Banana plantations - Costa Rica
In the late 1990s, the charges levelled at the banana industry centred on the effects on biodiversity of deforestation, waste generation and the continuous use of crop protection products. (Vargas, 2006).
A research study in Costa Rica was established to investigate and four of the resultant papers are listed below.
Indicators of biodiversity
In this research project ants, parasitic wasps, frogs, lizards and microbial levels, were used as indicators of biodiversity within the plantations and birds were used as indicators in adjacent forest fragments. Both ants and wasps are seen as useful indicators in this type of study; ants because of their fundamental role in ecological systems and parasitic wasps because they are sensitive to pesticides and because they imply an abundance of the insect herbivores on which they feed. Levels of microbial activity were indicated by measuring the decomposition rates of crop residues.
Vargas summarised papers from this and related studies and concluded that whilst crop protection products do impact on biodiversity and in this order; Herbicides (least impact) – Fungicides – Insecticides – Nematicides (most impact), other effects have a greater impact. Conservation efforts in banana plantations can be usefully directed towards:
- Protecting and extending bird forest habitats
- The even distribution of organic waste to encourage its decomposition through microbial activity. (The decomposition process releases nutrients for the banana plants thus reducing the need for non-organic fertilisers); and by
- Maintaining a level of weeds by combining
- Mechanical control of weeds along drainage systems (where plant communities are beneficial to bank integrity and wildlife populations)
- And use of a non systemic, contact herbicide within the banana plants. (This will kill the tops of the weeds but not the roots having a twofold effect of reducing soil erosion and enhancing microbial activity around the root systems).
As an outcome of this and related research projects, and appreciating the interconnectivity of farming practices, Peter Edwards worked with banana companies to develop the Principles of Integrated Farm Management. Suggestions as to how these principles can be applied to enhancing biodiversity in banana plantations are being developed and will become available from this site in the form of the Integrated Farm Management Wheel.
1. Vargas suggests that based on the above studies, future research should focus on
- risk assessment of insecticides/nematicides currently used where
- “Proper understanding of community structure and function should provide the basis for stability improvement to enhance biological control of insect pests”. (Vargas, p105)
2. The combination of these activities will create a structural diversity in banana plantations and future research might investigate how diversity has altered.
Resources and references:
Matlock, R. B., & Cruz, J. R. d. l. (2002). An inventory of parasitic Hymenoptera in banana plantations under two pesticide regimes. Agriculture, Ecosystems & Environment, 93(1-3), 147-164.
Matlock, R. B., & Cruz, J. R. d. l. (2003). Ants as indicators of pesticide impacts in banana. Environmental Entomology, 32(4), 816-829
Matlock, R. B., & Edwards, J. R. (2006). The influence of habitat variables on bird communities in forest remnants in Costa Rica. Biodiversity and Conservation, 15(8), 2987 - 3016.
Matlock, R. B., Rogers, D., Edwards, J. R., & Martin, S. G. (2002). Avian communities in forest fragments and reforestation areas associated with banana plantations in Costa Rica Agriculture Ecosystems and Environment. Agriculture, Ecosystems & Environment, 91(1-3), 199 - 215.
Vargas, R. (2006). Biodiversity in humid tropical banana plantations where there has been long term use of crop protection products. Agronomia Costarrricense, 30(2), 83-109.