Interactive effects of organic materials and electrical conductivity in the growing medium on the vase life of cut lisianthus flowers

This study was conducted to determine the effects of certain organic materials added to the growing medium prior to harvest on the vase life of cut lisianthus (Eustoma grandiflorum) flowers. Nine different growing media were prepared by supplementing a peat+perlite mixture with varying proportions of thyme compost, leonardite, vermicompost, and humic acid. In addition, the electrical conductivity (EC) of the growing media was adjusted to two levels: 1.1 dS m⁻¹ and 2.2 dS m⁻¹. Vase life was evaluated using a visual scoring system to assess deterioration symptoms in leaves and flowers. As a result, the longest vase life (22.0 days) was obtained from the application of 20% thyme compost + EC 2.2. This treatment was followed by applications of 10% and 20% vermicompost + EC 2.2, and 10% thyme compost + EC 2.2. The shortest vase life (8.33 days) was recorded in the control group containing only peat + perlite. The findings revealed that the use of thyme compost and vermicompost in combination with high EC levels significantly extended the vase life of lisianthus flowers. It has been determined that applications of humic acid and leonardite also exhibit positive effects on vase life. This result indicates that the application of organic materials in combination with appropriate EC levels during the pre-harvest period enhances the postharvest longevity of cut flowers.