrika. Tel: +27 12 003 2938.

Benevia® en Cyazypyr® is handelsmerke van FMC Korporasie of sy affiliate. Datum: 10/2018.

TD 18/181R

GEBRUIK PLANTBESKERMINGSPRODUKTE MET VEILIGHEID EN VERANTWOORDELIKE SORG. VOLG AANWYSINGS OP ETIKET TEN ALLE TYE MET TOEDIENING VAN PLANTBESKERMINGSPRODUKTE.

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Nr 192

28

ISSN 1015-85 37

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Cover Mclean’s Red Litchis is the second most grown cultivar in South Africa; it has a large seed and soft, sweet fruit.

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NEWS 5 5 7 7

World citrus organisation launched Groenteboer is TLU SA se Jongboer van die Jaar Netafim holding company undergoes changes CGT launches updated What’s Fresh career app

EDITORIAL Willie Louw (Group editor)

SUBTROPICAL FRUIT 9 11 13

Carien Daffue (Editor) 018 293 0622 info@mediakom.co.za PO BOX 20250, Noordbrug, 2522

Macadamia SA at the forefront Die Kelpak-effek op neute Avokado’s en kersies volgende vir China TECHNOLOGY

15 16 17

Sheltering the world from hunger MARKETS

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DESIGN Roelien vd Westhuizen westhuizenroo@gmail.com 072 930 6721

New focus to soil fumigation Keeping track with precision New sorting machine for potatoes Bly ingelig en volg ons op Facebook.

Keep up to date and follow us on Facebook.

- SA Groente en Vrugte/SA Vegetables and Fruit - www.facebook.com/SAGroenteenVrugte/

GREENHOUSE & UNDERCOVER FARMING 19

ADVERTISING Jana Greenall (011) 476 3702 082 780 9914 mediacom@lantic.net

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Tel: 018 293 0622 Email: info@mediakom.co.za

GENERAL 23 Battle in the orchard 24 Machine learning and spatial analysis cast light on

fruit fly distribution 27 Volhoubare wisselbou vir groente onder beskerming 28 Biological pest control

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INSECT COLUMN 30

Yellow pecan aphid (Hemiptera: Aphididae)

GROENTE & VRUGTE | NOVEMBER • DESEMBER 2019

Banking Details: Mediacom, ABSA, 632005, Acc no.:01-08118-0241 in case of address change, please enclose old address label.

Slegs op intekening beskikbaar • Available only on subscription

3

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Microcapsules make the difference: The sulphur particles in the formulation are selected based on the correct size to ensure both gas and contact action against mites and fungal diseases.

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READ THE LABEL FOR FULL DETAILS THIOVIT JET® contains sulphur (Reg. No. L1061, Act No. 36 of 1947).

THIOVIT JET® is a registered trademark of a Syngenta Group Company.

Syngenta South Africa (Pty) Limited, Private bag X60, Halfway House, 1685. Tel. (011) 541 4000. www.syngenta.co.za. © Syngenta Ag, 2000. Copyright of this document is reserved. All unauthorised duplication is prohibited.

@SyngentaSA

NUUS

World citrus organisation launched Recently the newly-founded World Citrus Organisation (WCO) was officially launched at Fruit Attraction, Madrid. With this official presentation, citrus fruits are finally placed at the same level of coordination worldwide as other fruit categories, such as pears and apples, kiwis, avocado or red fruits, which already have their own global platforms.

T

HE WCO WILL ACT as the global platform for dialogue and action between the citrus producing countries worldwide. The core aim of the WCO is to facilitate member countries to better face common challenges and seize opportunities for the collective benefit of the citrus sector, in a spirit of cooperation and transparency.

Led by AILIMPO, the Spanish Lemon and Grapefruit Interbranch Association, and the Citrus Growers’ Association of Southern Africa (CGA), sector representatives from Argentina, Chile, Italy, Morocco, Peru, Spain, and South Africa decided to join forces to create a global citrus platform where together they may address the many multifaceted changes

experienced by the citrus market over recent years. Other countries that were unable to attend the meeting have also committed to the project, and the remaining global producers are invited to join the organisation.

The primary objective of the WCO is to facilitate collective action in the citrus sector, for both fresh and processed categories. Most recently the sector has been faced with an extensive array of significant issues of global concern including growth in production, overlapping of seasons, changing climate conditions resulting in varied quality and biosecurity challenges, increased competition within the citrus category and between other fruit categories and food products as well as stagnating fruit consumption. The WCO will facilitate member countries to better face these common challenges and identify opportunities for the collective benefit of the citrus sector.

With South African citrus exports due to increase by 25% in the next five years, and similar expansion expected by other citrus-producing countries, this organisation will put citrus fruit in its rightful place in the consumers mind – as a nutritious, healthy option. Stimulating demand will help to grow the category and claw back some market share lost to other fruit sectors.

Groenteboer is TLU SA se Jongboer van die Jaar ‘n Groenteboer van die Koedoesrand-distrik by Maasstroom in Limpopo het tydens TLU SA se jaarlikse kongresdinee weggestap met ‘n oorsese reis na Frankryk en ‘n ruim kontantprys.

H

ENNA DU PLESSIS HET sewe ander finaliste van regoor die land uitgestof toe hy as die TLU SA / Old Mutual Insure Agri / Manitou / Mahindra-Jongboer van die Jaar aangewys is.

“Dit was vanjaar besonder moeilik om te besluit wie die wenner moes wees,” sê Bennie van Zyl, die hoofbestuurder van TLU SA en ook een van die beoordelaars. “Henna se spanwerk op die plaas en sy toewyding teenoor landbou, sy gemeenskapsbetrokkenheid en lojaliteit teenoor TLU SA maak van hom ‘n waardige wenner.”

Henna (33), wat reeds byna die helfte van sy lewe boer, boer benewens groente ook met wild op die plaas Rockferry. Familie is vir hom baie belangrik en sy grootste droom is om nog ‘n plaas te besit en die boerdery uit te brei. Hy en sy eggenoot Candice se eersteling is onlangs gebore.

GROENTE & VRUGTE | NOVEMBER • DESEMBER 2019

“Ek wil graag onthou word as ‘n eerlike persoon wat altyd sal help en graag betrokke wil wees,” sê hy.

Henna is ‘n lid van TLU SA se dinamiese Jongboer-komitee wat fondsinsamelings vir die Traumafonds doen. Die komitee het tydens die kongres R30 000 vir hierdie doel oorhandig.

AJ Wohlfarht (34) van Wohlfarht Pluimvee in Gauteng naby Magaliesburg is as naaswenner aangewys.

In die derde plek het Lukas Eksteen (33) van Buffelsfontein in Mokopane (Naboomspruit), Limpopo, sy plek ingeneem. Hy boer met beeste, spesifiek Bonsmara.

“Die gehalte van hierdie jongboere skep vir ons hoop vir die toekoms van landbou in Suid-Afrika,” sê Van Zyl. “Die uitnemendheid van elke finalis se boerdery is noemenswaardig en elke kandidaat het hom- en haarself in hulle spesifieke bedryf onderskei.”

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NEWS

Netafim holding CGT launches company updated What’s undergoes changes Fresh career app It has been almost two years since Netafim and Mexichem partnered. Mexichem completed its acquisition of an 80% stake in Netafim in 2018. Following the acquisition, Netafim continued its path as the world leader in precision irrigation solutions.

T

HE TRANSACTION FURTHER strengthened Netafim’s global leadership position, while leveraging the buyer’s increased resources, geographic reach, product portfolio and extensive experience in operations.

Recently, the next phase was entered when Daniel Martinez-Valle, CEO of the former Mexichem, announced Mexichem’s new brand, values, purpose and name. The global company will now be known as Orbia and will be driven by its chosen purpose to advance life around the world.

The change is prompted by the massive transformation and growth the company, founded in 1953, has undergone since its name change to Mexichem in 2005. “To become a future-fit, purpose driven company, we need to organise ourselves in a way that serves our customers best. Every single one of us has a role to play in addressing the global challenges we face, and they can only be tackled if we work together and shift our thinking from ‘me’ to ‘we’,” Martinez-Valle said.

“It took a lot of work and many conversations to understand how we are perceived as a company and how we can transform ourselves. It was a long journey to develop the concept of Orbia. We are ready to launch, ready to be open to the world, to share our ambition, to share how we will solve challenges and we are ready to work as a team.”

Orbia’s new name and long-term business strategy positions the company to respond to global opportunities.

“Every single one of us has a role to play in addressing the global challenges we face.”

GROENTE & VRUGTE | NOVEMBER • DESEMBER 2019

The Center for Growing Talent by PMA (CGT) launched a career app called What’s Fresh. It is designed to attract learners, students and young graduates to the fresh produce industry by giving them access to contact details of all the Produce Marketing Association (PMA) members in South Africa as potential employers.

Matia Mukama and Sandra Kalua both installed the career app called What’s Fresh.

