Biomass, grain and energy yield in Cynara cardunculus L. as affected by fertilization, genotype and harvest time

A three-year experiment was conducted in Sicily (South Italy) aimed at evaluating the effects of three fertilization levels (low, medium and high) and two harvest times (flowering vs. achenes ripening) on aboveground biomass, grain and energy yield of five Cynara cardunculus genotypes (three cultivated cardoons, one wild cardoon accession and one globe artichoke line). The cultivated cardoons showed the highest aboveground dry biomass yield (on average 26 t ha1 y1), grain yield (on average 1.2 t ha1 y1) and energy yield (on average 450 GJ ha1 y1). Among these, 'Bianco avorio' and 'Gigante di Lucca' were able to maximize their biomass and energetic response under medium fertilization level, and improved, also, their performances along the three-year experiment. The shift in harvest time from flowering to achenes ripening decreased the aboveground biomass yield (grain excepted) (on average, from 21.1 to 19.0 t ha1 y1), but without significant effects on energy yield, as a consequence of the energy obtained from grains. The results show that combining an adequate choice of genotype and agronomical technique can make C. cardunculus a very competitive and sustainable energy crop in Mediterranean environment. Agronomical and breeding innovations are needed to further improve and stabilize crop performances and its agro-ecological sustainability.