South African Avocado Growers’ Association
2019 Yearbook
Volume 42

Table of Contents

5 CHAIRMAN’S REPORT / VOORSITTERSVERSLAG

A Currie

PATHOLOGY

6 Using phosphonate foliar sprays for managing Phytophthora root rot in avocado

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

12 Validating spray timing for Cercospora spot

MH Schoeman and R Kallideen

22 Microbial biomes of South African avocado fruit

F Viljoen, M Bill, Z van Rooyen, P Novela, L Chidamba and L Korsten

30 Avocado sunblotch viroid in South Africa: Present status and future prospects

AEC Jooste, L Mataung, Z Zwane and A Msweli

34 Assessing the effect of rootstock and number of trunk injections on Phytophthora cinnamomi root DNA quantities in avocado

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

HORTICULTURE

41 Pollination: In vitro, in nets and open trees; avocado flower characteristics and bee activity

ES du Toit, MM Bezuidenhout, MS Stanton and PJ Robbertse

48 Water use of avocado orchards – Year 2

E Mazhawu, AD Clulow, MJ Savage and NJ Taylor

52 Report on the incidence of diseases (anthracnose, stem-end rot) and physiological disorders in ‘Hass’ avocado from Tzaneen region

H Fotouo-M, M Glowacz, D Lemmer and D Sivakumar

58 Soil health and the soil biota

JJ Bezuidenhout

ENTOMOLOGY

72 Controlling the false codling moth, Thaumatotibia leucotreta (Meyrick) with entomopathogenic nematodes

WP Steyn, MS Daneel and AP Malan

76 Quantifying and controlling thrips and scales in avocado

PS Schoeman and L Linda

POSTHARVEST

82 Further observations on the development of a total soluble solids (TSS) based maturity / ripening-efficacy measurement tool for South African avocado fruit

FJ Kruger, GO Volschenk and L Volschenk

86 Laboratory investigation into the effect that the time period between harvest and the application of a balanced atmosphere has on the quality and ripening patterns of South African export avocado fruit (with some comparative SmartFresh results)

FJ Kruger, GO Volschenk and L Volschenk

92 Development of intermittent balanced atmosphere conditions for South African export avocados using currently available logistics

FJ Kruger, GO Volschenk and L Volschenk

96 Managing the ‘Maluma’ avocado’s response to storage, ripening and post-ripening temperature settings

FJ Kruger, GO Volschenk and L Volschenk

100 Further observation and recommendations on the manifestation and control of vascular staining and grey pulp in ‘Maluma’ avocado fruit

FJ Kruger, GO Volschenk and L Volschenk

106 Packhouse misting of prochloraz: Concentrations and other influencing factors

MS Daneel and A Sippel

110 First results from a study aimed at quantifying the effects that ridges have on the yield and fruit quality of ‘Hass’ avocado

FJ Kruger, GO Volschenk and L Volschenk