This study was carried out during the two successive seasons (2017 and 2018) on the first and second ratoon of healthy uniform banana cv. Williams (Musa spp.) Plants grown in sandy soil under drip irrigation system in a private orchard located at El-Tahadi region, Cairo Alexandria desert road, Behaira governorate, Egypt. The investigation aimed to study the effect of different slow release potassium fertilizer (SRKF) (50% K2O) rates (100%, 75% and 50%) were added as soil drench during mid March, mid June and mid September while, potassium sulphate dose used in control treatment was added at monthly intervals as soil application from mid March until mid October on vegetative growth, productivity, total yield income and net return/feddan of banana plants. The obtained results showed that, all treatments had a significant effect on enhancing the vegetative growth parameters, i.e. number of green leaves /plant, plant total assimilation area (m2/plant), leaf total chlorophyll content (CCI) and leaf macro element content (N, P and K) as (%) as well as leaf micro element content (Fe, Zn and Mn) as (ppm). Also, improving yield (ton/feddan), bunch weight (kg), number of hands/bunch, hand weight (kg), number of fingers/hand, finger weight (g), finger length (cm), finger circumference (cm), finger pulp weight (g), finger pulp/peel (ratio), TSS (%), TSS/TA (ratio), total sugars (%). In addition, the total yield income (1000 LE) and net return/feddan (1000 LE) in both seasons. Moreover, all treatments had no significant effect on plant pseudostem height (cm), pseudostem circumferences (cm) and leaf area (m2) of plant in both seasons and bunch length (cm) in the first season only. Treatment of: slow release potassium at 100% gave the highest values of physical and chemical properties of banana plants cv. Williams in both seasons compared to, control treatment (100% potassium sulphate) and slow release potassium at 50% gave the lowest values.