Publications – Disease Management

GRAFT TRANSMISSIBLE DISEASES

Aldrich, D.J., Bester, R., Cook, G., Burger, J.T., and Maree, H.J. 2021. Evaluating high-resolution computed tomography to study citrus tristeza virus-induced stem pitting. Journal of Citrus Pathology. 8(1). DOI: 10.5070/C481050093

Aldrich, D.J., Kriel, J., Bester, R., Burger, J.T., and Maree, H.J. 2024. Applying volumetric electron microscopy to visualize xylem tissue impacted by citrus tristeza virus-induced stem pitting. Journal of Citrus Pathology. 11(2). DOI:10.5070/C411262569

Aldrich, D.J., Taylor, M., Bester, R., El-Mohtar, C.A., Burger, J.T. and H.J. Maree. 2024. Applying infectious clones and untargeted metabolite profiling to characterize citrus tristeza virus-induced stem pitting in citrus. Scientific Reports. 14:28490, 1-15. DOI: 10.1038/s41598-024-79402-2

Bester, R., and Maree, H.J. 2024. Validation of high-throughput sequencing (HTS) for routine detection of citrus viruses and viroids. Methods in Molecular Biology, 2732. Viral Metagenomics: Methods and Protocols 2^nd Eds. Pantaleo, V. and Miozzi, L. Springer Science and Business Media, New York. 2732, 199-219. DOI: 10.1007/978-1-0716-3515-5_14

Bester, R., Cook, G., and Maree, H.J. 2021. Citrus tristeza virus genotype detection using high-throughput sequencing. Viruses. 13, 168. DOI: 10.3390/v13020168

Bester, R., De Bruyn, R., Cook, G., Breytenbach, J.H.J., Steyn, C., and Maree, H.J. 2021. Towards the validation of high-throughput sequencing (HTS) for routine plant virus diagnostics: Measurement of variation linked to HTS detection of citrus viruses and viroids. Virology Journal. 18:61. DOI: 10.1186/s12985-021-01523-1

Bester, R., Karaan, M., Cook, G., and Maree, H.J. 2021. First report of citrus virus A in citrus in South Africa. Journal of Citrus Pathology. 8 (1). DOI: 5070/C481049000

Bester, R., Steyn, C., Breytenbach, J.H.J., De Bruyn, R., Cook, G., and Maree, H.J. 2022. Reproducibility and Sensitivity of High-Throughput Sequencing (HTS)-Based Detection of Citrus Tristeza Virus and Three Citrus Viroids. Plants. 11, 1939. DOI: 10.3390/plants11151939

Bougard, K., Maree, H.J., Pietersen, G., Meitz- Hopkins, J. C., and Bester, R. 2022. First report of coguvirus eburi infecting pear (Pyrus communis) in South Africa. Plant Disease. 106 (2), 772. DOI: 10.1094/PDIS-08-21-1630-PDN

Cook, G., Breytenbach, J.H.J., Steyn, C., De Bruyn, R., Burger, J.T., and Maree, H.J. 2021. Grapefruit field trial evaluation of citrus tristeza virus T68-strain sources. Plant Disease. 105 (2), 361-367. DOI: 10.1094/PDIS-06-20-1259-RE

Cook, G., Coetzee, B., Bester, R., Breytenbach, J.H.J., Steyn, C., De Bruyn, R., Burger, J.T., and Maree, H.J. 2020. Citrus tristeza virus isolates of the same genotype differ in stem pitting severity in grapefruit. Plant Disease. 104, 2362-2368. DOI: 10.1094/PDIS-12-19-2586-RE

Cook, G., Van Vuuren, S.P., Breytenbach, J.H.J., Burger, J.T., and Maree, H.J. 2016. Expanded strain specific RT-PCR assay used to profile citrus tristeza virus (CTV) sources used for cross-protection in the South African Citrus Improvement Scheme. Journal of Phytopathology. 164, 847–851. DOI: 10.1111/jph.12454

