Papaya Mosaic (Papaya mosaic virus )

• Positive sense single stranded RNA virus
• Genus:Potex virus
• Transmission: Myzus persicae

Symptoms

Leaves

• Initially, the leaves develop a rugose appearance
• The underside of the leaves shows thin, irregular, dark-green lines
• Younger leaves of the crown are generally stunted and severely chlorotic with vein-banding
• In mature leaves, the chlorotic pattern frequently is expressed as extensive veinclearing, and numerous small rings which are transparent and yellow to tan in color
• In severely affected trees, defoliation progresses upward until only a small tuft of leaves remains at the crown

Stem and petiole

• On the stems of infected plants are found pinpoint-size spots
• As the infection progresses, these spots may develop into linear or, in some instances, distinct concentric ring patterns which become more intense in color and larger in size
• On the petioles, the spots are more irregular in distribution, linear in shape, and at times more elliptical than on the stems
• They are also generally lighter in color than those of the stem
• In severe infections, petioles are stunted and may bend downward.

Fruits

• On the fruit, symptoms may be manifested in all stages of maturity.
• Small, dark-green ringspots, is observed on fruits as young as 2 weeks old
• Typically, rings initially show either on the stem end or blossom end
• The rings at first may be incompletely closed and irregular, but as the fruit develops, target like spots will increase in diameter and is slightly raised, concentric, brownish rings with a green outside ring
• On ripe fruit, there is no mottling of colors as found in papaya ringspot disease

Management

• Good field sanitation such as removal and destruction of affected plant reduce the spread of the disease.
• Losses can be minimized controlling the population of aphid

Chemical Control

Extremely Toxic

Highly Toxic

Moderately Toxic

Slightly Toxic