Although many people believe bananas grow on trees, these perennial plants are actually herbs. A sturdy pseudostem, which can grow as high as 25 feet, supports the growth of leaves, and within six or seven months, flowers. The flowers become the “berries” or fruit. Clusters grow into bunches, often called “hands” or “combs,” and the “fingers” (fruit) turn from green to yellow as starch is converted into sugar. Fruit can measure up to a foot in length with an average width of 1.5 to 2 inches.
References: Purdue University, University of California, Los Angeles.
TYPES, VARIETIES & CUTS
There are as many as 1,000 banana varieties, classified as either eating or cooking bananas. The most common variety in the United States is the Cavendish. Plantains are typically used for cooking; the peel changes from green to yellow then brown and finally black as it ripens. Plantains are starchy and considered inedible when green, but very sweet when fully ripened (black).
References: Banana Link, Purdue University.
PESTS & DISEASE
Anthracnose is caused by the fungus Colletichum musae, which infects the fruit as it ripens through injuries and skin splits. Panama disease arises from infection by the fungus fusarium oxysporum and has plagued banana production in Central America, Colombia, and the Canary Islands. Black Sigatoka, also called black leaf streak, can kill leaves, cause premature ripening, and significantly reduce yields. Originally discovered in Fiji, the disease has spread to Mexico, Central and South America, Florida, and several Caribbean countries as well. Stem-end rot is caused by fungi entering the cut stem, turning flesh soft and mushy; cigar-end rot dries out fruit ends, resembling cigar ash.
Bananas are exceptionally vulnerable to many species of nematodes, which can cause damage to roots and corms, retarding growth, and making plants susceptible to toppling. Most nematodes but can be controlled through the timely use of nematicides. Black weevils will bore into plants and tunnel up through the stem, while banana rust thrips will mar the peel, causing splits that expose developing flesh.
References: American Phytopathological Society, Purdue University, UC Davis Postharvest Technology website.