Effect of Nitrogen and Potassium Levels on the Potatoes Growth in the Chott Mariem Region of Tunisia

An experiment was conducted at the experimental station of Higher Institute of Agronomy, Chott Mariem, Sousse (Tunisia) to investigate the effect of similar levels of nitrogen and potassium on potato growth (Spunta variety). Four similar levels of nitrogen (N) and potassium (K) (0, 50, 80 and 120 kg ha-1) were randomized complete block design with four replications. Data collected on growth and yield parameters were analyzed using SPSS.20 computer software. Nitrogen (N) and potassium (K) levels showed significant effect on mostly growth and yield parameters. It can be show that N and K application at the level of 120 kg ha-1 significantly affected plant height (59.16 cm), number of leaves plant-1 (294), number of branches plant-1 (14.66), fruits plant-1 (20.96), and leaf area (422.66) index. Additionally the maximum of dry matter (13.83%), tuber size (79 mm), tuber yield (22.193) and tuber weight (203.66 g) were recorded with 120 kg ha-1. From this study, it can be concluded that the higher levels of nitrogen (N) and potassium (K) (120 kgha-1) can be used for optimum production of potato variety Spunta in the study area.