fruit flies PEST EXPERTS SHARE HOW TO SQUASH THIS BUG FOR GOOD

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1 CROP PROTECTION PHYTOSANITARY PRINCIPLES FRESH ISSUE THREE DECEMBER 2018 QUARTERLY fruit flies PEST EXPERTS SHARE HOW TO SQUASH THIS BUG FOR GOOD + THE SUCCESS OF FORELLE EARLY MARKET ACCESS + A COMPLETE GUIDE TO STONE FRUIT ROOTSTOCKS

2 FRESH QUARTERLY ISSUE THREE DECEMBER 2018 ISSUE THEMES In each issue the Fresh Quarterly will address certain themes pertaining to crop production, crop protection and postharvest. This issue s themes are: Phytosanitary principles for crop protection Stone fruit rootstocks for crop production Forelle Early Market Access for postharvest Copyright 2018 Fresh Quarterly All rights reserved. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the publisher, except in the case of brief quotations embodied in critical reviews and certain other noncommercial uses permitted by copyright law. For permission requests, write to the publisher, addressed Attention: Fresh Quarterly Permissions, at the address below. hugh@hortgro.co.za Printed in South Africa FRESH QUARTERLY for the deciduous fruit grower ISSUE 3, DECEMBER 2018 CROP PROTECTION PHYTOSANITARY PRINCIPLES Nip phytosanitary risk in the bud Sticking to phytosanitary principles is crucial to maintain access to export markets. Indigenous fruit flies: Keeping your orchard pest free Fruit industry entomologists and experts share vital tips and information regarding indigenous fruit flies, and how to protect your crop from them. Research Inventory A list of this theme s projects and publications CROP PRODUCTION STONE FRUIT ROOTSTOCKS Rootstocks: Choose what is best for your crop Researcher and rootstock specialist, Dr Piet Stassen, shares the characteristics of high potential stone fruit rootstocks for SA conditions. Rootstocks for stone fruit A practical guide to help you determine which rootstock your crop needs. Understanding rootstock evaluation Dr Piet Stassen gives growers a look at how rootstock trials actually work, and shares tips on choosing the best rootstock for your crop. Research Inventory A list of this theme s projects and publications POSTHARVEST FORELLE EARLY MARKET ACCESS Forelle Early Market Access: Unlocking new value from an old cultivar ExperiCo's Dr Ian Crouch shares how the FEMA programme is benefiting growers throughout all seasons. Research Inventory A list of this theme s projects and publications FRESH TAKE COLUMN A meander along South Africa's CA storage road Industry veteran, Richard Hurndall, gives an historic account SA's Controlled Atmosphere storage beginning and present. Editor Esté Beerwinkel Writers Dane McDonald, Anna Mouton, Richard Hurndall and Piet Stassen Layout and design Esté Beerwinkel Advisors Hugh Campbell, Richard Hurndall, Matthew Addison and Wiehann Steyn Contact us hugh@hortgro.co.za or

3 CROP PROTECTION PHYTOSANITARY PRINCIPLES foreword PEOPLE COUNT I did not realise all the things that they dealt with and the depth and width of their knowledge. Only now do I realise what an amazing contribution they made! Sadly, this is often the realisation that one has when someone leaves a position or when you spend more time than you normally do with an individual or group of individuals. In the technical and research arena this is even more relevant as experience is a cumulative reality where the more research projects a researcher does in a particular field, the more knowledge and experience they develop and the more value they add. Yes, there is always great value in renewal and bringing in new people with new ideas but this must be on the solid foundation of good science and experience. In the research environment, we are in the long term business where people count. Credibility is attached to an individual, not a project. At the end of December 2018 we take leave of one of our stalwarts who has contributed to this industry in so many ways over the past 35 years. Richard Hurndall started as the Technical Manager at the South African Apple and Pear Producers Association, now Hortgro Pome, in 1983 where he drove the implementation of maturity indexing. Through the years he played a pivotal role in connecting the dots and providing a facilitation, networking and implementation role in anything and everything regarding postharvest and so much more. Richard, we salute you! Hugh Campbell Hortgro Science General Manager Richard and his favourite things. Illustration by The Agency.

4 CROP PROTECTION PHYTOSANITARY PRINCIPLES NIP PHYTOSANITARY RISK IN THE BUD Dr Shelley Johnson, a quarantine entomologist, says the deciduous fruit industry s export market is based on sound phytosanitary principles monitoring in particular. Words by Dane McDonald Johnson, a Hortgro and Stellenbosch University researcher, says the ideal way to manage phytosanitary risk is to manage everything based on growers target export markets. But she holds a special place in the toolkit for proper monitoring. This is an issue with quite a few of our markets they want information on our monitoring systems and the monitoring data. We need to provide proof when we say a pest doesn't occur on a particular crop in South Africa. It is a matter of showing, not only telling according to Johnson. Growers need data to show that a particular pest is not present. You can t just say your crops are pest-free and have everyone accept it monitoring is key and it s not done as well as it should, she says. BONE OF CONTENTION Despite her residence in the university ivory tower, Johnson keeps in touch with growers and says monitoring remains a point of contention with some growers. Johnson advises growers to participate transparently in monitoring practises, as it is to the benefit for the industry's future practices and historical data capturing. The work being done in the Unites States by the University of California Agriculture and Natural Resources Division is a good example of how Integrated Pest Management (IPM) works. Their online resources promote IPM programs for a variety of crops and a major component of all IPM programs is monitoring and assessing pest numbers and damage. LESSONS LEARNT Johnson urges growers to learn from the recent False Codling Moth (FCM) issues. New European Union (EU) regulations came into effect in 2017 to prevent the entry of FCM into the EU via stone fruit imports from several countries including SA. Johnson says it would be a step in the right direction if growers moved from a situation where they have to participate in monitoring due to a push by regulatory bodies like the International Plant Protection Convention (IPPC) and the EU to a position where it s done proactively across the board. There are benefits to documenting monitoring data that go beyond just the requirements for international trade. She says the Peach and Nectarine FCM Management System and Phytclean Database are proud achievements for the industry in managing FCM. ACCESSING EXPORT MARKETS Hortgro's Trade and Market Access manager, Lindi Benić, says growers sticking to phytosanitary principles is critically important, since it affects exports and imports. Benić was at the coalface of events when the FCM announcement hit SA; in fact, she saw it coming in advance. The phytosanitary aspects of the fruit growing business are critical market access drivers. It's related to accessing new export markets, and drives activities related to increasing market maintenance challenges. Benić furthers that the fruit industry should pro-actively execute market access related research to maintain priority export markets. Phytosanitary mitigation measures and systems needs proper application, and must be established to keep up with changing requirements regarding market concerns. While the struggle continues for growers to apply phytosanitary principles, which includes adequate monitoring, the industry s achievements with FCM shows what can done when growers act as a collective. FQ 6 Hortgro Science Fresh Quarterly, December 2018 December 2018, Fresh Quarterly Hortgro Science 7

