Evaluation of Chlorophyll Fluorescence and Biochemical Traits of Lettuce under Drought Stress and Super Absorbent or Bentonite Application Journal title: Журнал ÑтреÑÑ-физиологии и биохимии Authors: Akram Ghale Beig, Seyyed Neamati, Ali Tehranifar, Hojat Emami Subject(s):