Spring growth of lucerne (Medicago sativa L.) after different times of winter defoliation
DOI:
https://doi.org/10.33584/jnzg.2024.86.3684Abstract
The aim of this work was to determine if autumn/winter defoliation affected the time of lucerne stem extension in spring. Two experiments were established at the Field Research Centre, Lincoln University. Experiment 1 was established on 01/06/2022 using an existing two year old stand of “Force 4” lucerne. There were four canopy defoliation dates (1/06, 03/07, 17/07, 1/08). Experiment 2 repeated the treatments on the same paddock in the following year on eight defoliation dates (1/5, 15/5, 1/6, 15/6, 3/7, 17/7, 1/8 and 15/8). In both experiments, five stems were marked in each plot and stem height was measured weekly. The start of stem extension was unaffected by canopy defoliation date in either 2022 (P = 0.20) or 2023 (P = 0.17). Initiation of stem extension was triggered by a base photoperiod of 11.1 ± 0.2 h. This meant the thermal time accumulated from final defoliation to the start of stem extension differed among treatments. These results suggest the time of autumn/winter defoliation (the winter clean-up graze) will not affect the time of the first spring grazing, provided the developing basal buds are not removed. All stands reached 150 mm height by mid-September and produced 3.0 t/ha of dry matter by the end of the month. This suggests, grazing of the first paddock at Lincoln should commence in the first week of September to create a staggered start to rotational grazing that can maximise lucerne yield and quality for animal liveweight production.
Downloads
Downloads
Published
How to Cite
License
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Copyright
This work is licensed under a Creative Commons Attribution-Non Commercial-NoDerivatives 4.0 International License. Rights granted to the New Zealand Grassland Association through this agreement are non-exclusive. You are free to publish the work(s) elsewhere and no ownership is assumed by the NZGA when storing or curating an electronic version of the work(s). The author(s) will receive no monetary return from the Association for the use of material contained in the manuscript. If I am one of several co-authors, I hereby confirm that I am authorized by my co-authors to grant this Licence as their agent on their behalf. For the avoidance of doubt, this includes the rights to supply the article in electronic and online forms and systems.