A range of irrigation scheduling methods has been developed to assist farmers to apply water more efficiently taking into account crop evaporation and rainfall. However at small farmers' level, such methods can not be applied in a practical manner as they require sophisticated monitoring equipment and data processing. Moreover, the irregularity of rainfall, and the absence of guidelines at a short time-step often complicate decision-making during the irrigation season. First, the paper presents a procedure for developing irrigation charts to help farmers in their day-today decisions. The charts are developed by considering the specific climate and soil characteristics of the region, the irrigation method and local irrigation practices. The chart guides the user in the adjustment of the irrigation interval to the actual weather conditions throughout the wheat growing season. In a second step, the paper evaluates, how well the chart expects irrigation interval comparing it to a more advanced irrigation scheduling software. The climatic data for six growing season are used to test the chart. In all case, the correspondence is remarkably good. The developed irrigation guideline accurately predicts the mean water balance components and the dynamic processes of the mean soil moisture for wheat. It is believed that the simplicity of the chart makes it a useful tool to help decision making for all actors involved in irrigation management.