SEED YIELD OF BRASSICA CARINATA LINES IN LOW AND HIGH ORGANIC FERTILIZATION LEVELS

Reducing agronomic input supply can significantly contribute to decrease the environmental impact of bioenergy cropping systems. Currently, there is a renewed industrial interest in non-food oil crops for different enduses application. Among species from Brassica genus, Brassica carinata A. Braun is an interesting winter annual crop in warm and semi-arid environments and may provide a rotation alternative with cereal crops, sourcing nonedible oil for the industry, additional incomes to the farmers and soil benefits. The present study compared four Brassica carinata lines (GID-6165, GIP-6164, GID-6091, GID-6084) under two different organic fertilization levels (80 and 160 kg N ha-1) in a semiarid Mediterranean area. These four lines have not been tested in Southern Italy previously, nor under the present low-input cultivation practices in semiarid Mediterranean area. Main findings showed a significant fertilization effect (P≤0.05), with the high-input providing higher seed yields and harvest index than low-input. There was no genotype effect, however, the gap between potential (i.e. seed yield at the programmed plant density) and actual yields was rather high for GID-6165 and GID-6080. On the other hand, genotype had the largest effect on the thousand seed weight and the residual biomass yield. In general, GID-6091 and GID-6165 reached seed physiological maturity earlier than GID-6084 and GID-6164 lines. The present study proved that improved B. carinata lines can be grown in semiarid Mediterranean area under low-input organic systems, providing satisfactory seed yields. However, seedbed preparation was noticed to be key to narrow the gap between potential and actual seed yield, particularly under the present clay soil.