ABSTRACT
According to the United States Department of Agriculture (USDA), Tunisia’s proportion of durum wheat production out of its total wheat harvest is always the highest of the Maghreb countries, comprising about 80% of Tunisia’s total wheat harvest. The goals of the Tunisian government include technology exchange, increasing certified seed usage, and reaching 120,000 ha of irrigated cereals in the short term. The new Tunisian cultivars are often characterized by high grain yield and are more responsive to increased seeding rates, added nitrogen fertilizer use, and additional supplementary irrigation and receptive to appropriate weed control techniques (Rezgui et al. 2008). However, most of the available water resources are of medium to poor quality, and the saline content is often high (Mougou et al. 2011). In arid and semiarid regions of Tunisia, the use of low-quality water for irrigation is accompanied by risks leading to plant stress and soil salinization with associated harmful consequences on plant development and yield. Salt accumulation in arable soils is mainly derived from 244irrigation water that contains trace amounts of sodium chloride (NaCl) and from seawater (Deinlein et al. 2014). In many coastal areas of Tunisia, excessive groundwater pumping from coastal freshwater wells increases saltwater intrusion, which leads to land contamination and salinization. Currently, about 50% of the total irrigated areas in Tunisia are considered at high risk for salinization (Bouksila et al. 2011). In these regions, salinity is one of the serious environmental problems, causing osmotic stress and reduction in plant growth and crop productivity. Projected climate-change impacts, rising temperature, rise in potential evapotranspiration rates, and declining rainfall exacerbate this problem of salinity.
