Authors : Tanaka Tutani; Richard Tandawa Masasa; Benjamin Chirambiwa; Justin Chipomho

Volume/Issue : Volume 9 - 2024, Issue 9 - September

Google Scholar : https://tinyurl.com/msruf99h

Scribd : https://tinyurl.com/ef6ms9jx

DOI : https://doi.org/10.38124/ijisrt/IJISRT24SEP888

Note : A published paper may take 4-5 working days from the publication date to appear in PlumX Metrics, Semantic Scholar, and ResearchGate.

Abstract : Rape (Brassica napus) is an important vegetable crop grown by smallholder farmers in Zimbabwe to achieve food and nutritional security. However, productivity and quality of rape are greatly dampened by aphids which reduce its palatability and quality. Chemical pesticides, while effective, pose environmental risks and can lead to pest resistance and resurgence, besides residual effects and bioaccumulation along the food chain. Tomato leaves are rich in phenolic and flavonoid compounds, that have shown promise as a botanical pesticide against aphids in other crops. This research aimed to establish the aphicidal components in tomato leaf extract using TLC and UV-Vis Spectroscopy; establish toxicity of the extract using laboratory bioassay, investigate the potential of different concentrations of tomato leaf extracts as a natural, environmentally friendly and sustainable approach to pest management against aphids in rape production at Kushinga Phikelela Agricultural College in Zimbabwe. A CRD with four treatments (0%, 20%, 40% and 60% of tomato leaf extract) and distilled water (negative control) replicated five times each was used. Aphid infestation (scored on a scale of 0-9), yield, leaf size, and plant height were measured fortnightly. Data was analysed for statistical significance using ANOVA while separation of significant means was done by Fisher’s Protected Least Significant Difference Test (LSD (5%). The results from combined analysis using TLC and UV- Vis Spectroscopy indicated that tomato leaf extract used in this research contained compounds (Solanine, Tomatine, Chaconine) which are known to be toxic to pests. There was a highly significant (p<0.001) difference among treatments on aphid mortality. The highest aphid mortality (95.57%) while the lowest (4%) was observed in 60% and 0% leaf extract respectively. Aphid infestation, leaf size and plant height were highly significant (P<0.001) during weeks 4, 6, 8 and 10 after transplanting. Aphid infestation in week 10 mean score was 8.8, 6.2, 3.8 and 0.8 for 0%, 20%, 40% and 60% tomato leaf extract respectively. Other parameters such as yield and leaf size were highest in the plots that received 60% tomato leaf extract sprays. Highly significant difference (P<0.001) in yield was observed in weeks 8 and 10, while significant difference (P<0.05) in yield was noted in weeks 4 and 6. However, in week two there were no significant differences among the treatments in yield and aphid infestation. Tomato leaf extracts contain secondary metabolites toxic to aphids and this can be used by resource constrained farmers. We recommend the use 60% tomato leaf extracts to control aphids in rape to sustainably achieve high yields.

Keywords : TLC, Tomato Leaf Extract, Nutritional Security, Botanical Pesticide, Sustainable Pest Management, UV-Vis Spectroscopy.

References :

