All About Onions Quiz Quiz

Explore key facts about onion cultivation techniques, ideal conditions, and crop management practices in horticulture. This quiz covers essential knowledge for beginner growers and those interested in agricultural basics.

1. Best Soil for Onion Cultivation

   Which type of soil is considered most suitable for successful onion cultivation due to its drainage and fertility properties?

   1. Rocky gravel soil
   2. Heavy clay soil
   3. Well-drained loamy soil
   4. Saline sandy soil

   Explanation: Well-drained loamy soil provides the right balance of fertility, texture, and drainage for healthy onion growth. Heavy clay retains too much water, leading to bulb rot. Rocky gravel soils lack nutrients and structure. Saline sandy soils can cause salt stress and poor water retention.

2. Planting Method for Onions

   Which of the following methods is commonly used to plant onions for commercial bulb production?

   1. Layering stem cuttings
   2. Direct sowing mature bulbs
   3. Planting flowering stalks
   4. Transplanting young seedlings

   Explanation: Transplanting young seedlings allows for better spacing and higher survival rates, leading to uniform crops. Direct sowing mature bulbs is not practical for new crops. Layering stem cuttings is not used for onions. Planting flowering stalks does not result in bulb formation.

3. Temperature Requirement for Onion Growth

   What is the ideal day temperature range (°C) for optimal onion bulb development?

   1. 31–40
   2. 13–24
   3. 3–8
   4. 0–5

   Explanation: Onions grow best between 13°C and 24°C, supporting proper bulb formation. Temperatures of 3–8°C and 0–5°C are too cold and can stunt growth. 31–40°C is excessively hot, possibly causing bolting or poor bulb quality.

4. Fertilizer Requirement for Onions

   Which nutrient is most critical to apply in adequate quantity for high-yielding onion crops?

   1. Zinc
   2. Nitrogen
   3. Calcium
   4. Sulfur

   Explanation: Nitrogen is vital for healthy foliage growth, which is necessary for overall onion development and bulb yield. Calcium is important but secondary to nitrogen. Zinc is required only in trace amounts. Sulfur plays a role but is less critical than nitrogen for basic growth.

5. Proper Onion Harvest Indicator

   What is the main physical sign that onions are ready to be harvested in the field?

   1. Neck or tops of the plants begin to fall over and dry
   2. Leaves turn dark green and thicken
   3. Roots become waterlogged
   4. Bulbs start producing flower heads

   Explanation: When onion tops fall over and dry, it indicates bulb maturity and readiness for harvest. Dark green, thick leaves mean continued growth. Waterlogged roots harm the crop. Flowering heads (bolting) reduce bulb quality and happen if harvest is delayed.