Main Article Content
Three famous medicinal plants; Bitter leaf (Vernonia amygdalina), Basil (Ocimum gratissimum) and Hibiscus (Hibiscus sabdariffa) were evaluated for their allelopatic interaction with parasitic nematode infestation in Makurdi yam field in Benue State, Nigeria where yam is intensively cultivated. The experiment was carried out using a randomized complete block design (RCBD) with four treatments for the three plants intercropped with "Hembakwase" white yam cultivar and the control group (without intercrop). This was repeated three times at a spacing of 1m x 1m occupying an area of 12m2. Data for tuber count/plant, tuber weight, tuber diameter, final nematode count/plot and root gall index were recorded. Separation of means was done using Duncan's multiple range test (DMRT) at a 5% probability level. The obtained results showed that the Vernonia amygdalina intercrops gave significantly higher number of tubers/plant (4.71), tubers length (34.22), tubers girth (21.22) and yield per plot (5.6) than other treatments, while the untreated control had lower yield (1.5). Significantly higher root gall index (P < 0.05) of Meloidogyne spp. was recorded from the peels of tubers in untreated treatment (4.3), Ocimum gratissimum (3.1), Hibiscus sabdariffa (2.3), and the lowest gall index was scored from yams grown with Vernonia amygdalina (1.3) intercrop, respectively. This further affirms the allelopathic potential of Vernonia amygdalina in suppressing nematode populations. It is recommended to encourage intercropping of bitter leaf in nematode infested fields among farmers as this will help suppress nematode populations and serve as stakes for yams planted.
Polycarp D, Afoakwa EO, Budu AS, Otoo E. Characterization of chemical composition and anti-nutritional factors in seven species within the Ghanaian yam (Dioscorea) germplasm. International Food Research Journal. 2012;19(3):985.
Posthumus H, Dengerink J, Dhamankar M, Plaisier C, Baltissen G. Enhancing food systems in Nigeria: scope and perspective for Dutch policy interventions. Wageningen University & Research; 2018.
Agu CM. Effects of organic manure types on root-gall nematode disease and African yam bean yield. The Journal of American Science. 2008;4 (1):67-77.
Kankam F, Adomako J. Influence of inoculum levels of root knot nematodes (Meloidogyne spp.) on tomato (Solanum lycopersicum L.). Asian Journal of Agriculture and Food Sciences. 2014;2(2).
Sikder MM, Vestergård M. Impacts of root metabolites on soil nematodes. Frontiers in plant science. 2020;10:1792.
Baetz U. Root exudates as integral part of belowground plant defence. In Belowground Defence Strategies in Plants Springer, Cham. 2016;45-67.
Adepoju IO, Oluwatayo JI, Iheukwumere, CC, Ekefan EJ. (2018) Allelopathic effect of hibiscus sabdariffa on the yield of some local best cultivars of white yam in nematode infested soil. FUW Trends in Science &Technology Journal. 2018;3( 2)B:1029 –1031
Alege, S. G., Matovu, J. K., Ssensalire, S., & Nabiwemba, E. (2016). Knowledge, sources and use of family planning methods among women aged 15-49 years in Uganda: a cross-sectional study. Pan African Medical Journal, 24(1).
Thoden TC, Korthals GW, Termorshuizen, AJ. (2011). Organic amendments and their influences on plant-parasitic and free-living nematodes: a promising method for nematode management? Nematology. 2011;13(2):133-153.
Zhung M, Ling B, Kong C, Liang G, Dong Y. Allelopathic effect of lantana (Lantana camera L) on Water hyacinth (Eichornea crasspes. solum). Allelopathy J. 2005;15: 125-130.
Alamgir ANM. Therapeutic use of medicinal plants and their extracts: Springer International Publishing AG. 2017;1.
Rani PU, Rajasekharreddy P, Nagaiah K. Allelopathic effects of Sterculia foetida (L.) against four major weeds. Allelopathy Journal. 2011;28(2):179-188.