Definitions

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Bitter pit – a physiological disorder in apples in which discolored corky areas form beneath the skin in the flesh near the calyx end, caused by calcium deficiency resulting from moisture stress
Chlorosis – the yellowing of leaves
Corking (cork spot) –
Dieback – progressive death of shoots, leaves, or roots, beginning at the tips
Little leaf – leaves are small, narrow, mottled, and bunched together at the tips of the shoots (rosette); typically associated with zinc deficiency.

Necrotic – Dead or dying tissue, usually accompanied by darkening to black or brown. “Necrosis” is the noun.
Rosette – when the distance between the leaves on the shoots is greatly shortened and a bunching at the tips occurs (associated with zinc deficiency)
Russet – When cork forms on the outer surface of fruit, often in a netlike pattern. It will appear as yellowish brown or reddish brown scar tissue.
Watercore – a condition of apple fruits in which the inner tissues become watersoaked; a condition of overmaturity
Witches' broom – disease symptom characterized by an abnormal, massed, brushlike development of many weak shoots arising at or close to the same point
Wither tip – when the terminal leaves turn yellow, wither, and fall; typically associated with copper deficiency and occurs in mid-June after apparently normal growth.

Updated July 12, 2004