Lethal Yellowing diseases of the coconut palm



 

•Introduction

•Lethal yellowing (LY) is a palm disease prevalent in Florida landscapes in the southern one-third of the state.

•In 2007, the disease was observed in Sarasota and Manatee Counties on the west coast of Florida, counties where it had not been observed previously.

•In 2012, the disease was observed in Indian River County on the east coast of Florida. LY is also observed in field nurseries. This disease has significantly reduced the number of tall-type Cocos nucifera (coconut) in Florida and the Caribbean Basin, and localized outbreaks continue to occur.

                     Pathogen and Hosts

LY is caused by a phytoplasma.The proposed name for the pathogen is 'Candidatus Phytoplasma palmae'. The phytoplasma is a systemic pathogen that is found only in the phloem tissue of palms.                    

 It is a systemic disease that transmitted by  plant hopper/leaf miner. The plant hopper is a piercing and sucking insect, meaning it feeds on the contents of the plant host vascular system, including the phloem. The insect moves the phytoplasma  from palm to palm as it moves during its feeding cycles. The recent spread of the disease beyond its historic range in Florida may be a consequence of mild winters during the last decade