Re: Interview- Dan Koeppel of "Banana" on KCRW
Black Sigatoka is a leaf spot disease of the banana that can cut fruit production in half. the fungus causes dark leaf spots that eventually enlarge and coalesce, causing much of the leaf area to turn yellow and brown. The high rainfall and humidity of tropical regions are especially favorable for disease development. the fungus that causes black Sigatoka, Mycosphaerella fijiensis, is spread from tree to tree by wind, rain, and irrigation water. the name black Sigatoka was given to the disease because it was first discovered in 1963 in the Sigatoka Valley of Fiji.
Black Sigatoka is a very difficult and expensive disease to control. it has been estimated that 15-20% of the price of bananas is due to the cost of the control measures that are used to produce the fruit. planes & helicopters are used to apply fungicides to leaves. cultural practices such as removing diseased leaves, pruning branches, & keep removing dead leaves to improve air circulation are also helpful in reducing the occurrence of the disease, but these practices are labor intensive.
since fungicides are used so frequently, growers find that the fungus is starting to become resistant to the fungicides applied to the crop. also, many of the farmers that operate small plantations cannot afford to purchase many of these fungicides. obviously a convenient and low-cost way to control the disease would be to grow banana varieties that are resistant to the disease, but the most popular banana cultivars grown are extremely susceptible to black Sigatoka, and breeding programs cannot address this due to the sterility of the Cavendish cultivars. some new banana hybrids being developed show resistance to this disease.