<i>Phytophthora</i> spp.’s effect on citrus industry: Current status, challenges, and emerging control strategies

Abstract Gummosis, caused by various Phytophthora species, poses a significant threat to citrus trees globally, leading to reduced fruit production and orchard decline. The primary pathogens responsible are P . citrophthora , P. nicotianae , and P . palmivora , which infect roots, trunks, and fruits, thriving in wet conditions and spreading through zoospores. This review highlights the economic impact of gummosis, detailing the symptoms such as bark cracking, gum exudation, and root decay that contribute to reduced orchard productivity. The infection process and pathogenicity mechanisms of Phytophthora spp. are examined, along with environmental factors like soil moisture and temperature that facilitate disease proliferation. Diagnostic methods, from traditional visual identification to molecular tools like PCR, are discussed for their effectiveness in detecting the pathogen. Management strategies focus on integrated approaches combining cultural, biological, and chemical controls. Key practices include improving soil drainage and irrigation, along with using biological agents like Bacillus spp. and Trichoderma spp. to suppress Phytophthora populations. Systemic fungicides, such as phosphonates and metalaxyl, also remain vital in managing high disease pressure. This review emphasizes the need for sustainable control measures to mitigate gummosis, ensuring long-term orchard health and profitability.