Growth Response of Four Conilon Coffee Varieties (Coffea canephora Pierre ex A. Froehner) to Different Shading Levels

Abstract

In order to select a conilon coffee (Coffea canephora Pierre ex A. Froehner) adapted to shade, four varieties (C153, JM2, LB1 and GG) were submitted to four shade levels (0, 30, 50 and 70) with evaluation of plant height, stem diameter, collar diameter, number of plagiotropic branches, number of fruits, root colonization by arbuscular mycorrhizal fungi and leaf anatomy. The experiment was carried out on a completely randomized design, in a 4 × 4 factorial scheme with ten replicates. We used organic compost based on cocoa shells for plant nutrition and cow urine for phytopathogenic fungi control. There was interaction between variety and shade factors for most of coffee characteristics analyzed. In general all coffee characteristics evaluated mainly fruit number and length of fruiting branches, significantly increased with increasing shade. Coffee varieties tested respond differently to the increasing of shade levels and leaf anatomy demonstrated the reduction of mesophyll thickness as the shading increased. The effect of shade levels on fruit yield fit to a positive linear regression for all four coffee varieties tested but the mycorrhizal colonization no presented differences among coffee varieties and shade levels. The varieties C153 and GG presented highlighted anatomical, growth and productive characteristics and can be indicated for shading cultivation, for example on agroforestry systems.