Chromolaena odorata, Euphorbia heterophylla and Tridax procumbens are common weeds that are prevalent in cowpea fields. The physiological influence of three dilution concentrations of the aqueous root and shoot extracts of the weeds were examined on seed germination, plumule length, radicle length, fresh and dry weights of plumule and radicle of two varieties of cowpea in the laboratory. The experiment was laid out in a completely randomized design replicated three times. Results revealed susceptibility of two varieties of cowpea (Vigna unguiculata L. Walp) (IT99K-573-1-1 and IT07K-292-10) to the allelopathic potential of all the extract concentrations of the selected weeds. Although, all the extracts reduced germination and seedling growth, shoot extracts at 75% concentration of the selected weeds significantly inhibited germination and seedling growth of the variety IT99K-573-1-1 compared with the control which produced 97% (germination %); C. odorata, E. heterophylla and T. procumbens shoot extracts produced 22, 20 and 50% germination, respectively. Consequently, C. odorata, E. heterophylla and T. procumbens shoot extracts produced 25, 18 and 28% germination respectively for variety IT07K-292-10 while the control yielded 99%. Bioassays also indicate that the inhibition was concentration dependent; the inhibition in the extract-treated seeds increased with the increase in the concentration of the extracts. Also, the degree of seed germination inhibition was higher in shoot extracts than root extracts of selected weed. It was clear from the investigation that the extracts of E. heterophylla exerted a stronger inhibitory effect on the germination process and seedling growth of the two cowpea varieties than that of C. odorata and T. procumbens.

This study was carried out in the Department of Plant Science and Biotechnology, Federal University Oye Ekiti, Ekiti State. Investigation was carried out on the effects of Fresh Shoot Biomass of Chromolaena odorata on okra Abelmoschus esculentus. For the laboratory experiment, about 5g, 10g, 15g and 20g each of Chromolaena odorata was weighed into plastic bottles each containing 250ml of distilled water for 24 hours. Two millilitres of the leachate was used to water the seeds of okra that was placed in Petri dishes. Each treatment had five replicates that contained four seeds of okra (Abelmoschus esculentus). For the screening experiment, loamy top soil, fresh shoot, stems and leaves of Chromolaena odorata were collected within Federal University Oye Ekiti environment and crushed into smaller bits using mortar and pestle. Three seeds, each of okra that was planted in all the pots. The growth variables considered include radicle length, plumule length, number of roots, for the green house experiment the plant height, leaf area, stem girth, and pod weight were also observed. The leachate of Chromolaena odorata resulted to a reduction in radicle length, plumule length and number of roots. The radicle length of okra treated with leachates of 15g/250ml were adversely affected, while the plumule length of 5g/250ml, 15g/250ml and 20g/250ml greatly decreased compared to the control. The highest decrease in number of roots was noticed in the 15g/250ml concentration. The control plant had the highest plant height increased in a concentration dependent manner with exception of those treated with 200g, the leaf area of the control plant was observed to be lower than all the treatment plants, but it increased in a concentration dependent manner. Also, there was a concentration dependent increase in the steam girth of A. esculentus. The pod weight of the treated plants were lower than the control. The plant treated with 50g highest moisture content, the fat content was higher in the control and plant treated with 50g than the other treated plant. The protein content of the treatment plants was observed to be significantly higher when compared to the control plant. Crude fiber content of the treatment plant was significantly higher than the treatment plants. The ash content of the control was significantly lower than the treated plants, the carbohydrate content of the control plant increased significantly compared to the treatment plant with the lowest at 150g treated plant. The study concluded that the leachate and FSB affected the seed germination, growth and the food content of Abelmoschus esculentus.

Seed priming is a promising technique that can improve the growth and yield of plants under optimum conditions. The specific priming duration and concentration required for adequate vegetative growth, yield quality, and phytochemical accumulation of Abelmoshus esculentus need clarification. This study was evaluated under screen house conditions, using a completely randomized design (CRD) approach. The seeds of Abelmoshus esculentus were subjected to priming with potassium nitrate for 6 and 12 h duration at a concentration of 0.5 and 1.00 mM while unprimed seeds served as the control. The results revealed that the primed seeds showed improved vegetative growth, yield components, and phytochemical constituents compared to the unprimed control seeds. This observation was irrespective of the priming duration and concentration of potassium nitrate used. Moreover, seeds primed for a 6 h duration at 1 mM were significantly higher in yield, fruit mineral, and phytochemical constituents compared to other treatments. At 12 h priming duration, seeds primed in 0.5 mM of potassium nitrate had higher growth and yield than at 1 mM. Priming with inorganic salts such as KNO3 induces faster growth and maximum crop yield of Abelmoshus esculentus. Priming for a short duration (6 h) 3 and at high concentration is sufficient to enhance the growth process and increased yield of Abelmoshus esculentus and has practical implications in the production of Abelmoshus esculentus .