“O

NCE STUDENTS ENTER THE job market, they could find themselves lost in an unknown territory, as they often have very little knowledge of who the potential employers in the industry are, especially in such a diverse industry that includes various product categories, value chains, services and end users. The What’s Fresh app provides an overview of the industry through descriptions of a range of employers, along with contact details for students to follow through on,” said Lindie Stroebel, General Manager of PMA in Southern Africa.

A fun feature on this app is a reflex game where players can compete against themselves and others in catching fruits falling from the sky, earning points for all the fruits they caught.

Commenting on the app, Angel Aphelele Goldsmith, an MSc student in Forest Sciences at the University of Stellenbosch said: “The app is useful because it is an information-hub providing necessary information for young graduates to start searching for companies and explore internships and jobs. This is an essential tool for students at institutions who do not know where to start looking for jobs. It provides information not only for jobs in agriculture, but also at various other companies associated with agriculture.”

Stroebel said: “This CGT initiative is funded by AgriSETA to provide a tailor made support to South African PMA members in order to attract and employ the finest talent in the fresh produce industry. With this app we hope to link the best and brightest youth to our industry and help businesses of all sizes, and in all places, to prosper generation after generation.”

The app is now available as a free download at www.careerfair.co.za.

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SUBTROPICAL FRUIT

Macadamia SA at the forefront The macadamia industry in South Africa is growing with leaps and bounds. To keep up with this rapid growth, Macadamia South Africa (SAMAC) is working hard to secure growing markets and open up new opportunities for export.

V

EGETABLES & FRUIT TALKED to Lizel Pretorius, CEO of SAMAC, about what is going on in the industry and what they are working on at the moment.

Lizel says that at the end of 2018 it was estimated that over 38 600 hectares of macadamias were planted. Many growers propagate their own trees, it can be safely assumed that the actual figures are much higher.

Over 19 959 new hectares were planted during the past six years. In 2018 KwaZulu-Natal planted the largest number of new trees, followed by Mpumalanga and Limpopo. Western Cape as well as Gauteng also established new hectares, even though it was minimal compared to the other provinces.

Beaumont remains the most widely planted cultivar. A4 has gained substantial popularity in recent years. Other commonly planted cultivars include 816, 814, Nelmak 2 and 842.

According to Lizel, South Africa overtook Australia in 2016 as the largest macadamia producer.

Macadamia in China Lizel says that during the past years, China has emerged as the upcoming producing country. Much speculation exists regarding the actual number of trees planted, volumes that will be produced, the quality of the nuts, and if China will become self-sufficient in supply. For global role players the main question is the actual production volumes, as it will influence the need to timely increase future demand, to compensate for the current lucrative prices.

However, what is certain is that the Chinese government has adopted the macadamia tree as the poverty elevation tree, and therefore provides financial assistance to

China has emerged as the upcoming producing country.

Lizel Pretorius, CEO of SAMAC.

producers to plant macadamias. During the recent International Nut and Dried Fruit Council (INC) Macadamia Council meeting held in the USA, Chinese production levels were discussed at great length. There are multiple forecasts for the Chinese production, and the Australia Macadamia Association (AMS) provided an estimated low, medium and high forecast.

The estimated global (South Africa’s included) production over the next seven years will be over 700 000 metric tonnes.

Taking South Africa’s own future production into consideration, it is essential that handlers as well as SAMAC look into strategies to increase demand in current markets, as well as ways to enter new markets.

According to Lizel, at the International Macadamia Symposium held in China in 2018, Myles Osborn (Commercial Director) presented the proposed minimum global kernel quality standards which were further deliberated on at the INC Macadamia Council meeting in Florida, USA. The majority of the standards have been accepted and a few will be ratified by the person to be appointed by the INC Macadamia Council.

The Handlers Forum has identified China and India as priority markets to reduce the respective import levies of 12% and >30%. However, the reduction of import levies cannot TO PAGE 10

GROENTE & VRUGTE | NOVEMBER • DESEMBER 2019

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SUBTROPIESE VRUGTE

Macadamia SA at the forefront FROM PAGE 9

be achieved by SAMAC alone, as it requires engagement and action from both our own Government and the Chinese government. SAMAC have started the negotiation process and also formally invited Chen Ying, Director of China’s Chamber of Commerce, to visit South Africa. The aim is to showcase our industry and also start discussions between the two governments. SAMAC also engaged with the (then) Department of Agriculture, Forestry and Fisheries (DAFF) and the Department of Trade and Industry (DTI). Both departments’ support regarding market access is highly reliant on proving successful transformation initiatives to ensure an inclusive environment.

Transformation Another big project Lizel is very passionate about is their transformation projects.

Lizel says that transforming the economy is a challenging and long-term project to ensure a shared vision of the end results. It is therefore critical to have clarity of where the industry is going, as well as practical and flexible strategies for getting there. The transformation committee was established to view past efforts and initiate new ideas, to set objectives on how to ensure that measurable targets are achieved in future.

To support emerging farmers, SAMAC has study groups and transformation projects. Through education the industry is transforming on a continuous basis. A SAMAC transformation coordinator is the link between the industry and emerging farmers. Their mission is to come together as one industry, and feels that as an industry it is their responsibility to ensure growth in all aspects. They continuously donate tools to make it easier for the small scale farmers to be more productive and efficient.

These farmers have found the study groups extremely

Over 19 959 new hectares were planted in South Africa during the past six years.

beneficial and have repeatedly expressed their gratitude toward these projects. Education is one of the most important steps in the process.

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Kontrole - boomopbrengs

18.6 kg

Kelpak - 3 x 0.3%

20.1 kg

Kelpak - 5 x 0.2%

21.4 kg

Een aan die boom is beter as twee op die grond Beter set en neutretensie beteken meer neute asook ‘n hoër kerngewig per boom. Kelpak, die natuurlike seewier ekstrak is wêreldwyd deur wetenskaplike proewe bewys om neutboere se opbrengs en wins aansienlik te verbeter.

SUBTROPICAL FRUIT

Die Kelpak-effek op neute

Gesonde makadamia’s

Neute het die afgelope paar jaar ‘n belangrike rolspeler in die Suid-Afrikaanse en internasionale markte geword. Met die onlangse groei van veral makadamia-aanplantings, word al meer klem gelê op navorsing en produkte wat die algemene bestuur en opbrengs kan verbeter.

P

EKANEUTE EN MAKADAMIA’S IS die twee mees aangeplante neutgewasse in Suid-Afrika en word beskou as hoë kwaliteit produkte op die wêreldmarkte. Kelpak is ‘n natuurlike en trots Suid-Afrikaanse produk wat reeds met groot sukses deur die hele aanplanting- en produk- siesiklusse van neute gebruik word.

Kelpak word wêreldwyd erken deur beide produsente en wetenskaplikes as ‘n markleier van natuurlike biostimulante en wat verskeie voordelige en volhoubare natuurlike reaksies in gewasse stimuleer. Hierdie vloeibare, suiwer seewierproduk word deur boere vertrou om beter algehele gesondheid, soos lowergroei en verbeterde opbrengste, te stimuleer. Kelpak is verder wetenskaplik bewys om tipiese neutprobleme op set en retensie teen te werk, as gevolg van die produk se vermoë om beter stuifmeelontkieming en sterker stuifmeelbuisgroei te induseer.

Hierdie eienskappe is uniek aan Kelpak, as gevolg van die koue selbars-ekstraksiemetode wat die sagte natuurlike hormone uit die Ecklonia maxima-seewierspesie verwyder en in die alombekende groen drom tot ‘n mengsel van natuurlike aktiewe middels bewerkstellig.

Die organies geakkrediteerde seewierproduk word eerstens op jong boompies in kwekerye aangewend vir sterker wortelgroei en vinnige ontwikkeling. Verder kan Kelpak tweeweekliks aangewend word op verskeie praktiese toedienings, soos wortelbenatting of blaarspuite. Tydens die uitplanting van jong boompies uit die kwekery na die moeiliker boordtoestande, help Kelpak om die gevreesde uitplantskok teen te werk.

Hierdie eienskap is te danke aan onder meer die Poli-amiengroep wat ook ‘n groot invloed op biotiese en abiotese stremmingsbeskerming het. Die hoë vlakke van poli-amiene, phlorotanniene, brassinosteroïede en ouksiene in Kelpak stimuleer wortelgroei, groter vrugte, stuifmeelontkieming, stuifmeelbuisgroei en werk sinergisties saam met die ander hormoongroepe in Kelpak vir die gewensde gewasstimulasie. Jong bome benut voedingstowwe en vog beter deur ‘n groot wortelmassa te genereer wat verbeterde groei aanhelp.

Sodra die aktiewe hormoongroepe deur die plant opgeneem word, sal die fisiologiese prosesse in die plant, soos fotosintese, vinniger beweeg en die plant by die optimum kan groei.

