Effect of pericarp removal methods and irrigation regime on Avicennia marina Forssk. Vierh. seedlings in the nursery

Producing seedlings using the correct methods can aid in their better establishment in their habitats and help restore the fragile mangrove forests of southern Iran. This study aimed to investigate the effect of different methods of pericarp removal, irrigation regimes, and their interaction on germination percentage and some vegetative characteristics of Avicennia marina Forssk. Vierh. in the nursery. To achieve this goal, 30 healthy and mature trees were selected from the Sirik forest in Hormozgan province, Iran, and propagules were collected from them. The researchers used a completely randomized factorial design to study the effects of the treatments. Four pretreatments were tested for pericarp removal: pre-soaking propagules in 100% fresh water, 50% fresh water + 50% seawater, 100% sea water for 48 hours, and manually removing the pericarps. The propagules were then planted in plastic pots and irrigated twice a day, daily, every other day, or every three days. The seed germinations were measured for four weeks, and after two leaves appeared, collar diameter and height were recorded at the beginning and end of the six-month period. The results showed that seed germination and the vegetative characteristics of Avicennia marina Forssk. Vierh. seedlings were higher in the 50% fresh water + 50% seawater pretreatment. Additionally, germination, diameter growth, height growth, root length, and leaf number of the seedlings after six months were significantly higher with twice-a-day and daily irrigation regimes. Overall, the best conditions for producing Avicennia marina Forssk. Vierh. seedlings in the nursery were daily irrigation and pericarp removal using 50% fresh water + 50% seawater treatment.