Effect of fungicide application on seed yield of perennial ryegrass

In four plot experiments established according to random blocks, application effectiveness of propiconazol + carbendazim (Tilt), propiconazol + fenpropimorph (Archer), flusilazol + carbendazim (Alert) and epoxiconazol + crezoxim-metil (Juwel) pesticides regarding the infection by fungal diseases of plant inflorescence structure, biological floret site utilisation, thousand seed weight and harvested seed yield of perennial ryegrass cv. Anna (2n) and cv. Maja (4n) was analysed. The Archer preparation was found to be the most effective, both in the case of Anna and Maja cultivars. Its application was found to increase seed yield in Anna and Maja cultivars by, respectively, 21,5% and 14,5%. Yield harvest was increased, primarily, due to improved plant health and biological floret site utilisation. On the basis of the analysis of profitability index, it turned out that the application of all the examined fungicides in seed plantations of Anna and Maja cultivars of perennial ryegrass was economically justified.