Influence of organic pre-sowing seed treatments on germination and growth of rosemary (Rosmarinus officinalis L.)

ABSTRACT Rosemary (Rosmarinus officinalis L.) is an important medicinal and aromatic herb, used by various pharmaceutical, food and cosmetics industries. For most species, seed-based multiplication is effective and convenient, but for rosemary, seed germination is a problem due to the mucilaginous seed coat, and sometimes the germination is no more than 10–20% resulting in non-uniform crop establishment. This investigation was carried out to improve seed germination by using low-cost organic seed priming techniques. Eleven pre-sowing seed treatments were tested, based on locally available resources, including: soaking seeds in water (cold and hot), bovine urine (5%, 10%, 15% and 20% concentration), bovine dung slurry, buttermilk, compost tea and Agnihotra ash, and comparing with an untreated control. All the pre-sowing seed treatments increased the percentage of seed germination in rosemary compared with the control, except buttermilk, which had an adverse effect. Among the different treatments, seed germination was significantly increased to 46.7% for seeds treated with bovine dung slurry and to 42.0% for seeds treated with bovine urine5.0%, compared with those in the control where the germination was 9.7%. The bovine dung slurry treatment also recorded uniform and early germination (9 days for initiation and completion at 43 days) resulting in a significantly higher rate of germination (1.4) than the control. The number of leaves, the root length and the seedling vigour were also recorded to be the highest for seeds treated with bovine dung slurry, followed by bovine urine5.0%.