Question

Mungbean seed required for the sowing one hectare land at 30cm x 10cm spacing with 92 per cent germination, 85 per cent purity and 36g weight of 1000 seed will be .

• A. 12.34 kg
• B. 15.34 kg
• C. 18.34 kg
• D. 20.34 kg

Hint:

First find plants per hectare from the spacing, convert to seed weight, then divide by germination times purity.

Answer 1

The Correct Option is B

Step 1: Find the plant population per hectare. Area of one hectare is 10000 sq m and each plant needs a spacing of 30cm x 10cm, that is \( 0.3 \times 0.1 = 0.03 \) sq m. So plant population is \( \frac{10000}{0.03} = 333333.33 \) plants per hectare.

Step 2: Find the pure and fully germinating seed weight needed. With 36g weight for 1000 seeds, the weight per seed is 0.036g. Total weight is \( 333333.33 \times 0.036 = 12000 \, \text{g} = 12 \, \text{kg} \).

Step 3: This 12 kg assumes 100 per cent germination and 100 per cent purity. Since actual germination is 92 per cent and purity is 85 per cent, the effective usable fraction of any seed lot is \( 0.92 \times 0.85 = 0.782 \). So the seed rate needed is \( \frac{12}{0.782} = 15.34 \, \text{kg} \).

The required seed rate is 15.34 kg, so option 2 is correct.