New Delhi: Valentine’s Day is over, but there’s a way to keep your flowers fresh for longer. A team of researchers has found that adding lemongrass essential oil to your vase can increase the life of cut flowers, especially the ubiquitous gladiolus.
In a study, published in the journal Scientific Reports Tuesday, researchers from the Council of Scientific and Industrial Research-Institute of Himalayan Bioresource Technology (CSIR-IHBT), Palampur, Himachal Pradesh, explained how a splash of lemongrass essential oil could solve premature wilting in gladiolus flowers thanks to its antimicrobial and antioxidising properties.
The gladiolus, a bulbous flower, is popular for its variety of colours and used widely in bouquets and other floral arrangements. However, the life of the flower is short post harvest, thereby limiting its marketing and commercial value.
The researchers found that treatment with just 5 microlitres of lemongrass oil per litre of distilled water could extend the vase life of gladiolus to up to 11 days, compared to seven days in plain distilled water.
“In the controlled conditions of the lab, cut gladiolus flowers last about seven days. Adding lemongrass essential oils extended the shelf life by two to four days,” Meenakshi Thakur, a researcher at CSIR-IHBT and one of the authors of the study, told ThePrint.
She said using a Scanning Electron Microscope (SEM), the team observed “intact vasculature” in the lemongrass-treated sample, indicating that the essential oil reduced microbial blockage at the stem end. Microbial blockage at the stem end is one of the main reasons for early ageing in cut flowers, as it disrupts water uptake and transport, causing water imbalance and wilting.
Moreover, the treated cut spikes had lower levels of genes associated with ageing and higher expression of antioxidant genes. These factors together helped extend the post-harvest life of cut flowers, she added.
While the team only worked with gladiolus for this project, Thakur said that lemongrass oil is likely to extend the vase life of other flowers as well since microbial blockage at the stem happens in all kinds of cut flowers.
The essential oil is needed in small quantities – just a few microlitres – making this very cost-effective for the flower industry, she added.
An eco-friendly solution
In the past, researchers have used different chemicals such as silver nitrate, silver thiosulfate, nano silver, calcium, and hydrogen gas to extend the shelf life of cut flowers. However, these chemicals are expensive and have negative impacts on the environment and human health, the study explained.
Essential oils, on the other hand, are eco-friendly agents that have antifungal, antiviral, antibacterial, and insecticidal properties. Lemongrass essential oil is rich in bioactive constituents which have demonstrated their antimicrobial activity by suppressing the growth of several bacteria.
By reducing microbial blockage at the stem end and enhancing antioxidant activity, lemongrass oil can improve the vase life of cut flowers, making them more commercially valuable. However, further research is needed to optimise the concentration and application of the oil to different cut flowers and to evaluate its impact on environment and human health.
(Edited by Geethalakshmi Ramanathan)
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