South African Avocado Growers’ Association
2018 Yearbook
Volume 41

Table of Contents

5 CHAIRMAN’S REPORT / VOORSITTERSVERSLAG

A Currie

ENTOMOLOGY

6 Entomopathogenic nematodes (EPNs) – Update of research on avocados and the way forward

WP Steyn, MS Daneel, AP Malan and R Slabbert

12 Relative numbers of fruit fly species in avocado orchards

T Grové

22 Integrated management of avocado pests with special reference to the coconut bug Pseudotheraptus wayi (Hemiptera: Coreidae)

PS Schoeman and L Linda

26 Finding the best pollinizer for ‘Hass’ avocado and the effect of bees as pollinators

MM Bezuidenhout, ES du Toit and PJ Robbertse

HORTICULTURE

37 Water use of avocado orchards – Year 1

E Mazhawu, A Clulow, MJ Savage and NJ Taylor

42 Influence of photo-selective shade nettings to improve fruit quality at harvest and during postharvest storage

PP Tinyane, D Lemmer and D Sivakumar

PATHOLOGY

50 Optimizing foliar phosphonate sprays for the preventative management of Phytophthora root rot on avocado – Preliminary report

SL Masikane, P Novela, JB Jolliffe, P Mohale, P Pieterse and A McLeod

58 The temporal nature of Phytophthora cinnamomi colonisation in avocado roots – Preliminary report

JB Jolliffe, EK Dann, SL Masikane, P Novela, P Mohale and A McLeod

64 The South African Phytophthora trail and the way forward

JJ Bezuidenhout

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

De V Fourie and J Coertzen

86 Cercospora spot on avocado – A preliminary report on the relook at the epidemiology of the pathogen

MH Schoeman and R Kallideen

92 Alternatives to synthetic fungicides to control postharvest diseases of avocados – Commercial trials with thyme oil vapours

M Bill, M Jongman, Z van Rooyen, S Mhlophe, D Sivakumar and L Korsten

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

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

106 Report on Avocado sunblotch viroid studies in South Africa

AEC Jooste and ZR Zwane

POSTHARVEST

110 Maluma avocado: Relationship between seed coat condition, orchard nitrogen status and grey pulp

FJ Kruger, GO Volschenk and L Volschenk

115 Towards the development of a total soluble solids (refractometer) based maturity measurement and ripening prediction procedure for avocado fruit

FJ Kruger, GO Volschenk and L Volschenk

118 Investigating the pre-harvest factors associated with the postharvest quality of ‘Hass’ avocados exported to the UK

M Glowacz, D Lemmer and D Sivakumar

124 Protocol for ripening avocados on commercial scale

JJ Bezuidenhout

126 The combined effect of edible coating and ozonated cold storage in avocado (Persea americana Mill.) fruit quality

SZ Tesfay, LS Magwaza and A Mditshwa