Ripe fruit rot

Ripe fruit rot, primarily caused by the fungus Aspergillus niger, is a significant postharvest and pre-harvest disease affecting various crops. It is characterized by its ability to thrive in warm, humid conditions, utilizing its enzymatic activity to break down plant tissues and absorb nutrients.

A wide range of crops is susceptible to this pathogen, including stone fruits and various vegetables. Common apricot is particularly prone to infection, especially during the final stages of ripening. Other susceptible hosts include grapes, onions, and various soft-skinned fruits that are easily damaged during harvesting or handling.

Symptoms initially manifest as small, soft, discolored spots on the fruit surface. These spots rapidly expand, and within a few days, the affected area becomes covered with a thick, sooty-black mass of fungal spores. The internal tissue quickly degrades, resulting in a watery, soft decay that emits a distinctive musty odor.

Environmental conditions play a critical role in the development and spread of the disease. Aspergillus niger prefers high temperatures (25–30°C) and high humidity. The spores are primarily air-borne, and they exploit any mechanical injury, insect-feeding site, or natural opening in the fruit skin to penetrate and establish infection.

Prevention and control strategies focus on minimizing damage and maintaining sanitary conditions to inhibit fungal growth:

• Rigorous sanitation to remove fallen or decaying fruit from the orchard.
• Implementation of careful harvesting techniques to minimize fruit bruising and skin punctures.
• Optimizing postharvest cooling and drying to reduce humidity around the produce.
• Effective pest control to prevent insect-driven fruit wounding.