Onafhanklike navorsing het gelei tot die geregistreerde aanbevelings van Kelpak op produserende neutboorde. Tipiese aanbevelings op makadamiabome sluit in vyf blaarspuite van 0,2% oplossing met maandelikse intervalle en waarvan die eerste spuit met die aanvang van blom toegedien word.

GROENTE & VRUGTE | NOVEMBER • DESEMBER 2019

Verbeter stuifmeelontkieming en stuifmeelbuisgroei

Makadamia-opbrengsverbetering oor 3 jaar met 2 Kelpak konsentrasies.

Kontrole

Kelpak

Kelpak verbeter stuifmeelbuisgroei en stuifmeelontkieming.

Pekanneut-produsente kan weer drie blaarspuite van 0,3% toedien met die eerste bespuiting wanneer die manlike blomme verleng vir ‘n beter uitkraakpersentasie, kernmassa per boom en algehele neutopbrengs.

Die voordele van Kelpak-toediening lei gereeld tot ‘n groter stamomtrek van neutbome, wat weer ‘n vinniger produksie van neute op ‘n jonger ouderdom tot gevolg het. Neutprodusente verwys gereeld na die suksesvolle verbetering wat Kelpak bied om seisoenale alternatiewe drag (alternate bearing) teen te werk – wat ‘n algemene kopseer is. Omdat hierdie natuurlike biostimulant die boom help om met volle potensiaal te groei, beskikbare bronne volledig te benut en meer weerstand teen stremming te bied, is die gevolg hoër gemiddelde opbrengste.

Die seewierproduk vergemaklik enige plaasbetuurder se taak omdat dit verenigbaar is met meeste chemiese en voedingstowwe wat algemeen op plase gebruik word en dit kan saam in oplossing gebruik word. Gevolglik hoef die boer nie bykomende spuitkoste aan te gaan nie. Verder bied Kelpak ook ‘n sinergistiese werking met die meeste chemiese en ander hormonale spuitstowwe om die effektiewe gebruik daarvoor aan te help.

Kontak Kelpak se personeel gerus op www.kelpak.com of die naaste landboukundige vir professionale advies.

11

Bevat 2 aktiewe bestanddele met kontak en sistemiese eienskappe vir langdurende beheer van 'n wye reeks siektes

Beide aktiewe bestanddele word opwaarts in die xileem vervoer om ook

nuwe groei te beskerm

Beter neutset en kwaliteit verseker optimale opbrengste

LEES DIE ETIKET VIR VOLLEDIGE BESONDERHEDE. AMISTAR® TOP bevat asoksistrobien 200g/L en difenokanosool 125g/L (Reg Nr. L7897, Wet Nr 36 van 1947) VERSIGTIG. AMISTAR® TOP is ’n geregistreerde handelsmerk van ’n Syngenta Groepmaatskappy.

Syngenta Suid-Afrika (Edms) Beperk, Privaatsak X60, Halfway House, 1685. Tel. (011) 541 4000. www.syngenta.co.za © Syngenta Ag, 2000. Kopiereg op hierdie dokument word voorbehou. Alle ongemagtigde reproduksie word verbied.

@SyngentaSA

15357/A IDEA ENGINEE ® S

reik vir die top

SUBTROPICAL FRUIT

Avokado’s en kersies volgende vir China Jan Greyling MEDEWERKER Gesoek: volhoubare en standvastige verskaffers van uitvoergehalte avokado’s en kersies. Dit is hoe ‘n kleinadvertensie vir baie groot onderneming in die Chinese vrugtemark sou kon lees, wanneer ‘n mens na toekomstige uitvoergeleenthede vir plaaslike produsente kyk.

C

HINA SE WIN-CHAIN invoergroep is te midde van daaglikse sake met die Suid-Afikaanse vrugtebedryf volstoom besig om sy huidige invoer van sitrus, appels en tafeldruiwe uit Suid-Afrika aan te vul met die beste gehalte avokado’s en kersies. Charley Xu, direkteur: verkryging van Win-Chain se invoervrugte sake-eenheid, nooi Suid-Afrikaanse produsente om deur die amptelike kanale deel te neem aan handel met China.

“Suid-Afrika is vir ons ‘n baie belangrike produksiestreek.

Ons het die afgelope 12 maande reeds 110 vraghouers Suid-Afrikaanse sitrus, hoofsaaklik pomelos en lemoene, suksesvol ingevoer. Hoewel Suid-Afrikaanse verskepers hard werk en ondersteunend is, soek ons in die sitrusbedryf na nog meer strategiese vennote,” het Xu tydens die 9de PMA Suidelike Afrika Fresh Connections-konferensie in Kaapstad aan Groente & Vrugte gesê. “Suid-Afrikaanse avokado’s en kersies is ons volgende prioriteite.”

Sitrus en ander produkte verloop glad Xu bevestig dat China en Suid-Afrika reeds ‘n protokol in werking het vir die invoer van lemoene, pomelos, appels en tafeldruiwe. Hy wys daarop dat China, weens klimaatvereistes en ‘n tekort aan landbougrond, sekere varsprodukte soos sitrus nie self kan produseer nie. In China word ‘n beperkte hoeveelheid lemoene verbou en uit verskeie lande ingevoer.

Ingevoerde lemoene uit die suidelike halfrond is egter sleutelbelangrik vir volhoubare voorsiening tydens ‘n seisoensoorgang. In die geval van pomelo’s is net Suid-Afrika en Israel betroubare voorsieners van gehalte produkte aan China.

Chinese het vereistes vir die volgehoue gebruik van appels uit Suid-Afrika. Xu sê die gehalte en veral voorkoms, kleur en smaak is vir die Chinese verbruiker baie belangrik.

“Suid-Afrika se appeluitvoerders moet volhard met hul goeie werk en miskien net fokus op konsekwentheid van eenvormige voorkoms, kleur en smaak per variëteit. Dit kan moontlik deur uitgebreide boordvestiging- en plantvaardighede verbeter word vir groter toekomstige uitvoermoontlikhede.”

Avokado’s en kersies Wat avokado’s en kersies betref het China nog nie ‘n protokol met Suid-Afrika onderhandel nie, omdat hulle ondersoek instel na die ideale invoervariëteite en invoertyd. Dit is veral belangrik om produsente of ondernemings te kry wat gerat is om op groot skaal ‘n volhoubare bydrae tot die Chinese sebehoefte aan die twee kommoditeite te maak.

“Sodra ons die logistiek en die fitosanitêre vereistes uitgeklaar het, sal ons amptelik onderhandel vir ‘n formele invoerprotokol.”

GROENTE & VRUGTE | NOVEMBER • DESEMBER 2019

Charley Xu, direkteur: verkryging van Win-Chain se invoervrugte sake-eenheid. Foto – Jan Greyling.

Xu is opgewonde oor die infasering van avokado’s in die Chinese mark. “Die Chinese verbruiker het uitstekende kennis oor die voordele van lemoene en pomelo’s, maar ons het werk om te doen met nuwelinge soos avokado’s. Die gewildheid hiervan sal mettertyd deur verbruikersopvoeding deur Win-Chain, in oorleg met die Suid-Afrikaanse bedryf, toeneem.”

Hy meen dat internasionale verbruikers nie net méér oor die voedingswaarde, ideale gebruike en voordele van vars avokado’s geleer moet word nie. “Vir die ideale ontwikkeling van die Chinese en ander markte van Win-Chain, sal klem ook gelê moet word op die korrekte winkel- en tuisrypmaakmetodes. Vir avokado’s en kersies is verbruikersopvoeding ‘n vereiste.”

Volgens Xu word gesê dat Colombië en Kenia ook die volume en gehalte avokado’s het om ‘n wesenlike bydrae tot die Chinese behoefte te lewer. Hy bevestig dat China reeds ‘n ooreenkoms met die Keniane gesluit het vir die uitvoer van bevrore avokado.

“Gevriesde avokado is veral in die voedseldienste- en spysenieringsmark baie belangrik, maar slegs wanneer ons nie voldoende vars avokado’s regdeur die jaar kan voorsien nie.

Weens die gesondheidswaarde daarvan is die groeiende vraag in ons afsetgebiede nou meer na vars avokado’s.”

Charley Xu is meer as ‘n dekade gelede in Frankryk in meganisasie opgelei. “Dit verskil grootliks van my passie vir sake en die soeke na wêreldklasprodukte vir Win-Chain se vrugtebehoeftes, maar sommige van die beginsels geld steeds. Ek maak eerder ‘n verskil in die behoefte vir gesonde vars produkte vir ons markte en geniet die verhoudings met uitvoerders baie.”

Hy sê die varsproduktebedryf is opwindend. “Weens klimaatsveranderinge weet ‘n mens nooit watter produkte volgende beskikbaar gaan wees of dalk glad nie meer beskikbaar gaan wees nie. Daarvoor moet plaasvervangers gevind word en ek geniet dit.”

