Papaya meleira

Papaya meleira, commonly referred to as the "sticky disease," is a severe viral disorder affecting papaya (Carica papaya) plantations worldwide. The term "meleira" is derived from the Portuguese word for honey, reflecting the most distinct symptom: the exudation of a sticky, viscous latex from the skin of the fruit.

The disease is caused by a virus complex, with the Papaya meleira virus (PMeV) identified as the primary etiological agent. This pathogen is highly host-specific, primarily targeting papaya crops. Its impact on yield and fruit quality makes it a significant concern for commercial producers in tropical regions.

The primary clinical sign of the disease is the appearance of small, sticky latex droplets on the surface of immature or ripening fruits. As the disease progresses, these areas oxidize and turn dark brown, often leading to necrosis and severe fruit malformation. Affected fruits lose their market value entirely due to the degraded appearance and altered metabolic processes within the fruit tissues.

The transmission of Papaya meleira is largely facilitated by mechanical injury to the plant. Because the virus can be spread through contact, contaminated pruning tools are major vectors for disease transmission across a field. Environmental factors such as high humidity and the presence of fruit-damaging insects exacerbate the spread by creating entry points for the pathogen.

Effective management and prevention of the disease rely on maintaining high sanitary standards within the orchard:

• Strict removal and destruction of infected plants to reduce the viral load in the field.
• Rigorous disinfection of all pruning and harvesting tools using sanitizing agents to prevent cross-contamination.
• Implementing integrated pest management (IPM) to reduce surface damage to fruits, which serves as a pathway for the virus.
• Continuous monitoring and early detection during the fruit development stage to mitigate major outbreaks.