I grow potted bananas in the greenhouse, and it seems sometimes they develop the brown spots in the center of the leaf-- if the leaf was somehow damaged while still spiraled up. Like if the wind blows them into the side of the greenhouse, or if they get knocked around, like a bruise on the leaf.
Edge browning usually means that they got too dry or the roots got too hot in the pot, or they are over fertilized.

If the NEW leaves are getting completely consumed by the brown necrotic spots though, you might have a fungal disease like botrytis, because usually overfertilizing or mechanical damage doesn't cause the entire leaf to die off. It is the time of year for leaf diseases, the temps are right, and the moisture is right. Daconil spray will take care of that.

If it's the bottom leaves that are dying off faster, that is normal for this time of the year, the plant is preparing to go dormant--and it seems that they lose bottom leaves faster here in the cool weather. Cut back on watering if the temps are cool.

And last of all, if the leaves are turning a silvery, sunburned color and dying off rapidly, look for spidermites on the bottom side of the leaves, and treat for those.

That's all the options I can think of, but maybe that will help you diagnose the problem...

Sandy@ Northern Tropics

Thanks. I will try to get some pictures of the leafs in the next day or so. I just brought the basjoo indoors as the last couple of days have seen highs in the upper 60's to low 70's but nights have been hitting the mid 40's. Tuesday afternoon found the leaves wilting and drying up. Brought her indoors adn within 24 hours she perked up some and then I noticed the black specks as well. At least now I dont have to worry about them. Just having a real bad time with brown, dried and dead spots throguh the leaves, the edges on some and the tips. Usually occuring within 2 days of the leaf fully opening.