Coconut phytoplasma diseases: Advances in detection and sustainable management strategies

Coconut palms are affected by a range of diseases, with phytoplasma-associated syndromes such as root wilt, lethal yellowing, lethal decline and Tatipaka disease posing major threats to their productivity worldwide. Phytoplasmas are wall-less, obligate phytopathogenic bacteria that infect the phloem of host plants and are primarily transmitted by phloem-feeding insect vectors belonging to families such as Cicadellidae, Fulgoridae and Psyllidae. These diseases are characterized by symptoms including yellowing, wilting, bronzing and eventual death of affected palms, leading to severe economic losses in coconut-growing regions. The molecular complexity, low titre, uneven distribution of phytoplasmas and similarity of symptoms to other stresses make detection and management particularly challenging. Recent advances have focused on the development of sensitive molecular diagnostic tools, identification of field-tolerant coconut varieties and experimental biotechnological approaches to enhance either pathogen detection or crop resistance. Biological control methods, including the use of beneficial microbes, show promise for integrated disease management. Despite some progress, sustainable and effective control remains elusive, necessitating further research into resistant cultivar development, rapid field diagnosis and innovative management strategies to safeguard global coconut cultivation.