Once cut and placed in a vase of water, flowers are susceptible to bacterial growth that shortens the length of time one has to enjoy the blooms. In addition, once the stems are cut and flowers added to a vase bacteria start to colonize the open ends of the stems and block the channels through which water enters. This is considered the main cause of a short-lived display of many flowers, no matter how expensive the flowers were to buy.

Although many florists provide a small packet of plant food with their bouquets, but this does not prevent the stems becoming blocked with bacteria. Some have said that adding a drop of household bleach helps, but this comes with a less-than-pleasant odor of bleach.

As an alternative, scientists have found that a few silver nanoparticles sprinkled into the water could be the answer to longer-lasting cut flowers. This results from research based at the Department of Horticulture at Ferdowsi University of Mashhad, Iran.

Researchers tested silver nanoparticles, which are known to have antibacterial activity, in extending the blooming life of cut lilies (Lilium orientalis). The researchers used suspensions of silver nanoparticles in water at levels of 5, 15, 25, 35 parts per million (ppm) and compared the floral life against controls with untreated vase water.

The scientists found that control blooms gave a bright flora display on average for just under a week; whereas the lower concentrations of silver nanoparticles extended this period by a couple of days. At 35 ppm their blooms were maintained with good color and healthy petals for almost twice as long as the controls (less than twelve days).

Analysis of the stems and water revealed that at this concentration of silver nanoparticles bacterial growth was stymied for the longest period compared with controls where bacterial growth began within the first two days. This could lead to a new ingredient to be added by the florist.

The findings have been published in the Journal of Postharvest Technology and Innovation, entitled ‘Effect of nano-silver particles on postharvest life of Lilium orientalis cv. 'Shocking'’.

Source: hortbiz.com