1. Ahmad, T., Fauzy, Z.M, Yoshia-Utami, T., Arbianti, R., Hermansyah, H. (2018). Production of bio-insecticides from extracted Carica papaya using NADES solvent with ultrasound-assisted extraction (USAE). In E3S Web of Conferences; EDP Sciences. Les Ulis, France. (2018). (67)) 03007.
2. Enda, S., Unil, A. S., Gina, D. P., & Mohammad, K. (2023). Repellent effect of plant leaves extract of tomato (Solanum lycopersicon L) against Aedes aegypti mosquitoes. World Journal of Biology, Pharmacy, and Health Sciences, 13(1), 198-202.
3. Friedman, M., & Levin, C. E. (2016). Glycoalkaloids and calystegine alkaloids in potatoes. In Advances in Potato Chemistry and Technology (pp. 167-194). Elsevier.
4. Friedman, M. (2013). Tomato glycoalkaloids: Role in the plant and in the diet. Journal of Agricultural and Food Chemistry, 50(5/51), 57-80.
5. Gupta, G., Sharma, S., & Kumar, N. (2020). Carica papaya aqeous leaf extracts as a potential botanical insecticide against rose aphids (Macrosiphum roseformis D.). Journal of Entomology and Zoology Studies. (2020). 8(3), 960-964.
6. Ha, M., Kwak, J. H., Kim, Y., & Zee, O. P. (2012). Direct analysis for the distribution of toxic glycoalkaloids in potato tuber tissue using matrix-assisted laser desorption/ionization mass spectromic imaging. Journal of Food Chemistry, 133, 1155-1162.
7. Laxmishree, C., & Nandita, S. (2017). Botanical pesticides – A major alternative to chemical pesticides: A review. International Journal of Life Sciences, 4, 722-729.
8. Li, L., Manning. W.J., & Wang, X. (2019). Elevated CO₂ increases in root mass and leaf nitrogen resorption in red maple (Acer rubrum L.) for more N demand. Forest. 10 (2019). 420. 10.3390/fl0050420
9. Lin, T., Organ, R. K., Lee, J. E., Kang, J. W., Kim, S. Y., & Cho, E. S. (2018). α-Solanine impairs oocyte maturation and quality by inducing autophagy and apoptosis and changing histone modifications in a pig model. Reproductive Toxicology, 75, 96-106.
10. Kanyange, C. D., Nyirenda, S. P., Mwamlima, I. H., Kamanula, J. F., Muntali, C. R. Y., Njera, D., & Mahura, P. (2022). Field and laboratory evaluation of pesticidal plants for bioactivity against rape and tomato pests in Malawi. Journal of Advances in Agriculture, 2022, 2858994. https://doi.org/10.1155/2022/2858994
11. Montgomery, E.G. (1911). Correlation studies in corn annual report. 24. Nebraska agricultural experiment station. Lincoln NB. USA. (1911). 108-159
12. Mhazo, M. L., Kunjeku, E. C., Addo-Bediako, A., & Blair, B. W. (2021). Evaluation of aphicidal effects of Solanum panduriforme extracts on cabbage aphid (Brevicoryne brassicae, Hemiptera: Aphididae). Universal Journal of Agricultural Research, 9(1), 1-5. DOI: 10.13189/ujar.2021.090101
13. Ngeba, P.M., Cui, G., Khalid, M.Z., Zhong, G. (2022). Use of botanical pesticides in agriculture as an alternative to synthetic pesticides. Agriculture. (2022). (12). 600. http://doi.org/10.3390/agriculture 12050600
14. Pahla, I., Moyo, M., Muzemu, S., & Muziri, T. (2014). Evaluating the effectiveness of botanical sprays in controlling aphids (Brevicoryne brassicae) on rape (Brassica napus L.). International Journal of Agronomy and Agricultural Research (IJAAR), 5(1), 1-6.
15. Rajashekar, Y., Bakthavatsalam, N., & Shivanandappa, T. (2012). Botanicals as grain protectants. Psyche, 2012, 1-13.
16. Regnault-Rogder, C., Vincent, C., & Arnason, J.T. (2012). Essential oils in insect control: Low – risk products in a high – stakes world. Annual review of entomology. 57. 405-424. https://doi.org/10.1146/annualrev-ento-120710-100554
17. Royta, A., Bunta, W., Jumpei, K., Masaru, N., Hyoung, J. L., & Naoyuki, U. (2022). Tandem gene duplication of dehydrogenases drives the structural diversity of steroidal glycoalkaloids in the tomato clade. Plant Cell Physiology, 63, 981-990. https://doi.org/10.1093/pcp/pcac064
18. Santoso, S. D., Chamid, A., & Pravitiwi, D. V. K. (2018). Mortality of Aedes aegypti mosquito larvae treated with plant leaf extract of tomato (Solanum lycopersicon L). Journal Sains Kesehatan, 2, 36-39.
19. Silbert, M. W., Thomas, J. D., Leonard, B. R., Gore, J., Catchot, A., Lorenz, S. D., & Silbert, J. D. (2012). Field evaluation of sulfoxaflor, a novel insecticide, against tarnished plant bug in cotton. *Journal of Cotton Science
20. Sibanda, T., Dobson, H.M., Cooper, J.F., Manyangarirwa, W., Chiimba, W. (2000). Pest management challenges for smallholder vegetable farmers in Zimbabwe. Crop Protection. (19). (8-10). 807-815.
21. Treulter, D. (2005). Significance of flavonoids in plant resistance and enhancement of their biosynthesis. Plant Biology. 2005. 7.581-591.