The banana plant claims membership in the Musaceae family and is native to southeast Asia. Several afflictions can bring on a browning and wilting of the leaves of this otherwise vigorously-growing, herbaceous plant.
Banana wilt, also called Panama disease, is caused by the fungus Fusarium oxysporum f. sp. cubense. It forces banana leaves to turn yellow at the base, before moving into the margins and then the center. The leaf then turns a brown or bronze color and begins to droop or wilt.
The banana leaf spot disease known as yellow Sigatoka also results in leaves of the plant developing extreme browning due to another fungus, Mycosphaerella musicola. It begins with tiny, yellow flecks that morph into larger, yellow streaks and eventually dark, brown lesions that cover the entire banana leaf.
Fungal disease in bananas is more likely a concern on commercial farms than in home gardens. Small growers may see their banana leaves turn brown or be otherwise damaged due to environmental conditions. The University of Florida Institute of Food and Agricultural Sciences indicates that temperatures above 98 F, extreme wind and drought conditions all result in the browning of banana leaves.