- Email: [email protected]
Reduction of Botrytis cinerea incidence in cut roses (Rosa hybrida L.) during long term transport in dry conditions
Postharvest Biology and Technology 76 (2013) 135–138
Contents lists available at SciVerse ScienceDirect
Postharvest Biology and Technology journal homepage: www.elsevier.com/locate/postharvbio
Research note
Reduction of Botrytis cinerea incidence in cut roses (Rosa hybrida L.) during long term transport in dry conditions Harmannus Harkema ∗, Manon G.J. Mensink, Dianne P.M. Somhorst, Romina P. Pedreschi, Eelke H. Westra Food & Biobased Research, Wageningen UR, P.O. Box 17, 6700 AA Wageningen, The Netherlands
a r t i c l e
i n f o
Article history: Received 16 May 2012 Accepted 5 October 2012 Keywords: Wet and dry transport Temperature Long-term Botrytis cinerea Postharvest Roses
a b s t r a c t Long distance transport of flowers to markets at low temperature is still hampered by Botrytis damage. This study is focused on quality effects of long dry and wet transport at low temperatures and high relative humidity of three rose varieties with a special focus on Botrytis development. Results showed that the type of transport (dry or wet), transport time and cultivar influence the Botrytis damage level, thus affecting the number of flowers in poor condition at the start of vase life. Clear differences in Botrytis damage level were observed between wet and dry transport at low temperatures, long term transport and high relative humidity. Botrytis developed with time during dry or wet transport but was significantly less severe in dry transport conditions. The ‘Red Naomi!’ variety was the most sensitive cultivar to Botrytis development. These findings show that dry transport of roses has a significant positive effect on product quality with special focus on Botrytis development. Thus, handling plus transport costs can be substantially reduced. © 2012 Elsevier B.V. All rights reserved.
1. Introduction Botrytis infection of cut flowers begins with deposition of conidia during flower development (Kerssies et al., 1995) and the disease symptoms are visualized later on the petals as small quiescent lesions (Pie and De Leeuw, 1991). If the conditions are favorable (very humid, >93% RH), then the lesions become necrotic and infect the petals (Williamson et al., 2007). The distances between production areas of cut flowers and consumer markets are long. Roses from South American countries are transported to USA or Europe, roses from Kenya and Ethiopia are transported via Western Europe to Eastern Europe and Asian countries. Currently a lot of focus is placed on flower transport by sea containers because of sustainability issues and lower costs. Even though long distance transport is carried out at low transport temperatures, Botrytis development still threatens successful transport to distant markets. This study is focused on the impact of dry and wet conditioned transport to distant markets at low temperatures and high relative humidity of three rose cultivars. The main aims of this study were: (i) to evaluate the effect of dry and wet transport on Botrytis development during the distribution and distribution plus retailer chains and its impact on vase life, and (ii) to evaluate the effect of transport time, cultivar and temperature on Botrytis development and quality of roses. Compared to previous reported studies on the subject,
∗ Corresponding author. Tel.: +31 0317 480120; fax: +31 0317 483011. E-mail address: [email protected] (H. Harkema). 0925-5214/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.postharvbio.2012.10.003
simulations of complete distribution (long transport) and distribution plus retailer chains on Botrytis incidence are considered. 2. Materials and methods 2.1. Plant material Cut flowering stems of Rosa hybrida L. cv. ‘Red Naomi!’, ‘Aqua!’ and ‘Avalanche+ ’ were obtained from commercial growers. The flowers were packed in bunches of 10 stems in polyethylene sleeves and placed in buckets containing tap water with sodium hypochlorite. Roses were transported to the laboratory the next day. 2.2. Treatments and conditions To simulate long term storage conditions at low temperatures for reefer transport, roses were dry or wet stored for 4, 7, 10, 14 and 21 days at 0.5 ◦ C and for 7 and 14 days at 2 ◦ C. Relative humidity was kept in all cases at 90–95%. Dry stored roses were packed in cardboard boxes of 160 mm × 290 mm × 960 mm. One bunch of each cultivar was independently packed in a box and filled up with dummy roses (not part of the experiment). Wet transported roses were recut and placed in buckets in Aqua Pack Boxes 570280 (Zwapak, Aalsmeer, The Netherlands). The buckets contained 2 l tap water with one Chrysal Professional 2 T bag (Chrysal International, Naarden, The Netherlands). The roses were stored in the darkness.
