Negash, Legesse (Professor)HaHu, Beira2018-06-222023-11-082018-06-222023-11-082016http://etd.aau.edu.et/handle/123456789/2968The experiment was conducted to evaluate the influence of different mixes of growth media on the growth and development of avocado, papaya and guava seedlings. It was undertaken in the nursery site of the Center for Indigenous Trees Propagation and Biodiversity Development. The study focused on addition of cattle manure and sand to topsoil. Six media mixes were prepared. The ratio of these media mixes, as treatment was determined on volume bases using flowerpot. Thus, treatments were: topsoil (Tl); topsoil, cattle manure & sand, 3:1:1(T2); topsoil, cattle manure & sand, 2: 1 :1(T3); topsoil, cattle manure & sand, 1:1: 1 (T4); topsoil & sand, 1 :I(TS); and topsoil and cattle manure, 1: 1 (T6) and studied in a complete randomized design with three replications separately for avocado (Persea americana), papaya (Carica papaya) and guava (Psidium guajava). The data on total shoot height and numbers of fully expanded leaves per plant were collected starting from 7 weeks after germination up to IS weeks of growth in the nursery at two weeks interval. Sample leaves were collected at the termination of the former two parameters for the determination of leaf fi'esh and dry biomass. The data taken at the termination of the measurement was used for analyses. The different media mixes did not significantly influence on any parameter of avocado; while leaf number and leaf dry weight of papaya; and the leaf fresh weight of guava seedlings were significantly influenced (p<O.OS). Therefore growth medium 3 (topsoil + cattle manure + sand, 2:1:1) v/v] gave significantly higher leaf number and leaf dry weight than growth medium 6 (topsoil + cattle manure in equal ratio) on papaya seedlings. Growth medium S (topsoil + sand in equal ratio) had significant influence on leaf fresh biomass of guava seedlings than growth media I (topsoil). Media mixes influenced at least one growth character of the seedling of papaya and guava. Generally the presence of sand in any propoliion in all the three seedling species gave better performance than the media mixes without sand mixture. All the seedling types were in a well growth performance till the termination of data collection and h ad reached the p lantable size except for some seedlings of papaya and guava. Thus, it is concluded that avocado, papaya and guava seedlings can grow in the vicinities of Tulu-Korma. However it deserves detailed investigation on their further growth up to yield.enBiologyThesis