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 m3/h) 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:

10 traps are placed in regions of intensive oilseed rape breeding across the country:
  1. Pomerania region (Experimental Station for Variety Testing in Rarwino near Kamien Pomorski);
  2. Pomerania Lakeland (Experimental Station for Variety Testing in Radostowo near Tczew);
  3. Mazuria and east Varmia ( Agro Fundusz Mazury in Drogosze);
  4. Great Poland (Institute of Plant Genetics PAS in Poznan);
  5. Mazovia (Experimental Station for Variety Testing in Glebokie near Kruszwica)
  6. Sudethian Foothills – Lower Silesia (Experimental Station for Variety Testing in Tarnow near Zabkowice Slaskie);
  7. South part of the Opole region (commercial enterprise “Arenda” in Charbielin);
  8. Lubuskie – Lower Silesia region (Institute of Plant Protection, Department in Sosnicowice near Gliwice);

  1. Carpathian Foothills and Cracow region (Krasne near Rzeszow and Department of Agrobiology and Envionment Protection at University of Rzeszow)
  2. Lublin region (Institute of Soil Science and Plant Cultivation in Pulawy).

The spatial scope of forecasting of each trap is defined on the basis of climatic regions of Poland (Wiszniewski and Chelchowski, 1987). Where there are two traps in the same region or where they are situated on the borderline of two or more regions, then as far as climate is concerned we make corrections for the specific location of each trap.

 

Monitoring of pseudothecia maturation

Fruiting bodies are divided into pycnidia (anamorph stage, producing pycnidiospores) and pseudothecia (teleomorph, producing ascospores). Pycnidiospores are unable to infect plants grown in different fields whilst ascospores produced in pseudothecia are released after rainfall and may infect the rapeseed plants over a wide area. Pseudothecia are divided into five classes of maturation A-E and among them the most infectious is class D with 8 fully mature ascospores in each ascus. Out of 44 locations, 10 of the pseudothecial maturation sampling sites correspond to ascospore trap locations and the remaining pseudothecial maturation sampling sites are located in other parts of the climatic regions or in the borderline areas between these regions.
Monitoring encompasses 45 locations in all provinces of Poland :

  • Lower Silesia: Tarnow, Zloty Potok
  • Kujavia and Pomerania: Glebokie, Naklo
  • Lublin region: Bezek, Lesniowice, Pulawy
  • Gorzow region: Malyszyn, Szprotawa, Świebodzin
  • Lodz region: Koscierzyn, Maslowice, Annoslaw, Walewice
  • Cracow region: Wieliczka
  • Mazovia: Radom, Radzikow, Siedlce
  • Carpathian Foothills: Krasne
  • Suwalki region: Lyski, Suwalki
  • Pomerania: Radostowo
  • Upper Silesia: Sosnowiec, Sosnicowice, Zawada, Zory
  • Swietokrzyskie region: Modliszewice
  • Warmia; Mazuria: Biala Piska, Drogosze, Warkały
  • Great Poland: Baborowko, Bielawy, Cerekwica, Jerka, Pawlowice, Dolaszewo, Poznan, Strzalkowo, Szczodrzykowo
  • West Pomerania: Szczecin, Rarwino

The results concernig pseudothecia maturity in Swietokrzyskie and Upper Silesia regions are shown as points on the map in the recent news column. Rapeseed cultivation is at risk of stem canker disease if class D pseudothecia are present. Private people, who gave us access to their fields and gardens, experimental stations of Research Center for Cultivar Testing, Plant Breeding Station in Strzelce (branch Malyszyn), experimental stations of IPG PAS, Research Center for Agricultural and Forest Enironment, Institute of Soil Science and Plant Cultivation, ecological station of Adam Mickiewicz University as well as commercial agricultural centers in Mazovia, Swietorzyskie and Lodz region take part in monitoring pseudothecia maturity.