Growth pattern of tall fescue and alfalfa mixture under different water regimes

The interspecific interferance in grass – legume mixtures results in growth pattern changes of the above ground part of plants. This pattern was measured in a 1:1 mixture of tall fescue (Festuca arundinacea) and alfalfa (Medicago sativa). A pot experiment was conducted in Drama Nothern Greece, frοm March to July 1994. Two water regimes were applied: irrigation up to the field water capacity and irrigation using the ¼ of the water used in the previous treatment, so that plants are grown under drought conditions. Above ground biomass of each plant, leaf area and LAR of the mixture were measured. Also, the ratio of above ground biomass of tall fescue to alfalfa was calculated. The results showed that the drought decreased above ground biomass, Leaf Area Index (LAI) and Leaf Area Ratio (LAR) of the mixture. The same treatment affected the seasonal changes of production and the species ratio in the mixture as well. In the irrigation treatment, tall fescue participation decreased. On the contrary, in the drought treatment its competitive ability was improved and its participation in the mixture was kept in high levels.