Currently deficiency of raw materials and initiative resources caused an increasing need of cellulose industries to new lingo cellulose products and resources. kenaf as a fibrous plant is considered along with the other plant sources that their bast has suitable fiber. This experiment was carried out in split–plot form with 4 replication in order to evaluation effect of harvest time and genotype on hemp production in Research Farm of Gorgan University of Agriculture Sciences and Natural Resources in 2007. Experiment factors were six genotypes consisting of cubana, Neiger, 9277, Cubana 2032 and 7551, and three harvest times consisting of 85, 105 and 135 days after swing. Result showed that yield, bast, pith, and stem yield were affected by harvest time. Bast to pith in second harvest time and leaf to stem in first harvest time was more than the other times. In addition, interaction between genotype and harvest time was not significant. Genotype Neiger was the best genotype for yield, bast, pith and leaf yield also Cubana 2032 and Cubana with 40.41 and 40.00 percent were the best genotypes for bast to pith ratio. Third harvest time was the best for most factors except leaf to stem ratio results of this study showed that increase in length of period of growing could be result in more production of fiber in kenaf.
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