Hi Merlyn, 

Panama disease or Fusarium wilt is a highly destructive disease affecting the vascular system of banana. The causal organism is a soil-borne fungus, Fusarium oxysporum f.sp. cubense,  which colonizes and occludes the xylem of susceptible cultivars to cause a terminal wilt. Chemical control measures are not effective against the disease and soil. Once infested with the pathogen, it cannot be planted with susceptible cultivars up to 10 years or more.

Measaures can be by: 

1. Plant/replant only with disease-free planting material. Or Plan resistant variety such as 

Cavendish tissue-culture variant (GCTCV 219)

 

2. Practice good sanitation on tools -- moving equipment and infected materials to prevent spread of the disease.

 

3. Remove diseased mat, including healthy plants found within a 5m radius, and treat the soil with formaldehyde solution, if possible, or fallow the soil for one year.

 

4. Minimize cultivation to prevent disease spread

Source: Online Course on Managing Common Diseses in Banana.