Organic Farming Practices and Shade Trees Reduce Pest Infestations in Robusta Coffee Systems in Amazonia

Abstract

Coffee agroforestry systems could reconcile agricultural and environmental objectives. While pests and diseases can reduce yield, their interactions with shade and nutrition have been rarely researched, and are particularly lacking in perennial systems. We hypothesized that intermediate shade levels could reduce coffee pests while excess shade could favor fungal diseases. We hypothesized that organic rather than mineral fertilization would better synchronize with nutrient uptake and higher nutrient inputs would be associated with reduced pest and disease damage due to higher plant vigor, yet effects would be less obvious in shaded plots as coffee growth would be light-limited. Using three-year-old trees of Coffea canephora var. Robusta (robusta coffee) in the Ecuadorian Amazon, we compared a full-sun system with four shading methods creating different shade levels: (1) Myroxylon balsamum; (2) Inga edulis; (3) Erythrina spp.; or, (4) Erythrina spp. plus Myroxylon balsamum. Conventional farming at either (1) moderate or (2) intensified input and organic farming at (3) low or (4) intensified input were compared in a split-plot design with shade as the main plot factor and farming practice as the sub-plot factor. The infestation of the following pests and disease incidences were evaluated monthly during the dry season: brown twig beetle (Xylosandrus morigerus), coffee leaf miner (Leucoptera coffeella), coffee berry borer (Hypothenemus hampei), anthracnose disease (Colletotrichum spp.), thread blight (Pellicularia koleroga), and cercospora leaf spot (Cercospora coffeicola). Coffee berry borer and brown twig beetle infestation were both reduced by 7% in intensified organic treatments compared to intensified conventional treatments. Colonization of coffee berry borer holes in coffee berries by the entomopathogenic fungus Beauveria bassiana was also assessed. Brown twig beetle infestation was significantly higher under full sun than under Inga edulis, yet no other shade effects were detected. We demonstrate for the first time how intensified input use might promote pest populations and thus ultimately lead to robusta coffee yield losses.

Consistency of attack level of coffee berry borer (Hypotenemus hampei Ferr.) on organic and conventional arabica coffee plantation in Aceh Tengah District, Aceh Province, Indonesia

“…The decrease in the level of CBB pests on organic coffee plantations is certainly not only due to the role of natural enemies, but also cannot be separated from the presence of various wild plant species in coffee plantations, both of which function as refugia for natural enemies of CBB and which function as repellents against CBB pests. Piato et al [10] reported that organically managed robusta coffee plantations were able to reduce CBB and brown twig beetle attacks by 7% lower than conventionally managed coffee plantations. Piato et al [10] suspect that one of the causes of the high incidence of CBB on coffee plantations that are managed conventionally is the intensive herbicide spraying on the land, causing the extinction of several weed species that act as CBB pest repellants.…”

“…Piato et al [10] reported that organically managed robusta coffee plantations were able to reduce CBB and brown twig beetle attacks by 7% lower than conventionally managed coffee plantations. Piato et al [10] suspect that one of the causes of the high incidence of CBB on coffee plantations that are managed conventionally is the intensive herbicide spraying on the land, causing the extinction of several weed species that act as CBB pest repellants. Due to the extinction of these repellent-producing plant species, the population of CBB in conventionally managed coffee fields has increased.…”

Agro-Ecological Management of Coffee Pests in Brazil

“…Spiders use non-crop plants as substrate to build webs, mainly on taller and ramified plants (Amaral et al, 2016) (Figure 11). Keeping and managing non-crop plants contribute to the maintenance of ants that nest in the ground and are important predators of CBB and CLM (Lomelí-Flores et al, 2009;Larsen and Philpott, 2010;Piato et al, 2021).…”

No Reduction in Yield of Young Robusta Coffee When Grown under Shade Trees in Ecuadorian Amazonia

“…However, contrasting shade effects have been reported on coffee growth, productivity, pests and diseases and arabica coffee cup quality [ 26 , 27 , 28 , 29 , 30 , 31 ]. This might be because shade effects interact with site biophysical parameters [ 32 ], diseases [ 26 ], shade tree species and their management [ 16 , 28 , 33 , 34 , 35 ], shade level [ 16 , 36 , 37 ], shade tree age and type of coffee clone [ 38 ]. Thus, it is crucial to test interactions among CAS components to highlight the specific conditions under which CAS can be viable.…”