13

NEXFUME BRINGS A NEW FOCUS ON SOIL FUMIGATION WITH AGROCELONE NE AND

INNOVATIVE APPLICATION TECHNOLOGY Pathogenic soil fungi and nematodes lead to replant disease which threaten the sustainable cultivation of various crops and can only be prevented when crops are planted in pathogen free soil.

The establishment of a new crop is a significant investment and soil disinfection, when done properly, can contribute to optimal yields!

Agrocelone NE consists of a combination of 1,3 dichloropropene and chloropicrin and is recommended as an effective treatment for replant disease.

NexFUME's innovative application equipment ensures accurate application with the implementation of precision farming technologies.

OUR GPS-DRIVEN TRACTORS USE: A closed system which combines GPS, tractor speed and regulated electronic application of the product An innovative three-shank application A highly sophisticated digital system that applies the product at a constant rate, which encourages broader diffusion and homogeneous penetration of the soil

CROPS PRONE TO REPLANT DISEASE: VEGETABLES

BERRIES

GRAPES

FRUIT AND NUTS

CONTACT US FOR MORE INFORMATION: 021-860 8040

www.nexusag.net

TEGNOLOGIE

New focus to soil fumigation Free-hand (left) and GPS technology (right) that ensures the treated strip runs exactly where the trees must be planted. This ensures that the entire bank is treated effectively, with improved homogeneity.

Soil health gets a lot of attention these days and for good reason. More research about the conservation and productive utilisation of land is being done, considering that soil is a critical building block of sustainable agriculture.

I

T IS A FACT THAT agricultural crops need healthy, living soil to grow to its full potential and generate profitable returns.

In cases where soil diseases and damaging micro-organisms achieve high population levels, such as nematodes which attack and destroy crops, soil becomes useless for agriculture purposes. Fumigation is recommended to reduce these populations to prevent damage to the crop.

Fumigation is an extremely effective method of treatment but requires special attention in order to deliver an effective outcome. Establishment of a new crop is a large investment and for that reason disinfection should be thorough.

In the past, soil was fumigated with methyl bromide gas which delivered successful results. Methyl bromide was a cornerstone of fumigation, but because methyl bromide has a detrimental effect on the ozone layer, it had to be phased out in terms of the Montreal Protocol. This led to the crop protection industry searching for appropriate alternatives. The sustainable cultivation of crops, such as apples, stone fruit, table grapes and other cash crops, which are impacted by re-settlement diseases and nematodes, is only possible when planted in clean, healthy soil.

Fortunately, crises such as the phasing out of methyl bromide, often leads to innovation, and an integrated service model was developed to fill the gap, through co-operation between the AQL group and NexusAG. Agricultural companies and researchers have already since the mid-1990s sought alternative strategies for soil disinfection to replace methyl bromide. None of the alternative strategies could provide the same function and effectiveness as methyl bromide. Considering the latter, researchers had to rely on the development of integrated methods to facilitate the use of alternatives and improve the efficacy thereof.

Global research proved that the best option contained a combination of 1,3 dichloropropene and chloropicrin. Agrocelone NE, manufactured by AQL and distributed by NexusAG, contains this combination. When the two active ingredients are applied together, there are synergies between the two, resulting in similar efficiency as its predecessor, methyl

GROENTE & VRUGTE | NOVEMBER • DESEMBER 2019

bromide. One of the restrictions is that it does not have the same distribution potential in the soil as methyl bromide.

NexusAG therefore provides an innovative solution through unique application equipment with three shanks that enables wider diffusion and in so doing, delivers homogenous penetration of the bank with maximum results. Producers are also guaranteed accurate application due to GPS-driven AQL-DAS technology, ensuring that 100% of the required dosage of the product is applied precisely where the trees will be planted.

This technology makes use of a closed system, which combines GPS and tractor speed and regulated electronic application of the product. The sophisticated digital system pumps the product at a constant tempo, individually through each of the three shanks into the soil. It improves distribution of the product and eliminates the use of dangerous, high-pressure containers of compressed gas or air, and guarantees accuracy.

Soil fumigation is only intended for the control of damaging micro-organisms that are present in the soil. Because the treatment may in some cases have a negative impact on populations of good and positive micro-organisms (such as saprophytes which digest organic material), it then becomes necessary, as per specific needs in a block, to supplement these beneficial organism populations or to stimulate their increase and to fill the so-called vacuum.

Soil disinfection therefore actually begins weeks before treatment of the soil, where an agriculturist joins the producer in looking at which crop is to be planted, identifying specific problems in the soil and comprehensive planning in collaboration with the producer to define the specific requirements. An appropriate treatment programme is created and the different integrated option for follow-up treatment of the general soil health is compiled.

Feel free to contact NexusAG about a fit-for-purpose treatment program and the different integrated options for follow-up treatments that promote general soil health: tel 021 860 8040.

15

TECHNOLOGY

Keeping track with precision

FarmTrack is a robust, accurate GPS tracking device designed for use with smaller tractors.

Real time tracking data helps to reduce risks and to improve productivity and efficiencies on farms. However, GPS tracking systems used on the tractors of many leading original equipment manufacturers are expensive.

F

ARMTRACK IS A ROBUST, accurate GPS tracking device designed for use with smaller tractors which can help farmers to save fuel, protect crops and optimise crop output.

Data from the tracking device is stored, processed and organised automatically with user-friendly farm management software. Producers gain access to the information in real time via any device with internet access.

Assistance with adapting and setting up the system according to the requirements of each farmer is provided by the after-sales support team who take their specific needs into consideration.

The system is especially useful for crop protection. It determines the movement of a machine, detects missed rows during spraying and ensures spraying is done at calibrated speeds. It provides accurate farm management reports that help producers with planning, cost-saving, efficiency and properly sprayed crops.

16

It allows farmers to view the activities of drivers at any given time. It tracks when the tractor stops, idles and is switched on and off. It also records the speed of drivers accurately, dangerous speed as well as movement in restricted areas.

Another benefit of using FarmTrack includes being able to determine the duration and/or distance driven between the orchard and refilling the tractor with diesel. It also keeps track of vehicle service duration.

To prevent theft, the latest feature of the system includes an immediate notification should the battery be disconnected from the tractor.

Developed by ETSE Electronics who has 20 years’ experience in the agricultural environment, FarmTrack is a simple, yet cost-effective device used on more than 100 farms countrywide.

Contact FarmTrack for information: tel. 021 880 1163 or visit www.farmtrack.co.za.

TEGNOLOGIE

New sorting machine for potatoes Gentle handling of the potato continues to be a key feature.

The TOMRA 3A, a new sensor-based sorting machine for freshly harvested root crops, developed in response to specific customer challenges, delivers improved foreign material removal to potato growers.

T

HE SORTER IS TYPICALLY used at the entrance to a potato storage shed, where it provides a final clean-up immediately after the freshly harvested crop has passed through a mechanical grader and soil removal equipment. The sorter employs an in-flight inspection and ejection process to detect and remove stones, soil clods and other debris from the incoming product. The TOMRA 3A is designed to operate at high capacity, because of the time pressure of short harvesting seasons, and to gently move the product without risk of damaging or bruising it.

“In developing this machine, we have learned from our experience working with farmers in this sector and have adopted market-leading technologies already proven in some of our other sorting applications,” says Jim Frost, Product Manager at TOMRA Food. “As a result, this machine gives farmers exactly what they want, which is greater capacity, green potato removal, no product bruising, greater robustness and excellent reliability, easy to use and to move around, more data and statistics, and lower cost of ownership.”

Imaging technology and automated functions The application’s sophisticated imaging system, unlike the FPS’s, has colour-detection capabilities to identify unwanted green potatoes. Solid-state, pulsed LED illumination technology with high resolution cameras is able to distinguish between the crop and foreign material. Amongst the range of signal responses from multiple tailored LED frequencies (some visible and some non-visible infra-red), advanced software analysis detects the presence of gross green on sun-exposed potatoes. The sorter is tolerant of overhead lighting effects and eliminates sensitivity to changes in light levels through daylight, evening, and night production.

The optical system has no moving parts when in operation, which improves reliability, and the fully-sealed camera enclosure is tolerant of environmental conditions such as rain, wind, dust and heat. Newly developed TOMRA technology such as automated camera alignment and calibration guarantee the sorter’s stability. In addition, new optical temperature control ensures consistency of optical signals, delivering unrivaled sorter stability and efficiency from the cool of the morning into the heat of the day.

“The optical system has no moving parts when in operation.”

The TOMRA 3A performs well when pushed to meet the tight deadlines of a short harvesting season, with capacity increased by up to 30%. To accommodate a range of input capacities, the sorter is available in three widths, with a 1 200 mm, 1 600 mm, and 2 400 mm infeed conveyance. This enables throughput of up to 45, 65, and 100 tonnes per hour.

