Effects of carbon levels on shoot growth and root characteristics of different kenaf (Hibiscus cannabinus L.) varieties grown on sandy bris soil

The effects of carbon levels on shoot growth and root characteristics of five kenaf varieties were assessed in a shade house experiment. The kenaf plants were grown in pots containing sandy beach ridges interspersed with swales (BRIS) soil. Organic carbons at levels of 0, 10, 20 and 30 t ha-1 were applied to pots using organic fertilizer. The plants at carbon levels 20 t ha-1 had the highest plant height, leaf area, shoot and root dry matter, total root length, root surface area, total root volume, and number of root tips. Increasing carbon levels had negatively affected shoot growth and root morphology of all varieties under study. There was an obvious difference in response to carbon levels among the five varieties with HC2 showing the highest performance in terms of shoot growth and root characteristics. These results provide significant insights into limitations and opportunities for growing of kenaf in BRIS soil with better organic carbon management.Key words: Kenaf varieties, carbon levels, root traits, root and shoot growth, sandy BRIS soil

Growth, yield and fiber morphology of kenaf (Hibiscus cannabinus L.) grown on sandy bris soil as influenced by different levels of carbon

The effects of carbon levels on plant growth, yield and fiber morphological properties are not available for kenaf that is considered as a potential source of low cost natural fiber and feedstock for energy production as well. A pot-culture experiment was conducted in shade house to determine the effects of carbon levels on plant growth, yield and fiber morphology of different kenaf varieties. The plants of five kenaf varieties were grown in pots containing sandy beach ridges interspersed with swales (BRIS) soil. Organic carbons at the levels of 0, 10, 20, 30 and 40 t ha-1 were applied to pots using organic fertilizer. At harvest, stem diameter, plant height, leaf number, leaf area, plant components biomass, bast and core fiber yield and fiber dimensional properties were determined. Maximum growth, dry matter and fiber yield, and morphological characters were achieved at the carbon levels 20 t ha-1 but the values of these parameters decreased with additional increase in carbon levels. Among the varieties, HC2 had the highest plant height, leaf biomass, total dry matter and fiber yield. The longest bast fiber was observed in variety HC2. The variety G4 showed the widest fiber and higher lumen width among others. The bast fibers of all the kenaf verities were longer than core fiber. The core fiber was wider and higher in lumen width than the bast fiber. The above results keep a significant role and would be useful to select better varieties of kenaf for the purpose of making quality paper and paper products and to grow kenaf on BRIS soil with adequate yield and fibre quality using better management of organic carbon.Key words: Kenaf varieties, carbon levels, growth, yield, fiber morphology, beach ridges interspersed with swales (BRIS) soil

Evaluation of cadmium bioaccumulation and translocation by Hopea odorata grown in a contaminated soil

Cadmium (Cd) contamination has an adverse effect on soil productivity and crop production. Phytoremediation is a long term and environmental friendly technology to remediate Cadmium polluted areas. This study was conducted to evaluate the potential of Hopea adorata for remediation of soils contaminated with Cd. Plant seedlings were planted in a clayey soil spiked contaminated with Cd in the amount of 0, 25, 50, 75, 100 and 150 mg kg-1 named as; Cd0, Cd1, Cd2, Cd3, Cd4 and Cd5 for a period of five months. The highest growth performance was recorded in the control (Cd0). Cd concentrations among plant parts were in the following trend: roots>stems>leaves. In order to evaluate the potential of species selected as phytoremediator, three indicators were used namely, bioconcentration factor (BCF, the metal concentration ratio of plant roots to soil), translocation factor (TF, the metal concentration ratio of plant shoots to roots) and removal efficiency (RE, total concentrations of metal and dry biomass of plants to total loaded metal in growth media). The highest total Cd concentration (290.23 ± 13.38 mg kg-1) and Cd removal efficiency (0.81± 0.06%) were found in Cd5 and Cd1, respectively. Cd2 exhibited the maximum total dry biomass (60.88 ± 1.78 g). H. odorata showed high BCFs (>1) and low TFs (<1). It can be concluded that this species is suitable to be used in phytoremediation of Cd-contaminated. For further confirmation, an evaluation under field condition will be needed.Keywords: Phytoremediation, Hopea odorata, heavy metals, soil pollution, removal efficiencyAfrican Journal of Biotechnology Vol. 11(29), pp. 7472-7482, 10 April, 201