South African Avocado Growers’ Association
2017 Yearbook
Volume 40

Table of Contents

5    CHAIRMAN’S REPORT / VOORSITTERSVERSLAG

     K Eloff

GENERAL

8    SAAGA’s Golden Anniversary: A 50 years perspective on research trends and future opportunities

     J Bezuidenhout

PATHOLOGY

18    Reducing reliance on phosphonates for managing Phytophthora root rot

        EK Dann, AW Whiley, D Armour and KG Pegg

24    Three “other” diseases impacting avocado productivity in Australia

        EK Dann and L Parkinson

28    Residue testing of avocado trees treated with phosphorous acid-based trunk injections for the control of Phytophthora cinnamomi

        M Grobler, JB Meyer and ZV Hlatshwayo

32    The dissemination of fungal pathogens on avocado trees in South Africa with reference to vector potential of insect pests

        J Coertzen and De Villiers Fourie

36    Bacterial dynamics and the prevalence of foodborne pathogens associated with avocado fruit Persea americana Mill.

        C Coetzee, E du Plessis, S Duvenage and L Korsten

42    Evaluating phosphite concentrations in avocado tree roots following phosphonate applications – Preliminary report

        A McLeod, P Novela, SL Masikane, P Mohale, P Pieterse and JPB Wessels

ENTOMOLOGY

48    Distribution, isolation and diversity of entomopathogenic nematodes from the north-eastern parts of South Africa and their biocontrol potential against the false codling moth, Thaumatotibia leucotreta (Lepidoptera: Tortricidae)

        WP Steyn, AP Malan, MS Daneel and R Slabbert

54    The successes of stink bug research and the Stink Bug Working Group in the Southern African avocado and macadamia industries

        GP Nortjé, A Botha, SP Schoeman and BM Botha

60    Innovations for the control of the coconut bug in avocado

        PS Schoeman

64    The correlation between fruit fly numbers trapped and damage levels in avocado orchards

        T Grové

70    Identification of a pheromone blend for the control of stink bug

        BM Botha

TABLE OF CONTENTS

POSTHARVEST

72    Prochloraz – a look into factors affecting the variability of residue levels on avocado fruit

        MS Daneel, A Sippel, MS de Beer and J Mlimi

78    Upgrading the ‘Maluma’ avocado export protocol: Determining the maximum allowable period from harvest to cooling and the (pre-harvest fruit quality dependent) maximum storage period

        FJ Kruger, D Lemmer, GO Volschenk, P Pieterse, W Retief, P Novela, A Ernst, B Snijder and E Volschenk

82    Further observations on the improvement of the late season marketing potential of ‘Lamb Hass’ avocado fruit

        FJ Kruger, D Lemmer, GO Volschenk, B Nzanza, P Pieterse, W Retief, P Novela and E Volschenk

88    Photo-selective nettings to improve postharvest fruit quality of avocados cv. Hass

        PP Tinyane, Z van Rooyen and D Sivakumar

92    Observations made during the 2016 season regarding certain factors that influence the ripening of South African avocado fruit

        FJ Kruger, E Volschenk and GO Volschenk

96    Further observations on the manifestation of certain physiological disorder variants in ‘Hass’ and ‘Maluma’ avocado fruit

        FJ Kruger, D Lemmer, A Ernst, B Snijder, E Volschenk and GO Volschenk

103 Using plant volatiles in biodegradable sachets and exposure of volatiles under pallet covers to control postharvest decay in avocados

       CP Obianom, L Korsten, Z van Rooyen and D Sivakumar

108 Carboxyl methylcellulose (CMC) containing moringa plant extracts as new postharvest organic edible coating for avocado (Persea americana Mill.) fruit

        SZ Tesfay, LS Magwaza and A Mditshwa

HORTICULTURE

117 Finding the best polliniser for ‘Hass’ avocado and the effect of bees as pollinators

        MM Bezuidenhout, ES du Toit and PJ Robbertse

123 Growing avocados under shade netting

        WA Stones, Z van Rooyen and JS Köhne

129 Complexities of ‘Hass’ avocado skin colour change during ripening

        N Mathaba, S Mathe, TP Mafeo, SZ Tesfay and J Mlimi