5 CROP PROTECTION PHYTOSANITARY PRINCIPLES INDIGENOUS FRUIT FLIES Keeping your orchard pest-free Words by Dane McDonald It is the trouble every fruit grower is trying to avoid finding a fruit fly larvae just one hit can ruin the day, if not the entire season. The invasive oriental fruit fly has hit the Western Cape fruit growing region via an unknown entry point and it is a concern. Nobody wants a maggot in their apple, says FruitFly Africa manager Nando Baard, with a smile. Fruit damage is caused by the fruit fly lifecycle. The female fruit fly lays her eggs under the skin of the fruit, where they hatch. Here the larvae feeds on the fruit until they crawl out of the fruit, fall onto the ground and pupate in the soil. At this stage the fly emerges allowing the life cycle to start again. At the FruitFly Africa facility, based in Stellenbosch, Baard shares the story about India which had its export market closed down due to the European Union s (a highly lucrative market) strike system for pests. About three years back they had numerous strikes which closed the EU market for them for 18 months, he says. According to Baard they needed to reapply for the following season and if it happens to the South African fruit industry it will be a big problem. It is estimated that crop losses and control costs as a result of fruit flies in the Western Cape alone amount to (a conservative estimate) of more than R20 million per year, according to Baard. INDIGENOUS FRUIT FLIES In South Africa there are three indigenous fruit flies of economic importance: Ceratitus capitata, C. rosa, and C. quilicii, which are of concern to the deciduous fruit industry in the Western Cape. But the term indigenous is contentious among the entomological experts at Stellenbosch University. Dr Minette Karsten who has been working on fruit flies for much of her postgraduate life says the fruit flies have an Afrotropical native range with very little information on the actual origin of the flies so the term indigenous might be a misnomer. 8 Hortgro Science Fresh Quarterly, December 2018 December 2018, Fresh Quarterly Hortgro Science 9

6 CROP PROTECTION PHYTOSANITARY PRINCIPLES A recent paper by Karsten and her colleagues listed 14 Afrotropical fruit flies of varying economic importance. Karsten says the flies have been in South Africa before the beginning of fruit cultivation activities. CHALLENGING TO MAP In terms of their distribution fruit flies are challenging to map, says Karsten, adding that information is patchy and that global distribution maps do not help at a local level. In most cases distribution seems to be driven by ambient temperature with C. capitata thriving in dry, hot conditions and C. rosa and C. quilicii faring better in colder conditions and at higher altitudes. Baard s colleague and Fruit Fly Africa field operations manager Elsje Schreuder takes a broader view and says fruit flies are found everywhere especially in home gardens in towns. Schreuder says the prevalence of fruit flies in home gardens is problematic because despite producers best efforts at pest control activities in orchards, very little control activities are being carried out in home gardens, towns and alternative hosts. FRUIT FLY MANAGEMENT Baard says the current management regime for fruit flies in South Africa varies depending on the region and who one speaks to, but mostly it will include monitoring, orchard sanitation and chemical control with some type of fruit fly bait. In the areas where we do area wide integrated pest management programmes we also do the monitoring. We try to get growers to do better orchard sanitation and we do aerial baiting with GF-120 (a protein bait spray) as well, according to Baard. The Fruit Fly Africa operation incorporates the use of a helicopter and/or fixed wing aircraft to bait effectively across its grower regions. Baard explains that the attractant is highly concentrated requiring only 1 litre of GF-120 per litre of water per hectare. In addition, while GF-120 attracts fruit flies it is not harmful to other insects which are not attracted to the bait. The fruit flies are then killed by the active ingredient Spinosad an organically certified product which Baard says presents minimal risk to other animals. The other arm of Fruit Fly Africa s activities involves Sterile Insect Technique (SIT). At the Facility 56 million sterile male Mediterranean fruit flies are bred per week. At the pupal stage the male flies are irradiated rendering them sterile. These sterile males fruit flies are then released across the relevant fruit growing areas where they compete effectively with sexually viable males for female mating opportunities leading to pest population control. AN EYE ON THE FUTURE While Baard and his team are currently effective in their fruit fly management workflow and receiving significant buy in from growers across the board, they are keeping an eye on future It s estimated that crop losses and control costs due to fruit flies in the Western Cape could be more than R20 million per year. developments predominantly biological pest control. Stellenbosch University entomologist Dr Pia Addison says a few potential biological control organisms have been developed largely nematodes, fungi and parasitoids with nematodes being the most effective option at the moment. Karsten, who works closely with Addison, says the challenge is finding biologicals that are native to the South African region and developing effective application methods for growers. Some of those technologies still have to be developed into products that can be bought off the shelf, says Karsten. CHEMICAL HEYDAY OVER Karsten says the fruit export market is moving away from harsh chemicals like organophosphates towards more biological options. People are becoming much more interested in the fruit production process and which chemicals are being applied, she says. Yet, the fruit fly fighters on the ground are not quite sure about the current economic viability of using biologicals in isolation. At the same time Baard agrees with his researcher colleagues; the markets definitely do not want organophospates sprayed on their fruits anymore. So, it will be baits, biological control, orchard sanitation, and effective monitoring, he says. FQ 10 Hortgro Science Fresh Quarterly, December 2018 December 2018, Fresh Quarterly Hortgro Science 11

