Research focus |
• Plant and crop physiology
• Stress physiology (drought, chemical and water stress)
• Biostimulants and natural product development
• Crop manipulation for improved stress tolerance and yield
• Screening and development of plant-based products

Research experience |
Peer-reviewed articles: 30
Peer-reviewed reports: 14
Non-reviewed congress contributions: 40+
Popular articles: 6

Postgraduate supervision |
MSc Agric: 14 completed and 10 ongoing
PhD: 8 completed and 4 ongoing
Postdoctoral fellow: 1

Undergraduate teaching experience |
Biological Principles in Agriculture (AGRI 1514): NQF 5, 2015–current
Crop Development (SCCS 2624): NQF 6, 2015–current
Stress and Crop Physiology (CROP 4814/6814): NQF 8, 2015–current
Seminar (SCCS 4808/6808): NQF 8, 2015–current

External examiner |
University of Pretoria: 8
North-West University: 1
University of Stellenbosch: 4
University of Fort Hare: 1

University of the Free State: 5

Technical University of Tswane: 1

Annamalai University in India: 1

Manuscript reviews for journals |
South African Journal of Plant and Soil: 5
African Journal of Plant Science: 3
South Asian Research Journal of Natural Products: 5
Annual Research and Review in Biology: 3
Journal of Agricultural Science: 1
Walailak Journal of Science and Technology: 1

PEER REVIEWED ARTICLES

1. Van der Watt, E. and Pretorius, J.C. 2001. Purification and identification of active antibacterial components in Carpobrotus edulis L.  Journal of Ethnopharmacology. Vol. 76 (1): 87-91.
2. Pretorius J.C., Craven P. and Van der Watt, E. 2002.  In vivo control of Mycosphaerella pinodes on pea leaves by a crude bulb extract of Eucomis autumnalis.  Annals of Applied Biology, 141: 125-131.
3. Pretorius J.C., Du Plessis A. and Van der Watt, E. 2008. Bio-stimulatory properties in seeds of plants from the families Caryophyllaceae and Fabaceae with application potential in agriculture. SA Journal of Plant and Soil 25(4): 194-203
4. Van der Watt, E. and Pretorius, J.C. 2011.In vitro and in vivo bio-stimulatory properties of a Lupinus albus L seed suspension. Crop and Pasture Science 62: 189-197
5. Van der Watt, E. and Pretorius, J.C. 2013.A triglyceride from Lupinus albus L. seeds with bio-stimulatory properties.African Journal of Biotechnology 12(35):5431-5443
6. Van der Watt, E. and Pretorius, J.C. 2013.A triglyceride from Lupinus albus L. seeds with bio-stimulatory properties.Acta Horticulturae 1009. In: Proceedings of the 1^st World Congress on the use of Bio stimulants in Agriculture, Strasbourg, France, November 26-29, 2012.
7. Antimicrobial activity of Buxus macowanii and its morphological effects on Bacillus cereus.Plant Medica (submitted 2018)

