Photosynthesis and Growth of Camelina and Canola in Response to Water Deficit and Applied Nitrogen – L Gao, CD Caldwell, Y Jiang – Crop Science 2017

Summary: Nitrogen (N) and water availabilities are two important environmental factors affecting crop growth and yield. Effects of applied N and water deficit imposition on photosynthesis rate (Pn), transpiration rate (E), stomatal conductance (gs), and shoot and root biomass accumulation in camelina [Camelina sativa (L.) Crantz] and canola (Brassica napus L.) were compared in a greenhouse. Water deficit significantly decreased Pn, E, gs, and shoot/root biomass ratio in both crops. The relative reduction of Pn, E, and gs caused by water deficit was greater in canola than in camelina. Under drought conditions, applied N enhanced Pn and gs but had less pronounced effects on E in camelina. Camelina maintained higher Pn at N levels >125 kg N ha−1 under water deficit. In contrast, when exposed to drought, applied N decreased Pn, E, and gs in canola. The shoot/root ratio was more responsive to applied N in camelina, whereas applied N did not affect the shoot/root ratio in canola. Under drought conditions, camelina maintained a higher shoot/root ratio than canola. These results suggest that camelina is more tolerant to drought stress and potentially has greater adaptability to dryland production than canola.