Evaluation of the Use of Oregano and Coconut Hydrolates to Improve Onion Seed Quality

Onion seeds are often contaminated by pathogenic fungi, such as Botrytis spp., Fusarium spp., which decrease seed quality. The usage of hydrolates is an alternative method to chemical treatment, and is safe for the natural environment, human health and life. The aim of the experiment was the determination of the effect of treatment with oregano and coconut hydrolates on the quality of onion seeds. Germination, vigour and seed health of two samples of onion seeds were tested. Seed germination was evaluated according to ISTA Rules, seed health by agar test and vigour by seed speed and uniformity of germination. Seeds were treated with hydrolate solutions at concentrations of 10, 20, 50 and 100%; untreated seeds and seeds soaking in water and treated with fungicide were control. Generally, the use of hydrolates improved the germination capacity at first and final count for both analyzed samples. After treating with hydrolate solutions, less abnormal diseased seedlings were also observed. Higher concentrations of hydrolates were effective in the limitation of the incidence of fungi A. alternata, Cladosporium spp. and Fusarium spp., either by complete elimination or a reduction of their presence on the seeds.