Does Deficit Irrigation Affect the Relation between Radiation Interception and Water Consumption for Durum Wheat (Triticum durum Desf)?

Abstract

Total Dray Matter (TDM), Photosynthetically Active Radiation Intercepted (PARabs), Water Consumption (WC), Water use-(WUE), Radiation use efficiency (RUE) and the relationship between Radiation Interception and Water Consumption for Durum Wheat were investigate under different irrigation amount (D 1 = 100 % ETc; D 2 = 70 % ETc; D 3 = 40 % ETc and D 4 = pluvial) and during three growing seasons (2005-2006, 2006-2007 and 2007-2008). Results showed that, the cumulative PAR abs decreased with deficit irrigation. In fact, D 1 treatment recorded the highest cumulative PAR abs and the lowest marked underD 4 treatment. Similarly, TDM and RUE were decreased with deficit irrigation. The highest RUE observed under the D 1 (from 1.32 to 1.43 g MJ -1 ) and the lowest under D 4 (from 1.17 to 1.29 g MJ -1 ). However WUE increased with deficit irrigation. The highest WUE were obtained under the D 4 (from 3 to 4 kg m -3 ) and the lowest were observed under D 1 (from 2.8 to 3.1 kg m -3 ). Significant linear relationship was found between cumulative PAR abs and cumulative water consumption with a high correlation coefficient (R 2 ) only under the two treatments D 1 and D 2 .