There is a global effort to eliminate the amount of the chemicals used in the production technology, by the introduction of biological and ecological substances. One of the possible solutions is the allelophaty, the use of a chemical interactions between plants. The substances with allelochemical potential are very diverse and are involved in many metabolic processes. These substances belong to different classes of secondary metabolites: phenols, terpenes, alkaloids and can be present in different plants organs.The aim of this paper is to establish an interface between the biochemical study and morphological study of the plants, emphasizing the structural and functional changes that the allelophatic biochemical interactions between plants can induce. The tolerance of Lolium perenne was assessed by the seedlings growing and by the externalization of the morphological characters, after the extracts application that contain pyrrolizidine alkaloids and ergot alkaloids obtained from the aerial part of Dactylis glomerata, Poa pratensis and Festuca rubra plants. The idea of the influence of some chemical substances eliminated in the environment by organisms on other neighboring organisms, was released when the results of some physiologists researchers led to the conclusion that the action of these metabolites is beneficial or not to the neighboring, receivers organisms. Based on the opinion that the plants from a vegetal community associate by the virtue of some " affinities" or "chemical tolerances," it was established an experience in which it was followed the extracts effect on the growth and development of Lolium perenne plants. The determination of the growing and development of the plants treated with extracts was made by biometrization and the applied extract doses were : 10ml/pot, 40ml/pot and 80ml/pot every 7 days. The biometric measurements were performed for the main sprout length, the number of leaves / sprout and the sprouts number. As regarding the influence of the extracts with alkaloids content on the growth and development of perennial ryegrass, the experience has shown that as the amount and the concentration of alkaloids increase, it affects in a negative way the growth and the development of Lolium perenne species.

perennial grasses, synthetic substances, ecological agriculture,extracts allelopathy

Presentation: oral