Previous research demonstrated that the interval between defoliation treatments based on the leaf stage is a promising tool for the management of annual ryegrass (Lolium multiflorum L.) pasture. The use of this tool, which is based on the physiological status of the plant, could also benefit the seed production. We assessed the effects of the time of defoliation based on leaf stage on seed yield and quality of annual ryegrass cut to three residual stubble heights (RSH) (50%, 25% and 0% of plant height pre-defoliation) and a second defoliation applied to certain treatments based on the leaf stage of the plant regrowth (two or three leaves per tiller). Higher defoliation intensities (lower RSH) increased the amount of harvested forage to 4.0 t DM ha^–1. Moderate defoliation (50%) undertaken at the 3-leaf stage combined with intense defoliation (25% and 0%) at the 2-leaf stage resulted in the highest seed yields (1.8 t ha^–1). However, lower RSH reduced mean seed weight and physiological seed quality, which was also associated with lower seed starch and protein content. Accelerated ageing (AA) tests were used to compare seed vigour between treatments. A second defoliation at the 3-leaf stage plus intense defoliation (RSH 0%) resulted in seed lots with a high rate of lipid peroxidation after the AA test, followed by lower catalase activity, germination, and seedling growth. The combination of a second defoliation at the 3-leaf stage and the retention of higher RSH (50%) promoted a greater proportion of leaf blades in the stubble, with a strong positive correlation with seed production and vigour. Antioxidant enzyme activity after the AA test is an important marker of annual ryegrass seed quality.

先前的研究表明，基于叶期的落叶处理间隔是管理一年生黑麦草 ( Lolium multiflorum L.) 牧场的有前途的工具。这种基于植物生理状态的工具的使用也有利于种子生产。我们评估了基于叶期的脱叶时间对一年生黑麦草的种子产量和质量的影响，该黑麦草切割至三个残余留茬高度 (RSH)（脱叶前植物高度的 50%、25% 和 0%）和第二次脱叶根据植物再生的叶子阶段（每个分蘖两到三片叶子）应用于某些处理。较高的落叶强度（较低的 RSH）将收获的牧草量增加到 4.0 t DM ha ^–1. 在 3 叶期进行的中度脱叶 (50%) 与在 2 叶期进行的强烈脱叶（25% 和 0%）相结合导致最高的种子产量（1.8 t ha ^–1）。然而，较低的 RSH 降低了平均种子重量和生理种子质量，这也与较低的种子淀粉和蛋白质含量有关。加速老化 (AA) 测试用于比较处理之间的种子活力。在 3 叶阶段的第二次落叶加上强烈的落叶 (RSH 0%) 导致在 AA 测试后具有高脂质过氧化率的种子批次，随后是较低的过氧化氢酶活性、发芽和幼苗生长。3 叶期的二次落叶和较高 RSH (50%) 的保留相结合，促进了留茬中叶片的更大比例，与种子产量和活力呈强正相关。AA 测试后的抗氧化酶活性是一年生黑麦草种子质量的重要标志。