Three experimental fertilization treatments of fertigation (FERT), Nitrogen-Phosphorus-Potassium (NPK), and poultry organic fertilizer (ORG) were applied on a cassava (TMS 30573) cultivation at the rate 300 kg/ha for NPK and ORG, while fertigation was injected at 1.5 litres/minutes. The results were compared with the control and unfertilized field using the same cassava cultivar. The results from the four treatments indicated that the cassava phenological development significantly responded to fertilizer applications. At 183-day after planting (DAP), the plant height under FERT was higher than NPK, OGR and CON by 19.0 cm, 60 cm and 80 cm. Conversely, under ORG, the leaf emergency (le) steady increased to 42 leaves at 183 DAP, whereas NPK reached peak (le) at 161 DAP and dropped to 41 at 183 DAP. Also, under the FERT and CON, le dropped to 38 and 33 leaves at 183 DAP. The rate of leaf death (ld) is significant at P<0.001 under fertigation, NPK and ORG, while insignificant under control treatment. Projected cassava yield per hectare estimated from phenological and morphological development indicated that ORG showed high possibility of producing cassava yield increase of 2.5 tons/hectare over FERT, 3.2 tons/hectare, 4.8 tons/hectare under NPK and CON respectively.