ALLELOPATHIC POTENTIAL OF Alternanthera brasiliana(L.) O. Kuntze ON SEED GERMINATION AND PERFORMANCE OF Zea mays L. IN IBADAN, NIGERIA

Abstract

Allelopathy refers to the influence of plant-produced secondary metabolites on the

growth and performance of other plants. Species of Alternanthera are known to contain

abundant bioactive compounds; however, information on the allelopathic effects of

Alternanthera brasiliana on Zea mays remains limited. Therefore, this study

investigated the effects of aqueous extracts of A. brasiliana on the germination and

growth performance of Z. mays in Ibadan, Nigeria. Aqueous Shoot Extracts-ASE and

Aqueous Root Extracts-ARE of A. brasiliana were prepared following the method of

Ahn and Chung (2000), with slight modifications to obtain 100%, 50%, 25% and

12.5% concentrations. The extracts were applied to Zea mays seeds in Petri dishes and

plants in pots using a syringe and measuring cylinder respectively. Experiments were

arranged in completely randomized design (r=4; r=3). Germination Percentage-GP

(%) of seeds was recorded at day 7; growth and yield parameters (plant height, stem

diameter, number of leaves/plants, leaf area, dry shoot weight) were determined at

eight weeks after sowing (WAS), and 100-seed weight at 10 WAS. Data were analysed

using ANOVA at α0.05.The GP of seeds treated with extracts ranged from 25.00±6.45%

(ARE-100) to 72.50±7.5% (ASE-12.5 and ARE-12.5), which were significantly lower

than control (82.50±2.7%) in the second trial. The control had plant height of

83.10±1.90, stem diameter of 1.61±0.02, number of leaves/plants of 10.00±0.00, leaf

area of 238.52±16.07 and dry shoot weight of 74.41±5.10, which were all significantly

lower than all aqueous extract treatments. Growth and yield parameters of plants

treated with extracts of A. brasiliana at varied concentrations were significantly lower

than control. Aqueous extracts from dry shoot and root of A. brasiliana significantly

reduced the seed germination and performance of Z.mays.