7 CROP PROTECTION PHYTOSANITARY PRINCIPLES RESEARCH INVENTORY COMPLETED PROJECTS CONTINUED 2017 Monitoring and database of Bactrocera dorsalis (L Brown) 2017 Forecasting Bactrocera invadens invasion potential using trait-based modelling approaches (J Terblanche) 2018 A study on the biological and physiological traits of Bactrocera dorsalis, with special reference to its invasion potential into the Western Cape of South Africa (P Addison) A list of phytosanitary and fruit fly-related research projects and publications. This theme s articles was compiled using information from industry funded research Exploration of orchard sanitation and the potential of parasitic wasps for the biological control of fruit flies in South Africa. (P Addison) CURRENT PROJECTS COMPLETED PROJECTS 2012 Monitoring and database of Bactrocera invadens (L Brown) 2012 Gene flow in Ceratitis capitata: invasion potential and dispersal capability (J Terblanche) 2012 Cold tolerance of Natal fly: geographic distribution of overwintering physiology (J Terblanche) 2013 Modelling the risk of importing pests in consignments of imported (K Pringle) Protocol for the comparison of the temperature sensitivity of laboratory - reared FCM in medium and in peach/nectarine research (T Ware) Ethyl formate fumigation technology upscaling application towards commercialisation (S Johnson) Phytosanitary status of false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) on pears (M de Villiers) Phytosanitary status of false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) on plums (M de Villiers) CATTS and ethyl formate fumigation as postharvest treatments for stone and pome fruit and associated phytosanitary insect pests (S Johnson) 2013 Gene flow in Ceratitis capitata: invasion potential and dispersal capability (J Terblanche) 2013 Biochemical responses of False Codling Moth, Thaumatotibia leucotreta to low temperature and modified atmospheres (J Terblanche) 2013 Modelling the risk of importing pests in consignments of imported fruit (K Pringle) 2014 Temperature-dependent flight performance of fruit flies (J Terblanche) 2014 Impacts of climate variability on fruit fly (Ceratitis spp.) performance and population dynamics (J Terblanche) 2014 Molecular analysis and biodiversity survey of fruit flies associated with deciduous fruit and vines, with focus on economically important species [Market Access] (P Addison) 2014 Controlled atmosphere temperature treatment system (CATTS) as a post harvest treatment for phytosanitary pests of deciduous fruit (S Johnson) 2014 High temperature disinfestation of False Codling Moth (J Terblanche) 2015 Bactrocera invadens: Pest Risk Analysis for the deciduous fruit industry in the South Western Cape (K Pringle) 2015 Grain chinch bug (Macchiademus diplopterus) thermal biology and the implications for postharvest control measures (S Johnson) 2017 Phytosanitary status of false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) on pears. [Market Access] (M De Villiers) 2017 Dispersal capacity of Bactrocera invadens (C Weldon) Scientific journal papers De Villiers, M.; Heunis, J.M.; Pringle, K.L Phytosanitary host status of apples as a host for false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae). African Entomology, Volume 23, Number 1, 1 March 2015 Karsten, M., Jansen van Vuuren, B., Addison, P., Terblanche, J.S. 2015, Deconstructing intercontinental invasion pathway hypotheses of the Mediterranean fruit fly (Ceratitis capitata) using a Bayesian inference approach: are port interceptions and quarantine protocols successfully preventing new invasions?. Diversity and Distributions, 21: Mgocheki, N & Addison, P. (2016). Investigating the validity of the species status of the false codling moth in South African fruit orchards using mating studies and mtdna. Bulletin of Entomological Research 106: Karsten, M., Addison, P., Jansen VAN Vuuren, B. & Terblanche, J.S. (2016). Investigating population differentiation in a major African agricultural pest: evidence from geometric morphometrics and connectivity suggests high invasion potential. Molecular Ecology 25: Johnson S.A Potential of Heated Controlled Atmosphere Postharvest Treatments for the Control of Thaumatotibia Leucotreta (Lepidoptera: Tortricidae). Journal of Economic Entomology, Volume 103, Issue 2, 1 April 2010 Johnson S.A. & L. G. Neven Heated-Controlled Atmosphere Postharvest Treatments for Macchiademus diplopterus (Hemiptera: Lygaeidae) and Phlyctinus callosus (Coleoptera: Journal of Economic Entomology, Volume 104, Issue 2, 1 April 2011, Pages , Curculionidae). Boardman.L. J G Sørensen, S.A.Johnson & J. S. Terblanche Interactions between controlled atmospheres and low temperature tolerance: a review of biochemical mechanisms. Front. Physiol., 02 December 2011 De Villiers M., Manrakhan A., Addison P. & Hattingh V The Distribution, Relative abundance and Seasonal phenology of Ceratitis capitata (Wiedemann), C. rosa (Karsch) and C. cosyra (Walker) (Diptera: Tephritidae) in South Africa. Environmental Entomology 42: Manrakhan, A. & Addison, P Assessment of fruit fly (Tephrittidae) management practices in deciduous fruit growing areas in South Africa. Pest Management Science 70: Karsten, M., Jansen van Vuuren, B., Addison, P., Terblanche, J. S. 2015, Deconstructing intercontinental invasion pathway hypotheses of the Mediterranean fruit fly (Ceratitis capitata) using a Bayesian inference approach: are port interceptions and quarantine protocols successfully preventing new invasions? Diversity and Distributions, 21: Pieterse, W., Manrakhan, A. & Addison, P The use of SHAPE analysis to differentiate between the mandibles of four economically important tephritid species. Journal of Applied Entomology 141: Pieterse, W., Terblanche, J., & Addison, P Do thermal responses contribute to the invasion of Bactrocera dorsalis (Diptera: Tephritidae). Journal of Insect Physiology 98: 1-6. Bekker, FGVH., Addison, MF & Addison, P Comparison of two trap types for monitoring Bactrocera oleae (Rossi) (Diptera: Tephritidae) in commercial olive groves of the Western Cape Province, South Africa. African Entomology 25: Pieterse, W., Benítez, H.A. & Addison, P The use of Geometric Morphometric Analysis to illustrate the shape change induced by different fruit hosts on the wing shape of Bactrocera dorsalis and Ceratitis capitata (Diptera: Tephritidae). Zoologischer Anzeiger 269: James, M., Addison, P. & Malan, AP Surveying and screening South African entomopathogenic nematodes for the control of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann). Crop Protection 105: Karsten, M., Barton, M., Addison, P. & Terblanche, JS A synthesis for managing invasions and pest risks simultaneously for fruit flies (Diptera: Tephritidae) in South Africa. Entomologia Experimentalis et Applicata. FQ 12 Hortgro Science Fresh Quarterly, December 2018 December 2018, Fresh Quarterly Hortgro Science 13

8 ROOTSTOCKS: CHOOSE WHAT IS BEST FOR YOUR CROP CROP PRODUCTION STONE FRUIT ROOTSTOCKS Researcher and rootstock specialist, Dr Piet Stassen, discusses the characteristics of high potential stone fruit rootstocks for South African conditions. This guide will help you to confidently choose a rootstock suiting your crop's needs. 14 Hortgro Science Fresh Quarterly, December 2018 December 2018, Fresh Quarterly Hortgro Science 15

