EFFECT OF SOWING TIME ON SEED PRODUCTION OF KENAF ( HIBISCUS CANNABINUS L . ) IN SICILY *

Kenaf is an interesting crop for fibre production and a good source of biomass for cellulose. Its high sensitivity to photoperiod limits seed production to the semi-arid environments of Southern Europe. With the aim of studying the effects of sowing time on seed yield, as an additional product of biomass, in a cultivar of kenaf cultivated in Sicily, ten sowings in total, ranging from late May to late July, were carried out in the two-year 200001. Irrespective of sowing time, flowering occurred in a rather restricted period (late September early October). In the average of the first sowing dates (late May) the crop produced almost 27 t ha of total biomass and 3.2 t ha of seeds. The delay of sowing time negatively affected dry biomass accumulation and decreased the pod percentage on total dry biomass. Sowings beyond half June significantly compromised seed yield that, in all cases, did not reach 1.8 t ha. Among components, number of total pods per plant affected seed yield, significantly varying with sowing date. A close correlation was found between the length of the interval ‘plant emergence-flowering’ and seed yield; in particular, the longest the interval, the highest the yield. The duration of the interval “plant emergence-flowering” decreases from 109 to 77 days with the reduction of the average photoperiod from 13.3 to 12.4 h.