Improvement of Seed Germination and Stand Establishment of Globe Artichoke under Salt Stress Conditions

Artichoke seeds germinate slowly and are difficult to establish by direct seeding in the open field compared to other vegetable seeds. The presented study aimed to reduce germination period, increase seed germination percentage, and also to improve seedling quality even under stress conditions. Seeds of globe artichoke, cv. Green Globe were either sown directly in the field soil, in cell trays filled with substrate or germinated under laboratory conditions into Petri dishes. Pre-treated seeds with hot (60 degrees C) or cold (7 degrees C) water, plant-strengthening agent (Bacillus subtilis) and CaCl2 (5 mM) were sown, and the germination percentage was recorded. The best early germinated seedlings in cell trays were exposed to three water EC levels (1.5, 4.5 and 7.5 dS m(-1)), and seedling quality was evaluated. Results showed positive effects for all seed pre-treatments in improving seed germination percentage compared to untreated seeds at all investigated conditions. Seed soaking into either hot or cold water was the best for seed germination. Salinity caused significant reduction in seedling quality (vegetative growth & nutrient contents). Vegetative growth characters, e. g., seedling height, leaf number, leaf area and dry weight of shoots & roots were gradually reduced by increasing EC level from 1.5 to 7.5 dS m(-1). Salinity reduced essential nutrients (K & Ca) and increased harmful elements (Na & Cl) in seedling tissues. Bacillus subtilis ranked first for improving seedling quality, followed by CaCl2, while seed soaking into hot or cold water showed little improvement for seedling under salinity conditions.