Physiological characteristics and development of coffee plants under different shading levels

Abstract

Differences in the availability of solar radiation can cause modifications in the structure and function of coffee plant leaves, such as physiological, growth and disease incidence alterations. The objective of this work was to evaluate the physiological characteristics and development of developing coffee plants submitted to five shading levels (0, 35, 50, 65 and 90% of shading) in the dry and rainy period. The evaluations were conducted in coffee plants of the Coffea arabica L. species, cultivar Catucaí Amarelo 2SL. The treatments were disposed in a randomized block design with plots subdivided in time, in which the shading levels and the evaluation periods were disposed in the plots and split-plots, respectively. The different shading levels and the seasonal modifications (rainy and dry period) to which the coffee plants were submitted promoted effects on the physiological characteristics, presenting better photosynthetic performance under 35, 50 and 65% shading levels in the rainy period. However, in the dry period, the plants submitted to the 50% shading level present higher CO2 assimilation. The 35, 50 and 65% shading levels provide better growth for coffee plants. Coffee plants under full sun present higher cercosporiosis incidence.