The influence of seed ageing on the plant on seed germination in Protea neriifolia (Proteaceae)

Abstract

Protea neriifolia R. Br. retains its seeds in the canopy in persistent, woody inflorescences. The effects of ageing on the plant on percentage germination and germination rates of seeds were examined in a controlled (light, temperature) environment and in an open environment under cover. The seeds were classified into the following age classes: current years crop, previous years crop and all seeds remaining in inflorescences produced prior to this. The aims of this study were to determine whether the germination patterns of seeds were influenced by seed age and the conditions under which the seeds germinated. The percentage germination of seeds did not decline markedly with increasing seed age but the germination rate decreased significantly. Seeds that were planted 3 to 5 mm below the surface of sand in germination trays took longer to emerge and appeared less synchronously than seeds placed on the surface. Seedlings from seeds 3 or more years old will experience a greater risk of mortality during germination and establishment because they take longer to emerge and start growing. Successful germination and seedling establishment in the field may require 4 or more weeks of moist conditions, a condition which would generally restrict germination to the rainy season.