Yield potential and adaptation of kenaf (Hibiscus cannabinus) in north-central Italy

In Italy several studies have identified kenaf (Hibiscus cannabinus L.) to be an interesting substitute for woody species utilized for paper pulp production. A field trial was carried out in 1991 and 1992 to evaluate yield potential and adaptability of H. cannabinus cultivars to the growing conditions of north-central Italy. At Cervia (Ravenna), 44.1 degrees N, 12.2 degrees E, 24 cultivars of H. cannabinus have been considered in a biennial experiment based on a randomized block design with three replications. Biomass yield ranged from 7.8 to 23.5 t ha(-1). Stem yield varied between 4.7 t ha(-1) and 17.0 t ha(-1). The most interesting performances have been obtained with a group of 12 varieties with a yield of stem dry matter of >= 15 t ha(-1). Among these genotypes almost all varieties did not reach their flowering stage before harvest time. The dry matter content of stems ranged from 15.9% to 22.5% and plant height ranged from 200 to 314 cm. The basal diameter varied from 15 mm to 21 mm, with an average of 18.3 mm. In 1992 and less so in 1991, botritis attacks have been registered in the later part of the growing period, which, however, did not significantly reduce the yield potential of the crop. Our results show the good yield potential of H. cannabinus, and confirm the possibility of its cultivation under conditions similar to those tested at Cervia. The problems that emerged are low chilling tolerance, photoperiod sensitivity and low genetic variability.