Question

Beneficial elements of plants are:
A. Sodium
B. Vanadium
C. Selenium
D. Cobalt
Choose the correct answer from the options given below:

• A. A, B and D only
• B. A, B and C only
• C. A, C and D only
• D. B, C and D only

Hint:

Remember the four classic beneficial elements using the acronym Co-Si-Na-V:
- Cobalt (essential for nitrogen fixation in legumes)
- Silicon (provides structural strength to rice/sugarcane)
- Natrium/Sodium (essential for halophytes)
- Vanadium (assists in micro-algal metabolism)

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Essential elements are those without which a plant cannot complete its life cycle.
In contrast, beneficial elements are those that promote growth, yield, or stress tolerance in certain plant species under specific conditions, but are not universally required by all plants to complete their life cycle.

Step 2: Detailed Explanation:
The term "beneficial elements" was established to classify nutrients that have positive effects on specific plant groups.
The four widely recognized beneficial elements in plant nutrition are:
Sodium (Na) [Statement A]: Essential for halophytes (such as Atriplex) and improves growth in sugar beets and other chenopods by assisting in turgor regulation and osmotic balance.
Cobalt (Co) [Statement D]: Essential for nitrogen-fixing microorganisms, including the Rhizobium bacteria in legume root nodules.
It is required for the synthesis of cobalamin (Vitamin B12), which is essential for hemoglobin formation in the nodules.
Vanadium (V) [Statement B]: Can substitute for molybdenum in certain nitrogen-fixing microorganisms and green algae, complementing their metabolic pathways.
Silicon (Si): Improves structural strength, lodging resistance, and disease resistance in silica-accumulating plants like rice and sugarcane.
While Selenium (Se) is absorbed by plants and is essential for animals, it is generally not classified under the classic set of beneficial elements for plant growth in standard agricultural textbooks.
Therefore, the classic beneficial elements listed in the options are Sodium (A), Vanadium (B), and Cobalt (D).

Step 3: Final Answer:
The beneficial elements are A, B, and D only.