De Bruyn, R., Bester, R., Cook, G., Steyn, C., Breytenbach, J.H.J., and Maree, H.J. 2022. Distribution and genetic diversity of Coguvirus eburi in South African citrus and the development of a real-time RT-PCR assay for citrus-infecting coguviruses. Plant Disease. 106 (8), 2221-2227. DOI: 10.1094/PDIS-11-21-2409-RE

Fuchs, M., Bar-Joseph, M., Candresse, T., Maree, H.J., Martelli. G.P., Melzer, M.J., Menzel, W., Minafra, A., Sabanadzovic, S., and ICTV Report Consortium. 2020. ICTV Virus Taxonomy Profile: Closteroviridae. Journal of General Virology. 101:364–365. DOI: 10.1099/jgv.0.001397

Jooste, T.L., Visser, M., Cook, G., Burger, J.T., and Maree, H.J. 2017. In Silico Probe-Based Detection of Citrus Viruses in NGS Data. Phytopathology. 107 (8), 988-993. DOI: 10.1094/PHYTO-10-16-0379-R

Khalilzadeh, M., Aldrich, D.J., Maree, H.J., and Levy, A. 2025. Complex interplay: The interactions between citrus tristeza virus and its host. Virology. 603, 110388. DOI: 10.1016/j.virol.2024.110388

Ruiz-García, A.B., Bester, R., Olmos, A., and Maree, H.J. 2019. Bioinformatic tools and genome analysis of Citrus tristeza virus. Methods in Molecular Biology 2015. Citrus tristeza virus: Methods and Protocols. Eds. Catara, A.F., Bar-Joseph, M., Licciardello, G. Springer Science and Business Media, New York. 163-178. ISBN 978-1-4939-9557-8. DOI: 10.1007/978-1-4939-9558-5_12

Steyn, C., Cook, G., Burger, J.T., and Maree, H.J. 2016. Construction and application of infectious citrus viroids for biological indexing. Journal of Citrus Pathology. 3. iocv_journalcitruspathology_37092. DOI: 5070/C431037092

Visser, M., Burger, J.T., and Maree, H.J. 2016. Targeted virus detection in next-generation sequencing data using an automated e-probe based approach. Virology. 495,122-128. DOI: 10.1016/j.virol.2016.05.008

Visser, M., Bester, R., Burger, J.T., and Maree, H.J. 2016. Next-generation sequencing for virus detection: covering all the bases. Virology Journal. 13:85. DOI 10.1186/s12985-016-0539-x

Visser, M., Cook, G., Burger, J.T., and Maree, H.J. 2017. In Silico analysis of grapefruit gene regulation in response to CTV and CDVd coinfection. Virology Journal. 14:200. DOI: 10.1186/s12985-017-0871-9

HLB

Da Graça, J.V., Cook, G., Ajene, I.J., Grout, T.G., Pietersen, G., Roberts, R., Bester, R., Pretorius, M.C., and Maree, H.J. 2022. A review of the ‘Candidatus Liberibacter africanus’ citrus pathosystem in Africa. Focus issue: Liberibacter Pathosystems. Phytopathology. 112 (1), 44-54. DOI: 10.1094/PHYTO-07-21-0296-FI (front page)

Fourie, P.H., Kirkman, W., Cook, G., Steyn, C., De Bruyn, R., Bester, R., Roberts, R., Jose, C., Bassimba, D., and Maree, H.J. 2021. First report of ‘Candidatus Liberibacter africanus’ from Citrus in Angola. Plant Disease. 105 (2), 486. DOI: 1094/PDIS-06-20-1392-PDN

Roberts R, Cook G, Grout TG, Khamis F, Rwomushana I, Nderitu PW, Seguni Z, Materu CL, Steyn C, Pietersen G, Ekesi S, le Roux HF. 2017. Resolution of the Identity of ‘Candidatus Liberibacter’ Species From Huanglongbing-Affected Citrus in East Africa. Plant Disease 101, 1481-8.

