Response to phosphorus of populations of white clover

Abstract

The response to phosphorus (P) of 8 semi-natural populations and 2 cultivars of white clover was investigated in 3 experiments. Vegetatively propagated plants from 15 genotypes of each population were planted into mixed swards, both grazed and cut, and into pure clover swards. These swards received various amounts of fertiliser P. In all 3 experiments, populations collected from low P soils had a higher percentage survival and higher yields than populations collected from high P soils. However, in all 3 experiments, populations from low P soils, on average, were also less responsive to added P than populations from high P soils. 'Grasslands Huia' wa:s among the lowest yielding populations in mixed sward when cut and in pure clover sward. Populations from low P soils had finer root systems than populations from high P soils when grown in pure swards.

Adaptation to low fertility hill country in New Zealand of white clover lines selected for differences in response to phosphorus

“…Selection for high P-response and low P-response populations of white clover in a controlled environment was not effective in producing lasting differences in growth of white clover in a low-P soil environment fertilised to a range of P fertility levels. Other studies have shown a similar disparity between controlled environment and field trials for growth response of white clover to P (Caradus & Snaydon 1986. In the glasshouse, selections were made principally on the basis of response to P, whereas in the present work low P was only one of a number of stresses encountered.…”

An assessment of the spaced-plant trial technique

“…However, significant population x P interactions might have been expected, since the populations have been shown to differ in response to phosphorus (Davies and Snaydon, 1974). The absence of such interactions may partly reflect the relatively small effects of phosphorus on the performance of spacedplants in this study (table 6), but may also be the result of the absence of competition, as shown by Caradus and Snaydon (1986).…”

“…Numerous studies by plant breeders, using both forage species (e.g., Lazenby, 1957;Knight, 1960;Copeman and Swift, 1966) and crop species (e.g., Syme., 1972;Fischer and Kertez, 1976), have shown that only weak correlations exist between the yield of genotypes or populations as spaced-plants and their yield in dense monocultures. Few such comparisons have been made in the context of the ecological genetics of plant species, and the effects of competition on attributes other than yield have received little attention, though Caradus and Snaydon (1986) have compared populations of T repens for a number of morphological and physiological attributes in a diversity of conditions; they found widely different correlations, depending on the particular attributes and conditions considered.…”

“…Under such competitive conditions, differences in initial ramet size may prove to have a greater effect on the relative performance of plants than was found under the non-competitive conditions used in this study, just as differences in initial seed size have proved to have a greater effect under competitive conditions (e.g., Black, 1958, Wultl, 1986. Similarly, the effects of nitrogen and phosphorus supply are likely to be greater under competitive conditions (e.g., Lazenby, 1965;Caradus and Snaydon, 1986).…”

Doğal Meralanrdan Toplanan Ak Üçgül (Trifolium repens L.) Genotiplerinin Performanslarının Belirlenmesi

“…This method also better predictor of similarities or dissimilarities (Marilley 1999;Hebeisen 1997;Deiglmayr 2006;Caradus 1986;Caradus 1992). Table 3 show that describing more than 70%, cumulative percent plant characteristics should be examined in five groups (Eigen value: 1,1254, proportion:0,080,cumulative percent: 76,1%).…”