Calcium application mitigates salt stress in Date Palm (Phoenix dactylifera L.)offshoots cultivars of Berhi and Sayer

摘要

The effectiveness of exogenous application of calcium in ameliorating the adverse effects of salt stress (15.9 dS m~(-1)) on date palm offshoots (Phoenix dactylifera L. cultivars of Berhi and Sayer) was investigated. Ca-fertilisers Polixal and Rexene were applied either as soil amendments or foliar spray. The results showed that Polixal at 30 ml offshoot"1 significantly increased plant height, leaf area, total chlorophyll content, RWC, proline concentration, peroxidase activity, IAA content, K~+ and K~+/Na~+ ratio in leaves of Berhi cultivar, whereas catalase activity, ABA and CI" content were decreased. Also Berhi cultivar responded to soil amendments more than to foliar spray. However, Ca-fertilisers mitigated salt stress in the two cultivars and Berhi cultivar was more salt stress tolerant than Sayer cultivar by maintaining the high ratio of K~+/Na~+ and regulating levels of IAA to ABA, in silty clay loam soil. These results suggest that calcium application can improve the defense system under saltstress conditions.