Hail
Identification
- Injury tends to be much more severe on windward side of the row
- Sharp hailstones tend to cause more injury than round ones
Shoots
- Broken shoots
- Localized indentations or shredding of epidermis of shoots
- Large hail stones can tear older branches and trunk
- In pear orchards with fire blight, damaged shoots may have new fire blight infections
Leaves
- Torn leaves with large holes
Fruit
- Gumming at site of injury on stone fruit
- Bruised, punctured or split fruit
- Early-season hail injury generally occurs at the calyx end or on one side because of the position of the fruits on the tree during this period. Later, when the fruits have become larger and heavier, they generally turn downward; so hail marks on well-developed fruits are more often on the stem end and on the blush side
- Fruits injured early tend to outgrow the internal condition produced, but they may become slightly misshapen as they develop. When fruits are struck by hail late in the season, the cuticle and skin covering the affected spots may or may not be cracked or torn
- The damaged flesh immediately below the sunken spot will be shallow and more or less follow the contour of the sunken surface. The bruised flesh beneath the affected areas is usually brown, spongy and dry
- Fruit knocked to the ground
Often Confused With
Bird injury on fruit: injury will be on all sides of the tree as opposed to the windward side; no shredded leaves
Period of Activity
During any severe rain storm.
Scouting Notes
Be aware of any severe weather that passes in the area of an orchard, and monitor closely after these weather events. Driving rain may also produce similar but minor symptoms, especially on leaves.
Management Notes
In pear orchards with fire blight, apply a streptomycin spray
Open wounds on the growing shoots, branches and scaffolds present entry points for bacterial and fungal pathogens and also insects (i.e., lesser peach tree borer). The grower should maintain a minimal pest management program that will protect trees during the wound healing process and not predispose trees to further damage, otherwise long-term health, productivity and longevity of the orchard may be severely compromised.
Apply fungicides to protect injured fruit.
Information included above excerpted from:
