Establishing tagasaste from seed in Waikato hill country

<p>Tagasaste (tree lucerne) can be difficult to establish from seed due to its hard seed coat and high levels of seedling mortality. Three experiments were performed. Experiment 1: Effect of gibberellic acid, potassium nitrate, seed nicking + soaking in warm water (38^oC for 24 hours), soaking seeds in boiling water and a coldwater control on germination. The highest germination percentage occurred from the warm and boiling water treatments. Experiment 2: Effect of slug bait, rhizobia and phosphorus fertiliser on establishment of tagasaste seed which had been hand sown into a herbicide-treated pasture. Of the 1600 hand-sown seeds, emergence was negligible, and no treatments varied significantly from the untreated control. Greater pasture suppression is required for successful establishment. Experiment 3: Examined removal of 20%, 40%, 60% or 80% of the height of a seedling on tagasaste branching. Branch number was similar for all treatments 83 days after trimming the main stem. Removing 20% or 40% of the seedling height produced three-fold greater edible dry matter than when 80% of the seedling height was removed (P<0.001). Although pruning treatments did not affect branch number, a less severe pruning regime resulted in the regrowth of the greatest amount of edible dry matter.</p>