Flower
bud initiation, growth to maturity
Within
a species flowering time often varies according to location. Also within a given population differences
can be found between individuals.
Flowering habits are strongly genetically controlled.
Time
from formation of flower bud to mature seeds may take from a few months to 3
years.
Flowering
habits vary with latitude. In the
temperate zones, bud initiation happens in the year before flowering, and 2-3 years
to mature fruit/seed is normal. In the
tropical zone short intervals of less than 6 months from initiation to maturity
are typical.
The
warmer conditions of lowland tropics may result in the earlier ripening
(altitude effect). Conifers take generally
longer time to make mature seed than hardwoods.
In
many tropical hardwoos, flower buds develop within a short period of time.
In Tectona grandis, for example, they can not
be seen easily until shortly before the flower open. A flower opens in the morning between 7 and
9, the pollen on the anthers start to appear between 9 and 10, and the stigma
is receptive from 10 in the morning till around 2 o’clock in the
afternoon.
If no pollination occurs, the
whole flower falls off during the coming days.
Fruit development lasts for 4 months after which time the fruits are of
full size. It takes still another 1-2
months for seed to mature.
In Gmelina
arborea the flower buds can be identified some 10 days before the flower opens,
and mature fruits are found after about 2 months.
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