effects of chemicals on vase life of cut carnation( dianthus caryophyllus l. 'delphi ') and microorganisms population in solution

the vase life of cut flowers and foliage is often shortened by vascular occlusions that constrict vase solution supply. reduction in stem conductivity is typically caused by blockage of cut stem ends and xylem conduits by microbes, physiological plugging, and disruption of water columns in xylem vessels by cavitations and air emboli. cut flower and foliage longevity can be greatly affected by the chemical composition of the vase solution. a broad range of biocides has been suggested to prevent the proliferation of microorganisms in vase solutions; however, their assumed antimicrobial action may be confounded by their other physicochemical effects. the effect of some chemicals on postharvest longevity and microorganisms in solution of cut carnation ‘delphi’ evaluated in a randomized complete block design with three replications. flowers harvested in paint brush stage and recutted to 60 cm stem length. vase life evaluated in 20±2oc temperature, relative humidity 60% and 1800 lux light intensity. the results showed that flowers longevity has significant different (p£0.01) and copper sulfate and halamid® (sodium n-chloro-para- toluenesulfonamide) were the best treatments. population (p£0.001) and relative water content (p£0.05) were significantly affected by treatments and halamid® was the best treatment to microorganisms control and water content. highly significant negative correlation of relative water content and the bacterial population in solution indicate that the main effect of bacteria in reducing the water uptake.