Fundamental Studies on Multiple Usage of Fiber Crop, Kenaf

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The cultivation of fiber crop, Kenaf (Hibiscus cannabinus L.), is said to have begun in Egypt, about 4000 BC. The traditional usages were restricted to its bast fiber and used for rope, sack and other fiber products. Now the biomass of Kenaf is recognized as a potential resource for human life and many aspects of usage is being investigated in the world. Even in Japan, companies like automobile, housing and IT industries developed kenaf bast fiber products as a new natural fiber usage.In this research, fundamental aspects of Kenaf cultivation and multiple usage were investigated to utilize the Kenaf biomass as a possible agro-forestry-industry system in rural region. In the pulp and paper field, to make a value added products a high viscosity pulping sequence including the ammonium oxalate treatment has been characterized. In more detailed study, layer separation of bast fiber was done and the contribution of each layer to the paper strength was discussed. Outermost layer had longest f … More iber length but the viscosity was lowest and the paper strength increased as the layer number increased. Also the influence of the stem height position and the harvesting time were investigated. Lower the stem height and later the harvesting time, the pulp viscosity increased.As biomass, Kenaf seed and leaf are also important to develop a sustainable cultivation system. Kenaf seed contains a lot of protein and fatty acids almost equivalent contents to soybean. We examined to make tofu (bean curd) from Kenaf seed to utilize them. Comparison experiment showed Kenaf seed is difficult to make tofu if the same method for soybean tofu making but it gave Kenaf tofu if starch were added as sesame tofu making method. The difference should be examined further. Kenaf leaf contains high proteins and known to be promising as forage (animal feed) in other countries. In Japan, addition to food like wheat flour noodle (udon) and cookie are reported. We examined to use the leaf as additive to kamaboko (traditional white fish meat paste). Because Kenaf leaf contains strong acidic substance (mainly hibiscus acid) the fish meat was difficult to solidify.As a diversification of cultivation method, a trial in a land in long-term timber production forest was done, but Kenaf did not grow enough. Main reason is not clear but the Kenaf growth showed a strong relationship to the luminous intensity. In the farmland, Kenaf stem as animal bedding is promising because the animal excrement increased the Kenaf yield higher. Less