Experimental results are brought together to demonstrate that forage kale population improvement involving full-sib and selfed families can be done on an annual cycle, followed by production of a synthetic cultivar. Furthermore, this new breeding method compares favourably with the two successful methods used to date, namely triple-cross hybrid cultivars from inbreeding and crossbreeding programmes and open-pollinated cultivars from population improvement programmes. The key findings were that natural vernalization of kale in south east Scotland occurred by mid-December so that plants could be pollinated in a glasshouse with heating and lighting by the end of February and seed harvested by the end of May. The resulting full-sib or selfed families could be assessed in a field transplant trial in the same year, from June to November, thus completing an annual cycle. Self-pollination resulted in shorter plants with lower fresh-weight, dry-matter and digestible organic-matter yields, and undesirably higher contents of S-methylcysteine sulphoxide, the haemolytic anaemia factor, and the goitrogenic thiocyanate ion. As a consequence of digestible organic-matter yield being reduced by as much as 22%, the estimated optimum number of selfed parents in a synthetic cultivar was four to eight. Synthetic cultivars are expected to yield as well as triple-cross hybrids as there was no reduction in yield when the latter were open-pollinated.

实验结果汇集在一起​​，以证明涉及全同胞和自交家庭的饲草羽衣甘蓝种群改进可以按年度循环进行，然后生产合成栽培品种。此外，这种新的育种方法与迄今为止使用的两种成功方法（即近交和杂交计划的三交杂交品种和种群改良计划的开放授粉品种）相比具有优势。主要发现是，苏格兰东南部羽衣甘蓝的自然春化在 12 月中旬发生，因此植物可以在 2 月底前在带暖气和照明的温室中授粉，并在 5 月底前收获种子。由此产生的全同胞或自交家庭可以在同年 6 月至 11 月的现场移植试验中进行评估，从而完成一个年度周期。自花授粉导致植株矮小，鲜重、干物质和可消化有机物质的产量较低，S-甲基半胱氨酸亚砜、溶血性贫血因子和致甲状腺肿的硫氰酸根离子含量过高。由于可消化有机物产量减少多达 22%，因此合成品种中自交亲本的估计最佳数量为 4 到 8 个。预计合成栽培品种的产量与三交杂种一样，因为当后者进行开放授粉时，产量不会降低。和致甲状腺肿的硫氰酸根离子。由于可消化有机物产量减少多达 22%，因此合成品种中自交亲本的估计最佳数量为 4 到 8 个。预计合成栽培品种的产量与三交杂种一样，因为当后者进行开放授粉时，产量不会降低。和致甲状腺肿的硫氰酸根离子。由于可消化有机物产量减少多达 22%，因此合成品种中自交亲本的估计最佳数量为 4 到 8 个。预计合成栽培品种的产量与三交杂种一样，因为当后者进行开放授粉时，产量不会降低。