Functionality of stomata in the basis of flower failure after long term storage

Long-term shipment of flowers in reefer containers as a replacement of airfreight is the method of choice with respect to saving on transport costs and decreasing the carbon footprint. Long term storage (buffering), also facilitates the required delivery of larger volumes on peak days such as Mother?s day or Valentine?s Day and may create new business opportunities. Optimal storage conditions have been developed over the years for a number of flowers and cultivars with varying degrees of success. In roses, the protocols consist of strict recommendations concerning:- the cultivars to be used, - the flower developmental stage at harvest, - the type of packaging, - the post-harvest application of fungicides and - the use of pre-treatment, transport and (when stored dry) rehydration solutions. Still several problems occur with long-term stored flowers. According to a large scale investigation on the causes of flower failure at the FloraHolland flower auction, the larger part of the auction- supplied roses ends their vase life due to water balance problems:- impaired flower opening, - premature wilting, - bent neck. Second main reason for end of vase life is Botrytis cinerea. Effective solutions to suppress botrytis infection during storage have been developed. A single 1 s dip in a hypochlorite solution proved effective in many of the investigated cases. The physical and physiological background of flower failure caused by a negative water balance following long-term storage was investigated. Long term storage did not affect the xylem hydraulic conductivity and did not alter the petal sugar status or petal electrolyte leakage (indicator of membrane integrity). Storage was found to affect the functionality of stomata leading to less adequate stomata closing in response to mild water stress. New solutions to improve flower quality after long-term storage are discussed in the paper. SourcesLONG-TERM STORAGE OF CUT ROSES FOR OPERATIONAL PURPOSES AND TO FACILITATE LONG DISTANCE TRANSPORT IN REEFER CONTAINERS Ernst J. Woltering*, Maxence Paillart, Bastiaan Brouwer Wageningen Food and Biobased Research, PO BOX 17, 6700 AA Wageningen, The Netherlands *ernst.woltering@wur.nlICH2018?Istanbul, 30th International Horticultural Congress, 12-16 August 2018, TurkeyPicture, rosa stomata by?Science Photo Library