Application of the multivariate approach to study the physiological responses of coffee (Coffea arabica L. var. Red caturra) to different levels of solar radiation

Agronomic responses of coffee trees to different sunlight exposition levels are well documented, but the physiological responses are being investigated. The adaptive responses of coffee trees (Coffea arabica L. var Red Caturra) to different irradiance levels (Open sunlight, 16,7 MJ m (-2)/d(-1), Regulated Shade, 9,8 MJ m(-2)/d(-1) and Non Regulated Shade, 6,4 MJ m(-2)/d(-1)) at Sierra Maestra mountain range, were investigated usin a combination of Multivariate Analysis and Factor Analysis. It was proved that using a combination of both multivariate analyses, more integral conclusions about the effect of contrasting light environment is possible. From the physiological point of view, a significantly decrease of plant growth: Leaf Area per plant, Leaf Area Index, Leaf Dry Weight, due to an increasing of leaves abscission in open sunlight treatment mainly at post flowering stages was observed. An increasing of specific leaf weight with higher irradiance levels was observed in both plant densities. The role of phenological phases in the adaptive responses to irradiance is discussed.