Allelopathic effect of preparations of Betula pendula Roth., Chamomilla recutita L. and Urtica dioica L. on the initial growth of Hordeum vulgare L.

Abstract

The experiment investigated the effect of preparations of Betula pendula, Chamomilla recutita, and Urtica dioica on the initial growth of Hordeum vulgare under laboratory conditions. The experiment involved a water solution of sap from the trunk of B. pendula, an infusion from Ch. recutita, extracts from leaves and rhizomes as well as macerated herbage of U. dioica, at the concentrations of 2.5%; 5%; 10% and 20%. During the first four days of the growth of the test plants, the plant preparations tested had a stimulatory effect on the length of leaves and roots in all the cases. The leaf increases were greater than those of the roots and became smaller with an increase in the concentration of the preparations. Continued watering of H. vulgare seedlings resulted in a further increase in leaf length after the application of U. dioica macerate and Ch. recutita infusion, with a simultaneous increase in root length with the macerate of U. dioica and B. pendula sap used at the concentrations of 2.5–10%. The other extracts made from U. dioica leaves and roots, irrespective of the concentration applied, strongly reduced the increase in leaves and roots from 11 to 27%. The weight of roots and leaves in H. vulgare, over the entire range of the concentrations applied and irrespective of the duration of the experiment, was stimulated only by B. pendula sap. The extracts from Ch. recutita and U. dioica, especially the leaf and root extracts, significantly reduced the root weight of the test plant.