Major Pomegranate Diseases, with a Focus on the Pathogenesis, Epidemiology, and Management Challenges of Alternaria alternata Diseases

Abstract

Pomegranate is a high-value crop severely affected by diseases caused by bacteria, viruses, and fungi, especially those caused by Alternaria alternata. This pathogen is responsible for two major diseases, black heart rot and black spot disease. Heart rot begins as a latent infection in the flower stigma, leading to internal aril necrosis, whereas black spot manifests as external necrotic lesions. While this review focuses on Alternaria diseases, it distinguishes these symptoms from internal rots caused by other fungi like Colletotrichum spp. and Fusarium spp. and surface lesions caused by Pseudocercospora spp. and Curvularia spp. We examined current knowledge on Alternaria epidemiology and the influence of physiological factors like fruit pH and calcium on susceptibility. Although disease control remains challenging due to limited fungicides and pathogen latency, some promising solutions include biological control with Bacillus species, antifungal extracts, and detection via X-ray and AI-based imaging. Ultimately, a deeper understanding of these diseases and improvement of management strategies are essential to sustain global pomegranate yield and quality.