A comparative study of oilseed crops (Brassica napus L. subsp. oleifera and Brassica carinata A. Braun) in the biodiesel production chain and their adaptability to different Italian areas

The Extravalore project aims to give added value to oilseed crops, considering them also for producing multiple products with the same economic value and being interesting for the market thanks to their various utilizations.An evaluation of the main cultivars of Brassica napus subsp. oleifera and Brassica carinata has been performed within the project, analyzing them in three Italian locations with different climatic conditions (Palazzolo dello Stella - North Italy, Osimo - Central Italy, Cassibile - South Italy) to assay their adaptability and production potential.During the 2010-2013 period, 43 varieties of rapeseed were evaluated, but only 13 of them for all the period considered; moreover, also 4 varieties of B. carinata were tested.The seed yields of tested cultivars of rapeseed varied a lot among locations, depending also by the seasonal trend. Central Italy was the less disadvantaged by climatic conditions: on average, it was reached a seed yield of 4tha-1, a theoretical oil production of 1.63tha-1 and more than 8tha-1 of crop residues. In Northern and Southern Italy, if compared with Central Italy values, the seed yields were both lower than 30% and theoretical oil productions lower than 60%; moreover, crop residues in Northern Italy were 12% lower than in Central Italy while in Southern Italy 65% lower. The agronomic behavior of varieties differed a lot among the three experimental areas: DK Expower was the best at North; Albatros, Artoga, Exagone and Excalibur in Central Italy; Excalibur, Zoom and PR46W14 at South Italy but none of them reached a seed yield of 2tha-1.Concerning B. carinata, the cultivars did not give good productions in any of the experimental areas, mainly because of the low oil content in the seeds. Even in Central Italy, where the best results were registered, the seed yield was on average 28% lower than in rapeseed and oil production 10% lower; the crop residues were double than rapeseed. In any case, the valorization of the crop residues is important with a wide range of possible utilization from the direct energetic use to the biochemicals extraction with consequent environmental advantages due to the substitution of dedicated or fossil feedstock with crop residues.