136
H. Harkema et al. / Postharvest Biology and Technology 76 (2013) 135–138
A
4.5 4
e
3.5
cd b
a
de
bc
3
b
a
2.5 2
B
5
flower opening (1 - 5)
flower opening (1 - 5)
5
d
cd
4.5
bc
b
4
c
3.5
ab
ab
a
3 2.5 2
0
3
6
9
12
15
transport simulaon (days) dry
water + add
0
3
6
9
12
15
transport simulaon (days) dry
water + add
Fig. 1. Flower opening at the start of vase life (A) and after 7 vase days (B). Each value represents mean of 12 replicates (4 per cultivar) at 0.5 ◦ C. Different letters on mean values stand for significant differences (p < 0.05) within each figure.
After the transport simulations, roses were recut and placed in Procona containers with a plastic collar (Pagter Innovations, Roosendaal, The Netherlands) containing tap water with Chrysal Professional 2 (1 T bag per 2 l water). To simulate chain conditions between purchasers and retailers, the roses in the Procona containers were stored for 4 days at 8 ◦ C and 80 ± 5% RH in the darkness, and subsequently for 2 days at 20 ◦ C and 60 ± 5% RH and 12/24 h light (12 mol m−2 s−1 photo synthetically active radiation (PAR)) as a simulation of retailer conditions. During the retailer simulation, the collars were removed from the Procona containers and the bunches were kept intact with the polypropylene sleeves. Then, the roses were recut to 45 cm (flower included) and the stems were placed in vases containing tap water with 10 g l−1 Chrysal Clear Professional 3 (Chrysal International, Naarden, The Netherlands). Leaves were removed until the edge of the vase. Each vase containing 10 stems were placed at 20 ◦ C and 60 ± 5% RH and 12/24 h light (12 mol m−2 s−1 PAR) to simulate vase life conditions. Seven days of vase life was chosen to evaluate the conditions of the flowers because it is the period of good quality guarantee many retailers provide. Reference flowers were placed in vases at the start of the experiment. Half of the reference vases were placed in the vase life room and the other half in a perspex box (‘hotbox’, RH 100% at 20 ◦ C).
material sub-section. Opening stage indexes and Botrytis indexes were recorded for each replicate. The percentage of rejected flowers caused by Botrytis and the percentage of rejected flowers due to other symptoms were also calculated. Non-parametric Kruskal Wallis test (p < 0.05) was used to account for significant differences followed by the Mann–Whitney test to account for significant differences between treatments (p < 0.05). Statistical analysis was carried out in IBM SPSS statistics 19.
