1 Department of Statistics, University College Dublin, Dublin 4, Ireland
Institute of Crop Science and Plant Breeding - Grass and Forage Science/Organic Agriculture, University of Kiel, 24098 Kiel, Germany. mwach{at}email.uni-kiel.de
In attempting to increase the reliability of clover contribution in clover/ryegrass systems it is important to understand the roles of (1) specific traits of the clover genotype (2) climate and (3) their interactions in determining clover behaviour in swards. Overwintering and spring growth of white clover (cultivars AberHerald and Huia) grown in binary mixtures with perennial ryegrass were measured at 12 European sites ranging in latitude from Reykjavik, Iceland (64°30' N) to Pordenone, Italy (46°30' N). In the overwintering period, tiller density of the grass was assessed and detailed morphological and chemical measurements were made on the clover at each sampling time. During the growing season, the clover contribution to total available biomass was recorded. Detailed climatic data were available at all sites. The annual growth cycle of swards was divided into four functional periods (spring, summer, autumn and winter). Within each functional period community responses were modelled. The models incorporated independent biotic variables characterizing each community within each site at the start of the period and independent variables characterizing the climate at each site during the period. The models were linked dynamically by taking, as response variable(s) for a functional period, the independent biotic variable(s) of the succeeding period. In general, the modelling strategy was successful in producing a series of biologically meaningful linked models. Essential prerequisites for this were (a) the establishment of a well-devised common protocol prior to the experiment and (b) the extensive gradients of climatic and other variables obtained by using numerous sites. AberHerald generally performed as well as, or better than, Huia throughout the annual cycle across the range of climatic conditions encountered, and especially under low temperature conditions in winter and autumn. Clover leaf area index appeared to be a key variable in determining clover performance over winter and through the following growing season. Grass tiller density had a strong negative effect on clover content in spring but only at low temperatures. This emphasizes the importance of a high clover leaf area index in autumn as the main biotic factor related to spring clover content in milder conditions. The importance of climatic variables in the models is their use in explaining the reliability of the contribution of clover in clover/ryegrass systems. Temperature was the primary climatic determinant of clover response in all periods, having a direct effect on clover content and leaf area index or mediating the effect of the associate species. Radiation strongly influenced clover dynamics during winter and spring but not in the other periods, possibly because it was confounded with the effect of higher temperature. Precipitation was positively related to clover growth during spring and autumn and was related to tiller density in a complex manner during autumn and winter.
Trifolium repens, white clover, AberHerald, Huia, Lolium perenne, perennial ryegrass, competition, overwintering, winter hardiness, spring growth, clover proportion, plant morphology, carbohydrate reserves
Submitted on April 19, 2001
© 2001 Annals of Botany Company
Overwintering and Growing Season Dynamics of Trifolium repens L. in Mixture with Lolium perenne L.: A Model Approach to Plant-environment Interactions
2 Institute of Grassland and Environmental Research, Aberystwyth SY23 3EB UK
3 Department of Plant Sciences, Crop and Weed Ecology, Wageningen University, Haarweg 333, 6709 RZ Wageningen, The Netherlands
4 SLU, Department of Ecology and Crop Production Science, Box 7043, SE-75007 Uppsala, Sweden
5 Departement voor Plantengenetica en-veredeling, Caritasstraat 21, 9090 Melle, Belgium
6 INRA—UMR Agronomie et Environnement Ensaia, 2, Avenue de la Forêt de Haye, F-54505 Vandoeuvre-les-Nancy Cedex, France
7 The Agricultural Research Institute, Keldnaholt, 112 Reykjavik, Iceland
8 Institute of Plant Sciences, Swiss Federal Institute of Technology (ETH), CH-8092 Zurich, Switzerland
9 Teagasc Research Centre, Athenry, Co. Galway, Ireland
10 Agricultural Research Centre of Finland, Resource Management Research, Karilantie 2A, FIN-50600 Mikkeli, Finland
11 Servizio Agricoltura—Aziende Sperimentali e Dimostrative Provinca di Pordenone, Via G. Ferraris 20, I-33170 Pordenone, Italy
12 Institute of Crop Science and Plant Breeding-Grass and Forage Science/Organic Agriculture, University of Kiel, 24098 Kiel, Germany
13 Chair of Grassland Science, Technische Universität München, D-85350, Freising-Weihenstephan, Germany
Revised on May 11, 2001
Accepted on June 1, 2001
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  M. A. Sanderson, R. A. Byers, R. H. Skinner, and G. F. Elwinger Growth and Complexity of White Clover Stolons in Response to Biotic and Abiotic Stress Crop Sci., November 1, 2003; 43(6): 2197 - 2205. [Abstract] [Full Text] [PDF]
|
|