Pests and Diseases:Papaya

1.1. Major Pests

• Fruit flies: the flies usually deposit their eggs in ripe fruit. Developing larvae cause rotting of ripening fruits.

Control: fruit should be harvested at the mature green stage. Over ripe and infested fruit should be buried.

• Red Spider Mites: mites suck the plant sap, leading to poor plant growth and blemishes on the fruit. Serious infestations occur during long dry periods

Control

Use recommended miticides.

• Root-knot nematodes: cause root swellings or root galls, resulting in yellowing and premature abscission of the leaves. Infestation by nematodes reduces growth and yield.

Control: do not replant papaya in the same field.

• Birds: they feed on the ripe fruit.

Control

Harvest when the fruits are physiological mature).

1.2. Major Diseases:

• Damping-off and Foot rot: it is caused by soil-borne fungi, and result to rotting of roots, stem and fruits.

• Seed treatment with Vitavax or Captan @ 2-3 g per kg of seed
• Sterilization of nursery bed by burning saw dust or rice hull (6 cm thick)
• Soil amendment by poultry litter at 5 t/ha
• Solarization of the bed prior to seed sowing
• Drenching of Ridomoil MZ @ 2 g/L
• Ripe fruit rots- Several fungal pathogens are involved in fruit decay.
• Powdery mildew: as the fruits develop, the white mould disappears leaving grey-scarred areas. (Use sulfur based fungicides)
• Papaya ring spot virus (PRSV): this virus is spread by aphids and it is also mechanically transmitted.  Severely infected plants do not flower and they die young. Infected fruits develop characteristic line patterns, which form rings and remain green when fruits ripen. (Destroy infected plants, doo not intercrop with host plants e.g. cucurbits).
• Anthracnose causes fruits to rot and makes them unmarketable.

Papaya mosaic virus

• Yellow patches are appeared on leaves and fruits, bending of petiole and plant growth become stunted
• The disease is transmitted by aphid