Cation nutrition and ecophysiological response of two Tunisian olive cvs, Chetoui and Chemlali (Olea europaea L.) under water stress

摘要

The cation nutrition results showed that potassium, calcium and magnesium absorption and partitioning varied depending on olive variety and water stress level. Chemlali and Chetoui cultivars showed a significant variation depending on water-stress levels for potassium concentration in leaves and stems, but no significant variation in root concentration. The higher the water stress, the higher potassium absorption by roots for Chemlali and Chetoui. Water stress had a significant effect for Chemlali Mgconcentrations in leaves and roots contrarily to Chetoui, which showed no significant variation. Chemlali showed a higher water-use efficiency (WUE) than Chetoui. The second water deficit level induced a higher decrease in leaf water potential (PSI_H) than the first level. PSI_H shows a higher decrease in Chemlali than in Chetoui under these two treatments. The higher the water deficit, the lower net photosynthesis (An) for these two cultivars. A decrease of about 85 % and 71 % was observed, respectively, for Chetoui and Chemlali under the second level of water deficit.