PRE-HARVEST

Carstens et al. 2021. Spatial and Temporal Genetic Analyses of Phyllosticta citricarpa in Two Lemon Orchards in South Africa Reveal a Role of Asexual Reproduction Within Sexually Reproducing Populations. https://doi.org/10.1094/PHYTO-05-20-0203-R

Coetzee et al. 2021. Discerning the global phylogeographic distribution of Phyllosticta citricarpa by means of whole genome sequencing. Fungal Genetics and Biology 162 (2022) 103727. https://doi.org/10.1016/j.fgb.2022.103727

Coetzee et al. 2021. Extending the knowledge of Phyllosticta citricarpa population structure in USA with re-sequencing and genome wide analysis . https://doi.org/10.1016/j.pmpp.2020.101591

Coetzee, B., Carstens, E., Schutte, G.C., Basson, E., Groeneveld, M.J., Mpholo, T., Moyo, P., Winn, J.C., Fourie, P.H. and Bester-van der Merwe, A.E. 2022. An allele-specific PCR assay for detection of mutations that confer benzimidazole resistance and zoxamide sensitivity in Phyllosticta citricarpa. South African Journal of Plant and Soil. https://doi.org/10.1080/02571862.2023.2185693

de Oliveira Fialho, R., Moyo, P., Fourie, P.H., Lanza, F.E., Machado, F.J. and Amorim, L., Silva-Junior, G.J. 2022. Citrusblack spot intensity and yield losses on sweet orange are affected by Phyllosticta citricarpa inoculum concentration andfruit developmental stage. Plant Pathology 71: 1606-1618. https://doi.org/10.1111/ppa.13586

de Oliveira Fialho, R., Pereira, R.G., Brandão, L.A., Martins, E.C., Primiano, I.V., Fourie, P.,Moyo, P., Amorim, L.A. and Silva Junior, G.J. 2024. Monitoring of Phyllosticta citricarpa in sweet orange orchards using molecular analysis and young citrus trees as spore traps. Plant Pathology 73: 2382-2394. https://doi.org/10.1111/ppa.13996

Gottwald et al. 2021. Probabilistic risk-based model for the assessment of Phyllosticta citricarpa-infected citrus fruit and illicit plant material as pathways for pathogen introduction and establishment. Crop Protection 142. https://doi.org/10.1016/j.cropro.2020.105521

Guarnaccia et al. 2019. Phyllosticta citricarpa and sister species of global importance to Citrus. Molecular Plant Pathology 20(12), 1619–1635. https://doi.org/10.1111/mpp.12861

J.M. van Niekerk, E. Basson, C. Olivier and A. McLeod. 2016. Mefenoxam sensitivity of Phytophthora citrophthora and P. nicotianae isolates in South African Citrus Nurseries. 13th International Citrus Congress, 18 – 23 September 2016, Mabu Thermas & Resort Foz do Iguaçu, PR – Brazil.

J.M. van Niekerk, C. Olivier, E. Basson and A. McLeod. Variation in mefenoxam sensitivity among Phytophthora spp. isolates from South African citrus nurseries. 9th Citrus Research Symposium, 23 August 2016, Champagne Sports Resort, Drakensburg, South Africa.

J.M. van Niekerk. 2017. Soil fumigation in citrus replant situations – making informed decisions. SA Fruit Journal April/May 2017: 56 – 58

J. van Niekerk, C. Kotze, J. North and P. Cronje. 2018. Effect of phosphonate applications, for Phytophthora Brown Rot Control, on ‘Nadorcott’ mandarin external fruit quality. Horttechnology 28(4): 470 – 475

J.M. van Niekerk, Charl Kotze, Jade North and Paul Cronje. 2018. Effect of phosphonate applications, for Phytophthora Brown Rot Control, on ‘Nadorcott’ mandarin external fruit quality. SA Fruit Journal Oct/Nov 2018: 70 – 73

J.M. van Niekerk, E. Basson, C. Olivier, G. Carelse and V. Guarnaccia. 2020. Chlorine and mefenoxam sensitivity of Phytophthora nicotianae and Phytophthora citrophthora from South African citrus nurseries. Phytopathologia Mediterranea 58: 629 – 638.

