Int. J. Adv. Res. Biol.Sci. 1(7): (2014): 94–104 94 International Journal of Advanced Research in Biological Sciences ISSN : 2348-8069 www.ijarbs.com Research Article Effect of growing media on seedling growth of African baobab (Adansonia digitata L.) Thembinkosi Mathowa 1* , Mpho Bosenakitso 1 , Witness Mojeremane 1 , Christopher Mpofu 1 and Gabatshele M. Legwaila 1 1 Department of Crop Science and Production, Botswana College of Agriculture, Private Bag 0027, Gaborone, Botswana *Corresponding author: tmathowa@yahoo.com Abstract Adansonia digitata L. is a major multipurpose tree species which has an important economic value not only for food but also medicine and fibre. A pot experiment was conducted in the net-shade at Botswana College of Agriculture from January to May 2014 to evaluate the growth response of A. digitata potted seedlings to different growth media. The experimental design was a completely randomized design (CRD) with four treatments each replicated four times. The four treatments were as follows; top garden soil (TGS), top forest soil (TFS), commercial compost (CC) and a mixture of the three (TGS+TFS+CC) being treatments 1-4, respectively. The results revealed a non-significant treatment effect (p>0.05) on plant height across treatments in weeks 2 and 4. The mixture (TGS+TFS+CC) significantly (p<0.05) increased seedling plant height from week 6 to 8 and a highly significant effect was observed from week 10 to 12 compared to other treatments. A non-significant (p>0.05) treatment effect was observed in A. digitata seedling leaf number across treatments in weeks 2 and 4. The number of leaves were significantly (p<0.05) higher in the TGS+TFS+CC treatment in weeks 8 and 10and highly significant in week 12. The collar girth of A. digitata seedlings was significantly (p<0.01) lower in the commercial compost than other treatments in the first two weeks following transplanting. A non-significant treatment effect was observed in weeks 4 and 6, but the collar girth was significantly increased in the TGS+TFS+CC treatment from week 10 until the end of the study. The TGS+TFS+CC treatment significantly (p<0.01) increased both total (roots + shoots) fresh and dry weights. TGS revealed significantly (p<0.05) lower plant biomass than the TFS and the TGS+TFS+CC treatments. Based on these results the soil mixture (TGS+TFS+CC) is recommended as the most suitable medium that can be used by tree growers to propagate A.digitata seedlings. Keywords: Adansonia digitata, growth media, completely randomized design, tree nursery Introduction The successful production of quality seedlings in a nursery is largely dependent on the composition of the growing media (Wilson et al., 2001; Osaigbovo and Orhue, 2012). A suitable potting medium should be well drained with the ability to retain sufficient water to reduce the frequency of watering (Unal, 2013). The selection of the proper media components is critical to the successful production of seedlings (James and Michael, 2009) because media play an important role in seed germination and directly affect the development and later maintenance of the extensive functional rooting system (Bhardwaj, 2014). Suitable growing medium provides sufficient anchorage or supports the plant, serves as a reservoir for nutrients and water; allows oxygen diffusion to the roots and gaseous exchange between the roots and atmosphere outside the root substrate (Abad et al., 2002). The quality of nursery seedlings is influenced by potting media (Agbo and Omaliko, 2006) because it does not only act as a growing media but as a source of nutrients (Bhardwaj, 2014). Quality of growth