PPDL Picture of the Week

December 15, 2015

Moko Disease of Banana and Plantain

Tom Creswell, Plant Disease Diagnostician/Director, Purdue Plant and Pest Diagnostic Lab

While cold winter weather has placed most plant diseases on hold in the Midwest we can look to tropical regions for active pathogens. Moko disease produces dramatic symptoms of wilt, dieback and death of banana and plantain. The bacterial pathogen responsible for this havoc is Ralstonia solanacerum, which is actually a complex of several strains and races (often corresponding to geographic regions), affecting a wide range of host plants in both tropical and temperate regions (1).  Vegetable gardeners in the Southeastern US often encounter this pathogen as the cause of bacterial wilt of tomato and eggplant.

 

Moko disease has been known since the mid 1800s but gained its name after it killed nearly all of Trinidad’s “Moko” plantain cultivar in the early 1900s.  This soil borne bacterium is now endemic to most of Central and South America and can cause losses of up to 100% in plantings where it becomes established. It is spread via infested tools; runoff water and moving diseased plant material (2).

 

On a recent trip to Columbia I visited with managers at a plantain farm and helped them identify Moko disease as the primary problem they were facing (Fig 1, 2). The decline had previously been thought to be caused by Fusarium wilt (another very serious problem of banana and plantain).  Identification of the problem led to management changes such as disinfecting tools and equipment, use of clean planting stock and a plans to shift to alternative control options like beneficial microorganism composts and rotation to non-host crops. There are no effective chemical control measures available to manage Moko disease.  


(1) http://www.padil.gov.au/pests-and-diseases/pest/main/136650

 

(2) http://www.fao.org/3/a-i3400e.pdf



 

Click image to enlarge



Fig. 1: Moko disease can rapidly destroy banana and plantain fields as shown here in the Meta region of Columbia.

 

 

Fig. 2: Symptoms include discoloration and plugging of vascular tissues of the banana or plantain pseudostems; shown here in an early stage (top) and later stage (bottom).