Solution pH alteration on induction of tuber initiation in hydroponically grown potatoes

Induction of tuber initiation in potatoes (Solanum tuberosum L.) is very important to increase the effectiveness of hydroponic systems grown in quality seed tuber production. Among different methods to increase the tuber induction, intermittent alteration of pH in the nutrient solution was evaluated in a hydroponics system to examine its effect on tuberization and to select the most effective intermittent pH to be maintained in the nutrient solution. Four different intermittent pH alterations (3.0, 3.5, 4.0 and 4.5) were compared with constant pH (5.5) and the intermittent pH were given for 8h at 4 and 6 weeks after planting. Popular potato variety Granola was selected for the experiment and plant height, number of stolons per plant and number of tubers per plants were evaluated. Intermittent solution pH was not significant on plant height at the early growth stages of potato plants. However intermittent pH of 3.5 showed significantly higher plant height at harvesting (54 cm). Number of stolons was significantly responded variations in intermittent pH alterations and the pH maintained at 3.5 intermittently resulted the maximum numbers of stolons (58) and tubers (38.66), achieving 110% increment compared to control. Overall results proved that alteration of pH in the nutrient solution was positive on tuberization of hydroponically grown potatoes and 3.5 was the optimum intermittent pH level.