Two field Experiments were conducted at Abd El-Maneim Ryad, South Tahrir, El- Beheira Governorate, Egypt, during the summer growing seasons of 2017 and 2018 to study the role of foliar application of potassium silicate for alleviating drought stress effect on peanut grown in sandy soil. This experiment carried out in a split plot design with three replicates where the drought stress treatments (irrigation after depletion of 40%, 55%, 70% and 85% Available soil water were occupied main plot, while potassium silicate concentration (control, 500, 1000 and 1500mg/l silicate) was allocated in sub main plot.
Results revealed that irrigation after depletion of 55% available soil water recorded the highest mean values of yield and yield components i.e. (100-pods weight, no. of pods/plant, pods yield/fed, biological yield/fed and straw yield/fed during both seasons, while, the irrigation after depletion of 40% available soil water recorded the highest mean values of harvest index percentage during both seasons).
Foliar application of potassium silicate at 1500 mg/l silicate recorded the maximum 100- pods weight, no. of pods/plant, pods yield/fed, biological yield/fed and straw yield/fed, while, control treatment recorded the highest mean values of harvest index percentage during both seasons. Chemical compositions i.e. (oil percentage and oil yield/fed) recorded the best values with irrigation after depletion of 40% available soil water, while, proline content recorded the highest mean values at irrigation after 85% depletion of available water; in addition, potassium silicate at 1500 mg/l silicate recorded the highest percentages of oil and oil yield/fed, while, proline content recorded the best values with control treatment, during both seasons. Water use efficiency recorded the highest mean value with irrigation after depletion of 85%available soil water during both seasons; with regard, potassium silicate at 1500 mg/l silicate gave the highest mean values of water use efficiency as compared with control treatment which recorded the lowest mean values of WUE during both seasons