2.3. Quality assessment
The extent of B. cinerea development was dependent on the variety as demonstrated with the ‘hotbox’ experiment. Botrytis indexes of 1.6, 2.5 and 3.0 were obtained for ‘Avalanche+ ’, ‘Aqua!’ and ‘Red Naomi!’, respectively after 7 days at 20 ◦ C and 100% RH. For the same varieties, Botrytis indices after simulation of the whole distribution chain (4–14 days at 0.5 ◦ C + 4 days at 8 ◦ C + 2 days at 20 ◦ C) of 0.6, 1.0 and 1.5 were obtained. Simulation of the whole chain (4–14 days at 0.5 ◦ C + 4 days at 8 ◦ C + 2 days at 20 ◦ C plus 7 days of vase life) yielded Botrytis indexes values of 1.4, 2.1 and 3.5 for the three rose varieties analyzed. These results show that the hotbox test is a good indicator of the rate of damage due to Botrytis in long distribution chains. The effect of transport time and transport type (dry or in water + additive) on the development of Botrytis in the flowers of the three analyzed rose varieties is displayed in Fig. 2. Table 1 shows the percentage of stems that were rejected at the start of vase life and after 7 days of vase life. From Table 1 and Fig. 2 it can be inferred that transport time, transport type (dry or wet) and variety have a big effect on the extent of Botrytis damage level and thus on the number of flowers affected at the start of vase life. The most sensitive rose cultivar to Botrytis was ‘Red Naomi!’. Transport simulation
Flower opening stage, visual symptoms of Botrytis, number of bent necks, wilted flowers and number of stems with flower damage and leaf damage were determined. Quality assessment was carried out at the start of vase life (day 0) and after 7 days of vase life. A five point scale was used for the flower opening stage index: 1, firm pointed bud; 2, loose pointed bud, cylindrical; 3, half open flower; 4, open flower; 5, maximally opened flower, heart is visible. A four point scale was used for Botrytis cinerea development: 0, no visible symptoms; 1, some lesions (maximum 3 on one petal or maximum 5 on more petals); 2, larger spots on maximum one petal; 3, one brown petal, or spots on more petals; 4, at least one brown petal including the heart of the flower or more than one brown petal. Roses that scored 3 or 4 of Botrytis development were rejected. 2.4. Statistical analyses Four replicates per treatment were used. Each replicate consisted of one bunch of roses as previously described in the plant
3. Results and discussion 3.1. Flower opening The mean flowering opening index of 3 cultivars exposed to transport simulations at 0.5 ◦ C is displayed in Fig. 1. Fig. 1A shows that the flower opening at the start of vase life was not influenced by wet or dry transport. After at least 7 days of transport, roses that were kept dry developed better during vase life than flowers that were transported in water (Fig. 1B). No relevant effect on flower development was found between 0.5 ◦ C and 2.0 ◦ C (data not shown). 3.2. B. cinerea development and vase life
H. Harkema et al. / Postharvest Biology and Technology 76 (2013) 135–138
Avalanche+, start vaselife
Avalanche+, vase day 7
water + add
dry
4 d
3 c
2 1
c
c
b b
a b
c a
0
Botrys index (0 - 4)
Botrys index (0 - 4)
dry
2 1
a
b
c b ab
a
a
0
0
e cde
3 2
a a
0 4 7 11 14 21 transport simulaon (days)
b a
1
a
a
Red Naomi!, vase day 7
d
b ab
0 4 7 11 14 21 transport simulaon (days)
dry Botrys index (0 - 4)
Botrys index (0 - 4)
cd
bcd ab
water + add
3
e
bc
1
Red Naomi!, start vaselife
4
water + add
4
4 7 11 14 21 transport simulaon (days)
dry
a
4 7 11 14 21 transport simulaon (days)
Botrys index (0 - 4)
Botrys index (0 - 4)
c
2
a
dry
3
a a
b
Aqua!, vase day 7
4
1
b
b
water + add
bc
c
c
3
Aqua!, start vaselife
2
water + add
4
4 7 11 14 21 transport simulaon (days)
dry
137
4 3
water + add b
a
a
a
b b a
a
2
1 0 4 7 11 14 21 transport simulaon (days)
Fig. 2. Effect of transport simulation time and transport type (dry or in water + additive) on the Botrytis index. Additive used corresponded to Chrysal Professional 2 T bags. Bars are mean values of 4 replicates. Different letters stand for significant differences (p < 0.05) within each figure.
