which is considered optimum temperature range for
germination of I. purpurea seeds (Cole and Coats, 1973). The
photosynthetic active radiation on the bench top of the greenhouse
in October was 690
mmol m
2
s
1
, and the R:FR ratio was1.12
(measurements taken at solar noon). Seeds in all experiments were
kept hydrated by adding 5 ml of deionized water as needed.
Germination and viability were evaluated after 14-day incubation,
and the germination percentage was calculated using the same
procedure described previously.