The sorter continues to employ a finger-based ejection system across the full width of the inspection area. The mechanical finger ejectors are designed for robustness and repeatability when removing even the largest and heaviest defective potatoes from the line, minimising the need for repairs or replacements. Finger actions are optimised to prevent collisions with neighbouring potatoes as they fall into the area for accepted product. Gentle handling of the potato continues to be a key feature of TOMRA sorters. The “accept” conveyor, through unique design, captures, decelerates and delivers good accepted potatoes without product collisions or bruising.

The TOMRA 3A is designed to operate at high capacity, because of the time pressure of short harvesting seasons, and to gently move the product without risk of damaging or bruising it.

TO PAGE 18

GROENTE & VRUGTE | NOVEMBER • DESEMBER 2019

17

TECHNOLOGY

New sorting machine for potatoes FROM PAGE 17

The system is managed by software from the TOMRA ACT platform, sharing the graphical user interface and many of the features of its big brother, the TOMRA 5A. For ease of use there is a 15-inch wide high-resolution touchscreen with a high-brightness mode. The TOMRA 3A interface includes alarm reporting, statistics, and diagnostics capabilities, with the option of remote support via a 4G modem connection.

Frost commented that “real-world field validations of the TOMRA 3A with farmers in Ireland and France, sorting freshpack and processed potatoes, have proven the great capabilities and reliability of this machine”.

Compac, part of TOMRA Food, offers through its local distributor CSESA, state-of-the-art sorting technology at the heart of its avocado packhouse solutions: Spectrim, the most powerful optical sorting platform in the industry, and Inspectra2, the next-generation near infraRed spectroscopy (NIR) platform that analyses the internal properties of the avocado to measure conditions such as dry matter content, which is key to the avocado market because of its correlation to fruit storability.

It delivers high grading accuracy and has the added advantage of being easy to implement in packhouse operations.

It uses Compac’s non-invasive, technology for analyzing the internal properties of the avocado, measuring conditions that are invisible externally. It also helps operators to optimise the

maturity and supply chain routing based on the avocado’s internal quality. A further benefit is the significant reduction in waste, achieved through the recovery and packing of avocados from lower quality lots, by minimising the good produce in the waste stream, and through a better understanding of maturity and eating quality.

“The mechanical finger ejectors are designed for robustness and repeatability.”

To accommodate a range of input capacities, the sorter is available in three widths, with a 1 200 mm, 1 600 mm, and 2 400 mm infeed conveyance.

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TOMRA 5A OPTICAL SORTER The TOMRA 5A classifies your product and maximizes food safety.

For more than 40 years, TOMRA Food designs and manufactures sensor-based sorting machines and integrated post-harvest solutions for the food industry, using the world’s most advanced grading, sorting, peeling and analytical technology. food@tomra.com www.tomra.com/food

KWEEKHUISE & TONNELVERBOUING

Sheltering the world from hunger Between now and 2050 it is estimated that the world’s population is likely to rise from 7,3 to 9,7 billion. In order to feed everyone, agricultural role players will need to solve problems such as poor and seasonal crop production and damage caused by sunburn, hail, insects and drought.

S

HADE NET IS AN option that can be implemented fairly quickly to not only overcome many of these impediments, but to also increase production, yield and income. Many farmers have already made the choice to erect large-scale shade net structures and are reaping the benefits from it.

In hot climates, vegetables and cut flowers are grown under shade cloth to reduce heat and light intensity. With the help of science, innovative light manipulation and UV management, photo-selective colour netting create an environment that can be manipulated into optimal growing conditions for crops to flourish in.

In the short-term, shade net structures boost farmers’

profits, by cutting costs and increasing their quantity and quality of yields. Over the longer term, it may even contribute to the solution of feeding the world’s growing population.

Knittex is an industry leading manufacturer of high quality knitted fabric that is durable and 100% recyclable. Their SpectraNet range gives producers the highest results and best return on their investment. This is backed by years of research and development to ensure that nets have a guaranteed lifespan of 10 years or more.

Contact Knittex for advice for shade netting needs. Tel. 011 692 1658 or e-mail: clientliaison@knittex.co.za or visit www. multiknit.co.za.

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PROTECTS YOUR CROP AGAINST DAMAGE CAUSED BY SEVERE WEATHER CONDITIONS

wind, sunburn, hail damage, birds & larger insects

PROTECTING YOUR

CROPS FROM THE 2

2

+27 (0)11 692 1658 www.knittex.co.za clientliaison@knittex.co.za

MARKETS

Joburg Market – smart, safe and clean Jan Greyling CORRESPONDENT

Welcome to the fresh produce “stock exchange” of South Africa. With a 44% share in the national fresh produce markets combined, the Joburg Market is the biggest of its kind in the country. Established in 1887 at the old Market Square in Johannesburg and situated at City Deep since September 1974, the market is still 100% owned by the City of Johannesburg.

T

HE JOBURG MARKET IS a pure commission market, generating a fixed 5% commission for the City of Johannesburg for the management and maintenance of the computerised sales system, cash collections, quality control, cleaning and waste collection, safety and security. All produce remains the property of the seller and later the buyer – at no stage the market or agent own the produce on sale.

Ananda Kanana, CEO of the market told Vegetables & Fruit that they sell about 1,4 m tons of produce per annum. “To date our 2018/19 revenue, unaudited results, is R7,9 billion, compared to R32,2 m in 1974. So, at least at our level of the value chain we ensure that produce move, and farmers can keep on farming. Currently the market runs on a reasonable surplus, covering its obligations with almost no additional tax money from the authorities.”

At the 9th PMA Southern Africa Fresh Connections Conference in Cape Town, Kanana shared his excitement about the development of this fresh produce gem recently.

Over the last two years, he has taken the bull by its horns.

He qualified as an auditor at Deloitte. As a governance specialist he moved to the City of Johannesburg as head of governance and reporting, “assisting politicians with the interpretation of company performance.” In addition, he is “a little into farming”, running a small feedlot on the West Rand.

Technology made easy With the buy-in of his team, he is actively managing a technology-based metamorphoses of this giant business hub.

20

BUCKLE PACKAGING (PTY) LTD Bag Closing Technology

The CEO of Joburg Market, Ayanda Kanana, shared the success and challenges of the largest fresh produce market in South Africa at the 9th PMA Southern Africa Conference and Trade Show in Cape Town. Photo – Jan Greyling.

Being the only fresh produce market in the country offering unlimited wi-fi, on a daily sign-on principle, the market has access to powerful information about the day to day registration of more than 12 000 people on their platform.

“While on our premises, and soon also from the comfort of their homes and offices, registered agents can lock into the system in real time. It is not only about technology, but also efficiency. I don’t want a truck wasting time inside the market for more than 25 minutes, taking up trade space and time,” says Kanana.

MARKTE Commission agents, the essential link As key stakeholders in the business, market agents represent the farmer as the grower, owner and seller of the beauty of freshness, harvested all over the country every day.

As CEO, Kanana has a seat in the IMASA meetings, the representative Market Agents’ Association of South Africa, where a slot exists to specifically discuss all issues about the Joburg Market.

“The market floor is manned by registered agents who receive between 5% and 9% commission on gross value of all sold produce. Many of them told us that in the 20 years or more they work here, it is the first time they have met the CEO of the market on the floor. That is how we build and sustain relationships.”

With 18 active market agent companies on the floor, the Joburg Market is currently working on space optimisation with agents, to separate people from machinery to ensure more space for trading.

Building bridges From the outset Kanana decided to walk the market floor instead of just relying on reports.

“That is how you learn the business and environment.

We have declared 2019 as ‘the year of the farmer’. So, after I walked my floor, I am now walking the fields where our produce come from. We are visibly in the industry and firmly believe in relationships as the core to success.”

Kanana invites farmers who consider doing business with Joburg Market to visit their website at www.johburgmarket. co.za.

Farmers need to be aware of the product requirements. If possible, they need to visit the market to see how it operates.

The market agent of choice needs to obtain the grower’s name, trading name, ID number, banking details and contact details.

At the Joburg Market buyers are segmented into platinum, gold and diamond groups. Key account managers are responsible to focus on the needs of allocated clients.

“By engaging with them, we close the gap and learn exactly what buyers need. Often needs such as cooling facilities are imperative to assist them in complying with HACCP and other food safety requirements.”

Adding value Currently the Joburg Market is working on the development of an agri business hub on the adjacent Pyramid premises.

“At the 9th PMA Southern Africa Fresh Connections Conference in Cape Town, Kanana shared his excitement about the development of this fresh produce gem.”

GROENTE & VRUGTE | NOVEMBER • DESEMBER 2019

“With 18 active market agent companies on the floor, the Joburg Market is currently working on space optimisation with agents, to seperate people from machinery to ensure more space for trading.”

