Growth and physiological quality in clonal seedlings of Robusta coffee

Resumo

The intrinsic characteristics of the vegetative propagule may influence the rooting speed and shoot growth,
as well as the final physiological quality of clonal seedlings of Coffea canephora. The aim of this study was to evaluate the
growth and physiological quality of ‘Robusta’ coffee seedlings produced from propagules (stem cuttings) with different cutting
ages. The study was conducted in a greenhouse, in the district of Ouro Preto do Oeste, in Rondônia, Brazil (10˚45’43” S and
62˚15’10” W). The ages of the cuttings were 30, 60, 90, 120 and 150 days, corresponding to five positions on the secondary
orthotropic stem (sprout), from the apex to the base. Dry matter accumulation, and relative and absolute growth rates were
evaluated for 188 days after cutting, as well as the vegetative characteristics of the seedlings at 125 days after cutting. It
appears that growth can be divided into three phases: 1) Initial: slow growth, lasting approximately 83 days; 2) Intermediate:
fast growth, lasting approximately 40 days; and 3) Final: slow growth, starting approximately 125 days after cutting. With
physiological quality, although all the cuttings showed similar growth curves, those of 60, 90 and 120 days produced, 125 days
after cutting, the best vegetative performance in the seedlings.