346-3 Relevance of Wheat Yield Gap Concept in Tunisia.
The objective of this study is to assess wheat yield gap in Tunisia under rainfed and irrigated conditions in order to identify factors which are limiting wheat production at regional and national scales. The wheat yield gap is defined as the difference between yield potential and the average yield of farmer fields. We followed the methodology and protocols developed by the Global Yield Gap Atlas (http://yieldgap.org/). Different wheat buffer zones were identified based to delimitation of climatic zones and wheat area distribution. The WOFOST model was used to estimate wheat yield potential based on 10 years (2003-2013) of daily weather data.
A large variation of average yield was observed among regions, ranging from 0.3 to 2.1 t.ha-1 under rainfed conditions and 0.8 to 3.1 t.ha-1 under irrigated conditions. The wheat yield gap is about 2.8 t.ha-1 and 3.2 t.ha-1 under water and no-water limited conditions respectively. This result could be explained by a weak WUE in irrigated systems.