The CEO of Joburg Market, Ayanda Kanana, shared the success and challenges of the largest fresh produce market in South Africa at the 9th PMA Southern Africa Conference and Trade Show in Cape Town. Photo – Jan Greyling

“Imagine, buying produce which is transported from the field to the market by forklift only, to manufacture freshly squeezed juice. We are starting to do efficient things and we trust to reach compliance soon.”

As “an added value” the Joburg Market operates a testing laboratory from where the department of agriculture and the farmer are informed about unsafe residue levels. Since testing from the floor sometimes result in late results, the market work closely with farmers to test on farms, prior to delivery.

“Feedback from international and other visitors indicates that Joburg Market is safe and clean because of valued cooperation from all stakeholders. Our philosophy is not to clean on anyone’s behalf. Our stakeholders clean as they go, otherwise it will cost about R1 m per month just to manage litter, which does not make sense. So, our slogan is ‘keep your space clean’.”

Kanana says market refuse is collected by the municipality.

“Unfortunately, 1% of the 1,4 milliard kilograms of perishable produce offered for sale annually still goes to waste. This is an opportunity we should turn into revenue. Farmers need to ensure timely that they do not send defective quality produce to the market as we are not a dump site.”

He told conference that produce markets often experience an identity crisis and ask themselves if they are a landlord or in agricultural business. “As the market we do not farm, but we need to understand farming. We are stewards of produce and revenue and need to ensure that stocks are protected.”

21

BENEFITS OF CULTIGROW

Ca2+

Maintain tree energy levels throughout the growing season

Enhanced root development

Enable the tree to handle higher fruit load

Improved mineral content of fruit

Promote healthy rhizosphere environment

Induce systemic resistance

THE CULTIGROW PROGRAMME

= 3X CULTIGROW

APPLICATIONS

SET AND FRUIT RETENTION

1st Spray

RETENTION AND INCREASED FRUIT

2nd Spray

ACT / WET 36 / 1947 REG. No ZAR B4018 • FERTILIZER GROUP II • NAM NF0918 • COPYRIGHT © NOVEMBER 2019 • ALL RIGHTS RESERVED ORO AGRI, CULTIGROW and OROWET are registered trademarks of Oro Agri SA (Pty) Ltd.

IMPROVED COLOUR AND FRUIT FINISH

3rd Spray

ALGEMEEN

Battle in the orchard Johan Janse van Rensburg Head of Marketing, Oro Agri Sub Sahara Africa | ORO AGRI Plants interact with a range of organisms, some of which are harmful, while others are beneficial. Since plants lack mobile defender cells (such as white blood cells in mammals) and an adaptive immune system, their defences rely on the innate immunity of each cell and on systemic signals originating from infection sites (Dangl and Jones, 2001; Ausubel, 2005).

O

VER TIME, PLANTS EVOLVED highly sophisticated strategies to counteract attackers. Some of these strategies are pre-existing, while others are referred to as induced resistance (Sticher et al., 1997). Whatever the strategy, it is controlled by the plant’s genes. Induced resistance acts systemically throughout the plant and is characterised by a broad spectrum of effectiveness. Systemic acquired resistance (SAR), Induced systemic resistance (ISR) and herbivore-induced direct and indirect defence are some of the best studied samples of induced resistance.

(Vallad & Goodman, 2004) Priming the plant Defence systems that are induced after pathogen invasion are often too weak to protect host plants against disease caused by virulent pathogens, but if these defences can be induced before the pathogen attack, they can be highly effective (Ahmad et al., 2010). Plants are primed for enhanced defence, using and manipulating microbe-associated molecular patterns (MAMPs), Pathogen-associated molecular patterns (PAMPs) and/or damage-associated molecular patterns (DAMPs) (Nicaise et al., 2009). In primed plants, defence responses are not activated directly by the priming agent but are accelerated following perception of biotic or abiotic stress signals, resulting in an enhanced level of resistance.

Priming results in a faster and stronger induction of defence mechanisms after pathogen attack (Conrath et al., 2006). It has been shown in numerous trials that inducing resistance in such a way, plays an instrumental role in reducing plant stress and disease (Vallad & Goodman, 2004).

Cultigrow Cultigrow is a mixture of bioflavinoidsfrom Citrus aurantheum, as well

UNTREATED

CULTIGROW

Improved root development of lettuce treated with Cultigrow. Left is untreated roots and right treated with Cultigrow.

as other plant extracts and organic acids.

Cultigrow has been shown to enhance photosynthesis levels and increase root exudation. These increases in root exudates increase the activity of beneficial soil organisms, as well as improve colonisation of roots (Figure 1), by beneficial organisms such as mycorrhizae. The increase in microbes in the rhizosphere leads to an increase in MAMPs, which in turn prime the plant for enhanced defence.

Extensive research on Cultigrow over more than a decade showed that a programme approach works best. Spraying Cultigrow repeatedly throughout the season and following this programme over several years, leads to superior results in terms of yield and quality of fruit. Follow the label recommendations for the best results. These recommendations are the result of extensive scientific trials over several years.

Summary Induced resistance is important for plants to resist disease and abiotic stress, as well as to recover from disease caused by a wide range of pathogens (Vlot et al., 2008). It is becoming clear that using products that act as elicitors of induced resistance in a wide range of crops, is a viable option in most crop management programmes.

Induced resistance does not render plants impervious to the pathogen, but

GROENTE & VRUGTE | NOVEMBER • DESEMBER 2019

rather increases the plant’s overall tolerance. Importantly, induced resistance is mostly not effective once the pathogen has established itself (Vallad & Goodman, 2004), but should be used in a preventative programme. Products such as Cultigrow, is successfully being used to unlock a crop’s genetic potential to resist climatic stress and infectious diseases.

Cultigrow is fast becoming an important part of the total crop protection toolbox. A tool that can help producers win the battle in the orchard.

References Ahmad, S., Gordon-Weeks, R., Pickett, J. & Ton, J. 2010. Natural variation in priming of basal resistance: from evolutionary origin to agricultural exploitation. Molecular Plant Pathology 11: 817827.

Conrath, U., Beckers, G.J., Flors, V., GarcıaAgustın, P., Jakab, G., Mauch, F., Newman, M.A., Pieterse, C.M., Poinssot, B. & Pozo MJ (Prime-A-Plant Group). 2006. Priming: getting ready for battle. Molecular Plant Microbe Interaction 19: 1062-1071.

Dangl, J.L. & Jones, J.D.G. 2001. Plant pathogens and integrated defence responses to infection. Nature 411, 826-833.

Nicaise, V., Roux, M. & Zipfel, C. 2009. Recent advances in PAMP-triggered immunity against bacteria: pattern recognition receptors watch over and raise the alarm. Plant Physiology 150, 1638-1647.

Sticher, L., B. Mauch-Mani & J-P. Me´ traux.

1997. Systemic acquired resistance. Annual Review of Phytopathology 35: 235-270.

Vallad, G.E. & Goodman, M. 2004. Systemic acquired resistance and induced systemic resistance in conventional agriculture. Crop Science 44: 1920-1934.

Vlot, A.C., Klessig, D.F. & Park, S. 2008. Systemic acquired resistance: the elusive signal(s). Current Opinion in Plant Biology 11: 436-442.

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GENERAL

Machine learning and spatial analysis cast light on fruit fIy distributions Dr Gulu Bekker and Prof Pia Addison UNIVERSITY OF STELLENBOSCH E-mail: gulu@sun.ac.za and pia@sun.ac.za

Fruit flies in the family Tephritidae (true fruit flies) are major pests throughout the world, particularly in heterogeneous fruit production regions. They feed on a huge variety of fruit and vegetable hosts and are therefore prolific over large spatial scales in the landscape.

K

NOWING WHEN AND WHERE pests occur, contributes to the knowledge base of farmers to make a better decision regarding pest management. However, one crucial aspect, which changes the way we plan pest management strategies, is the knowledge of why pests occur in specific locations at specific times. This information is critical in employing sustainable pest management strategies, which are integrative in nature.

These basics are also true for fruit fly management and, therefore, we launched an investigation into the spatio-temporal distribution of the Mediterranean fruit fly or Medfly (Ceratitis capitata) at different spatial scales (farm and regional scale), using high-end up to date technologies, which included geospatial analysis and machine learning.

Geospatial analysis is the process of analysing any data with a reference to a location within a spatial context, making

use of a geographic information system (GIS); while machine learning is the process whereby computer algorithms are trained to perform certain tasks or solve complex problems by learning from experience.

We studied the spatial distribution of fruit flies, first using high intensity trapping on a small farm, to assess the local-area movement of fruit flies across orchards, home gardens and natural habitats. This is important for setting up

24

Draslovka

A DAFF accredited and licensed soil fumigation company that specialise in soil fumigation for fruit-, vegetable- and berry farms, nurseries, golf courses, sports field and more.

ORCHARD REPLANT FUMIGATION

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Fumigate before new grass seeds are sown to prevent it from getting infected by fungi and invested by parasitic nematodes.

