Publications – Disease Management


Aldrich DJ, Bester R, Cook G, Burger JT, Maree HJ. 2021. Evaluating the utility of high-resolution CT scanning technology to study citrus tristeza virus-induced stem pitting. Journal of Citrus Pathology 8 (1).
Bester R, Cook G, Maree HJ, 2021. Citrus Tristeza Virus Genotype Detection Using High-Throughput Sequencing. Viruses 13.
Bester R, Karaan M, Cook G, Maree HJ, 2021. First report of citrus virus A in citrus in South Africa. Journal of Citrus Pathology 8 (1).
Bester R, Cook G, Breytenbach JHJ, Steyn C, De Bruyn R, Maree HJ, 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.
Cook G, Breytenbach JHJ, Steyn C, De Bruyn R, van Vuuren SP, Burger JT, Maree HJ. 2021. Grapefruit Field Trial Evaluation of Citrus Tristeza Virus T68-Strain Sources. Plant Disease 105, 361-7.
Cook G, Kirkman W, Clase R, Steyn C, Basson E, Fourie PH, Moore SD, Grout TG, Carstens E, Hattingh V. 2019. Orchid fleck virus associated with the first case of citrus leprosis-N in South Africa. European Journal of Plant Pathology 155, 1373-9.
Cook G, van Vuuren SP, Breytenbach JHJ, Burger JT, Maree HJ. 2016. Expanded Strain-Specific RT-PCR Assay for Differential Detection of Currently Known Citrus Tristeza Virus Strains: a Useful Screening Tool. Journal of Phytopathology 164, 847-51.
Cook G, Van Vuuren SP, Breytenbach JHJ, Steyn C, Burger JT, Maree HJ. 2016. Characterization of Citrus tristeza virus Single-Variant Sources in Grapefruit in Greenhouse and Field Trials. Plant Disease 100, 2251-6.
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
Cook G, Steyn C, Breytenbach JHJ, De Bruyn R, Fourie PH, 2020. No detection of seed transmission of citrus tatter leaf virus in ‘Meyer’ lemon. Journal of Plant Diseases and Protection 127, 895-8.
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
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. E-probe based detection of citrus viruses in NGS data. Phytopathology. 107 (8), 988-993. DOI: 10.1094/PHYTO-10-16-0379-R
Ruiz-García AB, Bester R, Olmos A, Maree HJ. Bioinformatic Tools and Genome Analysis of Citrus tristeza virus. In: Catara AF, Bar-Joseph M, Licciardello G, editors. Citrus Tristeza Virus: Methods and Protocols. New York, NY: Springer New York; 2019. 163–78. Available from:
Steyn C, Cook G, Burger JT, Maree HJ, 2016. Construction and application of infectious citrus viroids for biological indexing. Journal of Citrus Pathology 3 (1).
Visser M, Bester R, Burger JT, Maree HJ. 2016. Next-Generation Sequencing for Virus Detection: Covering All the Bases. Virology Journal 13, doi:10.1186/s12985-016-0539-x.
Visser M, Cook G, Burger JT, Maree HJ. 2017. In silico analysis of the grapefruit sRNAome, transcriptome and gene regulation in response to CTV-CDVd co-infection. Virology Journal 14, 200.
Visser M, Burger JT, Maree HJ. 2016. Targeted virus detection in next-generation sequencing data using an automated e-probe based approach. Virology 495, 122–8.



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: 10.1094/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.


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


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.