Re: Why is one of my plants wilting?
1) How much direct sun is the plant getting at the window? Young plants at his stage need bright sunlight, but not direct sun and radiant heat.
2) The heating and AC in a house will lower the humidity. These plants are from a greenhouse with high humidity & misting several times per day. So misting the plant 2 or 3 X's per day will help.
3) The last photo of the roots shows a fine commercial type potting soil with very little or no course material. I suggest adding 50% perlite to increase drainage of the soil.
4) The 1st photo appears to show a pot with a self contain saucer. Bananas like Fresh water and can not tolerate stagnate water. Make sure the pots drain all excess water out of the pot.
5) Root rot: The white roots you see are not the roots that take up water and nutrients. That is done by a hair like root and those may have rotted away. It will take a little time to regrow new roots. Root rot had not progressed to the corm. ... Foliar spraying with miracle grow and water misting will help the plant to recover until new roots can grow.