• Narrow. Philippines. Major disease of bananas, plantains, Heliconia, and weeds.
• Bacterium identical to that causing moko disease (see Fact Sheet no. 525) of Cavendish bananas (AAA) grown on plantations, whereas bugtok attacks plantains (ABB, e.g., Cordaba) and BBB, e.g., Saba) grown by smallholders (see Acknowledgement for abbreviations). Bugtok threatens food security, and crop diversity.
• Leaves and fruits appear normal; leaf-like ‘bracts’ over male flowers fail to fall, fruit stems blacken, dry and distort, and inside of stems develop brown streaks in the vascular tissues. If fruit are present, the pulp may show brown or reddish rots, but not premature ripening (see Fact Sheet no. 523) and, occasionally, vascular streaking occurs in leaf sheaths (main stem), but leaves do not wilt.
• Spread: insects; unlikely in water or in suckers.
• Biosecurity: risk from unofficial introduction of diseased cuttings for propagation, and trade in fruit. Official movement of germplasm should always follow the FAO/IPBGR Technical Guidelines.
• Biocontrol: none.
• Cultural control: most important recommendations for smallholders are: (i) monitoring and removal of disease plants as soon as seen, but leaving suckers to grow; (ii) removal of unopened male flower buds (called 'de-budding') using forked stick; and (iii) keeping cutting tools clean and free from bacteria (bleach). Others: do not plant near diseased plots (especially downwind); weed; bag flowers after emergence until fruit set (if bell removed); Cavendish (AAA) varieties have field resistance (see Fact Sheet no. 525).
• Chemical control: not a method to use.

Bugtok disease of banana.

Ralstonia solanacearum race 2, biovar 1; previously, it was known as Pseudomonas solanacearum, Burkholderia solanacearum. It is the same strain that causes moko disease in Asia, Africa, Central and South America, and more lately has been introduced into the Philippines (see Fact Sheet no. 525).