8. Fabrizio Giuseppe Casales; Elmarie Van der Watt and Gesine Maria Coetzer (2018) In vitro propagation of pecan – A review.  African Journal of Biotechnology.  Vol. 17(18), pp. 586 – 605
9. B.J. Kay; V.R. Swart and E. van der Watt (2019)  Evaluation and comparison of various plant extracts as repellents against Lucilia spp. African Entomology 27(1): 000–000 (2019) DOI: httpS://doi.org/10.4001/003.027.0000
10. B Ngobeni; S Masele; NJ Mabelo; E Van der Watt ad IT Manduna (2020)   Disruption of microbial cell morphology by Buxus macowanii.  BMC Complementary Medicine and Therapies Planta Medica (published)
11. Zaid Bello, Johan Barnard, Elmarie Van der Watt and Neo Mathinya (2020) Response of malt barley (Hordeum vulgare L.) grain quality characteristics to increasing irrigation water salinity.  South African Journal of Plant and Soil, 38:2, 159-170, DOI: 10.1080/02571862.2021.1888391
12. Sakumona, M., Allemann, J. and Van der Watt, E., 2020. Physiological responses of spring wheat cultivars in two ecotopes. [Journal details incomplete – additional information required].Tropical Agricultural Research & Extension 25 (1): 2022
13. Khetsha, Z.P., Sedibe, M.M., Pretorius, R.J. and Van der Watt, E., 2021. Effects of amalgamated phytohormones on leaf trichome density and essential oil yield and quality of simulated hail-damaged rose geranium (Pelargonium graveolens L’Hér.). Annals of the Brazilian Academy of Sciences, 93(4). https://doi.org/10.1590/0001-3765202120191529
14. Khetsha, Z.P., Sedibe, M.M., Pretorius, R.J. and Van der Watt, E., 2021. The effect of plant growth regulators on the leaf mineral status and phenolic composition of simulated hail-damaged rose geranium (Pelargonium graveolens L`Hér. cv. ‘Bourbon’). [Journal details incomplete – additional information required].
15. Khetsha, Z.P., Sedibe, M.M., Pretorius, R.J. and Van der Watt, E., 2023. Biostimulants improve the leaf micro-morphology and essential oil biosynthesis of simulated hail-damaged Pelargonium graveolens (L’Hér.). Acta Horticulturae, 1372, pp.271–278. https://doi.org/10.17660/ActaHortic.2023.1372.37
16. Tandathu, T., Kotzé, E., Van der Watt, E. and Khetsha, Z.P., 2024. Effect of biostimulants and glyphosate on morphophysiological parameters of Zea mays (L.) seedlings under controlled conditions. Agronomy, 14(10), 2396. https://doi.org/10.3390/agronomy14102396
17. Khetsha, Z.P., Van der Watt, E., Masowa, M., Legodi, L., Satshi, S., Sadiki, L. and Moyo, K., 2024. Phytohormone-based biostimulants as an alternative mitigating strategy for horticultural plants grown under adverse multi-stress conditions: Common South African stress factors. Caraka Tani: Journal of Sustainable Agriculture, 39(1), pp.167–193. https://doi.org/10.20961/carakatani.v39i1.77606
18. Moyo, K., Khetsha, Z.P., Masowa, M.M., Van der Watt, E., Moloantoa, K.M. and Unuofin, J.O., 2024. Eco-organic system and silicon-based biostimulant as a strategy for vegetable production under multistress conditions in South Africa: A review. Journal of Applied Horticulture, 26(1), pp.83–89. https://doi.org/10.37855/jah.2024.v26i01.15
19. Mota, M.M., Van der Watt, E. and Khetsha, Z.P., 2024. Foliar application of brassinosteroids improve the yield and morpho-physiological characteristics of Arachis hypogaea (L.), Glycine max (L.), and Phaseolus vulgaris (L.). Applied Ecology and Environmental Research, 22(1), pp.355–371. https://doi.org/10.15666/aeer/2201_355371
20. Venter, P., Van Niekerk, J. and Van der Watt, E., 2024. The sustainability of new generation future commercial farmers in South Africa: A North-West Province case study. South African Journal of Agricultural Extension, 52(3), pp.103–131. https://doi.org/10.17159/2413-3221/2024/v52n3a15635
21. Legodi, L.M., Van der Watt, E., Masowa, M.M. and Khetsha, Z.P. Accepted for publication. Potential use of seaweed- and silicon-based biostimulants to alleviate the multistresses on tomato (Solanum lycopersicum L.) in South Africa: A review. Acta Horticulturae.1416. ISHS 2025. DOI 10.17660/ActaHortic.2025.1416.25
22. Somi, Z., Kotzé, E. and Van der Watt, E., 2024. Using an uptake enhancer to mitigate nitrogen leaching while enhancing uptake efficiency. Applied Sciences, 14(12), 5271. https://doi.org/10.3390/app14125271
23. Tandathu, T.; Kotzé, E.; Van DerWatt, E.; Khetsha, Z.P. 2024. Effect of Biostimulants and Glyphosate on Morphophysiological Parameters of Zea mays (L.) Seedlings under Controlled Conditions.  Agronomy 2024, 14, 2396. https://doi.org/10.3390/agronomy14102396
24. Satshi, S., Masowa, M.M., Van der Watt, E. and Khetsha, Z.P., 2025. Recovery response mechanisms of horticultural plants to multi-stress: Plant-based biostimulants as a potential alternative strategy for lettuce (Lactuca sativa L.) in South Africa. Acta Horticulturae, 1416, pp.447–454. https://doi.org/10.17660/ActaHortic.2025.1416.60
25. Sadiki, L.C., Van der Watt, E., Masowa, M.M. and Khetsha, Z.P., 2025. Using silicon-based biostimulant and phosphorus application as an alternative solution for beetroot (Beta vulgaris L.) grown under multi-stress in South Africa: A short review. Acta Horticulturae, 1416, pp.173–180. https://doi.org/10.17660/ActaHortic.2025.1416.24
26. Tandathu, T.E., Van der Watt, E., Kotzé, E. and Khetsha, Z.P., 2025. Insight on the impacts of brassinosteroid- and seaweed-based biostimulants on glyphosate-resistant commercial crop growth, yield and soil microorganisms: A scoping review. Agronomy Research, 23(X), pp.xxx–ccc. https://doi.org/10.15159/AR.25.005
27. Mutsamba-Magwaza, E.F., Baudron, F., Franke, A.C., Van der Watt, E. and Nyagumbo, I., 2025. Learning from positive deviants` practices to improve the performance of mixed crop-livestock systems in Zimbabwe. Agricultural Systems, 228, Article 104300. https://doi.org/10.1016/j.agsy.2025.104300
28. Khumalo N, Van Der Watt E, Van Der Merwe R. 2025. Membrane stability and antioxidant enzyme activity of vegetable type soybean seedlings in response to short-term drought stress. Mol 25: 1.
29. Maipato Margaret Mota 1, Elmarie Van Der Watt 1 and Zenzile Peter Khetsha 2,* (2026) Effects of different mesotrione residual levels on morphological, physiological, and yield characteristics of brassinosteroid treated soya bean (Glycine max L. Merr.). Agrochemicals, 5, 27 https://doi.org/10.3390/agrochemicals5020027
30. Mutsamba-Magwaza, E.F., Baudron, F., Franke, A.C., Van der Watt, E. and Nyagumbo, I., 2026. Seasonal rainfall impacts the relative performance of maize-legume intercropping systems in semi-arid Zimbabwe. Experimental Agriculture (2026), vol. 62, e11, 1–17, doi:10.1017/S0014479726100350

