Forecast models of coffee leaf rust symptoms and signs based on identified microclimatic combinations in coffee-based agroforestry systems in Costa Rica

Shade tree traits and microclimate modifications: Implications for pathogen management in biodiverse coffee agroforests

“…vastatrix lifecycle will significantly change under different shade tree canopies; (2) these changes will be partially explained by canopy characteristics and shade tree leaf traits; and (3) patterns of CLR incidence will correspond to key shade tree traits. Our findings will complement detailed phytopathology research that describe pathogen micro‐processes at the leaf level (see Merle et al, 2020), by exploring the role of shade tree traits on microclimate variability and pathogen dynamics.…”

“…Our findings will complement detailed phytopathology research that describe pathogen micro-processes at the leaf level (see Merle et al, 2020), by exploring the role of shade tree traits on microclimate variability and pathogen dynamics.…”

“…This obligate biotrophic fungus infects coffee leaves via dispersed uredospores that penetrate through coffee leaves' stomata with appressoria. Microclimate conditions largely determine the success of various lifecycle stages of the H. vastatrix fungus at a fine temporal scale (Merle et al, 2020). More specifically, uredospore dispersal is encouraged by high wind speeds and rainfall energy (Kushalappa & Eskes, 1989;Rayner, 1961b;Waller, 1982); uredospore germination requires wet leaves (Rayner, 1961a); and uredospore germination, penetration, and colonization excel within specific air temperature ranges and low light conditions (Avelino et al, 2004).…”

Land in Central America will become less suitable for coffee cultivation under climate change

“…Climate change is expected to progressively increase the occurrence and severity of the most important pests and diseases like the coffee berry borer (Hypothenemus hampei) and the coffee rust (Hemileia vastatrix) over time (Jaramillo et al 2011(Jaramillo et al , 2009Merle et al 2020;Ward et al 2017). Some even consider the past outbreak of coffee rust in Central America as an early warning of what may become more recurrent in the future (Avelino et al 2015).…”

Editorial - Crop health in agroforestry systems: An introduction to the special issue

“…However, symptom appearance can be affected by complex combinations of meterological variables acting at different times and duration. Merle et al (2019) by using a statistical approach, identify the complex interactions of weather variables responsible for changes in lesion status. Based on this, the authors develops three models predicting lesion emergence probability, lesion sporulation probability and growth of its infectious area, which take into account temperatures and rainfall values for specific stages of the disease cycle.…”