9 CROP PRODUCTION STONE FRUIT ROOTSTOCKS Not all soil problems can be rectified with rootstocks. The necessary soil preparation, effective drainage, initial nematode treatments, effective irrigation, well rooted, hardened off and healthy nursery material are part and parcel of a successful rootstock. Timeous planning will ensure quality nursery trees with adequate feeder roots. Propagation techniques must be upgraded and adapted as necessary to deliver such quality plant material. When planted, these trees must grow and perform optimally with zero dieback. We are fortunate to have rootstocks complementing our scion cultivars, which provide the grower with opportunies to positively increase yield and fruit quality in their orchard. However, this is only possible if one begins with well-prepared soil medium, quality plant material and optimally managed orchard practises. Dip all trees in Agrobacterium strain 84, both in the nursery and before planted in the orchard, to avoid serious crown gall development. Paint the trunk with a white paint or copper solution especially in sandy soils. The first year in the orchard is crucial to promote feeder root development and vegetative growth. ineffective irrigation, clay soils). External biotic and abiotic factors predispose trees to diseases. Very sensitive to wetness especially also when feeder roots are limited this can cause fungal infections (Phytophthora cactorum and others). Very sensitive to root-knot, root-lesion nematodes and crown gall. GF 677 is the standard for calcareous soils and performs well in the Robertson/Bonnievale region and also in moderate saline conditions. Other propagation methods should be used to ensure successful nursery trees. Smaller fruit with nectarines compared to Atlas and Cadaman. SAPO 778 Complex hybrid MARIANNA P. cerasifera x P. munsoniana Very sensitive to ring nematodes, bacterial canker and fungal infections especially so in sandy soil (external biotic and abiotic factors predispose trees to diseases). Small fruit when stressed and high numbers of ring nematodes occur. Shallow horizontal growing rootstock (need about 40mm good soil) therefore ideal for soil with clay layers in underground. Good rootstock for medium to high potential soil. MARIDON Tetraploïd of Marianna FLORDAGUARD Peach x Prunus davidiana hybrid. P. davidiana is a wild peach species Excellent for sandy (and or stony) soil. For very low chilling regions (even less than 200 Infruitec cold units, but also for higher chilling regions). Well synchronised with early cultivars. Immune towards root-knot nematodes. Not for soils that can be wet or calcareous/high ph/carbonate or bi-carbonate soils. When ring nematode numbers higher than 500/ 300 cm³ soil) fruit weight negatively affected. Sensitive to bacterial and fungal infections. Short dormancy period and hardening off in the nursery may be a problem. Nursery trees may have inadequate reserves and then trees must be headed back after planting in the orchard. Red-coloured leaves. ATLAS Multispecies, complex hybrid A consistently good performer over a wide range of soil types. Very good fruit size. Stronger root system compared to Viking. Grow and performed well in sandy soil also in sandy, calcareous soil. Show some lime induced iron chlorosis in free lime conditions, but influence on performance not significant. Need about 300 and more Infruitec cold units. Fruit a few days later compared to trees on Flordaguard. Tolerant to bacterial and fungal infections. Host to ring nematodes but that does not affect yield and fruit size. Resistant to root-knot and moderate tolerant to root-lesion nematodes. CADAMAN Peach x P. davidiana Also known as Avimag. A strong grower and good for sandy soils (it is 12% stronger compared to GF 677). Good yield and fruit size. Sensitive to bacterial and fungal infections. Only minor yellowing in calcareous soil. Resistant to some root-knot, moderate tolerant to ring and sensitive to root-lesion nematodes. Good host to ring nematodes but can still have good yield and fruit size. VIKING Multispecies, complex hybrid Good overall rootstock for many soils but not recommended for sandy (stony) soil. Can easily dehydrate in sandy soils during warm summer months and then become more sensitive to ring nematode infestation. Fruit later compared to Flordaguard and Kakamas seedling, same as Atlas. Take caution not to let roots dry out before plant. More tolerant to bacterial and fungal infections compared to peach x almond hybrids. Resistant to root-knot nematodes. More sensitive to rootlesion nematodes than Atlas. GF 677 Peach x almond hybrid Take and rooting % low from hardwood cuttings and many nursery trees have limited feeder roots. This can cause dieback of trees after plant in orchards, especially in stressful situations (sandy soil, Not recommended for low-chill regions ( 100 to 350 Infruitec cold units), or early cultivars. Synchronisation between early cultivars and this rootstock in stress situations (sandy soil/ fluctuating water tables) can cause fungal infections (Leucostoma). Ripening is delayed. Sensitive to calcareous or saline soil. Tolerant against ring nematodes. Very good fruit size. GARNEM Nemared peach x almond hybrid Red-coloured leaves and strong grower. Good host for ring nematodes but performs well in terms of yield and fruit size even when high numbers occur. Resistant to root-knot nematodes but has increased susceptibility to bacterial canker. Peach x almond hybrids are sensitive to bacterial and fungal infections when external biotic and abiotic factors predispose trees to diseases. A 20% stronger grower than GF 677). Not enough information regarding sandy soils. Included in new evaluation trials. GUARDIAN Nemaguard peach cross Not enough local information. Included in new evaluation sites especially in sandy soils. Fruit weight suspicious poor fruit weight, the same as a Kakamas seedling under stress conditions, but yield is better than Kakamas seedling. Not for calcareous soil. Vigour more like Atlas but less than Garnem. Resistant to root-knot nematodes. Host to ring nematodes but less so than Marianna. According to overseas information this rootstock is resistant to bacterial diseases. Shallow horizontal growing rootstock (need about 40mm good soil) ideal for soil with clay layers in underground. Relatively less sensitive to bacterial canker than Marianna. Flowers abundantly in Little Karoo region putting fruit size under pressure. High numbers of ring nematodes probable and moderately sensitive for calcareous soil (less than Flordaguard, SAPO 778 and Kakamas seedling). Small fruit when stressed and when high numbers of ring nematodes occur. KAKAMAS SEEDLING Peach seedling selection A semi-dwarfing rootstock. Easily stressed on sandy soils and during warm autumns bud drop occurs. Fruit size negatively influenced by stress conditions (sandy soil, root-knot nematodes, high ph, saline and wetness). Good rootstock for medium to high potential soil, free from any stress factors or limitations. Sensitive to crown gall must be treated with Agrobacterium strain 84. Not recommended for sandy soils where yield and fruit weight are negatively affected. Rather use Flordaguard or Atlas, depending on the site conditions. ROYAL SEEDLING Apricot seedling Compatible with all South African apricot scion cultivars. Excellent for well-drained shale soils, sensitive to wet soils. To use any of the other rootstocks available to the peach and plum growers, Royal interstem is a prerequisite to avoid breakage at the bud union. Very sensitive to bacterial and fungal diseases. FQ 16 Hortgro Science Fresh Quarterly, December 2018 December 2018, Fresh Quarterly Hortgro Science 17

