How is Citrus tristeza closterovirus primarily transmitted?

Citrus tristeza closterovirus is primarily transmitted through grafting techniques. In horticulture, grafting is a common practice where tissues from different plants are joined together to grow as a single plant. If one of the grafted plants is infected with Citrus tristeza virus, the virus can easily transfer to the healthy plant during the grafting process, thereby spreading the infection within citrus orchards.

Although other transmission methods exist, such as insect vectors like aphids, grafting is a significant avenue for the transmission of this specific virus, particularly in commercial citrus production where grafting is routinely employed to propagate desired cultivars. Understanding the methods of transmission is crucial for managing and preventing the spread of plant pathogens like the Citrus tristeza virus in agricultural settings.