Rhizosphere and rhizoplane of fababean (Vicia faba), melochia (Corchorus olitorius), sesame (Sesamum indicum) and soyabean (Glycine max) plants are inhabited with fungi, mostly Aspergillus flavus, A. niger, Fusarium oxysporum, Penicillium corylophilum, P. cyclopium, P. funiculosum and Rhizopus stolonifer. All fungal species have the ability to produce gibberellin (GA) but F. oxysporum was found to produce both GA and indole-acetic acid (IAA). The optimum period for GA and IAA production by F. oxysporum was 10 days in the mycelium and 15 days in the filtrate at 28 °C. The contents of GA, IAA and cytochrome P-450 were increased at 0.5 and 1% NaCl after 5 days, but GA and IAA were lowered at 4% (700 mM) NaCl. Calcium decreased NaCl stress on F. oxysporum by significant elevating GA biosynthesis at 40mM Ca2+/700 mM Na+. GA at 10 mM and Ca2+ at 10 mM enhanced the germination of seeds under 175 mM Na+.
Elemental analysis of some Nigerian grains for cobalt, zinc, iron, and chromium, was done by thermal NAA. The concentration of these essential trace elements were found as follows: rice /0.18–0.98 ppm Cr, 27–307 ppm Fe, 0.133–0.237 ppm Co, 12.4–17.8 ppm Zn/; soyabean /0.32–0.59 ppm Cr, 67–81 ppm Fe, 0.244–0.358 ppm Co, 42–45 ppm Zn/; maize /0.05–0.75 ppm Cr, 22.7–47.6 ppm Fe, 0.20–0.65 ppm Co, 15.8–33.4 ppm Zn/; ground-nut /0.22–2.02 ppm Cr, 27.2–34.8 ppm Fe, 0.08–1.73 ppm Co, 24.3–38.2 ppm Zn/. No pattern was established for the elemental concentration in the grain samples. The result obtained suggest that an average diet of these grains will provide an adequate concentration of these essential elements.