Potential benefits of silicon nutrition to hydroponically grown sweet basil

Abstract

Sweet basil (Ocimum basilicum L.) is a globally cultivated and consumed herb known for its unique aroma and flavor. Sweet basil grows best in warm temperatures, and productivity and marketability decrease when grown under cool conditions (<10 °C). Silicon (Si) is not considered an essential plant nutrient, but it can be beneficial to Si macroaccumulator plants by alleviating several biotic and abiotic stresses. Recent studies have shown that some microaccumulator species may also benefit from Si. In this study, we examined the effects of different levels (0, 25, and 75 ppm Si) of Si amendments on hydroponic basil grown at 23 °C. Si (75 ppm) significantly increased shoot height and weight with no negative impact on plant morphology. All Si-treated basil plants absorbed Si in small quantities and affected the uptake of phosphorus, magnesium, sulfur, iron, manganese, copper, zinc and molybdenum. After an unintentional frost event, basil plants treated with 75 ppm had significantly higher survival rates and reduced cold injury symptoms. We concluded that Si amendments can have a positive impact on hydroponically grown sweet basil, and that such amendments may reduce plant damage due to occasionally cooler growing temperatures.