10 ROOTSTOCKS FOR STONE FRUIT GROWTH VERY STRONG GROWTH MODERATELY STRONG GROWTH SEMI-DWARFING CROP PRODUCTION STONE FRUIT ROOTSTOCKS Garnem, Cadaman, Flordaguard GF 677, Atlas, Viking, SAPO 778, Marianna Kakamas seedling, Maridon This is a generic guide set up by Dr Piet Stassen to assist growers in their rootstock decision-making. SOIL TEXTURE CALCAREOUS HIGH PH FREE LIME CARBONATE SOIL GF 677, Atlas, Viking, Garnem, Cadaman SAND: 90% and higher (also high percentage stone) SAND: 80% to 90% Flordaguard, Atlas, Cadaman Atlas, Flordaguard, Viking, Garnem, Marianna/Maridon (not for peaches), SAPO 778, Cadaman Flordaguard excellent for low chill region and early cultivars Maridon not for Little Karoo regions SENSITIVITY TO BACTERIAL AND FUNGAL INFECTIONS VERY SENSITIVE Garnem, GF 677, Marianna SILT AND CLAY: 20 to 35 % CLAY: below 20% Atlas, GF 677, Marianna/Maridon (not for peaches), Viking, Garnem, Cadaman, SAPO 778, Kakamas seedling SAPO 778 not for low chill regions and early cultivars SENSITIVE Flordaguard, Cadaman, SAPO 778 MODERATELY TOLERANT TOLERANT Kakamas seedling Viking, Atlas CLAY: below 20 to 30 % Viking NEMATODES FRUIT SIZE VERY GOOD FRUIT SIZE Atlas, Garnem, SAPO 778 GOOD Cadaman, GF 677. Flordaguard, Viking, Marianna, Maridon, Kakamas seedling ROOT-KNOT RING IMMUNE: Flordaguard, Marianna and Maridon RESISTANT: Atlas, Viking, Guardian and Garnem VERY SENSITIVE: Kakamas seedling and GF 677 All rootstocks are good hosts for ring nematodes. VERY SENSITIVE: Marianna and Maridon SENSITIVE: GF 677 and Kakamas seedling SENSITIVE TO TOLERANT: Flordaguard and Viking TOLERANT: Atlas, Cadaman and Garnem TOLERANT TO MODERATELY RESISTANT: SAPO 778 SMALL FRUIT UNDER STRESS CONDITIONS Viking (summer months), Flordaguard, Marianna, Maridon (when high numbers of ring nematodes occur). Kakamas seedling under any stress condition (sandy soil) ROOT-LESION VERY SENSITIVE: GF 677 SENSITIVE: Flordaguard, Cadaman, Viking, SAPO 778, Kakamas seedling, Marianna and Maridon TOLERANT: Atlas and Garnem 18 Hortgro Science Fresh Quarterly, December 2018 December 2018, Fresh Quarterly Hortgro Science 19

11 CROP PRODUCTION STONE FRUIT ROOTSTOCKS UNDERSTANDING rootstock evaluation Every stone fruit grower knows when it comes producing an excellent crop you have to get your rootstock right. But the true conundrum lies in that there s not magic rootstock to guarantee you ll get cash for your crop. Fresh Quarterly asked deciduous fruit industry veteran and rootstock expert Dr Piet Stassen to guide growers in their rootstock selection. After completing 24 stone fruit rootstock evaluation trials in the past 15 years, Stassen says it boils down to an unwavering principle: proper planning. Many people think rootstock evaluation is straight forward. Is this true? No. Many factors play a role in this process because they influence yield, fruit size, and root and tree growth. Soil is the most important factor to consider. Other factors include: water tables and drainage problems, calcareous soils, plant parasitic nematodes, and the predisposing factors for bacterial and fungus diseases. All of these factors must be quantified accurately, in order to draw up generic information about each rootstock. Each rootstock trial site is selected to get very specific information. Every site must be well defined in terms of the abovementioned factors and climatic conditions so one can ultimately draw up generic information about each rootstock. In the past most, rootstock trials were done on experimental farms. These farms weren t always representative of the regions where the rootstocks would be planted, and the farm management wasn t at the same standard as that of leading producers. With the co-operation of some producers, I planted rootstock trials within commercial orchards. This is a great system, but needs plenty of good communication the information you get from evaluation trials is only as trustworthy as the effort and support provided by those involved. What should a researcher consider when advising growers on rootstocks? Not all soil problems can be solved by rootstocks. The necessary soil preparation, effective drainage systems and nematode treatment must be in place. Rootstocks can't necessarily fix wrong cultivar choices and problems. But, can significantly improve horticultural traits and soil adaptability of good scion cultivars. It's important to have all information about the soil, climate, pests and diseases. Researchers give better recommendations when they have a feeling for the soil, region, location and cultivation practices of a specific farm. Is there a single rootstock that'll do well under the various conditions South African stone fruit growers encounter? Presently, there is no super rootstock for all conditions. An all-rounder like Atlas performs consistently well in terms of yield, fruit size, and tolerance to plant parasitic nematodes and diseases under many conditions. Flordaguard excels in low chill areas and well drained sandy soil, and works well for early cultivars. GF677 is the standard rootstock for calcareous soils, but Garnem, Cadaman, Atlas and Viking provide the same results depending on the factors involved. A rootstock must compliment the scion cultivar to optimise yield and fruit quality over the lifespan of the orchard. It must be adaptable to the soil conditions in a specific orchard, as well as be resistant or tolerant to pests and diseases. What are the most common mistakes growers make when choosing rootstocks? Long-term planning is a necessity. To get good quality plant material from nurseries, planning must be done well in advance. Key tips here include: Growers having information on their rootstock of choice two years in advance, this almost guarantees they ll get the most suitable rootstock from the nursery. Skipping the planning phase can lead to growers losing out on their choice of rootstock, and having to settle for second-best. Using the easy to propagate rootstock to skip on bearing royalties isn t always the cheaper option. Only choose this option if the situation calls for it. Commercial rootstocks may greatly outperform standard rootstocks in terms of yield, fruit size, and root and tree development. It all depends on which rootstock will be more adaptable to the conditions of that specific orchard. Clonal rootstocks can provide sad results due to: poor feeder root development, trees that weren t hardened off, or nursery trees with inadequate reserves to sustain performance in the orchard. This issue needs attention so clonal rootstocks don't get a bad reputation. Could growing rootstocks through tissue culture and growing nursery trees in bags improve the quality of trees and their orchard performance? Improving propagation methods requires attention. Producing nursery trees by seedlings provide good rooting and taproot trees, which can better withstand the transplant to the orchard. Previously, virus free Kakamas pips were abundantly available from canning factories. Kakamas isn't a preferred peach cultivar anymore, and pips aren t easily available. Pips can also mixed with those of other cultivars. The solution is to get virus free pips from trees planted from seed in mother blocks. When in the mother blocks, protect these trees from other trees to keep them virus free, genetically uniform and free from bacterial and fungal diseases. Presently, Kakamas seedling as rootstock provide limited adaptability to medium and high potential soil where no abiotic or nematode limitations occur. Guarantee genetic uniformity of horticultural and other traits by using clonal rootstocks in the stone fruit industry. Rootstocks like GF677 however, have a low take and rooting percentage from hardwood cuttings in the nursery; making it less economically viable for nurserypersons. It may also produce poor root systems without enough feeder roots, and can put the trees at risk when planted in the orchard especially in risky soil conditions, where irrigation is ineffective, and other poor management conditions. 20 Hortgro Science Fresh Quarterly, December 2018 December 2018, Fresh Quarterly Hortgro Science 21

