Arvind Kumar

Chilling injury and frost injury are both caused by cold temperatures but differ in the temperature range and the mechanism of damage. Chilling injury occurs at temperatures below 10-15°C but above freezing, while frost injury occurs at temperatures below 0°C. Chilling injury damages plant membranes, leading to symptoms like pitting and browning, whereas frostbite damages tissues by forming ice crystals, resulting in a mushy texture.

Thanks!

The difference between chilling injury and frost injury lies primarily in the temperature threshold at which they occur and the mechanism of damage they cause to plant tissues. Here's a clear comparison:

Chilling Injury

AspectDescriptionTemperature Range Occurs above freezing point, usually between 0°C and 15°C.Affected Plants Tropical and subtropical plants MechanismMechanism Disruption Disruption DisruptionMechanismDisruption of cell membranes and metabolic processes without ice formation. SymptomsSymptoms- Wilting - Surface pitting - Internal browning - Poor ripening - Water-soaked areasReversibilitySometimes reversible if exposure is brief and mild.

Frost Injury (Freezing Injury)

AspectDescriptionTemperature RangeOccurs below 0°C (freezing point).Affected PlantsAffects a wide range of plants, especially temperate and unprotected ones.MechanismIce crystals form inside or between cells, causing cell rupture and tissue death.Symptoms- Blackened leaves or flowers - Brittle tissues - Death of buds or growing pointsReversibilityOften irreversible, especially if tissues are deeply frozen.

🔑 Key Differences

FeatureChilling InjuryFrost InjuryOccurs at tempsAbove 0°CBelow 0°CInvolves ice?❌ No✅ YesPlant typeMostly tropical/subtropicalBroad (temperate or subtropical)Damage typeMetabolic and cellular disturbancePhysical rupture from ice crystals

🌱 Example

• Chilling injury: A banana stored at 5°C may show black spots and fail to ripen properly.
• Frost injury: A rose plant exposed to -2°C may have blackened flower buds and wilted leaves.

Frost injury damage to the tissue occurs due to prolonged exposure to temperatures below zero degrees, and chilling injury occurs when the temperature is above the freezing point, typically between 1-10 degrees.@Arvind kumar

Chilling injury and frost injury both caused by exposure to cold; they differ in their temperature ranges, mechanisms of damage, affected crop types, and severity. Chilling injury is a physiological disorder caused by low but non-freezing temperatures, whereas frost injury involves the physical destruction of tissues due to freezing and ice formation.

Chilling injury occurs in plants when they are exposed to low, non-freezing temperatures typically between 0°C to 15°C, which is particularly harmful to tropical and subtropical crops such as banana, mango, papaya, and tomato. These crops are sensitive to such temperatures because their cellular structures and metabolic processes are not adapted to the cold. Chilling injury leads to physiological disruptions like damage to cell membranes, enzyme dysfunction, and impaired respiration. Common symptoms include surface pitting, internal browning, water-soaked spots, delayed ripening, and the development of off-flavors. In some cases, the damage may be reversible if the exposure to cold is brief, but prolonged exposure can cause lasting harm. To prevent chilling injury, sensitive crops should be stored at optimal temperatures above their critical threshold and may require protective packaging or controlled storage conditions.

In contrast, frost injury results from exposure to freezing temperatures below 0°C, which causes the formation of ice crystals inside plant tissues. This type of injury is more common in temperate crops like wheat, barley, grapevine, potato, and pea, although subtropical crops can also be affected during unseasonal frosts. The formation of ice crystals leads to the rupture of cell walls and membranes, causing irreversible physical damage. Typical symptoms of frost injury include leaf blackening, wilting, cracking of stems and fruits, and necrosis of plant tissues. Since frost damage is permanent, preventive measures focus on protection, such as using frost covers, wind machines, heaters, sprinkler irrigation, and adjusting the timing of planting to avoid frost-prone periods.

The difference between chilling injury and frost injury lies mainly in the temperature range, type of damage, and plant sensitivity.

Chilling Injury

• Temperature Range: Occurs at low, non-freezing temperatures, typically 0°C to 15°C (32°F to 59°F).
• Affects: Tropical and subtropical plants (e.g., banana, tomato, cucumber).
• Mechanism: Cellular membranes become less fluid and more rigid. Metabolic processes are disrupted. Enzymatic activity declines.
• Symptoms: Surface pitting Internal browning Water-soaked appearance Delayed ripening Increased susceptibility to pathogens
• Reversibility: Sometimes reversible if the plant is returned to proper conditions early.

🔹 Frost Injury

• Temperature Range: Occurs at freezing temperatures, below 0°C (32°F).
• Affects: Almost all plant types, but severity depends on hardiness.
• Mechanism: Ice crystals form inside or outside plant cells. This causes physical rupture of cell walls and dehydration.
• Symptoms: Wilted or blackened leaves Cracked fruit or stems Tissue death
• Reversibility: Usually irreversible damage.