CYTOLOGICAL EFFECT OF TILT-250 EC IN THE SUCCESSIVE PHASES OF THE TRITICALE RUST DISEASE PROCESS CAUSED BY PUCCINIA-RECONDITA F-SP TRITICI

The disease process caused by rust (Puccinia recondita f. sp. tritici) in Triticale (triticale-Wittmack cv. Bolero) and the effect of the ap plication of the propikonazole - Tilt 250 EC are described. In plants not protected chemically one could observe the whole pathogen developm ental cycle ending with the appearance of uredinia with urediniospores . The highest pathogen susceptibility to chemical agent was observed a t the time of inoculation, during incubation and at the beginning of t he actual disease. By inhibiting the ergosterol biosynthesis in the fu ngus cells the preparation (propikonazole) inhibited the development o f the intra- and extracellular mycelium. The mycelium degeneration man ifested itself by the irregular growth of intercellular hyphae, perfor ation of septa, homogenization of protoplasts and cell collapse. The t hickening of the cell wall, modification of the perihaustorial space a nd protoplast obliteration were observed in the haustoria.