The seed was subjected to a freeze-blotter seed health assay,
modified bydu Toit et al. (2005). For each combination of treatment
and soil, 250 seeds in 2009 and 425 seeds in 2010 and 2011
were transferred to a plastic Petri dish (10 cm in diameter) with
germination paper (Frisenette Aps, EDB no. 742.085) and moistened
with 4 mL of sterile deionised water.