Soil fumigation will help render the greenhouse’s soil without having to relocate the greenhouse to new unused soil.

ALGEMEEN an integrated pest management (IPM) strategy, especially in a heterogeneous orchard environment.

Next, we looked at fruit fly distribution on a regional scale, making use of long term fruit fly trapping data (number of fruit fly trap catches and GPS coordinates of traps), along with long term environmental variables, in order to determine the most important geographic drivers of Medfly population distributions. Finding the drivers that affect fruit fly spatial movements can improve the planning of management strategies to effectively combat this pest, particularly on an area-wide basis.

Farm-scale study At the orchard level, it was found that two species of fruit fly were present in the Stellenbosch region; the Medfly and the Cape fruit fly (previously known as Natal fruit fly). Both species tended to aggregate spatially in the same locations (notably home gardens, natural vegetation, citrus and nectarines). The natural vegetation was dominated by wild olives, eucalyptus trees and yellowwoods, and is thought to provide refuge and shelter. The fruit flies were, however, not aggregated temporally, meaning that Medfly tended to aggregate towards the end of the season, while Cape fruit fly aggregated more at the beginning of the season. The reason for this could be that Cape fruit fly prefers cooler weather (and therefore specialised on utilising early-ripening fruits), while Medfly is more tolerant of hotter weather, thereby utilising later maturing fruits.

The patterns observed in this small orchard-scale trial suggest that fruit flies invade commercial orchards from home gardens and refuge areas into commercial orchards and that the ripening of these hosts plays an important role in their observed patterns. The implication for growers is that home gardens with unmanaged fruit trees should be included in fruit fly management actions.

Internationally several such actions have been proposed, such as timeous harvesting and destroying unused/unharvested fruits, perimeter trapping on borders of commercial orchards to determine the need for control, and female mass-trapping (50 traps/ha) supplemented with bait applications.

Where the Cape fruit fly is problematic,

Yellow bucket trap in a nectarine orchard baited with a food-based lure to monitor fruit fly adult activity. Photo: Gulu Bekker.

Male Medfly sitting on a citrus leaf soaking up the morning sun. Photo: Gulu Bekker.

Late season spatial clustering maps of Medfly (far left) and Cape Fly (middle) and their spatial association (far right). Red areas indicate significant clustering of high average trap counts and blue areas with significant clustering of low average trap counts. Map: Gulu Bekker.

early-season monitoring and control are critical, while early-season control for Medfly would prevent a build-up of populations later in the season.

Regional-scale study For investigating regional Medfly spatial distribution, we used long-term trap-monitoring data of four consecutive fruiting seasons, obtained from FruitFly Africa’s sterile insect technique programme in Stellenbosch. Long-term (30 years) monthly and annual minimum and maximum temperature and rainfall data, positive chill units, the mean number of heavy frost occurrences, accumulated annual heat units, accumulated summer heat units and accumulated winter heat units comprised the climatic variables to explain regional Medfly spatial distribution. In addition, topographic variables (elevation and slope), landscape variables (distance to urban areas, grapes, citrus berries and stone fruit, respectively) were also investigated as possible drivers of fruit fly distribution using machine learning techniques.

The results showed a clear concentration of hot spots (i.e. areas where high fruit fly trap catches were significantly aggregated) in areas that are drier and warmer, compared to cooler, wetter

areas, confirming the results of the orchard-scale study.

The machine-learning algorithm showed that the most important variable driving Medfly hot and cold spots in our study area were long term rainfall, and to a lesser degree temperature, and that the hot and cold spots of at the latter part of the fruit season was strongly related, related strongly to the climate of the preceding months. Mild, dry winters could, therefore, indicate a potential fruit fly problem in the coming season.

It was interesting to find that distance to urban areas and other fruit kinds did not generally result in strong predictions of fruit fly population distributions in the model. However, hot spots were most prominent during March, which coincides with the time when the majority of fruits are being harvested, suggesting that host fruits are still important within the limits of climatically suitable areas.

Conclusions and recommendations The results of the investigation highlight the value of the available technologies and of long-term pest monitoring data and long-term environmental data in improving the understanding of the spatial distribution of Medfly trap catches TO PAGE 26

GROENTE & VRUGTE | NOVEMBER • DESEMBER 2019

25

GENERAL

Machine learning and spatial analysis cast light on fruit fIy distributions FROM PAGE 25

in complex agricultural systems.

The work highlights the need for a more tailor-made approach to fruit fly management, in which areas with fruit fly hosts that are hotter and drier receive scaled-up management actions compared to very wet and cold locations, and that a blanket approach to fruit fly control will not have the necessary impact.

With increasing temperatures and more intense drought conditions occurring in future, the fruit fly problem could escalate even more. This really emphasises the need for area-wide monitoring programmes, which can provide information-rich data for impactful planning of fruit fly management actions.

Long term Medfly hot and cold spot map for March in the EGVV fruit production area in the Western Cape. Red blocks indicate significant hot spots and green blocks indicate significant cold spots. Map: Gulu Bekker.

26

SALAMANCA

ALGEMEEN

Volhoubare wisselbou vir groente onder beskerming Die belangrikheid van wisselbou vir volhoubare groenteproduksie word toenemend beklemtoon as gevolg van klimaatsverandering en die afname in beskikbare bewerkbare landbougrond.

Voortdurende produksie van dieselfde gewasse in ‘n spesifieke streek het verskeie newe-effekte, soos verhoogde siektedruk, afname van grondvrugbaarheid en gevolglik laer opbrengste.

W

EERPATRONE IS GROOTLIKS onvoorspelbaar en stel die grense waarbinne ‘n produsent moet beplan.

Met huidige struikelblokke het die produsente innoverende planne nodig sodat hulpbronne vir die toekoms behoue bly om sodoende volgehoue sukses en produktiwiteit aan te moedig.

Die afwisseling van verskillende gewasse in opeenvolgende plantseisoene is ‘n belangrike bestuursinset waarvoor die produsent tegniese kennis benodig om winsgewendheid te verhoog. Hierdie insette word veral benodig in ‘n boerderypraktyk waar gewasse onder bedekking geplant word, aangesien ‘n mikro-klimaat geskep word. Verbouing onder beskerming verminder klimaatswisseling en het verhoogde opbrengste, onder gematigder bestuurspraktyke, tot gevolg. Beperkende faktore soos verhoogde siektedruk, voedingstofbehoeftes en insetkoste kan verminder word deur wisselbou toe te pas.

Die korrekte identifikasie van plantsiektes, lewensiklus en verspreiding, asook gasheerplantspesies, is uiters belangrik vir die beplanning van ‘n wisselboustelsel. Afwisseling met gewasse wat nie potensiële gashere van ‘n spesifieke plantsiekte is nie, veroorsaak dat die lewensiklus onderbreek word.

Hierdie metode bied ‘n omgewingsvriendelike en kostebesparende alternatief vir plaagbeheer. Skadelike insekte kan ook op hierdie manier bekamp word, deur te verhoed dat die nodige voeding en reproduksie plaasvind. Wisselbou skep ook ongunstige toestande vir onkruide, aangesien dit die ontkieming van onkruid en die mededinging van gewas met onkruid beïnvloed deur die groei van die gewas te bevoordeel.

Grondvrugbaarheid kan aangevul word deur peulplante soos lupiene, boontjies, ertjies en canola in ‘n gewasrotasiestelsel in te sluit. Peulgewasse hersirkuleer stikstof in die grond deur middel van ‘n mutualistiese voordelige verhouding met rhizobium-bakterieë. Peulgewasse bied ook ‘n unieke geleentheid om kontantvloei beter deur die jaar te versprei, aangesien ‘n gewas soos boontjies in ander tye van die jaar as hoofgewas verbou kan word.

Verhoging in opbrengs en gehalte kan bereik word deur gewasse in ‘n spesifieke volgorde volgens voedingstofbehoeftes te plant. Koolgewasse soos broccoli, blomkool en kopkool word beskou as swaar voerders en het voldoende stikstofvoorraad nodig. Dit is gevolglik wys om koolgewasse in die opeenvolgende seisoen na peulgewasse te plant, waar ‘n gewas met laer voedingstofbehoeftes soos wortels, beet en radyse eerder twee of drie seisoene later geplant kan word.

Sakata Saad SA beskik oor rankboontjievariëteite van hoë gehalte wat besondere resultate in ‘n gewasrotasiestelsel vir produksie onder beskerming lewer.

GROENTE & VRUGTE | NOVEMBER • DESEMBER 2019

Salamanca het ‘n sterk vegetatiewe groeiwyse vir hoë gehalte en gee ‘n eerstegraadse uitpakpersentasie van 95%.

Salamanca het kenmerkende eenvormigheid en lewer konstante reguit, ferm peule van uitnemende gehalte.

