The effect of seed treatment and depth of sowing on seedling emergence in Primula species.

摘要

This study looked at the percentage emergence of 16 species of Primula native to Europe and the Sino-Himalayan region, in response to different seed treatments and storage periods when sown at different depths (0 mm, 5 mm, 10 mm). The research was undertaken to investigate whether the practice of raking seed into the soil following broadcast sowing to create a horticultural meadow vegetation would increase or decrease seedling emergence. As dry-stored untreated seed, most species showed maximal emergence when surface sown (0 mm). However in many species, seed that was non dormant (fresh or chemically treated) was able to achieve satisfactory emergence from a sowing depth of 10 mm. Species could be categorised into three groups on the basis of the response of their dry-stored, untreated seed to the environmental stimuli (for example light and diurnal temperature fluctuation) operating at the soil surface: (i) surface sowing increased emergence, (ii) surface sowing did not increase emergence in the absence of moist chilling, (iii) surface sowing was not required for germination and emergence. The results are discussed in relation to seed sowing practice in the field.