2.7.1 The screening for drought tolerance under rainfed environment and control environment
2.7.1.1 Rainfed environment
Evaluation under rainfed environment has been used in studies of Jerusalem artichoke for drought resistance (Monti et al., 20os: schittenhei 1999). Rainfed environment is identical to the natural occurring condition of plant growth. However, this approach has to be conducted in the climate zone with dry spell that is long enough for effective evaluation of the crop and plant can complote its life cycle. This approach has its limitations. The variability in environmental conditions between confounds sites, arising from variation in amount and distribution of rainfall,confounds the intrinsic genotypic traits contributing to drought resistance and unexpected rainfall might occur during the experimental period.