Rankboontjies Salamanca het ‘n sterk vegetatiewe groeiwyse vir hoë gehalte en kwaliteit, met ‘n eerstegraadse uitpakpersentasie van 95%. Hierdie rankboontjie is ‘n staatmaker met ‘n gekonsentreerde vrugset wat goeie opbrengste van tot 36 ton per hektaar kan lewer. Salamanca is ideaal vir die uitvoer- of varsmark, met kenmerkende eenvormigheid en ‘n uitstekende raklewe. Peule is ongeveer 15 tot 17 cm lank, dit het ‘n deursnee van 8 tot 9 mm en is baie ferm, wat skade tydens vervoer verminder.

Moraleda is ‘n unieke rankboontjie met ‘n korter lewensiklus en kan ongeveer 10 tot 14 dae vroeër as Salamanca geoes word. Hierdie variëteit gee meer lugvloei met minder vegetatiewe groei en lewer meer eenvormige toediening.

Moraleda het ‘n hoë opbrengspotensiaal met eerstegraadse peule wat kenmerkend reguit en ferm is. Dit is ideaal vir die uitvoer- en varsmark en lewer eenvormige peule van tussen 14 en 16 cm in lengte en 8 tot 9 mm in deursnee.

Skakel Sakata by 011 548 2800 of besoek die webwerf www.sakata.co.za vir meer inligting oor hulle boontjievariëteite.

AFWYSENDE KLOUSULE: Hierdie inligting is op Sakata se waarnemings en/of inligting van ander bronne gebaseer. Aangesien gewasprestasie afhang van die interaksie tussen die genetiese potensiaal van die saad, die fisiologiese eienskappe daarvan en die omgewing, insluitend bestuurspraktyke, gee Sakata geen uitdruklike of geïmpliseerde waarborg vir die prestasie van gewasse relatief tot die inligting nie. Sakata aanvaar nie enige aanspreeklikheid vir enige verlies, direk of as gevolg van die inligting, wat mag ontstaan te wyte aan enige oorsaak nie. Lees eers asseblief Sakata Seed Southern Africa (Pty) Ltd se verkoopsvoorwaardes voordat saad bestel word.

27

GENERAL

Biological pest control

For fruit exported to Europe, softer pesticides and biological control are required.

Consumers, and consequently supermarkets, demand products free of pesticide residues. With much of the citrus produced by Endulini Fruit being exported to Europe, requirements by the European Union (EU) has led to the citrus producer using softer pesticides and introducing biological pest control. Directive 2009/128/EC of the EU aims to reduce the risks and impact of pesticides on human health and the environment.

“M

ARKET DRIVERS, EUROPEAN regulations and our understanding of the impact of pesticides on the environment and bio-diversity has led to us using 90-95% less red label products and biological pest control for crops,” remarks Endulini Fruit CEO, Pietie Ferreira. “We want to protect our environment for future generations. Knowing that many pests have built up a resistance to pesticides, demonstrates that the exclusive use of hard chemicals isn’t a long-term solution.”

Introducing biological pest control Biological pest control is an environmentally safe alternative to conventional chemical control. Talking about the introduction of biological pest control at Endulini Fruit, Stephen

Meeding, Technical Manager, remarked: “Biological control involves the use of one or more types of beneficial organisms, to reduce the numbers of another type of organism. As a result, Endulini is able to deliver a product that is kinder to the environment and eliminates pesticide residue.”

The use of biological control leads to a continuously growing industry, currently still in its infancy in South Africa, compared to the rest of the world.

Drawing on this insight and experience, Endulini Fruit has introduced two types of biological control: classical biological control to protect its crops against pests of foreign origin and augmentative biological control to increase the population of the natural predators of local pests.

Classical biological control involves the introduction of

28

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ALGEMEEN provision of alternative food sources for natural enemies such as nectar, pollen, alternative prey or shelter.

Endulini Fruit has introduced two types of biological control: classical biological control to protect its crops against pests of foreign origin and augmentative biological control.

specialist natural predators from the pest’s place of origin and is a long-term fight against alien pests. Augmentative biological control increases the populations of the natural enemies by means of massive releases of agents purchased from bio-factories.

Augmentative biological control can be inoculative where the natural predators are introduced in small numbers early in the season, usually for greenhouse crops. They then go on to reproduce and feed on the pest and therefore suppress pest populations. The inundative approach involves mass releases of commercially reared natural enemies and is used for rapid pest suppression when the population of natural enemies is expected to be low and insufficient to control pests.

There is a third form of biological control, though not to be introduced as yet on the Endulini farms: conservation biological control. This process involves the manipulation of the agricultural environment to preserve and enhance the existing populations of natural enemies. Manipulations include the

Integrated pest management The introduction of biological pest control is part of an integrated pest management (IPM) plan to reduce the impact of pesticides on the environment and bio-diversity. Biological control is the cornerstone for IPM, an ecosystem-based strategy that focuses on the long-term prevention of pests through a combination of techniques such as biological control, cultural methods (habitat manipulation, modification of cultural practices, and use of resistant varieties) and pesticides. Pesticides are only invluded after monitoring indicates they are needed and applied in a manner that minimises risks to human health, beneficial and non-target organisms, and the environment.

“Many believe pesticide residue has an impact on human health, but the risk assessment for pesticide residues in food by the Joint FAO/WHO Meeting on Pesticide Residues (JMPR), establishes safe intake levels,” remarks Meeding. “Acceptable daily intakes are used by governments to establish maximum residue limits (MRLs) for pesticides in food, with limits enforced by authorities to ensure that the amounts of pesticide residues consumers are exposed to through eating food over a lifetime will not have adverse health effects. We adhere to these levels when using pesticides to ensure food safety. Our focus is on protecting our environment for future generations.”

29

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ INSECT COLUMN

Yellow pecan aphid (Hemiptera: Aphididae)

Pecan nut trees (a native of North America) was first imported to South Africa at the end of the 19 century, and the industry has been expanding with increasing momentum ever since. In addition to the production of delicious nuts, the wood of pecan nut trees is used for furniture making and wooden flooring, and as a flavouring-fuel for smoking meats. Although South Africa has far fewer problems with pests when compared to other countries such as Australia, Mexico and the USA, there are still a number of insects that can have a detrimental impact on pecan nut yields.

The yellow pecan aphid is one of these pests. th

Andri Visser IPM-PROGRAMME NORTH-WEST UNIVERSITY POTCHEFSTROOM

e-mail: visseran3@gmail.com

Yellow pecan aphid classification: Class: Insecta Order: Hemiptera Family: Aphididae Genus: Monelliopsis Species: Monelliopsis pecanis

T

HE YELLOW PECAN APHID, Monelliopsis pecanis, is a native pest of pecans in the United States of America and has been considered a pest of pecans in South Africa since 1977 – a year after it was first detected. This species of aphids is associated with several members of the Juglandaceae plant family, but pecan is the only known hostplant in South Africa.

The yellow pecan aphids do not cause damage to the nuts directly but impair overall tree growth and vitality, which impacts the tree’s productivity and nut quality. During the spring and summer season, both the adults and nymphs feed on the underside of the leaves. This feeding behaviour results in the withdrawal of carbohydrates and water from the leaves and causes damage to the vascular system. Large amounts of honeydew are also produced by the aphids, which coats the leaves and serves as a medium for the growth of the sooty mold fungus (Capnodium sp.). This fungus shades the leaves and greatly reduces photosynthesis. Heavy infestations in the summertime can defoliate trees, which adversely affects nut size and fill.

Yellow pecan aphid nymphs are tiny, yellow, soft-bodied and wingless. Likewise, the adults are small (3 - 4 mm) and soft-bodied, and under magnification, two tiny spots may

Yellow pecan aphid larva.

30

Yellow pecan aphid.

be visible on either side of the 5th abdominal segment. The winged yellow pecan aphid adults are easier to identify than the nymphs due to the wings that are characteristically free of markings and are held in an acute, roof-like position over the body when at rest.

Yellow pecan aphids overwinter as fertilized eggs in crevices in the bark or other protected places on the tree. The eggs are round and orange in colour when freshly laid, but darken and appear malformed as they start to shrink over time.

Wingless females, known as stem-mothers, hatch from these eggs with the arrival of spring time. When they reach maturity, these stem-mothers give birth to living young, without mating. The offspring are all female, and at maturation, they too produce living female young. A population of yellow pecan aphids can produce approximately 22 to 32 generations per year, with the adults giving rise to as many as 100 offspring each. As the day-length shortens and temperatures fall in late autumn, male aphids are brought forth, in order to mate with the females and produce fertilized eggs for the overwintering generation.

There are several natural enemies that prey on the yellow pecan aphids, including predatory ladybirds, spiders, hover flies, ants and hymenopterous parasitoids. Although highly effective registered insecticides are available to combat this aphid, it is suggested that the use of integrated pest management strategies should be the first line of defense, since natural enemies are often able to keep small populations of this aphid in check.

NOVEMBER • DECEMBER 2019 | VEGETABLES & FRUIT

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