Re: Fusarium wilt
can you get a close up of the infected areas? i can't tell from this photo. if you do have Panama disease you need to quarantine the plant away from your others and when you you throw away the soil out it in your garbage not your yard or compost - you can spread it from tools, your shoes, your hands, or anything that that will help spread Fusarium from on container to another.
some symptoms of Panama disease: first external symptoms of Panama disease are a yellowing of the oldest leaves or a longitudinal splitting of the lower portion of the outer leaf sheaths ON the pseudostem especially near the base. this is followed by a wilt and buckling of leaves at the petiole base, in some cases, these leaves will remain green. as the disease progresses, younger and younger leaves collapse until the entire canopy consists of dead or dying leaves. typically your suckers will not be infected unlike Pseudomonas solanacearum (bacterial wilt, aka Moko disease) which has similar symptoms but effects the suckers also. if you cut into a p-stem infected with Fusarium it will be harder than a healthy one and you will noticed brownish-red to blackish spots in the tissue
if you suspect Panama disease there is nothing you can really do because the disease cannot be cured, if you repot into clean soil it will only be a matter of time until that soil is contaminated.