Lemongrass Essential Oil Production and Qality in Response to Root Growth Restriction

Abstract

Lemongrass (Cymbopogon citratus) (Poaceae) is an essential oil rich plant widely used as a flavoring due to its lemon scent. Conditions of stress are often associated with an increase in secondary metabolite production. Studies with root growth restriction have shown that under this stressful condition plants are dwarfish. The factors responsible for the observed effects are not clear, being commonly attributed to water and nutrient restrictions and hormonal effects. In this work the effects of root growth restriction on lemongrass growth and essential oil production were evaluated. Plants were grown in 0.5, 1.5, 6.0, 11.0, and 42.0 L pots. They were harvested at 60, 90, 120, 150, and 180 days after planting. Leaf emission, nutrient contents, essential oil content and citral percentage were evaluated. Root growth restriction did not affect leaf emission rate. Essential oil contents was negatively influenced by root growth restriction. Citral accumulation pattern was not affected, but in 0.5 L pots plants showed reduced percentage. All nutrient contents were reduced with plant age. The observed effects on essential oil contents were linked to nutrient deficiency which in turns can impair plant yield.