Effects of chlorination and acidification on postharvest physiological properties of alstroemeria, cv. ‘Vanilla’ and on microbial contamination of vase solution

Abstract

Leaf yellowing is the major postharvest crisis for cut alstroemeria flowers. Most studies have focused on hormone application to overcome this problem, while other important aspects of postharvest treatment such as vase solution microbial contamination and biocide effects have been ignored. Therefore, this study aims at evaluating the vase life and physiological performance of ‘Vanilla’ alstroemeria cut flowers in response to biocide application and microbial flora during postharvest handling. During two experiments flowers were treated with environmentally friendly and safe to use biocides such as citric acid (as acidifying agent) and sodium hypochlorite (as chlorination agent). Subsequently postharvest physiological parameters, namely vase life, side effect, weight change, solution uptake, chlorophyll content, and microbiological features of the vase solution such as microbial population, proliferation, and composition were studied. The results of the physiological study indicated a beneficial effect of chlorination on the vase life and most physiological parameters, especially chlorophyll content, and consequently, the green appearance of the leaves. Vase solution acidification, however, did not have a long lasting beneficial effect on physiological properties. Furthermore, microbiological studies show the efficacy of chlorination in reducing the vase solution microbial population and proliferation. By contrast, the vase solution acidification with citric acid was not able to control microbial proliferation. Microbial identification indicated Bacillus bacterial contamination as the dominant microbial vase solution flora.