Solar Irradiance in the emergence and the initial development of Arabica coffee seedlings in the south of Goiás

The photosynthesis is considered the greatest physiological process of growth, being essential to the supply of raw material for the development of plants. This work was developed with the objective of evaluating shading meshes (35%, 50%, 80% light retention mesh and in full sun), in the emergence and development of Arabica coffee seedlings (Acaiá do Cerrado, Catuaí Amarelo and Mundo Novo), with three replications, totaling 36 experimental units. The plot consisted of 4 plants, totaling 144 plants. Initially, the percentage of seedling emergence and the emergence speed index (IVE) were evaluated. At 180 days, the plant height, stem diameter of the seedlings, leaf area index of the first fully expanded pair of leaves, root length and number of leaf pairs were evaluated, as well as dry and fresh root and shoot. It was concluded that the 35% shading mesh was the one that best favored the IVE of coffee seedlings. There was no significant difference between the shading grids and between the cultivars in relation to the percentage of seedling emergence and the initial development of seedlings for any of the characteristics evaluated. The production of coffee seedlings in full sun is not recommended in the southern region of the state of Goiás.