Enhancing Seed Germination and Seedling Growth of Tropical Almond (Pithecellobium dulce ) through Seed Soaking Treatments

• Samah Ali Hadi Ayad Assi Obaid

  Author

    A greenhouse experiment was conducted at the Department of Horticulture and Landscape Engineering, College of Agriculture, University of Diyala, during March 2024/2025, to evaluate the effects of different plant growth stimulants on the germination and early growth of Indian almond (Pithecellobium dulce L.) seeds were obtained from a local nursery. The study employed a Completely Randomized Design (CRD) with five treatments—control (distilled water), gibberellic acid (GA₃, 50 mg L⁻¹), benzyl adenine (BA, 50 mg L⁻¹), 2,4-dichlorophenoxyacetic acid (2,4-D, 30 mg L⁻¹), and Etonk (4 mg L⁻¹)—with three replicates of 50 seeds each. Seeds were soaked for six hours and sown individually in paper cups filled with Dutch peat moss under polyethylene cover to maintain moisture. The results revealed that GA₃ significantly enhanced germination percentage (16.3%) and reduced germination time to 12.66 days, compared to the control (5.3% and 24.33 days). Treatment with 2,4-D produced the tallest seedlings (11.88 cm) and the highest number of leaves (6.82 leaves per seedling), while BA application significantly increased leaf chlorophyll content (33.59 SPAD units). These findings indicate that different plant growth stimulants selectively enhance germination and seedling growth traits, with GA₃ being most effective in promoting germination, 2,4-D in vegetative growth, and BA in chlorophyll accumulation.

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