EFFECTS OF PARTIAL ROOT-ZONE DRYING IRRIGATION IN COMPARISON WITH DEFICIT AND FULL IRRIGATION ON POTATO (Solanum Tuberosum L.) GROWTH, YIELD AND WATER USE EFFICIENCY UNDER SEMI-ARID CLIMATE CONDITIONS IN TUNISIA

Abstract

A series of severe drought years that have afflicted Tunisia since 2016 has resulted in a critical water shortage, particularly in surface water resources. This, in turn, has led to a decrease in agricultural production, including the potato crop. To address this challenging situation, the adoption of water-saving irrigation techniques has become imperative in the Tunisian context, rather than merely an option. To evaluate the impact of the Partial Root-zone (PRD) irrigation technique on potato growth, yield, and irrigation water use efficiency (IWUE), a two-year experiment was conducted at the Technical Centre of Potato and Artichoke in the lower valley of the Medjerda. The experiment encompassed three treatments: Full Irrigation (FI), which received 100% of the ETc (crop evapotranspiration); Deficit Irrigation (DI75), receiving 75% of the ETc; and the PRD treatment, which was supplied with only 50% of the ETc. The results revealed that, given the specific soil and climatic conditions of the experimental site, the PRD technique, even with only 50% of the required water, did not significantly hinder potato growth and yield when compared to the FI and DI75 treatments. On the other hand, the PRD technique allowed significant increase of the IWUE and tuber dry matter than the FI treatment with 43.2% and 7.6% respectively.