An examination of assessor variation during spore counting on spore traps of <i>Neonectria fuckeliana</i>


  • A.J.M. Hopkins
  • M.A. Dick



In an investigation of the forest fungus Neonectria fuckeliana ascospores from the air were trapped on petroleum jellycoated glass slides that were replaced weekly for a year To determine variation in spore counts between assessors examining the spore traps four assessors counted the same ten spore traps and spore numbers were compared Results were highly variable between assessors with almost 100 ascospores (54 of the higher count) being the difference between the highest and lowest counts for a single trap in one extreme case To explore sources of assessor variation the four assessors also counted the same five single transects of a spore trap and results were still highly variable Two possible sources of variation identified were poor visualisation of ascospores and misidentification of ascospores Potential solutions to assessor variability include further training using multiple assessors for each trap and calibrating assessors Molecular techniques could also be used to quantify spore numbers




How to Cite

Hopkins, A.J.M., and M.A. Dick. “Gt”;. New Zealand Plant Protection 62 (August 1, 2009): 250–255. Accessed December 8, 2021.