12 CROP PRODUCTION STONE FRUIT ROOTSTOCKS To produce high quality nursery material with an effective feeder root system the industry must consider and evaluate any propagation methods (including tissue culture, and micro- or mini-propagation) and tree management system (bags, growing mediums, effective nutrient and water systems, netting structures and less handling) to promote fine root development, tree health and tree growth any effective and practical solution to provide the grower with high quality nursery material. Most nurseries find it difficult getting ideal nursery soils every year. Using bags with mediums that promote root formation, tree health, and development may be a good solution. It is imperative for growers to plant healthy trees with effective feeder roots, and to manage those trees optimally to prevent dieback or poor tree growth that affects the orchard performance. An orchard s first year determines its longterm potential. Don t spend money on soil preparation, draining systems, ridges, training and irrigation systems, and netting then neglect choosing the best suited rootstock and highest quality nursery material available to us. Improving propagation and using top quality rootstocks must be a priority to increase production, fruit quality, orchard health and tree development. What are the key characteristics of a good rootstock evaluator? This person must have the following: A good knowledge of fruit trees, and their problems and behaviour. A practical understanding of soils and soil related problems. The skill to combine all relevant aspects into practical information to benefit the grower. Excellent relationships with growers and nurserypersons, since the industry must trust the information and recommendations made available to them. What is your prediction for our stone fruit industry 30 years from now? Focussing on rootstocks and cultivation practices. I'm optimistic about the future. The industry has a generation of young innovative growers, keen to get and use research information, and who are prepared to invest in technology to optimise their fruit businesses. In the next few decades I see many rootstock breeding programs run by various research or private institutions; using intraspecific and interspecific crosses, and marker-assisted selections to identify specific advantageous genes. High potential rootstocks from current programs will be available. The plum industry is growing, and is a lucrative business for the committed grower. Climatic conditions and land availability may shift many of these plantings towards the Worcester, Robertson, Bonnievale and little Karoo regions. How would you like those in the stone fruit industry remember you for? My career spans over decades, and rootstock evaluation was a small part in my research career. Although the majority of my research is stone fruit based, I ve also done several studies on apples, and was fortunate to work with other committed researchers and fruit and soil specialists. During the 1970 s and 1980 s, I worked on improving the cultivation practices of stone fruit orchards. The importance of the autumn period in supporting the budding stage with its associated improvement in budding, flowering and fruit set of quality fruit was established. Studies on nitrogen timing and quantity of application on the spring development of the tree were conducted. The principles of achieving higher yield per unit surface area sooner through higher density plantings along with better light management by correct tree manipulation, training systems and summer pruning was developed. The importance of carbohydrate reserves and its employment for energy requirements and as carbon building blocks was studied in detail. I began the first rootstock evaluation program for peaches in 1971, and for plums in I would like to be remembered for all these contributions as the first steps on the path of developing a more scientific fruit industry, and for my commitment in helping fruit growers being successful. I want to pay tribute to all the researchers I ve worked with and the support from growers and the fruit industry. FQ Above: Plum rootstock trials in Robertson. Far right: GF 677 tissue culture plants in a growth medium in bags. Right: GF 677 cuttings produced in a growth medium in bags. Left: Plum rootstock trials. PHOTOS COURTESY OF DR PIET STASSEN. 22 Hortgro Science Fresh Quarterly, December 2018 December 2018, Fresh Quarterly Hortgro Science 23

13 CROP PRODUCTION STONE FRUIT ROOTSTOCKS RESEARCH INVENTORY A list of rootstock-related research projects and publications. This theme s articles was compiled using information from industry funded research. COMPLETED PROJECTS CURRENT PROJECTS Investigate the effect of stone fruit rootstocks on fruit quality of nectarines (Gustav Lötze) Comparative economic efficiency of training systems and rootstocks for Alpine nectarines (Piet Stassen) Evaluation of peach rootstocks for the South African fruit industry at Vaalwater, Limpopo (Iwan Labuschagne, Piet Stassen) Evaluation of peach rootstocks for South African fruit industry: Rawsonville planting (Slanghoek) (Iwan Labuschagne, Piet Stassen) Evaluation of plum rootstocks for the South African industry at Simondium (Keunenberg) (Iwan Labuschagne, Piet Stassen) 2010 Evaluation of apricot rootstocks (Piet Stassen, Hester de Wet, Gustav Lötze) 2010 Evaluation of peach rootstocks (Piet Stassen, Hester de Wet, Gustav Lötze) 2010 Evaluation of plum rootstocks (Piet Stassen, Hester de Wet, Gustav Lötze) Tolerance and susceptibility of commercial stone fruit rootstocks to plantparasitic nematodes (Piet Stassen, Freddy Rabothata) Determining the chill requirement of important stone fruit rootstocks available to the South African fruit industry (Laura Allderman) 2018 Evaluation of apricot rootstocks (Piet Stassen) 2018 Evaluation of peach rootstocks (Piet Stassen) 2018 Evaluation of plum rootstocks (Piet Stassen) Evaluation of plum rootstocks for South African fruit Industry: Robertson planting (Roodehoogte) (Iwan Labuschagne, Piet Stassen) PUBLICATIONS Scientific journal papers Stadler, J. D. & Stassen, P. J. C An evaluation of rootstocks for apricots on sandy soils. S. Afr. J. Plant Soil. 3, Scientific conference proceedings Stassen, P.J.C Rootstocks for stone fruits in South Africa. Acta Hort. 1130, Stassen, PJC., Wooldridge, J., Haasbroek, P.D. & Booyse, M Performance of 'African Delight' plums on several rootstocks and planted on two different soil situations. Acta Hort. 1058, Stassen, PJC., Wooldridge, J. & Booyse, M Rootstocks for Alpine nectarines on sandy, nematode-infested soils. Acta Hort. 1058, Stassen, PJC Performance of nectarine rootstocks on different soil types. Acta Hort. 903, Stassen, P.J.C. & Reinten, E.Y Performance of rootstocks for plums (Prunus salicina) on different soil types. Acta Hort. 903, Popular articles Please refer to the SA Fruit Journal and Die Krat as this list is extensive. FQ 24 Hortgro Science Fresh Quarterly, December 2018 December 2018, Fresh Quarterly Hortgro Science 25

