What disease causes banded necrosis on the leaves and flowers of Vanda orchids?

Distribution: Worldwide. Pathogen: Vandaorchidleaf virus (Vanda mosaic virus). Host: Vanda genus (Vanda). Symptoms: Petals and sepals are distorted, flower color is mottled; faint or inconspicuous spots appear at leaf tips. Control: Controlling viral diseases mainly involves removing diseased plants, improving environmental hygiene, and disinfecting tools to prevent their spread. Currently, the internationally recognized better disinfectant solutions are: 1. 2% formalin and % sodium hydroxide aqueous solution (cannot be used once it turns green); 2. 164g of anhydrous or 377g of crystalline trisodium phosphate (Na3PO4) added to 1L (1000cc) of water. It can be used to disinfect tools, environments, etc. (Chen Xinqi, Ji Zhanhe)