Staging coffee seedling growth: a rationale for shortening the coffee seed germination test

Abstract

The species Coffea arabica L. is one of the most important agricultural commodities in Brazil. Despite considerable effort at vegetative propagation of coffee plants, they still are propagated by seedlings produced directly from seeds. An undesired trait of coffee seeds is that they have slow and asynchronous germination, which makes it difficult to obtain seedlings of desirable quality. In addition, this slow and asynchronous germination makes rapid viability and/or vigor evaluations difficult because of the excessive time required to obtain results. The objective of this study was to describe coffee seedling growth developmental stages by documenting morphological changes during germination and post-germination growth. Eight seedling growth stages were described. Description of stages permits a more accurate characterization of coffee seedling development than days after imbibition since environmental factors have a major bearing on the speed and uniformity of seedling growth. In addition, current Rules for Seed Testing in Brazil require 30 days before germination can be assessed. These data demonstrate all essential seedling parts are present on coffee seedlings at stage 6, which occurs at 15 days. Such data suggest that the standard germination test for coffee seeds can be substantially shortened to provide more rapid seed quality assessment.