Abstract

Kenaf (Hibiscus cannabinus L.) is an annual non wood plant which has shown great potential as an alternative source of papermaking fiber. No information is available on kenaf cultivation in south-Iran in spite of the need to replace imported long fibers through local production of alternative sources. The purpose of this research is to investigate the effect of kenaf cultivars and harvest times on component yield and fiber quality. Six cultivar of kenaf (Cubano, Niger, Cuba 2032, 9277, 7551 and 7566) were planted on May 19, 2007 in the research farm of Agronomy Department Gorgan University. The three harvest times are 85, 105 and 135 days after planting. Result showed that bast yield, stem yield, bast: stem ratio and total dry matter, were affected by harvest time.  Bast to stem ratio in second harvest time was more than any other times (40.02). Niger cultivar was the best cultivar for stem yield, bast yield and total dry material, also Cubana 2032 and Cubano were the best cultivar for bast to stem ratio with 40.41 and 40.00% respectively. Fiber morphology results showed that interaction between cultivar and harvest time was significant. The bast fiber length increased with plant age in all cultivars except Cuba 2032. Although core fiber length increased with age in 7551, 7566, 9277 and Cuba 2032 cultivars but it decreased, in Niger and Cubano cultivars. The result indicated that kenaf bast fiber were long and slender, while the core fiber were much shorter and wider. Morphology analysis indicated that bast and core fibers were significantly different. The bast fiber dimension was better than the core in the production of quality paper.

Key words: Hibiscus cannabinus, kenaf, harvest time, cultivar, yield, fiber morphology.