Genecology of white clover (Trifolium repensL.) from wet and dry hill country pastures

Abstract
Populations of white clover were collected from north-facing and south-facing aspects of dry and wet hill country farms and compared in a uniform, spaced plant environment. Root systems were compared in another study where plants were grown in field tiles. These populations were also compared with the cultivars Grasslands Huia, Grasslands Tahora, and Whatawhata Early Flowering in both studies. The dry hill country populations as a group were more cyanogenic, larger-leaved, taller, and had larger tap-root diameters and different leaf mark characteristics, than the wet hill country populations. Tahora and Whatawhata Early Flowering both resembled the "dry" populations more than the "wet" populations, except that Whatawhata Early Flowering had a higher percentage of plants flowering early than either collected population group. Huia was larger-leaved, more erect, and had thicker taproots than all other lines in the study. Within dry farms, populations from north-facing aspects had a higher percentage of full V leaf mark but a lower percentage of V point leaf mark than populations from south-facing aspects. Within wet farms, populations from south-facing aspects were more susceptible to stem nematode than populations from north-facing aspects. This study did not support the premise that early and profuse flowering is a feature of naturalised white clover populations in dryland areas. Populations from dry farms were more upright and tap-rooted than populations from wet farms.