Effects of different osmotic solutions on onion seed emergence

Abstract

This experiment was aimed at the optimisation of emergence with onion seeds. For this reason, onion seeds (Allium cepa L.) short-days cultivars (Aki and Alix) and long-days cultivars (Banko and Suluova) were primed with different concentrations of polyethylene glycol (PEG (6000)) in inorganic salts (KNO(3) and KH(2)PO(4)) for different periods of time (3 and 6 days or until 1% radicle emergence) at 15 degrees C. After the treatments, the effects of priming on seedling emergence were evaluated at optimal (20 degrees C) and suboptimal (11 degrees C) temperatures, under field conditions. Priming in all KNO(3) and KH(2)PO(4) reduced the days to emergence without significant loss in emergence ratio. In contrast, seed priming with PEG was ineffective. In field experiments, which were conducted in different periods (at two week intervals in February and March for spring and in September and October for autumn), the emergences of primed seeds were not earlier than those of untreated seeds, except 'Alix'. In this variety, seeds primed with KNO(3) and KH(2)PO(4) emerged approximately four days earlier than the control seeds, regardless of the sowing date.