Emergence, transplant vigor, stand establishment and juvenile growth of soursop (Annona muricata L.) seedlings as affected by seed weight and nursery media
Poor seedling emergence and vigour are some of the constraints in soursop production. Soursop seed weights of 0.3-0.5 g (light weight) and 0.6-0.8 g (heavy weight) were germinated in five nursery media: topsoil (Ultisol), sawdust (Triplochiton scleroxylon), topsoil-poultry manure mixture (50:50), sawdust-poultry manure mixture (50:50) and standard nursery mixture as control (topsoil (3): poultry manure (2): river sand (1)). The 5×2 factorial arrangement was laid out in a completely randomized design and replicated four times. Sawdust-poultry manure mixture and sawdust accelerated early emergence (28.5 and 31.3 days, respectively) while topsoil-poultry mixture delayed emergence of seedlings (47.7 days). Heavy seeds emerged earliest (37.3 days) as compared to light seeds (41.7 days). Heavy seeds had also higher emergence (68%) than the light seeds (42.7%). Sawdust favoured higher percentage emergence (76.7%) than standard nursery mixture (60%). However, standard nursery mixture sustained vigorous seedling growth in terms of plant height (32.6 cm) and number of leaves (21.9) at 6 months after sowing (MAS) in the nursery. The seedlings raised from heavy and light weight seeds showed 78.3 and 36.7% survival, respectively, at 6 MAS in the nursery. Seedlings that emerged from heavy seeds showed better growth vigor as compared to light weight seeds. Soursop stand establishment was not significantly affected by seed weight and nursery media. However, stand vigor was significantly affected by seed weight and nursery media. Soursop seedlings raised from heavy seeds in standard nursery mixture produced tall seedlings (81.3 cm) in the field. Therefore, for improved soursop seedling production in the nursery and stand establishment, seeds of 0.6-0.8 g weight should be raised in standard nursery mixture.
Okoli, N.A., Obiefuna, J.C., Ibeawuchi, I.I., Alagba, R.A. and Emma-Okafor, L.C. (2020). Emergence, transplant vigor, stand establishment and juvenile growth of soursop (Annona muricata L.) seedlings as affected by seed weight and nursery media. Acta Hortic. 1273, 347-354
germination, juvenile growth, heavy seeds, light seeds