14 POSTHARVEST FORELLE EARLY MARKET ACCESS Forelle Early Market Access: Unlocking new value from an old cultivar Words by Anna Mouton Forelle has been around for 350 years, says Dr Ian Crouch, director of research at ExperiCo. Historically it s been eaten as a sweet and juicy pear. But our problem was that Forelle becomes mealy if it s sold before it s had 12 weeks of cold storage. Forelle is a bicolour pear. A typical bicolour pear season starts with the export of varieties that don t have a chilling requirement, such as Rosemarie and Flamingo. In the past, there was then a hiatus until Forelle came out of cold storage. This gave other countries a chance to muscle in on the bicoloured pear market. The moment you have a break in continuity the supermarkets go to other exporters like Chile, explains Crouch. Once they have a supply and they re happy with the quality, they may not come back to South Africa. The 12-week cold storage period also put producers under pressure to pick as early as possible so as to export soonest. This led to harvesting of suboptimally mature fruit. We had a huge number of complaints from supermarkets about astringency, recalls Crouch. Astringency is the drying, puckering sensation in the mouth caused by tannins in green fruit. The problems didn t end with green fruit. At the end of the 12-week period, there was a glut of Forelle coming onto the market. The spike in volume crashed the price. No wonder that researchers tried everything to bring the Forelle season forward and close the gap. Harvest maturity, ethylene, cold shocks, hot shocks we just couldn t get it right, relates Crouch. A PEAR THAT EATS LIKE AN APPLE The solution came in thinking outside the box. What if consumers would accept a crisp pear instead of the traditional juicy Forelle? We let the pear hang on the tree for longer and we push the sugar so it s a sweet fruit and then we stop it ripening with SmartFresh [1-methylcyclopropene (1-MCP)], explains Crouch. You get a crisp sweet pear. Thus the Forelle Early Market Access program, or FEMA, was born. The biggest challenge was to sell this concept to the market, says Crouch. To sell a pear that eats like an apple initially we wondered whether we could do this. Forelle harvested later and treated with Smart- Fresh can be exported immediately without any risk of mealiness. You re putting fruit into the market earlier and getting a sustained price throughout the whole season. So now we start with FEMA fruit when Rosemarie and Flamingo come to an end. Extensive research showed that certain markets preferred FEMA fruit over traditional Forelle. In hot areas they were 100 percent for this program, because it s 40 degrees out there. With FEMA you don t get pears that overripen between the distribution center and the supermarket it s opened up new markets for us in the Middle and Far East. Managing consumer expectations at all stages of the Forelle season was critical. On each of the FEMA pears we had a little sticker that said, Crisp and sweet. But the rest of the Forelle come in after 12 weeks and these are soft and juicy, explains Crouch. You have a crossover period when the fruit this week is totally different from last week. You have to make sure people know what they re getting. Crouch admits that the FEMA pear is his personal favourite, I love the crisp and sweet fruit. Juicy fruit have a risk of being either astringent or mealy and both those are bad eating experiences. BENEFITS AND CHALLENGES In the past, the 12-week cold storage period motivated producers to harvest as soon as their orchard or area was released. With the FEMA program, we take the pressure off people to harvest earlier. Once you have your normal release, the fruit can remain on the trees for maybe another two weeks and then you may get a FEMA release, explains Crouch. If you have a FEMA release, you could be in the market five or six weeks earlier than usual. Because fruit is in the market earlier, the price is sustained throughout the whole season. And the FEMA fruit lasts longer so you can maintain quality as well. If you have a slow market, you don t need to discard fruit you have that buffer to ride through the slower market until it picks up again. The FEMA program has been instrumental in growing the market for Forelle exports. It s opened new markets and improved the price. It s had a huge impact Forelle is now our second-largest cultivar and people are still planting Forelle. But the FEMA program does present its own challenges. Some farmers are putting all their orchards into the race. The first orchards that make the FEMA grade are fine, but they might have pushed other orchards a little past where they should have been picked for the 12-week cold storage, cautions Crouch. The challenge is to ensure that you look after your whole Forelle program on farm. Don t compromise fruit that don t make the FEMA grade. If you do have fruit that are a little bit too mature than you can still treat them with SmartFresh and sell them as your last Forelle fruit. So even if you put all your orchards forward you don t want to end up with pears that are overripe and have internal issues and limited storage capability. FQ You re putting fruit into the market earlier and getting a sustained price throughout the whole season. 26 Hortgro Science Fresh Quarterly, December 2018 December 2018, Fresh Quarterly Hortgro Science 27

