Limited water supply on Kenaf( Hibiscus cannabinus L.) in central Italy

The prospects for kenaf becoming an alternative crop for fibre production are dipendent on the possibility of obtaining large enough amounts of biomass at low production costs. This paper presents the results of three-year trial carried out in three locations of Central Italy wich aimed at examining how kenaf respond to limited water supply. Two kenaf varieties, G4 and Tainung 2, were submittedto a comparison using different irrigation treatments based on two criteria: 1) replacement of 33%, 66% and, only at Perugia, also 100% of evapotranspiration (A33, A66 and A100 treatments); 2) restoration of field capacity at given stages of the crop cycle: F2 and F3 treatments (2 and 3 applications, respectively). Two or three harvests were done to evaluate both the yield at the end of the cycle and moisture loss. At Grosseto and Rome, at the mid-October harvest, Tainung 2 provided on average 13 t/ha and 26 t/ha of dry matter (DM) stems, respectively, with a restoration of 66% of evapotranspiration. These yields were obtained with a high number of applications (3-6). Limiting the water supply to only two applications, some 13 t/ha DM were obtained at Grosseto and 25 t/ha at Rome. A third irrigation (F3) produce no significant advantages with respect to F2. At Perugia, two irrigations were not sufficient to achieve the yield results obtained by the plots that were watered more (12.5, 15.3 and 18.9 t/ha for F2, A66 and A100, respectively). The three-year results have shown that kenaf adapts well to being grown on the plains of Central Italy. At Rome and Grosseto the yields were particularly intersting especially with regard to the reduction of irrigation water.