Research Article

A comparative study on the growth and development of avocado (Persea americana) seedlings from small and large seeds under different growing conditions.

Gaspard Rwami Ntabakirabose¹, Marie Henriette Uwera², Gerard Kayiranga³, Clementine Mukanoheri⁴, Alfred Niyobyose⁴, Eleonore Kambabazi⁵, Mory Vital Karinda⁶, Jean de Dieu Mbarushimana⁷, Gilbert Siborurema⁸, Festus Maniriho⁹, Donat Nsabimana¹⁰ and Mbabazi Mbabazize¹¹

^1,4,5,6,7,8 Forest Research Department, Rwanda Forestry Authority, Huye, Rwanda

²Forest Management Department, Rwanda Forestry Authority, Huye, Rwanda

⁴Biodiversity and Ecosystem Management Research Group, School of Life Sciences and Bio-Engineering, The Nelson Mandela African Institutions of Science and Technology, Arusha /Tanzania

⁹Forest Investment Program, Rwanda Forestry Authority, Huye, Rwanda

¹⁰College of Agriculture, Forestry and Food Science, University of Rwanda, Busogo, Rwanda

¹¹Faculty of Business and Commerce, ISBAT University, Kampala, Uganda

*Corresponding author e-mail: gmutago@gmail.com

(Received: 20/07/2025; Revised: 19/09/2025; Accepted: 30/09/2025; Published: 20/12/2025)

ABSTRACT

Avocado (Persea americana Mill.) is a high-value tropical and subtropical fruit crop whose early seedling vigor and graft success are strongly influenced by seed size and growing conditions. This study evaluated the effects of seed size (small: 45–75 g; large: 75–120 g) and propagation environment (soil-based nursery vs. water-based hydroponic) on the growth and development of avocado seedlings, including grafted plants. A comparative factorial experiment was conducted with 60 seeds, and seedlings were monitored for height, stem diameter, leaf number, root length, and graft success over 120 days. Large seeds consistently produced taller seedlings with more leaves under both soil and hydroponic conditions, while small seeds exhibited compensatory stem thickening at later stages. Hydroponic seedlings showed slightly higher growth rates and a higher graft success rate (90%) than soil-grown seedlings (80%). Regression analysis indicated that seed size, rootstock quality, and scion compatibility were significant predictors of grafted seedling vigor. Interaction effects between seed size and growing environment were not significant, suggesting independent influences on growth. The findings highlight the importance of selecting larger seeds, implementing controlled propagation systems, and optimizing grafting practices to improve nursery efficiency, uniformity, and post-grafting performance of avocado seedlings.

Keywords: Avocado, seed size, seedling growth, hydroponics, grafting