Effects of Some Amino Acids and Organic Acids on Enzymatic Activity and Longevity of Dianthus caryophyllus cv. Tessino at Pre-Harvest Stage

Carnation (Dianthus caryophyllus L.) is one of the most important cut flowers in the world. This experiment was carried out to evaluate the effects of pre-harvest application of some amino acids and organic acids on enzymatic traits and longevity of carnation flowers (Dianthus caryophyllus cv. Tessino) based on completely randomized design with 13 treatments and three replications. The treatments included ascorbic acid (AS), citric acid (CA), malic acid (MA), arginine (Arg), phenylalanine (Phe) and glutamine (Gln), each at two levels of 50 and 100 mg/l. The unsprayed pots constituted the control. The foliar application was carried out three times at 10-day intervals and it was so scheduled that the last stage of spraying was in the green pea stage. Sampling and evaluation of plant traits such as fresh and dry weight, petals anthocyanin, total leaf chlorophyll, phenylalanine ammonia-lyase (PAL), peroxidase (POD), catalase (CAT), superoxide dismutase (SOD) activities and flower longevity were measured on plants at the stage that at least two florets have been opened in the cluster. The results showed that 100 mg/l malic acid had the greatest effect on the improvement in fresh and dry weight, petals anthocyanin, and total leaf chlorophyll. Citric acid, ascorbic acid, and phenylalanine, all at the rate of 100 mg/l, had the greatest effect on improving the activity of catalase, superoxide dismutase, peroxidase, and phenylalanine ammonia-lyase enzymes. Also, 100 mg/l glutamine could improve the longevity of flowers on the plants. Therefore, according to the results of this study, it can be concluded that pre-harvest foliar application of amino acids and organic acids improved enzymatic traits and the longevity of flowers on the plants in carnation (Dianthus caryophyllus) cv. Tessino.