ABSTRACT

The production and pest susceptibility of eight clover cultivars were compared over two years in the pasture at two contrasting sites: a rain-fed Waikato cattle-grazed pasture and an irrigated Canterbury dairy pasture. The cultivars were four white clovers (Trifolium repens L.) (Grasslands Kopu II, Grasslands Mainstay, SF Quest and Weka), two red clovers (T. pratense L.) (Grasslands Relish, Rubitas), a strawberry clover (T. fragiferum) (Palestine) and a white clover × Caucasian (T. ambiguum M. Bieb.) hybrid (Aberlasting). Grasslands Relish outperformed all other clovers and was associated with the fewest root-damaging nematodes. Both red clovers were less susceptible to insect pests than the white clovers, but Rubitas was vulnerable to root pathogens in Waikato. The poorest performing cultivar was Aberlasting, which was the most susceptible cultivar in all pest and disease measures. The white clovers and strawberry clover performed similarly across most measures. An assay using soils from each site showed that clover seedlings grown in pasteurised Waikato soil were almost ten times larger than those in the non-pasteurised soil whereas pasteurisation made no significant difference with the Canterbury soil. This study demonstrated that root health was a major factor in the contrasting site and cultivar differences in the early years of production.

摘要

在两个对比地点的牧场中比较了八种三叶草品种的产量和害虫易感性两年多的时间：雨养怀卡托放牛牧场和灌溉坎特伯雷奶牛牧场。栽培品种是四株白三叶草 ( Trifolium repens L.) (Grasslands Kopu II, Grasslands Mainstay, SF Quest 和 Weka)，两株红三叶草 ( T. pratense L.) (Grasslands Relish, Rubitas)，一株草莓三叶草 ( T. fragiferum )（巴勒斯坦）和白三叶草 × 高加索人（T. ambiguumM. Bieb.）混合（Aberlasting）。Grasslands Relish 的表现优于所有其他三叶草，并且与破坏根部的线虫有关。两种红三叶草都比白三叶草更不容易受到害虫的影响，但 Rubitas 在怀卡托很容易受到根部病原体的侵害。表现最差的品种是 Aberlasting，它是所有病虫害措施中最易感的品种。白三叶草和草莓三叶草在大多数测量中的表现相似。使用来自每个地点的土壤进行的分析表明，在巴氏杀菌怀卡托土壤中生长的三叶草幼苗几乎是在非巴氏杀菌土壤中生长的三叶草幼苗的十倍，而巴氏杀菌与坎特伯雷土壤没有显着差异。