- yellowing of normally green tissues caused by inadequate light.

- overgrowth of tissue formed in response to injury in an effort of the plant to heal the wound.

-shortening of the internodes of shoots and stems forming a crowding of the foliage in a rosette

Involve death and protoplast, cell or tissue

Sudden death of young buds, inflorescence or the young fruits.

- extremely tiny spots on leaves, fruits, stems, etc

Inhibition/failure in the differentiation or development of some aspect of plant growth

-drying backward from the tip of twigs or branches.

rotting of seedlings prior to emergence or rotting of seedling stems at an area just above the soil line.

long, narrow necrotic lesions on leaves or stems.

-development of chlorophyll in tissues or organs where it is normally absent.

-cupping or pocketing of leaf parts, due to underdevelopment of veins of leaf margins.

- yellowing of normally green tissues caused by inadequate light.

low temperatures slightly above freezing

-superficial brownish roughening of the skin of fruits, tubers or other fleshy organs due to suberization of sub and epidermal tissues following injury to epidermis.

Internal; seen only upon dissection of diseased plant portion and examination under the microscope.

-yellowing cause by some factor other than light, such as infection by a virus or a mycoplasma.

-large, irregular spots on leaves or fruits with necrotic injury of epidermal cells.

-slightly raised, rough, ulcer-like lesions due to epidermal and cortical tissue overgrowth with rupturing and suberization of cell walls.

metamorphosis of sepals, petals, stamens, or carpels into leaf-like structures.

-oozing out of viscid gum from wounds in bark

Injury caused by too high temperature

-abnormal swelling of the bark above wounds due to the accumulation of food materials

perforated appearance of a leaf as the dead areas of local lesions drop out.

yellow or brown discoloration in the vascular system.

Excessive multiplication, enlargement or overdevelopment of plant organs including abnormal prolonged retention of green color.

often sunken necrotic area with cracked border that may appear in leaves, fruits, stems and branches

-flow of plant sap from wounds.

-presence (leaves) of variegated patterns of green and a yellow shades with sharply defined borders

extensive, usually sudden, death of host tissue.

- variegation is less defined than mosaic and boundaries of light and dark variegated areas are more defused

- clustering of roots, flowers, fruits or twigs around a common focus.

-localized necrotic area also referred to as a lesion, circular, angular or irregularly shaped.

Pre-necrotic "near death"; changes before actual death of protoplast or cell; involves protoplasmic disorganization and degeneration

- tissues a light-colored and blistered, due to prolonged exposure to high temperature and bright sunlight.

-slightly raised, rough, ulcer-like lesions due to epidermal and cortical tissue overgrowth with rupturing and suberization of cell walls.

- leaf veins are translucent or pale while the rest of the leaf is its normal color.

General Classification of Symptoms

-define depressions/pits found on surface of fruits, tubers and other fleshy organs resulting in a pocked appearance.

- disintegration and decomposition of host tissue

injury when temperatures is below 0°C

- premature falling of leaves, fruits or flowers due to early laying down of the abscission layer

Injury of too low temp

- infected fruit is converted to a hard, dry shriveled mummy.

-due to the infectious agent often leads to death of the plant unless controlled in time.

- abnormal bending/leaf curling caused by over-growth on one side of leaf or localized growth in certain portions

Malformations and other changes visible to the naked eye.