Scientific Name : (Vaccinium spp.) are a member of the heath family (Ericaceae), grown as a perennial crop .

Blueberries have a blue to blue-black epidermis or skin that is covered by a waxy bloom, giving the fruit a light blue appearance .

Berries have two kinds :

1.Highbush : blueberries are tall, with some cultivars reaching a height of 6 to 8 feet. Their berries are larger and more abundant than those of the lowbush type, although their flavor may be somewhat less intense and sweet.

2.lowbush : these shrubs grow no taller than 2 feet and may be smaller, depending on soil and climate.

highbush berries require fewer chill hours and can lose fruit to frost damage if grown in areas where Spring temperatures drop to < 0 °C

Pre-cooling Conditions: Blueberries for fresh market should be forced-air cooled to < 10 oC , then maintained under refrigeration at 0 to 3 °C , Pre-cooling to 5 ºC .

Can cause condensation problems in lowbush blueberries when packed at ambient temperatures, but should be incorporated when delays between picking and packing exceed 21 h

Optimum Storage Conditions: Blueberries should be held at -0.5 to 0 ºC , with > 90% RH, for up to 2 weeks for lowbush .

Controlled Atmosphere (CA) Considerations: highbush, and lowbush blueberries benefit from 10 to 15% CO2 + 1 to 10% O2

when held at or below 5 ºC .

Retail Outlet Display Conditions: Blueberries should be stored and displayed under refrigeration with temperatures as close to 0 °C as possible.

Chilling Sensitivity: Blueberries are not known to be chilling sensitive.

Ethylene Production and Sensitivity: Ethylene production ranges from 0.5 to 2 μL kg-1 h-1 for highbush .

Physiological plant disorders are caused by non pathological disorders such as poor light, weather damage, water-logging or a lack of nutrients, and affect the functioning of the plant system. Physiological disorder are distinguished from plant diseases caused by pathogens , such as a virus or

fungus .

While the symptoms of physiological disorders may appear disease-like, they can usually be prevented by altering environmental conditions. However, once a plant shows symptoms of nutrient deficiency it is likely that that season’s yields will be reduced.

1- Ripe rot : Anthracnose or ripe rot is a common pre- and post-harvest fruit rot of highbush blueberry in British Columbia. It is caused primarily by the fungus Colletotrichum acutatum.

2 -Fruit shrivels or drought : Blueberries do not wilt as readily as many other plants. Berries will shrivel and drop before leaves

die .

3 -Frost Injury causes fruit to have a dark, shrunken appearance that readily distinguishes them from unaffected fruit. Severely damaged fruit appear hollow when cut in half. Frost or freeze injured fruit may drop to the ground prematurely before harvest.

4  -Alternaria Fruit Rot : causes black or dark moldy growth on the blossom end of the berry. Berries later shrivel and darken.

5 -Mummy Berry infected fruits shrivel and turn pink. They are inedible. Mummified fruit drop to the ground prematurely. These overwinter to cause primary leaf infections the following spring.

Thank You

Name : Aya Sameeh Soulyman

Number : 0083875