Total germination rate of cup plant seeds stored at 30 cm soil depth depending on duration of storage in soil. Total germination rate was calculated as sum of seeds germinated in the soil and in the pots after sowing. 100% corresponds to 30 seeds. The darker the dots are, the more dots are on top of each other. The red line is fitted by LM: y = 90.5 – 41.6*ln(x), Adj. R² = 0.72, p < 0.001. The red ribbon shows the 95% confidence interval of the model. n = 32.