Sources of vase life variation in cut roses: A review

In determining vase life (VL), it is often not considered that the measured VL in a particular experiment may greatly depend on both the preharvest and evaluation environmental conditions. This makes the comparison between studies difficult and may lead to erroneous interpretation of results. In this review, we critically discuss the effect of the growth environment on the VL of cut roses. This effect is mainly related to changes in stomatal responsiveness, regulating water loss, whereas cut flower carbohydrate status appears less critical. When comparing cultivars, postharvest water loss and VL often show no correlation, indicating that components such as variation in the tissue resistance to cavitate and/or collapse at low water potential play an important role in the incidence of water stress symptoms. The effect of the growth environment on these components remains unknown. Botrytis cinerea sporulation and infection, as well as cut rose susceptibility to the pathogen are also affected by the growth environment, with the latter being largely unexplored. A huge variability in the choices made with respect to the experimental setup (harvest/conditioning methods, test room conditions and VL terminating symptoms) is reported. We highlight that these decisions, though frequently overlooked, influence the outcome of the study. Specifications for each of these factors are proposed as necessary to achieve a common VL protocol. Documentation of both preharvest conditions and a number of postharvest factors, including the test room conditions, is recommended not only for assisting comparisons between studies, but also to identify factors with major effects on VL

Validation of the effects of a single one second hypochlorite floral dip on Botrytis cinerea incidence following long-term shipment of cut roses

The effect of a pre-shipment hypochlorite treatment on botrytis incidence was evaluated in a large number of rose cultivars and under different long-term storage conditions. Application parameters, stability and sources of hypochlorite were investigated. Irrespective of the type of packaging and shipment conditions, roses that received a pre-shipment treatment with 100 to 150 mg/L hypochlorite showed a significantly decreased botrytis incidence compared to non-hypochlorite treated roses. The hypochlorite treatment generally was more effective than a comparable treatment with commercial fungicides. Dipping the flower heads for approximately one second in a hypochlorite solution was more effective than spraying the heads. In few cases minor hypochlorite-induced damage on the petal tips was observed at higher concentrations (>200 mg/L). Apart from the effect on botrytis incidence, the treatment resulted in reduced water loss that may have an additional beneficial effect on the eventual flower quality. It is concluded that, apart from other obvious measures to reduce botrytis incidence (prevention of high humidity at the flower heads) a pre-shipment floral dip in 100 to 150 mg/L hypochlorite from commercial household bleach is an easy and cost effective way to reduce botrytis incidence following long term storage/transportation of roses. © 2015, International Society for Horticultural Science. All rights reserved

Sodium hypochlorite: A promising agent for reducing Botrytis cinerea infection on rose flowers

Botrytis cinerea is a fungal pathogen that greatly reduces the postharvest quality of rose flowers. A postharvest dip in 200 µL L-1 sodium hypochlorite (NaOCl) for 10 s at 20 °C provided the greatest control of B. cinerea on ‘Akito’ and ‘Gold Strike’ flowers. NaOCl derived from Clorox® Ultra household bleach solution was more effective than laboratory grade NaOCl in reducing disease symptoms. Lowering the pH of the NaOCl solution from pH 9.7 (unadjusted) to pH 7.0 greatly improved its efficacy. Treating ‘Gold Strike’ flowers in this pH-adjusted NaOCl solution was more effective in reducing the level of infection on petals than postharvest dips in the conventional fungicides Medallion®, Phyton®, Switch® and Vangard®. Applying NaOCl prior to a 3- or 10-d commercial shipment also provided the most consistent disease control for a wide range of rose cultivars as compared to conventional fungicides. Of particular interest, the efficacy of NaOCl and Phyton® was greatest when these compounds were applied to ‘Gold Strike’ flowers after incubation at 20 °C and 90% RH for 6–9 h. Our findings highlight NaOCl as a promising new candidate for the control of B. cinerea on rose flowers

Variability of responses to 1-methylcyclopropene by banana: influence of time of year at harvest and fruit position in the bunch

To examine the effect of early-climacteric (postripening) 1-methylcyclopropene (1-MCP) exposure on the shelf-life and quality of green Cavendish bananas (Musa acuminata cv. Williams) from the middle section of the bunch, bananas were harvested bimonthly and treated with 100 μL L -1 ethylene for 2 consecutive days prior to exposure to 0, 100, 300, 1000, 3000 or 10 000 nL L-1 1-MCP for 24 h prior to storage at 22°C. 1-MCP treatment at a concentration of 300 nL L-1 or above increased banana shelf-life significantly compared with the control, regardless of the month in which fruit were harvested except March where a higher concentration was needed (3000 nL L-1). Fruit harvested in May were the most responsive with a greater than twofold increase in shelf-life. To examine the effect of fruit position in the bunch on 1-MCP efficacy, green fruit from the top or bottom of bunches were treated with 100 μL L-1 ethylene for 2 consecutive days prior to early-climacteric 1-MCP (300 nL L -1) exposure for 24 h at 22°C. In spring and autumn but not in summer, application of 1-MCP to early-climacteric fruit was more effective in fruit from the top than in those treated from the bottom of the bunch, increasing shelf-life. Firmness of 1-MCP-treated fruit was up to 19% greater than that of the control across the year, except in fruit from the bottom of the bunch. Given that 1-MCP is less effective in extending the shelf-life of summer-harvested fruit (particularly those from the bottom of the bunch), we conclude that preharvest conditions and fruit position in the bunch affect their responsiveness to ethylene and their behaviour during the ripening process. © 2007 The Authors.F. Moradinezhad, M. Sedgley, A. Klieber & A.J. Abl