Six genotype of Triticum aestivum L. in 1991 and one genotype of Triticum durum Desf. and three of T. aestivum L. in 1992 were studied under different water regimes: full irrigation (R1), mild water stress (R3) and severe water stress (R2) at Magneraud (France). Traits evaluated were grain yield and its components, stress susceptibility index (SSI) and normalized difference vegetation index (NDVI). The analysis of variance revealed significant differences between regimes and among the cultivars for all traits except between regimes for thousand grains weight in 1991. The regime × variety interaction was significant for grain yield, thousand grains weight and NDVI in 1992 and for grain yield in 1991. For all traits, durum wheat (T. durum Desf.) has higher reduction in the two water stress than the common wheat (T. aestivum L.). Correlations studies revealed that grain yield, grains number/m², thousand grains weight and NDVI were associated with each other except for correlations between thousand grains weight on one hand and grain yield (1992) and grains number/m² (1991) on the other hand. 51.55, 27.88, 4.12% (1991) and 75, 43 and 20.2% (1992) of grain yield, grains/m² and thousand grains weight variability, respectively were explained by means NDVI variability. The grain yield and grains number/m² could be predicted using a single regression with NDVI.
Key words: Grain yield, grain yield components, NDVI, durum wheat and bread wheat.
SSI, Stress susceptibility index; NDVI, normalized difference vegetation index; TOL, tolerance index; MP, mean productivity; STI, stress tolerance index; SR, simple ration