Báo cáo nghiên cứu nông nghiệp " Flowering biology " pot
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Flowering biology
• Differences between species
• Flowering and seed development cycle.
• Factors affecting seed production.
Eucalyptus nitens seed
development cycle
June Year 1 Feb Year 2 Nov Year 2
Jan Year 3Feb Year 4Feb Year 5
Objectives of Seed Orchard
Management
• Early flowering;
flowering can begin at 3
years for E. nitens.
• Simultaneous flowering
between trees; ensures
out-crossing.
• Promote abundant
flowering and abundant
seed crops.
Seed yields for E. nitens
• Some sites produce very little
seed. Quoted seed crops are
usually less than 100 g per
tree.
• Crops of 1 kg seed per tree
are possible (200,000 seeds).
• Site conditions and
management important for
good seed production.
Factors affecting seed
production -
Eucalypts
• Hormone treatments
• Nutrition –
Fertiliser ( P & K )
• Spacing and topping
• Irrigation
• Genetics
• Environment
• Hormone treatments
• Nutrition –
Fertiliser ( P & K )
• Spacing and topping
• Irrigation
• Genetics
• Environment
Factors affecting seed
production -
Eucalypts
Promoting seed production
–Spacing
• Tree crowns need plenty of light to
produce seed.
• Shaded branches do not produce
seed.
• Early thinning needed to keep
crown low.
• Stocking
must be less than 300
stem per ha.
Mahogany
• Small flowers are borne in axillary or
sub-terminal inflorescences.
• Flowers are unisexual, with both
sexes similar, and the trees
monoecious,
• Each inflorescence is 10-20 cm in
length
Mahogany
• Pollination is by insects, bees and
moths
Mahogany
• The fruits are large (12-15 x 6-8 cm),
woody, erect, capsules,
• When dry, the 4 or 5 valved fruits split
open from the base, or from the base and
the apex simultaneously.
• Seeds are chestnut coloured and 7.5-
12 cm in length
• There are usually about 35-45 winged
seeds per fruit.
Mahogany
• Flowering usually takes place when
trees are deciduous or just coming
into new leaf and shortly before the
rainy season
• The fruits mature in 10-11 months.
Teak – flower characteristics
• Stamens 6 (5 or 7), 3-4 mm long,
• Style 4-5 mm long & stigma 2-lobbed,
lobes often adpressed.
• Fruit drupaceous, 1.2-1.8 cm
long and wide, seeds ?
Teak – flower characteristics
• Stamens 6 (5 or 7), 3-4 mm long,
• Style 4-5 mm long & stigma 2-lobbed,
lobes often adpressed.
• Fruit drupaceous, 1.2-1.8 cm
long and wide, seeds 1-4
Teak – flower characteristics
• Inflorescence contains a few thousand flowers
buds;
• 1-3 of them bloom each day;
• Anthesis for the entire inflorescence occurs
over 1-2 months.
• Pollen is shed within a few hours of flowers
opening.
• Peak receptive period is between mid-morning
and early afternoon; after this time the pollen
viability gradually decreases
Teak – flower characteristics
• Teak is insect-pollinated mainly by bees
• Flowering season varies ordinarily from
June to August or September. The fruits
ripen from November to January and fall
gradually
Teak – seed characteristics
• Fruits/seeds – for transport and storage it
is useful to remove the calyx by rigorous
rubbing and winnowing.
• Fruit can be dry-stored in airtight sealed
tins for up to 2 years.
• The viability of its seeds varies from 40-
85%.
Teak – seed characteristics
• Various pre-sowing treatments have
shown to improve germination
• Seed storage - orthodox
• Vegetative propagation by cuttings;
grafting; tissue culture
