Question

Optimum seed rate for a good crop stand of Isabgol is:

• A. 1.0 kg/ha
• B. 2.0 kg/ha
• C. 4.0 kg/ha
• D. 10 kg/ha

Hint:

Because Isabgol seeds are very small, they should be mixed with fine sand in a 1:10 ratio before sowing to ensure even distribution along the rows.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Isabgol (Psyllium *Plantago ovata*) is an important medicinal crop cultivated primarily for its seed husk, which is used as a natural laxative.
Its seeds are very small and light, requiring careful calibration of the seed rate to avoid overcrowding or a thin crop stand.

Step 2: Detailed Explanation:
For a healthy crop stand of Isabgol under standard line sowing (with a spacing of \( 22.5\text{ cm} \) to \( 30\text{ cm} \) between rows), the recommended seed rate is:
\[ 4.0 \text{ to } 6.0 \text{ kg/ha} \] A seed rate of \( 4.0\text{ kg/ha} \) (Option C) provides the optimum plant population (about 300,000 to 400,000 plants per hectare) under good management conditions.
If the seeds are broadcast, the rate may be increased up to \( 6.0\text{ kg/ha} \) or \( 8.0\text{ kg/ha} \).
Rates like \( 1.0\text{ kg/ha} \) or \( 2.0\text{ kg/ha} \) are insufficient for a uniform crop stand because of the seed's small size and potential germination losses.
A rate of \( 10\text{ kg/ha} \) is too high, leading to dense crowding and increased susceptibility to downy mildew, which is a major disease of this crop.

Step 2: Final Answer:
The optimum seed rate for establishing a good crop stand of Isabgol is 4.0 kg/ha.