Question

Mahua oil cake acts as

• A. Poison and manure
• B. Poison only
• C. Manure only
• D. As disinfectant

Hint:

Mahua Oil Cake Dosage: 2500 kg/ha-m.
Wait Period: 15 days (until toxicity vanishes).
Active Ingredient: Saponin (Mowrin).
It is the only organic piscicide that significantly boosts primary productivity after use.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question addresses the dual role of Mahua oil cake (Madhuca latifolia) in pond preparation for aquaculture.
Detailed Explanation:

• Piscicidal Action (Poison): Mahua oil cake contains about 4% to 6% of a toxic glycoside called Saponin. When applied to ponds at a rate of 2500 kg/ha-m, it acts as a fish poison by causing hemolysis (rupturing) of the red blood cells. It is used to eradicate unwanted predatory and weed fishes during pre-stocking management.

• Nutritional Value (Manure): After its application, the toxic effect of saponin persists for about 10 to 15 days, after which it degrades. As the cake decomposes, it releases essential nutrients like nitrogen, phosphorus, and potassium into the water. This promotes the growth of natural fish food (plankton).

• Economic Efficiency: This dual functionality—first clearing the pond of predators and then fertilizing it—makes Mahua oil cake a highly efficient and popular organic management tool in Indian aquaculture.

Step 3: Final Answer:
Mahua oil cake acts as both a poison (piscicide) and a manure (organic fertilizer).