keywords: Water Stress, Nicola, Marabel, Potato, yield
This study was conducted in Jos North Local Government Area of Plateau State, Nigeria to investigate the effect of water deficit on the growth and yield of two varieties of Potato. In this study, three (3) regulated water application depths at 50, 75 and 100% with respect to daily evapotranspiration values were applied to Nicola yellow and Marabel Irish potato (Solanum Spp.) varieties. The experiment involves six treatment laid in a Randomized Complete Block Design (RCDB). Data were collected from week three (3) to week eight (8) and analyzed at α < 0.05. The results showed that number of leaves show no significant difference (p>0.05) for both -varieties during the course of the study. However, plant height and collar girth only showed significant statistical (p<0.05) difference due to variety at week four (4) and week one (1) respectively. Nicola yellow yield of 14.19 t/ha was significantly higher (p<0.05) than that of Marabel at 9.61t /ha. As water depth increases from 50% to 75% and 75% to 100%, there was a corresponding significant (p<0.05) yield increase by 21.66% and 15.78% respectively. The results indicated that Nicola yellow shows more resistant to water stress when compared to Marabel. Nicola yellow cultivation combined with water depth level of 75% can successfully be adopted to obtain optimum yield in Irish potato cultivation under limited water condition in the study area.