Shoot and root lengths (A,B), fresh and dry weight (C–F), of sweet basil (Ocimum basilicum) after foliar application of trehalose and salicylic acid individually or in combination during drought stress. One month old seedlings were watered to 100% (control, open bars) or 60% (drought, filled bars) field capacity (FC) for 20 days. Trehalose (Tre) and/or salicylic acid (SA) were then applied twice with a 5 day interval between applications. The watering conditions were maintained for an additional 2 weeks until plants were harvested. Data are the means ± SE (n = 6). Different letters above the bars represent significant differences according to Duncan’s multiple-range test at the p < 0.01 level.