by Kori Goldberg, Master in Environment and Natural Resources
Introduction: The banana is one of the world’s most popular fruits but the cultivar we are familiar with does face an uncertain future. Interestingly, this would not be the first time society has had to adopt a new mass-produced banana cultivar.
Background: The Gros Michel cultivar, considered high quality because of its resilience, longer shelf-life, creaminess, and better taste, was the most popularly grown banana until the 1950s (Stergiopoulos et al., 2016; Prisco, 2016). By 1965 nearly every Gros Michel plantation in the world had succumbed to the fungal disease Fusarium wilt (Stergiopoulos et al., 2016). The soil-dwelling fungus targeted the roots and vascular system making it impossible for banana plants to uptake necessary water and nutrients. Producers found a reasonable substitute in the resilient Cavendish cultivar, the banana we recognize today as the standard supermarket banana.
Cavendish susceptibility: Banana species of diverse colors, shapes, and sizes exist but the Cavendish banana is a monocrop, meaning each banana of this species is genetically identical. While this helps with economies of scale for producers and reduces the chance of imperfections, low genetic diversity does make Cavendish bananas extremely susceptible to threats (Ordonez et al., 2015).
Main Concern: Although the Cavendish cultivar was initially chosen for its immunity to Panama Disease, a new strain called Tropical Race 4 has caused recent problems for growers in Australia, the Middle East, Africa, and Asia but has not yet reached Latin America, the largest producer and exporter of bananas (Ferdman, 2015). Cavendish bananas have also shown recent susceptibility to Black Sigatoka, a fungus that causes leaf deterioration resulting in poor photosynthesis and lower quality fruit (Cordoba and Jansen, 2014; Stergiopoulos et al., 2016).
Management: Both fungi do not respond well to fungicide application. Growers routinely apply fungicide more than 50 times per growing season to manage Black Sigatoka (Stergiopoulos et al., 2016). Intense fungicide use can be expensive and may cause impacts to the environment, human and wildlife health, and make the fungus more resistant. Since Tropical Race 4 grows and remains in the soil it is difficult to eradicate once it has established on a plantation.
The best management option remains prevention. Soil transfer from banana plantations should be limited as much as possible and plants, materials, and equipment should be cleaned thoroughly to prevent contamination. The development of new, genetically diverse banana cultivars is also recommended by scientists to increase resilience (Ordonez et al., 2015).
Bottom Line: The Cavendish banana is at risk for eventual commercial extinction if management of these fungi is not successful.
Kori Goldberg is a student at The Ohio State University pursuing her Master’s in Environment and Natural Resources. In her free time she loves to be outside, whether climbing, kayaking, or enjoying green spaces in Columbus.
For more information, see Worse Comes to Worst: Bananas and Panama Disease—When Plant and Pathogen Clones Meet, available at http://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1005197.
Works Cited (MLA)
Cordoba, Diana, and Kees Jansen. “Same Disease-different research strategies: Bananas and Black Sigatoka in Brazil and Colombia.” Singapore Journal of Tropical Geography 35.3 (2014): 345-61. Web.
Ferdman, Roberto A. “Bye, bye, bananas.” The Washington Post. WP Company, 04 Dec. 2015. Web. 24 July 2017.
Ordonez, Nadia, Michael F. Seidl, Cees Waalwijk, André Drenth, Andrzej Kilian, Bart P. H. J. Thomma, Randy C. Ploetz, and Gert H. J. Kema. “Worse Comes to Worst: Bananas and Panama Disease—When Plant and Pathogen Clones Meet.” PLOS Pathogens 11.11 (2015): n. pag. Web.
Prisco, Jacopo. “Why bananas as we know them might go extinct (again).” CNN. Cable News Network, 08 Jan. 2016. Web. 21 July 2017.
Stergiopoulos, Ioannis, Andre Drenth, and Gert Kema. “Can science stop looming banana extinction?” CNN. Cable News Network, 25 Oct. 2016. Web. 23 July 2017.
This blog post was an assignment for Societal Issues: Pesticides, Alternatives and the Environment (PLNTPTH 4597). The views expressed are those of the author and do not necessarily reflect the views of the class, Department of Plant Pathology or the instructor.