MECHANICAL/FIELD INJURY: Bruising  

Bruises are the most common type of mechanical damage. Fruit can be bruised on the tree during hand thinning, or during picking. They can also be bruised by adjacent fruit or tree limbs. Once harvested, fruit bruise easily in the bins through rough handling. Loading fruit in the dump tank and running on packing line equipment can also bruise fruit. Although mostly considered a cosmetic downgrade, bruises can make fruit susceptible to rot.

Figure 1: This single bruise occurred at harvest.

Figure 2: Multiple bruises like this are common to thinning, where one fruit is held out of the way while removing another in a cluster.

Figure 3: Fruit can be bruised on tree by rubbing against other fruit or limbs.

MECHANICAL/FIELD INJURY: Frost  

Frost is a serious problem both early in the season and late season. Frost occurring around blossom or fruit set can cause complete fruit loss. Lat-season frost affects mostly late season varieties, leaving the affected fruit with a characteristic ring russet scar from where the frost settled on the fruit. It can be confused with the russetting caused by powdery mildew. However, mildew russet is more netlike across the fruit.

Figure 1: Late-season frost damage appearing as a pale red russet band around the lower half of Red Delicious fruit.

Figure 2: Golden Delicious with late-season frost damage visible as a brown russet band around the center of the fruit.

MECHANICAL/FIELD INJURY: Hail  

Hail damage can occur any time during the growing season. What the damage looks like at harvest will depend on how mature the fruit was and how large and hard the hail was it struck. A hard impact early in the season could cause a very deep depression and deformation of the fruit. Later-season damage could appear more bruiselike.

Figure 1: Damage to this Red Delicious probably occurred midsummer, leaving a noticeable depression. Cracking is not uncommon. A mark like this can be confused with insect damage. Notice that this fruit also has a large bin bruise unrelated to the hail mark.

MECHANICAL/FIELD INJURY: Chemical Burn   

Chemical burns originating in the orchard may appear differently depending on the variety's susceptibility to the chemical and which chemical is responsible. Any chemical applied in or around an orchard can cause fruit burns. This includes oils, pesticides, herbicides, fertilizers and growth regulators depending on how the chemical was applied. Unfortunately, the resulting burns may be hard to identify because the damage may take time to develop and may look like insect or other types of damage.

Figure 1: The burns shown here were caused by a nutrient spray that left large droplets on the fruit surface.