Disease Clinic

Avocado cultivation faces a myriad of challenges due to the prevalence of pathogens and pests, ranging from the notorious Phytophthora root rot to the elusive Avocado Sunblotch Viroid. The resilience of avocado orchards against these threats relies on the early and accurate diagnosis of these diseases. Recognizing this critical need, the ARP Disease Clinic emerges as a beacon of support for avocado growers in South Africa, with a variety of diagnostic services tailored to pinpointing avocado diseases. Our mission is clear: to empower growers with the knowledge and tools necessary to combat existing threats and to stay vigilant against emerging ones. Through our efforts, we endeavor to ensure that South Africa's avocado industry remains resilient and poised to tackle the ever-evolving landscape of avocado pathogens. Contact us today for further information or a quote and let us partner in protecting the future of your avocado orchards.

 

 

How to sample for submissions?

  • Identify diseased plant/s.

  • Identify the symptoms (wilt, death, cankers, root rot, die-back etc.).

  • Identify any environmental link to the symptoms, if possible.

  • Take photographs of the symptoms, if possible.

  • Samples should be taken from 4-5 randomly selected plants in an infection site.

  • Package the samples separately in appropriate packaging (specified below) and label with the following: Collectors name, date, sample number, locality and cultivar.

  • Complete online FABI Diagnostic Clinic: Sample Information Sheet.

  • Pack samples in a sturdy box and send with the Sample Information Sheet to the Avocado Disease Clinic.

 

Specific tissue sampling

 

Leaves

  • Collect individual leaves, place between blotting paper (paper towel), seal in an envelope and label the sample.

 

Stems/Branches

  • Collect a sample that spans the diseased area, including +/- 2cm of healthy tissue on either side of the lesion.

  • Place in a paper bag/ envelope and label the sample.

 

Roots/Soil

  • Collect 150-300g of soil from under the diseased tree at a depth of 10-15 cm, seal in a plastic bag and label the sample.

  • Collect root pieces (healthy and diseased) from the soil and seal in an envelope.

 

Online submission: FABI - ARP Diagnostic Clinic: Sample Information Sheet

 

Send the samples by fast mail or courier to the Avocado Disease Clinic @ FABI, give us a phone call and email to let us know to expect a parcel from you.

 

Disease Information Sheets

 Phytophthora cinnamomi

 

 Dematophora necatrix

                         

             

Avocado Sunblotch Viroid

         

Ambrosia beetles

 

Armillaria root rot

 

Avocado branch canker

 

 

Contact Details

 

FABI - Clinic Manager - Dr. Lieschen De Vos

Tel: +27 (012) 420 3938/5826

Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

ARP - Clinic Manager - Ms Alicia Vermeulen

Tel: +27 (012) 420 3177

Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
Address:
Lunnon Road
University of Pretoria
FABI - Avocado Disease Clinic
Hatfield, Pretoria
South Africa
0002

ARP Group Leader

Prof Noelani van den Berg

Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

 

 

New Publications

Hlongwane NL, Dzomba EF, Hadebe K, van der Nest MA, Pierneef R, Muchadeyi FC. (2024) Identification of signatures of positive selection that have shaped the genomic landscape of South African pig populations. Animals 14:235. 10.3390/ani14020236
De Vos L, van der Nest MA, Santana QC, van Wyk S, Leeuwendaal KS, Wingfield BD, Steenkamp ET. (2024) Chromosome-level assemblies for the pine pitch canker pathogen Fusarium circinatum. Pathogens 13(1):70. 10.3390/pathogens13010070
Joubert M, van den Berg N, Theron J, Swart V. (2024) Global transcriptomic analysis in avocado nursery trees reveals differential gene expression during asymptomatic infection by avocado sunblotch viroid (ASBVd). Virus Research 339:199263. 10.1016/j.virusres.2023.199263. PDF
Anbu SP, Swart V, van den Berg N. (2023) Unmasking the invaders: NLR-mal function in plant defense. Frontiers in Plant Science 14:1307294. 10.3389/fpls.2023.1307294 PDF
Backer R, Naidoo S, van den Berg N. (2023) The expression of the NPR1-dependent defense response pathway genes in Persea americana (Mill.) following infection with Phytophthora cinnamomi. BMC Plant Biology 23(1):548. 10.1186/s12870-023-04541-z PDF
Kooverjee BB, Soma P, van der Nest MA, Scholtz MM, Neser FWC. (2023) Copy Number Variation Discovery in South African Nguni-Sired and Bonsmara-Sired Crossbred Cattle. Animals 13(15):2513. 10.3390/ani13152513
Dzomba EF, Van der Nest MA, Mthembu JNT, Soma P, Snyman MA, Chimonyo M, Muchadeyi FC. (2023) Selection signature analysis and genome-wide divergence of South African Merino breeds from their founders. Frontiers in Genetics 13:932272. 10.3389/fgene.2022.932272
Wingfield BD, Berger DK, Coetzee MPA, Duong TA, Martin A, Pham NQ, Van den Berg N, Wilken PM, Arun-Chinnappa KS, Barnes I, Buthelezi S, Dahanayaka BA, Durán A, Engelbrecht J, Feurtey A, Fourie A, Fourie G, Hartley J, Kabwe ENK, Maphosa M, Narh Mensah DL, Nsibo DL, Potgieter L, Poudel B, Stukenbrock EH, Thomas C, Vaghefi N, Welgemoed T, Wingfield MJ. (2022) IMA genome‑F17 Draft genome sequences of an Armillaria species from Zimbabwe, Ceratocystis colombiana, Elsinoë necatrix, Rosellinia necatrix, two genomes of Sclerotinia minor, short‑read genome assemblies and annotations of four Pyrenophora teres isolates from barley grass, and a long-read genome assembly of Cercospora zeina. 13:19. 10.1186/s43008-022-00104-3
Swalarsk Parry BS, Steenkamp ET, Van Wyk S, Santana QC, van der Nest MA, Hammerbacher A, Wingfield BD, De Vos L. (2022) Identification and characterization of a QTL for growth of Fusarium circinatum on pine-based medium. Journal of Fungi 8(11):1214. 10.3390/jof8111214
Wienk R, Mostert‑O’Neill M, Abeysekara N, Manosalva P, Freeman B, van den Berg N. (2022) Genetic diversity, population structure and clonal verification in South African avocado cultivars using single nucleotide polymorphism (SNP) markers. Tree Genetics and Genomes 18(41) 10.1007/s11295-022-01573-8 PDF