Frost Damage. In: Compendium of Pea Diseases and Pests

Authors: HAGEDORN, D - University Of Wisconsin; Porter, Lyndon

Submitted to: American Phytopathological Society Press
Publication Type: Book / Chapter
Publication Acceptance Date: 7/17/2020
Publication Date: N/A
Citation: N/A

Interpretive Summary: Frost damage is widespread and common in pea-growing areas causing significant economic losses by reducing both the yield and quality of the pea crop. Frost-injured pea plants may also be more susceptible to attack by fungal pathogens such as powdery mildew. Frost impacting the crop during seed formation can result in reduced seed germination rates. A symptom of freezing injury to young pea plants is the death of the growing point. Freezing temperatures can kill the apical point that is the most susceptible tissue to frost damage. Death of the plant’s growing point activates the dormant buds at the base of the plant. Several buds may be active, but ordinarily only one becomes dominant and develops fully maturing, harvestable peas. However, these peas often mature later compared with uninjured plants in the same field. Frozen young leaves may develop roughened, jagged edges or become bilobed and feel leathery. When frost affects slightly older leaves, they develop water-soaked, translucent lesions between the main veins on the undersides. This destroyed parenchyma tissue may turn necrotic and even fall out of the leaf. Frost can also cause a lacy, white damage to leaves and pods. Death of interveinal tissue is the most diagnostic symptom of frost injury. Temperatures of 0°C or below can cause freezing injury. The degree of injury depends on the degree of coldness, the length of exposure, sugar content, plant maturity or a combination of these factors. If a pea crop develops under cool conditions prior to exposure, the young plants may become acclimatized, or cold-hardened, and may be better able to withstand freezing temperatures than plants growing in warmer temperatures prior to a frost event.

Technical Abstract: Frost damage is widespread and common in pea-growing areas causing significant economic losses by reducing both the yield and quality of the pea crop. Frost-injured pea plants may also be more susceptible to attack by fungal pathogens such as powdery mildew. Frost impacting the crop during seed formation can result in reduced seed germination rates. A symptom of freezing injury to young pea plants is the death of the growing point. Freezing temperatures can kill the apical point that is the most susceptible tissue to frost damage. Death of the plant’s growing point activates the dormant buds at the base of the plant. Several buds may be active, but ordinarily only one becomes dominant and develops fully maturing, harvestable peas. However, these peas often mature later compared with uninjured plants in the same field. Frozen young leaves may develop roughened, jagged edges or become bilobed and feel leathery. When frost affects slightly older leaves, they develop water-soaked, translucent lesions between the main veins on the undersides. This destroyed parenchyma tissue may turn necrotic and even fall out of the leaf. Frost can also cause a lacy, white damage to leaves and pods. Death of interveinal tissue is the most diagnostic symptom of frost injury. Temperatures of 0°C or below can cause freezing injury. The degree of injury depends on the degree of coldness, the length of exposure, sugar content, plant maturity or a combination of these factors. If a pea crop develops under cool conditions prior to exposure, the young plants may become acclimatized, or cold-hardened, and may be better able to withstand freezing temperatures than plants growing in warmer temperatures prior to a frost event.