15 POSTHARVEST FORELLE EARLY MARKET ACCESS RESEARCH INVENTORY CURRENT PROJECTS A list of Forelle Early Market Access research projects and publications. This theme s articles was compiled using information from industry funded research. COMPLETED PROJECTS 2002 Temperature manipulation of Forelle pears to reduce the storage period (P de Vries) 2005 Post harvest physiology of Forelle pears, with emphasis on woolliness (D Holcraft, M Huysamer) To assess internal browning development potential from high water core incidence FEMA Forelle (D Viljoen) NEW PROJECTS Revision of FEMA release standards when fruit do not make FEMA firmness or sugar criteria (S Daiber) To develop marketing protocols for FEMA designated orchards that are harvested two to three weeks after normal release but do not qualify for FEMA release (S Daiber) 2009 Determine the benefits of using SmartFresh TM on storage quality of optimum and post optimum harvested Forelle pears (H Bergman, M Taylor) 2010 Treatment of Forelle pears to shorten the prescribed storage period (E Crouch) 2012 Evaluation of MAP and other technologies to improve storage quality of Forelle pears and decrease the 12 week mandatory storage period (S van Zyl, M Taylor, D Moelich) Effects of short term CA storage and a simulated RA shipment period on the poststorage eating quality of Forelle pears (K van der Merwe) Early market access of Forelle pears to EU market using SmartFresh SM and targeted maturity fruit (I Crouch) Determine the optimal maturity for late harvested Forelle pears, to establish early market access, utilising SmartFresh SM (I Crouch, H Berman) MEALY FORELLE PEAR. PHOTO: DR IAN CROUCH 2016 To determine the minimum flesh firmness that FEMA fruit can be exported without becoming overripe after storage, and to determine the effect of extended storage of FEMA fruit [stock rolling] (I Crouch) 2016 To determine the maximum delay in SmartFresh SM application from harvest to room filling for fruit destined for the FEMA programme (I Crouch) 2016 To determine if pear cultivars, other than Forelle can be successfully cold stored using the FEMA model by harvesting fruit at a more advanced maturity and then retarding ripening through the use of SmartFresh SM (I Crouch) 2018 To determine the effect of sugar/acid ratio and other maturity indices on the eating quality of Forelle pears destined for the FEMA programme, as a means of improving the FEMA release criteria (S Daiber) 28 Hortgro Science Fresh Quarterly, December 2018 December 2018, Fresh Quarterly Hortgro Science 29

16 FRESH TAKE COLUMN A MEANDER ALONG SOUTH AFRICA'S CA STORAGE ROAD following Words by Richard Hurndall the first commercial Controlled Atmosphere (CA) cold storage room in Kent, UK in 1929, Molteno Brothers built a 7 room complex in 1934, each room holding about 6000 wooden lug boxes of apples. This complex was enlarged to lugs capacity, making it one of the largest CA installations in the world at the time. It was initially impossible to make these rooms fully gas-tight, but they achieved storage conditions of 3,3 degrees C, 8% O2 and 5% CO2. Apparently the operator became quite breathless when he went inside to change lime, examine the fruit and inspect the ammonia coils! Nevertheless the marketing of Ohenimuri apples could be extended to August, and Winter Pearmain to September. This was followed in 1936 by a lug capacity 4-room complex by the Elgin Fruit Company (now Two-A- Day). With the advancement of Regular Atmosphere (RA) storage in the 1950 s and 1960 s, first using central ducts for air circulation, and later false ceilings, there was a great improvement in the out-turn of fruit from RA storage, and CA storage consequently took a back seat. While the rest of the world steadily increased their CA capacity, it was only in the late 1970 s that local interest was rekindled in CA storage. In 1979, a delegation comprising growers, cold-store operators, consulting engineers, and postharvest technologists visited CA storage facilities in Europe, Israel, UK and USA. They returned with a vast amount of information and the latest technology, which helped considerably to rapidly establish CA storage as a viable enterprise in South Africa. The first exports of fruit from CA stores took place in CA capacity increased rapidly, and by 2000, the capacity had increased to over tons. A technical working group was established in 1978, and subsequently became the CA Storage and Postharvest Group in The group was taken under the wing of the SA Apple and Pear Producers Association in At the time of my introduction into the industry in 1983, John Findlay was the enthusiastic chairman of the group. John s mantra was that members were there to share their mistakes, as that was the quickest way to learn. Subsequent chairmen included Albert Schultz (Ceres Koelkamers) and Piet van Bodegom (Kromco). The CA Group used to meet twice annually, once in the production regions where the latest technology was viewed, and an AGM in November at Infruitec where there the fruit of various CA storage trials was displayed. Research was always a strong focus of the group, and to this end SAAPPA donated experimental chambers to the Agricultural Research Council (8 in 1982 and a further 4 in 1988; capacity 15.6m3). Under SAAPPA s auspices, this body issued a quality assurance mark in the form of a CA label. The SAAPPA CA label guaranteed that the fruit was packed and stored under optimum CA storage conditions. It was issued only to registered members of the CA group whose CA stores had passed an annual evaluation and had been registered by the PPECB in accordance with the Perishable Products Export Control Act, 1983 (Act no. 9). The annual evaluation ascertained whether CA rooms of members complied in all respects with the recommended CA storage conditions under which apples and pears should be held to attain a product of high quality. The evaluations were conducted by Bertie Truter, and subsequently Kobus van der Merwe of the Agricultural Research Council. If the CA stores observed the relevant criteria, permission was granted for the use of the CA label. This was used in the form of a label, rubber stamp or printed on the carton and the wording Guaranteed packed and stored according to SAAPPA Controlled Atmosphere Regulations. SAAPPA is the registered patent holder of the CA mark. Any reproduction was an infringement of the copyright. The design allowed for an individual number, which was an inspection number given to all registered producers, to be printed on the label. The inspection number facilitated the follow-up of transgressors. The annual inspections, of course, led to much rivalry between organisations, as the CA trophy was awarded to the best storage operation at the annual AGM meeting. These procedures led to an extremely high standard of safety and operational efficiency, which was probably unique in the world. Apart from the sharing of information, one of the major outputs of the CA Group was the CA Manual, available on the Hortgro website. With the advent of deregulation in 1997, the CA Group was disbanded. Consultants now conduct inspections of CA stores upon request. Marketing operations now have their own internal quality management systems and market their fruit under their respective brands. Dynamic Controlled Atmosphere (DCA) experts were brought in in the intervening years to facilitate the introduction of this technology into the industry. This included the co-founder of the DCA technology, Dr Robert Prange of Canada s Agriculture and Agri-Food Research and Development Centre, and Dr Angelo Zanella (Laimburg, Italy), the foremost implementer of the DCA technology on a large scale. The CA Group was revived in 2015, under the auspices of the Packhouse Action Group, and an annual meeting is held to give research feedback to the industry, as well as to showcase new technology. A local CA operator s tour was held in EGVV region in 2016 to view 2 different CA storage technologies. SAAP- PA, now Hortgro Pome, donated CA research equipment of 3 CA suppliers to Stellenbosch University in 2018, to increase the research capacity in the industry. FQ 30 Hortgro Science Fresh Quarterly, December 2018 December 2018, Fresh Quarterly Hortgro Science 31