Table 1 Analysis of variance (ANOVA) of the effect of seed storage time (3, 6, 9, 12, 18 and 24 months) and temperature (3 °C, −3 °C, −10 °C, −20 °C, −196 °C) on Populus nigra seed germination. Seeds were desiccated to a water content of 0.07 g H₂O g⁻¹ dry mass. ANOVA mixed model with “tree” as a random effect. Seed from harvest in 2010. ST Storage time, STE storage temperature, DF Den degrees of freedom in the denominator of the test

From: Optimal seed water content and storage temperature for preservation of Populus nigra L. germplasm