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ตารางที 13 การประมาณความตองการใชเมล็ดไม ้
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1. Species (a) Pinus kesiya (b) Tectona grandis
2. Plants per ha
(a) Number planted 1670 (3 x 2 m) 1111 (3 x 3 m)

(b) Additional for replacing field
casualties - percent 15 35
- number of plants 250 389
(c) Total requirement -

plantable plants 1920 1500
(d) Additional for nursery losses
and culls - percent 20 1) 62.5 2)

- number of plants 480 2500
(e) Total requirement -
germinated seedling 2400 4000

3. Estimated number of germinated seedling per kg of seed 3) received 32000 500
4. Basis for estimate in 3. 1980 crop ex 1979 crop ex
Zambia, dewinged Trinidad, with

And cleaned involucres removed
5. Number of kg of seed needed per ha 0.07 8.0
of plantation (13.3 ha/kg) (0.12 ha/kg)
6. Annual planting area (ha) 12000 5000

7. Annual requirement of seed (kg) 900 40000
Note : 1) Losses and culls represent 20% of the germinated seeds. This is equivalent to 25% of the
plantable plants.

2) 25% of germinated seeds are estimated to produce plantable plants in one year and a further
12.5% at the end of a second year in the nursery. Losses and culls therefore amount to 62.5% of germinated
seeds, equivalent to approximately 167% of plantable plants.

3) In P.kesiya the sowing unit is a true seed. In T.grandis the “seed” or sowing unit is botanically a
fruit, which may contain 0-4 true seeds.

Source : Willan R.L. ,1984