Interference in pure and mixed populations of Agrostemma githago.

Published online
01 Jan 1982
Content type
Journal article
Journal title
Journal of Applied Ecology

Watkinson, A. R.

Publication language


The response to density of the annual Agrostemma githago were investigated over a wide range of densities in pure populations and also in the presence of a constant density of wheat. In monoculture a 2500-fold variation in the input of seeds gave only a 1.6-fold range of seed output, whilst in the presence of wheat, yield varied to a much greater extent. Considerable self-thinning occurred in both sets of populations at high densities. A. githago responded to increasing density not only through an increase in mortality but also through a reduction in the shoot dry wt. of survivors, the number of capsules/plant, the number of seeds/capsule and mean seed wt. In both pure and mixed populations, density and fecundity of A. githago were negatively related. Mathematical models are developed from the data and used to describe the various interrelationships.

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