Stimulation of Short-term Plant Growth by Glycerol Applied as Foliar Sprays and Drenches under Greenhouse Conditions

Abstract

The effects of aqueous solutions applied as foliar spray and drench applications of glycerol were tested on the ‘Chantenay’ carrot (Daucus carota L.) family Apiaceae, corn (Zea mays L.) family Poaceae, and spearmint (Mentha spicata L.) family Lamiaceae under greenhouse conditions. Foliar sprays and drenches were administered to carrots at concentrations of 0, 1, 3, 5, 10, 25, or 50 ml·L−1. Fresh weights, dry weights, and taproot diameter from carrot seedlings sprayed with a solution containing 5 mL·L−1 (50 mm) glycerol increased 105.6%, 158.4%, and 53.8%, respectively, when compared with untreated carrots. Foliar sprays were administered to corn at concentrations of 0, 0.1, 0.3, 0.5, and 1 ml·L−1 and spearmint at concentrations of 0, 1, 5, and 10 mL·L−1. Growth responses increased in corn and spearmint by using certain glycerol concentrations. Fresh weights, dry weights, and shoot length from corn seedlings sprayed with a solution containing 0.5 mL·L−1 (5 mm) glycerol increased 83.5%, 154.6%, and 90.9%, respectively, when compared with untreated corn. Fresh weights, dry weights, and shoot length from mint plants sprayed with a solution containing 5 mL·L−1 (50 mm) glycerol increased 46.6%, 68.7%, and 102.5%, respectively, when compared with untreated plants. Glycerol applications can stimulate growth responses in diverse plant species.