The quantity of seed sown per unit area.

2. How do I calculate seed
per hectare?

3. • Quantity of seed sown per unit area.
• The seed rate depends on spacing or plant
population, test weight, germination
percentage.
• Seed rate (kg/ha)=
𝑷𝑷𝑷𝑷𝑷𝑷𝑷𝑷𝑷𝑷 𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑× 𝑻𝑻𝑻𝑻𝑻𝑻𝑻𝑻 𝒘𝒘𝒘𝒘𝒘𝒘𝒘𝒘𝒘𝒘𝒘𝒘× 𝟏𝟏𝟏𝟏𝟏𝟏 × 𝟏𝟏𝟏𝟏𝟏𝟏
𝒈𝒈𝒈𝒈𝒈𝒈 𝒈𝒈𝒈𝒈𝒈𝒈𝒈𝒈𝒈𝒈𝒈𝒈𝒈𝒈𝒈𝒈𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑 × 𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑 𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑𝒑 × 𝟏𝟏𝟏𝟏𝟏𝟏𝟏𝟏 × 𝟏𝟏𝟏𝟏𝟏𝟏𝟏𝟏
• Plantpopulation=
𝒍𝒍𝒍𝒍𝒍𝒍𝒍𝒍 𝒂𝒂𝒂𝒂𝒂𝒂𝒂𝒂
𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔𝒔

4. 1. Calculate the seed rate of mung bean for sowing 1 hectare of
crop from the following:
spacing=30cm×10cm
germination %=92%
purity %=85%
1000 grain weight =36g
Solution:
Plant population=
10000𝑚𝑚𝑚
0.3𝑚𝑚×0.1𝑚𝑚
=333333.33
Seed rate =
333333.33×36×100×100
92×85×1000×1000
=15.34 kg/ha (Ans).

5. 2. Calculate the seed rate of pigeon pea for sowing 1 hectare of
crop from the following:
spacing=60cm×25cm
germination %=87%
purity %=86%
1000 grain weight =70g
Solution:
Plant population=
10000𝑚𝑚𝑚
0.6𝑚𝑚×0.25𝑚𝑚
=66666.67
Seed rate =
66666.67×70×100×100
87×86×1000×1000
=6.23 kg/ha (Ans).

6. 3. Calculate the seed rate of ground nut for sowing 1 hectare of
crop from the following:
spacing=50cm×20cm
germination %=92%
purity %=95%
1000 grain weight =200g
shelling%=60%
Solution:
Plant population=
10000𝑚𝑚𝑚
0.5𝑚𝑚×0.2𝑚𝑚
=100000
Seed rate of kernels=
100000×200×100×100
92×95×1000×1000
=22.88≈23 kg/ha
Quantity of unshelled pods needed for sowing in kg/ha =
100/60×23=38.33 kg/ha (Ans).

7. 4. Calculate the seed rate of green gram for sowing 1 hectare of
crop from the following:
spacing=45cm×10cm
germination %=80%
1000 grain weight =48g
Solution:
Plant population=
10000𝑚𝑚𝑚
0.45𝑚𝑚×0.1𝑚𝑚
=222222.22
Seed rate=
222222.22×48×100
80×1000×1000
=13.33 kg (Ans).

8. 5. Calculate the seed rate of Jute for sowing 1 hectare of crop
from the following:
spacing=25cm×10cm
germination %=90%
purity percentage= 85%
test weight =6.5g
Solution:
Plant population=
10000𝑚𝑚𝑚
0.25𝑚𝑚×0.1𝑚𝑚
=400000
Seed rate=
400000×6.5×100×100
90×85×1000×1000
=3.39 kg (Ans).

9. 6. Calculate the quantity of maize seed for sowing 1 hectare of
crop from the following:
spacing=75cm×20cm
germination %=90%
purity percentage= 90%
test weight =250g
seed required for gap filling=5% of total weight of seeds.
Solution:
Plant population=
10000𝑚𝑚𝑚
0.75𝑚𝑚×0.2𝑚𝑚
=66666.67
Seed rate=
66666.67×250×100×100
90×90×1000×1000
=20.576 kg
Amount of seed required for Gap filling=
5
100
×20.576= 1.028 kg
Total seed required for 1 hectare area= 20.576+1.028=21.604≈
22kg/ha (Ans).

10. 7. Calculate the seed requirement for upland rice for sowing 1
hectare of crop from the following:
spacing=20cm×30cm
germination %=95%
purity percentage= 90%
test weight =25g
No. of damaged seeds by birds, which are to be replaced 10seeds
per square meter i.e., 10/m².
Solution:
Plant population=
10000𝑚𝑚𝑚
0.2𝑚𝑚×0.3𝑚𝑚
=166666.67
Replacing bird damaged seeds, 1m² area= 10 seeds
10000m² area= 100000seeds
Total no. of plant population= 166666.67
+100000=266666.67
Seed rate=
266666.67×25×100×100
95×90×1000×1000
= 7.79≈8 kg/ha (Ans).

11. 8. Calculate the seed requirement for rice in kg/ha for sowing
1 hectare of crop from the following:
spacing of hill=20cm×20cm
No. of seedlings per hill=3
germination %=95%
purity percentage= 90%
test weight =25g
seedlings required for gap filling=12/5 m² area
Solution:
Plant population=
10000𝑚𝑚𝑚
0.2𝑚𝑚×0.2𝑚𝑚
=250000×3= 750000
Seedlings required for gap filling.
For 5m² seedlings required= 12
For 10000m²= 12/5×10000=24000 seedlings.
Total plant population= 750000+24000=774000
Seed rate=
774000×25×100×100
95×90×1000×1000
=22.63 kg/ha (Ans).