J.M. van Niekerk, Elaine Basson and Charmaine Olivier. 2020. Phosphonate application effects on growth of citrus seedlings and root infections by Phytophthora nicotianae. SA Fruit Journal Aug/Sept 2020: 57 – 60.

Moyo P, Du Raan S and Fourie PH. 2020. Models for predicting pseudothecium maturity and ascospore release of Phyllosticta spp. in South African citrus orchards. S Afr J Sci.: 116(11/12).

Moyo P, Fourie PH, Masikane SL, de Oliveira Fialho R, Mamba LC, du Plooy W, Hattingh V. 2020. The Effects of Postharvest Treatments and Sunlight Exposure on the Reproductive Capability and Viability of Phyllosticta citricarpa in Citrus Black Spot Fruit Lesions. Plants 9(12):2. 1813.

Moyo, P., Cook, G., Basson, E., Steyn, C., Bester, R., Olivier, C. and Fourie, P.H. 2022. Monitoring Benzimidazole Resistance in Phyllosticta citricarpa Using a Molecular Assay Targeting Mutations in Codons 198 and 200 of the β-Tubulin Gene. Plant Disease 106: 1374-1380. https://doi.org/10.1094/PDIS-07-21-1459-RE

Moyo, P ., Fialho, R., Silva Junior, G.J. and Fourie, P. 2025. Citrus black spot symptoms on fruit, exposed to Phyllosticta citricarpa infections, at different developmental stages. Plant-Environment Interactions 6: e70031. https://doi.org/10.1002/pei3.70031

O.P.J. Stander, J. North, J.M. van Niekerk, T. van Wyk, C. Love and M.J. Gilbert. 2019. Influence of nonpermanent netting on foliar spray deposition, insect pest prevalence, and production of ‘Nadorcott’ mandarin (Citrus reticulate). Hortscience 54 (4): 667-675

Theron, E., van Niekerk, J.M. and J. van der Waals. 2025. A review of the use of phosphonates in the management of Phytophthora nicotianae in citrus in South Africa. Phytoparasitica 53:11. https://doi.org/10.1007/s12600-024-01234-7

POSTHARVEST

Erasmus, A., Lennox, C.L., Korsten, L., du Plooy, W., Kellerman, M., and Fourie, P.H. 2021. Imazalil resistance management for sustainable citrus green mould control: limited options and alternatives. Acta Hortic 1323:105 – 110.

Fourie, P.H., Erasmus, A., Lennox, C.L. and du Plooy, W. 2021. Optimisation of postharvest fungicide application in citrus packhouses: low-tech but high impact. Acta Hortic. 1323:137-142.

Mamba, L.C., Meitz-Hopkins, J.C., Stevens, C., Fourie, P.H., du Plooy, W., Erasmus A. and Lennox C.L. Citrus sour rot management by propiconazole drench application in South Africa. Acta Hortic 1323:177 -182.

Olivier C.,Savage C.,du Plooy W,Fourie P.H,Erasmus A., and Lennox C. Sanitisation of fungicide drench solution and effects on green mould and sour rot control. 4th International Symposium on Postharvest Pathology, 2 June 2017, Skukuza, Kruger National Park, South Africa.

Olivier, C., Savage, C., du Plooy, W., Fourie, P.H., Erasmus A. and Lennox C.L. Sanitisation of fungicide drench solution and effects on green mould and sour rot control. Acta Hortic 1323:183 – 188.

Stevens, C., Lennox, C.L., Mamba, L.C., Fourie, P.H., du Plooy W. and J.C. Meitz-Hopkins. 2021. Propiconazole baseline sensitivity and molecular identification of Galactomyces sp. from citrus sour rot. Acta Hortic 1323: 31-34.