Effect of intra-specific competition on development and growth of Alopecums myosuroides Hudson

Observations were made on the effects of different levels of plant density and nitrogen nutrition on the development and seed production of a weed (Alopecurus myosuroides Hudson). Experiments were conducted in two greenhouses with one plant per pot in order to avoid competition for nitrogen absorption. The density effect was studied by increasing the number of pots per unit surface. The results indicated that the leaf and tiller appearance rates were modified by nitrogen availability on plant density. The lack of nitrogen and higher plant density increased the leaf and tiller appearance rate. Growth and seed production was strongly influenced by the plant density, and the increased nitrogen availability at a given density did not modify the values of growth parameters. Some parameters as flowering time or seed viability were not modified in our experiment conditions. Possibilities of using these results in cropping systems to improve the control of A. myosuroides are discussed.