Banana Pest and Disease Management in the Tropical Pacific: A guidebook for banana growers
Chapter I: Importance of an Integrated Pest Management Program for Banana
Banana (Musa sp.) is among the most important fruit crops in Hawai‘i in terms of economic, cultural, and nutritional value, and Hawai‘i ranks at the top within the United States in banana production (NASS 2012). Commercial banana production occurs on all major Hawaiian Islands, with 80% of the production located on the islands of Hawai‘i and O‘ahu (Constantinides and McHugh 2003). In 2011, Hawai‘i growers generated 17.4 million pounds of fresh market banana on 1,300 acres of land, producing a farm-gate value of $11.3 million (NASS 2012). However, banana yields in Hawai‘i have declined since the year 2000, when 29 million pounds of fresh market banana were produced (NASS 2008). Much of the decline is attributed to Banana bunchy top virus (BBTV, Nanoviridae), transmitted by the banana aphid, Pentalonia nigronervosa (Hu et al. 1996), which has resulted in the cessation of production in many areas and significantly reduced production on farms that have persisted. However, a recent survey also suggests that although this continual decline is largely caused by BBTV, plant-parasitic nematodes are playing a role (Wang and Hooks 2009). Drought conditions in 2011 exacerbated the damage caused by the nematodes.
Despite hardships caused by drought and diseases, banana revenues increased 7% from 2010 to 2011 due to a price increase for banana, from 60 cents per lb. in 2010 to 65 cents in 2011. The current lifting of fruit fly quarantine restrictions has also generated an increased opportunity for Hawai‘i banana growers to export bananas to the continental U.S. This can significantly increase profits for banana growers in Hawai‘i and other underrepresented Pacific Islands. Increasing local food production and consumption is another driving force for the recovery of banana industry in this region. The Integrated Pest Management (IPM) program for banana set out here aims to reduce the production cost and increase the profitability of banana cultivation and ultimately to encourage more self-sustainable rural banana producers in the Pacific Islands.
Integrated Pest Management (IPM) program for banana
IPM is an effective and environmentally sensitive approach to pest management that takes into consideration pest biology, economic thresholds, environment factors, and host plants’ resistance if feasible. IPM relies on comprehensive knowledge of the pests and their interaction with the environment, in combination with multiple pest-control methods to manage pests through the most economical means, with the least risk to people and the environment.
Based on the U.S. EPA IPM Principles factsheets, there is a four-tiered approach to IPM: setting an action threshold, monitoring and identifying the pest, prevention, and control.
The action threshold is the pest infestation level or environmental conditions at which the pest will become an economic threat. It is not necessary to kill all known pests in a field unless the pest population densities are reaching an economic damage threshold. The population densities of certain pests, i.e., fungal or bacterial pathogens, are difficult to monitor, thus knowing the relationship between the environmental conditions and the pest population development could be another way to determine action threshold. For example, to manage yellow Sigatoka disease in Australia, banana growers are recommended to trim excess banana leaves if more than 15% of the leaf is showing visible symptoms during the wet season, but only trim if more than 30% of the leaf is symptomatic during the dry season (State of Queensland 2003).
Appropriate and accurate identification and monitoring of pests are essential for making management decisions. In conjunction with ascertaining the action threshold, monitoring and identification avoid the possibility of unnecessary pesticide use, which can reduce costs for producers. Most importantly, reducing the amount of unnecessary pesticides will minimize the development of pesticide resistance, a common dilemma of the pesticide treadmill.
The pesticide treadmill is a situation in which pesticides
have become a regular and indispensable part of an agricultural cycle, partly
due to failure of natural remedies. An escalated form of the pesticide
treadmill is when the effective elimination of one target pest population
allows another pesticide-resistant population to thrive, resulting in the
farmer’s having to use other pesticides to eliminate the new pest population.
Prevention should be the first line of defense in IPM. Pest avoidance, or preventing pests from entering your fields, can be accomplished by quarantine; planting clean propagules; practicing field sanitation, such as removing diseased crop residues; using clean tools and equipment; making the environment less conducive to pests and pathogens by adjusting row spacing or trimming leaves; selecting pest-resistant varieties; or instituting a crop rotation sequence.
Once the pest reaches the economic threshold, and prevention is no longer effective, the next logical step in IPM is to identify effective control measures. Integration of multiple approaches that pose low risk to humans and the environment should be the preferred control strategy. Broadcast spraying of non-specific pesticides should be used as a last resort. Examples of less risky methods include using pheromones for mating disruption or to trap insects, and planting cover crops that release toxic compounds to suppress plant-parasitic nematodes.
This banana production guidebook aims to help banana growers practice a whole-farm management approach. Several pests and pathogens are simultaneously occurring in many banana orchards or gardens in the Pacific Islands. A versatile banana IPM program should be beneficial in managing multiple pests while compatible with profitable marketing. Contact the extension service in your area for more details on how to practice IPM in your area. For growers in Hawai‘i, you can visit locations of Cooperative Extension Offices and Research Stations at http://www.ctahr.hawaii.edu/site/map.aspx.
Home Gardener’s Corner
Banana is a hardy plant and can be grown successfully by home gardeners. How to manage banana pests is often the question most frequently asked by banana gardeners. Most of the IPM principles outlined in this publication can be applied to home gardeners. Contact your local Master Gardener Helplines at http://www.ctahr.hawaii.edu/uhmg/helpline.asp if you are in Hawai‘i.
Constantinides, L.N., and J. McHugh, Jr. 2003. Pest management strategic plan for banana production in Hawaii. College of Tropical Agriculture and Human Resources, University of Hawai‘i at Mānoa. http:// www.ctahr.hawaii.edu/bbtd/downloads/HIBanan- aPMSP.pdf.
Hu, J.S., M. Wang, D. Sether, W. Xie, and K.W. Leonhardt. 1996. Use of polymerase chain reaction (PCR) to study transmission of banana bunchy top virus by the banana aphid (Pentalonia nigronervosa). Ann. Appl. Biol. 128: 55–64.
NASS. 2012. Hawaii Farm Facts August 2012: 5–8.
State of Queensland. 2003. Plant Protection Amendment Regulation (N0. 4) 2003. Regulatory Impact Statement for SL 2003 No. 303. 27 pp.
U.S. EPA IPM Principles factsheet. http://www.epa.gov/opp00001/factsheets/ipm.htm
Wang, K.-H. and C.R.R. Hooks. 2009. Plant-parasitic nematodes and their associated natural enemies within banana (Musa spp.) plantings in Hawaii. Nematropica 39:57–73.