Spore trap operation
Monitoring of Leptosphaeria maculans and L. biglobosa spore density in the air is performed continuously between 1st September and 30th November (autumn) and 1st March and 31st May (spring) by means of 7-day volumetric spore trap (Burkard Manufacturing Inc., UK and Lanzoni, Italy). The traps suck in air actively (10 l/min) together with hovering spores and pollen which are deposited inside the trap on a tape covered with vaseline. The tape is fixed to a clockwork drum that rotates at 2 mm/h. After one week the tape is removed from the drum and cut into 48 mm pieces, each representing 24 hours of trap operation. Observation of the tape slides under the microscope can determine when exactly (day and hour) spores were present in the air. As the speed of air flow is known and constant, it is feasible to estimate precisely the concentration of spores in 1 m3 of air. A value of 1 on the graph (Y axis) means that in 1 m3 of air one spore was present in a given day (X axis), a value of 100 means that in 1 m3 of air 100 spores were present. Volumetric spore samplers trap spores of various fungal species as well as various pollens. Spores of L. maculans and L. biglobosa have a specific shape and definite size, thus they are easily recognizable among other spores. Ascospores of both Leptosphaeria species are similar, therefore it is impossible to identify species by means of microscopic observation (spores can be one of the mentioned species or both in different proportions).
Location of traps in Poland:
9 traps are placed in regions of intensive oilseed rape breeding across the country:
- Pomerania region (Margowo);
- Pomerania Lakeland (Experimental Station for Variety Testing in Radostowo near Tczew);
- Mazuria and east Varmia (Agro Fundusz Mazury in Drogosze);
- Great Poland (Institute of Plant Genetics PAS in Poznan);
- Mazovia (Experimental Station for Variety Testing in Glebokie near Kruszwica)
- Lubuskie and Lower Silesia region (Experimental Station for Variety Testing in Kroscina Mala);
- Sudethian region (“Arenda” in Charbielin);
- Carpathian Foothills and Cracow region (University of Rzeszow)
- Lublin region (Lublin University of Life Sciences)
The spatial scope of forecasting of each trap is defined on the basis of climatic regions of Poland (Wiszniewski and Chelchowski, 1987).
Wiszniewski W., Chełchowski W. (1987) Regiony klimatyczne. W: Atlas hydrologiczny Polski. Wydawnictwa Geologiczne, Warszawa