ISHS Acta Horticulturae 700: International Symposium Towards Ecologically Sound Fertilisation Strategies for Field Vegetable Production
EFFECT OF TEMPORARY N LIMITATION ON GROWTH, DEVELOPMENT, AND N UTILIZATION BY TWO CAULIFLOWER CULTIVARS (BRASSICA OLERACEA L. BOTRYTIS) |
| Authors: | M. Rogolini, C. Bissuel-Bélaygue , P. Leterme |
| Keywords: | nitrogen deficiency, dry matter, leaf expansion rate, root development, N partitioning, N remobilisation, genotypic N efficiency |
| Abstract:
Cauliflower crops in Brittany are characterised by intensive fertilizer application, including use of organic input. Management of lower N input could induce periods of N deficiency for the plants. In this study, we investigated the effect of a temporary N-limitation on growth, development and N use on two cauliflower cultivars, C5 and C10. An experiment was performed in a plastic tunnel, with individual plants grown in sand until 80 days after sowing (DAS). A non limiting N supply was maintained in control treatment. A limiting N supply (10% of the need of control plant) was applied from 53 to 67 DAS in the N-limited treatment. Results show that dry weight (DW) of N-limited plants was not significantly affected before 80 DAS, but development and dry matter partitioning differed between cultivars. For C5, absolute growth rate (AGR) of expanding leaves was strongly reduced, whereas leaf number per plant and root DW were not affected. On the contrary, for C10, AGR of expanding leaves was less affected, whereas leaf number and root DW decreased. During the N limitation for both cultivars, N concentration in DW as well as percentage NO3--N of total N decreased strongly compared to the control. N-limited plants remobilized about 40% of internal N present on day 53, while control plants about 12%. Following day 67, when N supply was no more limited, N status of N-limited plants recovered partly. If no difference in N use efficiency was noticed between cultivars in terms of plant dry matter production, differences were determined on plant development, leaf expansion and N allocation between organs. | |
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