Crop Sensitivity — Frost-Prone Species Among the following, which crop's plants are highly sensitive to frost injury in the field?

Introduction / Context:
Understanding crop–climate relationships is crucial for agronomy and farm risk management. Frost events can damage cellular structures, impair photosynthesis, and kill sensitive seedlings or mature plants. Different crops vary widely in their tolerance to freezing temperatures.

Given Data / Assumptions:

• We compare barley, cotton, and maize for frost sensitivity.
• “Highly sensitive” implies severe injury or death near 0°C exposure in the field.
• General agronomic knowledge and extension guidelines are applied.

Concept / Approach:
Cotton is a tropical/subtropical crop and one of the most frost-sensitive major field crops. Even light frost can cause severe injury to leaves, squares, and bolls, and can kill young plants outright. Barley, a cool-season cereal, has relatively good frost tolerance (particularly during vegetative stages). Maize is sensitive to frost as well, but cotton is typically cited as more vulnerable, especially during early growth and pre-harvest cold snaps.

Step-by-Step Solution:

Verification / Alternative check:
Agronomy guides routinely warn that cotton should not be planted before the last expected frost date; barley, conversely, can overwinter (as winter barley) in colder climates with proper management.

Why Other Options Are Wrong:

• Barley: Not “highly” sensitive; relatively tolerant among cereals.
• Maize: Frost-sensitive, but cotton is more critical in common rankings.
• None of the above: False; cotton is indeed highly frost-sensitive.

Common Pitfalls:
Assuming all warm-season crops have equal frost sensitivity. Degree matters; cotton is exceptionally vulnerable compared with many cereals.

Final Answer:
Cotton