Designing pest-suppressive multistrata perennial crop systems: shade-grown coffee in Central America

Background

This paper analyzes opportunities to achieve the benefits of microflora and fauna through species selection and complimentary characteristics & density and spatial arrangement of tree species on coffee plantations to reduce the presence of pests and pathogens, such as leaf rust, coffee leaf minor, berry borer, and the American leaf spot. Pests (and pathogens) have been increasing in Central America since the introduction of the coffee leaf rust in 1976 and the berry borer in 1971. The use of synthetic pesticides and fertilizers has increased yield significantly, but it has also increased production costs, pest resistance, secondary pests, and risks for human health. The paper hypothesizes that for every soil and climate for coffee, there is a multistrata system that creates a micro-environment that can create a complex ecosystem to resist pests as a whole as opposed to a pest-by-pest strategy.

Conclusions & Takeaways

The duration of dry and rainy seasons help determine the tree crop species and the amount of shade required to provide a habitat for the microfauna that helps combat the pests (and pathogens).
Shade from Inga paterna and Erythrina poeppigiana helped mitigate extreme variations in climate by lowering leaf and soil temperatures (which improves photosynthesis), reduced the amount of weeds (through leaf litter as well as shade), and reduced the vapor pressure. Studies on certain pathogens suggest that more shade contributes to higher rates of infection indicating that one size does not fit all. More research is required.