Morphology and field performance of Brassica transplants propagated under different day and night temperature regimes

Abstract

Brussels sprouts, cabbage and swede were propagated under different temperature regimes to determine if morphology and final yield of plants were influenced by the difference (DIF) between the mean day and night temperature during propagation. For all species, transplant hypocotyl and petiole were shorter under negative DIF than under positive and zero DIF. The investment of assimilates in leaves relative to petioles and hypocotyls was highest under negative temperature difference, and the strategy for dry matter partitioning seemed to be an important component of the response to temperature difference in brassicas. Temperature treatment during propagation influenced the amount and quality of the final yield. The elongated swede transplants from positive DIF later gave more cylindrical roots with a lower market value than those from the other temperature treatments. Brussels sprouts and cabbage transplants propagated under negative DIF yielded better than transplants propagated under positive DIF.