time was positively correlated with the extent of Botrytis damage. The type of transport (dry or wet) effect on the Botrytis damage was significant (p < 0.05). Roses kept at 0.5 and 2.0 ◦ C during dry transport was less affected by Botrytis damage than those that were transported in water. In addition, dry transport of roses at low temperatures and high relative humidity had a positive effect on vase life compared to wet transport. Our findings are in agreement with the study of Faragher et al. (1984) in which Rose cv. ‘Mercedes’ was stored for 10 days at 2 ◦ C and 95% RH either in dry and wet conditions. The dry stored roses displayed a longer vase life than wet stored ones. Cevallos and Reid (2001) found no benefit of wet storage in rose ‘Ambiance’ stored for 6 days at 2.5 and 5 ◦ C but at temperatures above 5 ◦ C vase life was a slightly longer after wet
storage. Hu et al. (1998) on the contrary showed a longer vase life after 2–3 days wet storage of Rose ‘Bridal Pink’. Previous studies suggest that wet transport might be unnecessary for other species. For example, for Narcissus ‘King Alfred’ and ‘Paper White’ wet storage for 6 days at 0–10 ◦ C showed no significant benefit as well as Chrysanthemum maximum (0 ◦ C), tulips (0 ◦ C), Iris ‘Telstar’ (0–10 ◦ C) and carnation ‘Imperial White’ (0–10 ◦ C) (Cevallos and Reid, 2001). Campanula medium ‘Champion Blue’ showed no difference in the number of open flowers due to wet or dry storage of 1–3 weeks, however, at the end of vase life wet stored stems showed less senesced flowers than dry stored stems (Bosma and Dole, 2002). Matthiola incana ‘Vivas Blue’ had a longer vase life when dry stored
138
H. Harkema et al. / Postharvest Biology and Technology 76 (2013) 135–138
Table 1 Percentage of rose stems rejected due to Botrytis or other symptoms. Start of vase life
After 7 days of vase life
Stems rejected due to
Botrytis
Botrytis
TS dry or wet
Dry
Wet
Dry
Avalanche+ 4 days 0.5 ◦ C 7 days 0.5 ◦ C 7 days 2.0 ◦ C 11 days 0.5 ◦ C 14 days 0.5 ◦ C 14 days 2.0 ◦ C 21 days 0.5 ◦ C
0a 3ab 0a 0a 3ab 5ab 45d
0a 3ab 0a 20bc 25c 24c 80e
10ab 13ab 3a 20ab 8a 15ab 50cd
Aqua 4 days 0.5 ◦ C 7 days 0.5 ◦ C 7 days 2.0 ◦ C 11 days 0.5 ◦ C 14 days 0.5 ◦ C 14 days 2.0 ◦ C 21 days 0.5 ◦ C
1ab 0a 0a 0a 25cde 4ab 20bcd
2ab 11abcd 10abc 29de 61f 39e 74f
30abc 21ab 15a 34abc 59def 34abc 43bcd
Red Naomi 4 days 0.5 ◦ C 7 days 0.5 ◦ C 7 days 2.0 ◦ C 11 days 0.5 ◦ C 14 days 0.5 ◦ C 14 days 2.0 ◦ C 21 days 0.5 ◦ C
0a 3a 0a 10a 18ab 18ab 100f
3a 35bc 40c 53cd 70de 78e 100f
93ab 88ab 85ab 100b 88ab 78a 100b
Other symptoms Wet
Dry
Wet
25ab 33bc 20ab 70de 88ef 72e 98f
0a 3a 0a 3a 5a 3a 8a
0a 0a 3a 5a 3a 8a 0a
49cde 72fg 49cde 88g 88g 68efg 89g
4a 21ab 15ab 26b 18ab 15ab 58c
3a 10ab 13ab 10ab 5a 18ab 9ab
0a 0a 0a 0a 3a 0a 0a
3a 0a 0a 0a 3a 0a 0a
93ab 100b 100b 100b 85ab 100b 100b
The statistical analysis was carried out independently for each rose variety at the start of vase life and after 7 days of vase life for the different response variables (Botrytis and other symptoms). Different letters stand for significant differences among the different treatments (p < 0.05).
