Wybrane zagadnienia z epidemiologii brunatnej plamistości liści pszenicy i pszenżyta – charakterystyka i znaczenie źródeł infekcji pierwotnej [Some topics in tan spot epidemiology – characteristic and significance the sources of primary infection]

Abstract

The aim of this studies was characteristic of the sources of primary infection for tan spot. During the period 1998–1991 the development of ascomata and conidimata of Pyrenophora tritici-repentis on naturally infected wheat and triticale straws was monitored. The process of pseudothecia formation was extending over the time. It started immediately after harvest and protothecia of the fungus was commonly occurred each year already in the fall. The first fruit bodies with maturated typically pigmented ascospores were observed in January 2001 and in February 1998 and 1999. The percentage of pseudothecia with maturate ascospores successively increased richening maximum in April when the massive liberation of spores from asci occurred. After the total ascospore release on surface of empty ascomata aroused conidiophores with conidia which may also act as inoculum source. Moreover this type of sporulation was observed directly on over wintered cereals stems especially after prolonged period of rains. The present studies indicated also on infected by P. tritici-repentis wheat and triticale seeds as a source of inoculum for tan spot.