CHAPTER IN BOOKS

1. Pretorius, J.C. and Van Der Watt, E.2011.Natural Products from Plants: Commercial prospects in terms of antimicrobial, herbicidal and bio-stimulatory activities in an integrated pest management system.In: Dubey N.K. (eds) Natural Products in Plant Pest Management.
2. Pretorius JC and Van Der Watt E. 2015.Antifungal compounds from wild plants and its commercial potential. IN:K Vadivel, S Ganesan, Annamalai.Sustainable Crop Disease Management using Natural Products

POPULAR ARTICLES

 (1)     Pretorius, J.C. and Van der Watt, E. 2005. Gewasproduksie se risiko verlaag.  Landbouweekblad.

(2)      Pretorius, J.C. And Van der Watt, E. 2006. Plant bonanza.  SA Gardening and Tuinpaleis

(3) Van der Watt 2023.  Better eienskappe kan koringplante pantser teen hitte.  Landbouweekblad

4) Van der Watt 2024: Landbouweekblad Biostimulants: Boosting Crop Resilience and Sustainability for Farmers

5) Boosting Potato Yield Under Heat and Cold Stress with Biostimulants. Chips

6)The Role of Biostimulants in Sustainable Potato Production, Chips

1. Screening of crude extracts from South African plants for possible application potential in agriculture. Aspects covered include antibacterial, antifungal, herbicidal, bio-stimulatory and insecticidal properties as well as the potential of an extract to improve systemic induced resistance (SIR) in crops towards abiotic and biotic stress factors. Once a potential has been identified, the active compounds are isolated and purified and the structural formula elucidated by means of NMR spectroscopy.
2. Natural plant extracts with the most potential are further investigated in terms of mechanism of action both metabolically and on gene level. The development of natural products is considered when the active compound and its mechanism of action have been elucidated. At this stage the compound is patented.
3. An aspirant new natural product is tested under field conditions in terms of its potential to be applied in a chemical manipulation program with the aim of increased tolerance against stress conditions in crops as well as yield improvement.The development of new crops and all its Agronomic requirements is considered and investigated when donor plants show above average potential.
4. A new addition to our research is an organic system approach with the aim of returning to nature via a) soil sanitation and remediation with active silicon as well as other bio-stimulants and their effect on soil micro-organisms, b) Remediation of soil after contamination (for example by herbicides) and possible repair of soil biology c) seed treatment with mychorrhiza and d) crop treatment with natural chemicals from plants to induce resistance against stress conditions, improve its physiology and metabolism in turn increasing yields.

AREAS OF SPECIALIZATION

• Screening and development of natural products like bio-stimulants, herbicides and fungicides for the agricultural industry
• Determining its effect on the enzymology, physiology and biochemistry of crops under both normal and stress conditions both under laboratory and field conditions

• Manipulation of crops in terms of cultivation, propagation and characterization using various techniques like tissue culture
• Operations planning and product development including various skills like chromatography, isolation, purification and identification of any secondary and primary products

2015-present -              AGRI 1514 (Biological principles in agriculture) lecturer

                                   AGRI 1514 (Biological principles in agriculture), coordinator

                                   SCCS 2624 (Crop development)

                                   CROP 4814 (Crop and Stress Physiology)

                                   SCCS 4808 (Research project and Seminar)