Handbook of Plant and Crop Physiology

108 CHONG ET AL.

Tilia american

Basswood

T. cordata

LindenTiliaceae

Tsuga canadensisT. caroliniana

HemlockPinaceae

DT DT ETET

Sept.–winterSept.–winter Sept.–winterSept.–winter

2–3 years at

1–5°C with10–12%moisturecontent

4 years at 1–5

C

and 6–9%moisturecontent

HNO

3

30 min

then H

SO 2

4

30–60 mi

(^33) 1–41–4
For best results, harvest
fruits as soon as ripened.Treat seeds immediately.Dried seed has deeperdormancy. Both fall andspring sowing result ingermination over a 2–3year period. Seeds haveboth hard seed coat andimpermeable outerpericarp, hence the needfor both acid scarificationtreatments.
See note 5.Spring sowing is
recommended. Fallsowing eliminates needfor chilling but results inpoor seedling survival.
See note 4.
TABLE 3
Continued
Pretreatment
Stratification (months)
Plant
Collection
Warm
Cold
Species
type
date
Storage
Scarification
(20–30
C)
(1–5
C)
Remarks