Patterns of nodal rooting in Trifolium repens (L.) and correlations with stages in the development of axillary buds

Abstract

Forty per cent of while clover nodes had roots when a pasiure was rotationally grazed by sheep compared with 29% when grazed continuously by set stocking. Nodal roots were most frequent during spring and least frequent during summer. About 5% of nodes had a root primordium which had not developed but was still viable. A high proportion of nodal roots (66%) occurred within 10 nodes of the apex. Root presence was highly correlated with the establishment and survival of branches but was less closely related to branch initiation or the viability of axillary buds. It is suggested that the association between nodal roots and branches is strongest when resources are limited, and that root survival at a node is enhanced by the presence of a branch originating at the same node.

Morphological plasticity of white clover (Trifolium repens L.) in response to spatial and temporal resource heterogeneity

“…One possibility is that the difference in their responses was the result of intrinsic seasonal effects. In New Zealand pastures, for example, seasonal temperature and moisture regimes (Chapman 1983;Newton and Hay 1994) result in higher stolon elongation rates of clover in summer (Chapman 1983; see also Sackville Hamilton and Harper 1989). Nodal activity, however, is markedly lower in early spring and highest during autumn and winter ).…”

Testing simulations of intra‐ and inter‐annual variation in the plant production response to elevated CO2 against measurements from an 11‐year FACE experiment on grazed pasture

“…Some N fixed by legumes can become available to other species (particularly the C3 grasses in this instance) very rapidly through exudation (Wacquant et al ., ) or through grazing animals, however, much of the N becomes available over time, often many months, as the nodules and plant organs, especially the roots, of the legumes senesce and release N (Broadbent et al ., ; Ledgard, ). The period of greatest legume senescence in the environment of the FACE experiment is at the start of spring when there is maximum decay of both stolons (Brock et al ., ; Hay & Kelly, ) and roots (Newton & Hay, ). This coincides with the period of maximum pasture growth rates – spring growth contributing 63% of total annual production over the 11 years of the experiment.…”

Distribution of phosphorus and calcium from nodal roots of Trifolium repens: the relative importance of transport via xylem or phloem

“…o TT inn<N TT I i j & Hay, 1994), Hence plants can have non-rooted Trifolium repens L, (white clover) is a plagiotropic sections of stolon where leaves, branches or flowers species that persists in moist, temperate environ-are dependent on the distribution of resources from ments via clonal growth. The apical meristem nodal roots located on nodes distanced from them, continually differentiates new nodes spaced by Pre\'ious studies using T. repens have shown that internodes of variable length and acquires a new radioactive phosphorus (^~P) exported from a nodal meristem whenever an axillary bud at a node root is translocated mainly acropetally (Keniball & develops to form a branch.…”