The effect of storage conditions on coffee seed and seedling quality

Abstract

Obtaining commercially useful coffee seedlings is hindered by slow, uneven germination and low tolerance to desiccation as well as reduced coffee seed longevity. Coffee seeds have been considered recalcitrant, orthodox and even intermediate with varying results. Current recommendations suggest that coffee seeds can be safely stored between 10-11% f.w.b. at 15°C. However, after drying and storage, coffee seeds lose vigour, and seeds stored after drying cannot be used for producing seedlings. Coffee seedling producers usually sow seeds immediately or lightly dry them after harvest for a short storage period, if necessary. It is highly desirable that seeds are stored safely to optimize coffee seedling production at the appropriate time and season with ideal climatic conditions for planting in the field. The objective of this study was to determine the quality of coffee seedlings produced from seeds stored with high, medium and low moisture levels under hermetic conditions at 10 and 20°C. Seed and seedling quality were assessed before and after nine months storage. Only the germination of seeds harvested at the cherry stage, evaluated before and after the storage at 10°C, was not affected by moisture content, but these seeds lost vigour and did not produce suitable seedlings for planting when stored for nine months. Seedlings produced in the nursery from seeds with 47 and 12% moisture content performed the same as those from greenish-yellow seeds, but they produced a leaf area that was five times smaller, a stem height three times shorter, and had 1.7 times fewer pairs of true leaves than coffee seedlings produced from fresh seeds. Storage at 20°C was not suitable for coffee seeds, especially those at 18% moisture content whose quality declined drastically. These results suggest that coffee seeds do not tolerate desiccation and that their storage behaviour classification should be reviewed.