The intensity of competitive interactions between spring wheat (Triticum aestivum L. emend. Fiori et. Paol) and spring barley (Hordeum vulgare L.) under different fertilisation conditions

Competitive interactions between spring wheat and spring barley were traced based on a pot experiment. In the years 2003-2004, three cycles of the experiment were carried out in a greenhouse. Two spring cereals - wheat and barley, sown in a mixture and in a monoculture, with different mineral fertilisation levels, were the object of evaluation and comparison. The experiment was set up according to the additive scheme, determining dry weight values for both species in 5 growth stages (emergence, tillering, shooting, heading and ripening). Results were used to determine relative yields and competition ratios. It was demonstrated that competition between the cereals started already from the emergence stage and lasted till the end of vegetation, manifesting itself with the greatest strength at the heading stage, but thereafter it weakened in the NPK poorer environment. Access to a larger pool of macroelements resulted in the intensification of competitive interactions. Spring barley used the limited growth factors better than wheat from shooting till the ripening period, and a reverse relation was exhibited only at the tillering stage