A review of the role of grazing management on the growth and performance of white clover cultivars in lowland New Zealand pastures

Abstract

The current state of knowledge of white clover clonal growth processes and defoliation management is reviewed, and general recommendations on grazing principals made. Defoliation frequency determines herbage productivity through the manipulation of size/ density compensation between plant organ size (leaves) and numbers of growth units (growing point density). Hence large-leaved cultivars (Pitau, Kopu, Aran) are generally more productive under rotational grazing, whereas small-leaved cultivars are better suited to frequently grazed or set stocked conditions (Tahora, Prestige). The key to persistence is high growing point density, and the development of large-leaved densely branched cultivars should have superior performance over a wider range of grazing managements (Demand, Sustain). Grasses (perennial ryegrass, cocksfoot and tall fescue) grow by similar clonal processes to white clover and react in a similar manner to grazing management. Maintenance of pasture density (growing points/tillers) is crucial to persistence and is best achieved by rapid rotations or set stocking during spring/early summer. This provides protection against drought, and allows better exploitation of the genetic potential of species and cultivars through alternative grazing strategies over the remainder of the year. Keywords: clonal growth, cultivars, grazing management, morphology, populations, rotational grazing, seasonal growth patterns, set stocking, Trifolium repens L., white clover