Sanal Krishnan, Ph.D., Horticulture Research Scientist, Smithers-Oasis Company, Kent, OH, USA
The vibration and temperature increase during transportation can induce stress related ethylene production which can cause flower wilt and drop, leaf yellowing and premature flower opening and death. EthylBloc is a proven ethylene action inhibitor technology that effectively controls ethylene damage of plants. Calcium chloride has been reported to reduce flower meltdown caused by Botrytis cinerea during transport and storage. There are questions in the industry whether treating with calcium chloride could also alleviate ethylene damage during transport and storage.
To determine whether calcium chloride could alleviate or suppress ethylene damage similarly to EthylBloc treatment.
Commercially grown petunia plants “Supertunia Royal Velvet’ at full bloom were purchased from a local greenhouse. All the treatments below were sprayed with low concentrations of Florel to generate approximately 2 ppm ethylene to induce ethylene damage.
Treatment.1: Potted petunia plants challenged with ethylene (Control)
Treatment.2: Potted petunia plants sprayed with calcium chloride @ 1200 ppm followed by ethylene challenge.
Treatment.3: Potted petunia plants treated with EthylBloc Sachets as per recommendation followed by ethylene challenge.
After 4 days, flower wilt and drop was observed in control plants that were challenged with ethylene (Treatment.1). Similarly, flower drop was also observed in plants treated with calcium chloride @ 1200 ppm and challenged with ethylene (Treatment.2). No flower drop was observed in petunia plants treated with EthylBloc and challenged with ethylene (Treatment.3).
Fig.1: Potted petunia plants (Supertunia Royal Velvet) 4 days after treatment: Flower drop is clearly visible due to ethylene damage in treatment 1 and 2. EthlyBloc treated plants (Treatment 3) showed no flower drop and symptoms of ethylene damage.
This study demonstrated that calcium chloride application will not reduce or suppress ethylene damage in petunia plants. Therefore, it can be concluded that calcium chloride cannot substitute EthylBloc technology for preventing ethylene damage.