Preservative solutions on quality and biochemical aspects of calla lily flowers

The knowledge of physiological and biochemical aspects occurring at the postharvest phase of flowers is critical to guide efficient conservation techniques for maintaining quality and longevity. Factors that cause deterioration of cut flowers after harvest are dehydration, low carbohydrate contents, the presence of microorganisms in vase solution or stem and late stage of development at harvest. Thus, the objective was to determine the effect of harvest stages of calla lily stems and storage solutions on water relations and contents of starch and sugars. Flower stems were harvested in the following opening stages of the spathe: early-stage (cartridge) and 1/3 open and were arranged in six storage solutions containing 1, 2, 4 and 6% glucose and the controls with water and solution with 5% sucrose. Results indicate that at early-stage and 1/3 open harvesting stages, the addition of glucose at concentrations of 4% and 6% stimulated flower opening. Calla lily flower stems maintained in water and in solution with 1% glucose had lower percentages of fresh weight loss and better maintenance of water balance, with a small reduction in the contents of starch and soluble sugars. The addition of sugars in the storage solution was efficient in opening early-harvested stems. Harvest the floral stems in initial stages allow the maintenance of the commercial quality for longer period, without pollen production. The use of water relations allowed the determination of the better sugar concentration for the conservation of open-harvest of floral stems.