compared to wet stored for 2 weeks at 2 ◦ C (Regan and Dole, 2010). 4. Conclusion Transport of roses in water or wet transport at low temperatures is not necessary and even it can have a negative impact on the quality of the product compared to dry transport at low temperatures and high relative humidity conditions. Weight loss of flowers during transport at low temperatures will not be highly affected due to the low vapor pressure deficit in the surrounding air. The preconception that flowers need to be transported in water (wet transport) should be reconsidered, in particular for species that are susceptible to Botrytis. These results showed that Botrytis development can be substantially reduced in three varieties of roses by using dry transport at low temperatures and high relative humidity. Transport and handling costs in addition can be substantially reduced. Acknowledgements The experiments were part of the research project ‘Containerisation and Conditioning in Ornamental Produce Chains (CoCoS)’. The
project was initiated by the Association of Wholesale Trade in Horticultural Products in the Netherlands and financed by the Dutch Horticultural Board. We would like to thank Dr. Roberto Molteni and Dr. Eric Boer for their help with the statistical analysis. References Bosma, T., Dole, J.M., 2002. Postharvest handling of cut Campanula medium flowers. HortScience 37, 954–958. Cevallos, J.C., Reid, M.S., 2001. Effect of dry and wet storage at different temperatures on vase life of cut flowers. HortTechnology 11, 199–202. Faragher, J.D., Mayak, S., Tirosh, T., Halevy, A.H., 1984. Cold storage of rose flowers: effects of cold storage and water loss on opening and vase life of ‘Mercedes’ roses. Scientific Horticulture 24, 369–378. Hu, Y., Doi, M., Imanishi, H., 1998. Improving the longevity of cut roses by cool and wet transport. Journal of the Japan Society for Horticultural Science 67, 681–684. Kerssies, A., Bosker-van Zessen, A.I., Frinking, H.D., 1995. Influence of environmental conditions in a glasshouse on conidia of Botrytis cinerea and on post-harvest infection of rose flowers. European Journal of Plant Pathology 101, 201–216. Pie, K., De Leeuw, G.T.N., 1991. Histopathology of the initial stages of the interaction between rose flowers and Botrytis cinerea. Netherlands Journal of Plant Pathology 97, 335–344. Regan, E.M., Dole, J.M., 2010. Postharvest handling procedures of Matthiola incana ‘Vivas Blue’. Postharvest Biology and Technology 58, 268–273. Williamson, B., Tudzynski, B., Tudzynski, P., van Kan, J., 2007. Botrytis cinerea: the cause of grey mould disease. Molecular Plant Pathology 8, 561–580.
Contents lists available at SciVerse ScienceDirect
Postharvest Biology and Technology journal homepage: www.elsevier.com/locate/postharvbio
Research note
Reduction of Botrytis cinerea incidence in cut roses (Rosa hybrida L.) during long term transport in dry conditions Harmannus Harkema ∗, Manon G.J. Mensink, Dianne P.M. Somhorst, Romina P. Pedreschi, Eelke H. Westra Food & Biobased Research, Wageningen UR, P.O. Box 17, 6700 AA Wageningen, The Netherlands
a r t i c l e
i n f o
Article history: Received 16 May 2012 Accepted 5 October 2012 Keywords: Wet and dry transport Temperature Long-term Botrytis cinerea Postharvest Roses
a b s t r a c t Long distance transport of flowers to markets at low temperature is still hampered by Botrytis damage. This study is focused on quality effects of long dry and wet transport at low temperatures and high relative humidity of three rose varieties with a special focus on Botrytis development. Results showed that the type of transport (dry or wet), transport time and cultivar influence the Botrytis damage level, thus affecting the number of flowers in poor condition at the start of vase life. Clear differences in Botrytis damage level were observed between wet and dry transport at low temperatures, long term transport and high relative humidity. Botrytis developed with time during dry or wet transport but was significantly less severe in dry transport conditions. The ‘Red Naomi!’ variety was the most sensitive cultivar to Botrytis development. These findings show that dry transport of roses has a significant positive effect on product quality with special focus on Botrytis development. Thus, handling plus transport costs can be substantially reduced. © 2012 Elsevier B.V. All rights reserved.
1. Introduction Botrytis infection of cut flowers begins with deposition of conidia during flower development (Kerssies et al., 1995) and the disease symptoms are visualized later on the petals as small quiescent lesions (Pie and De Leeuw, 1991). If the conditions are favorable (very humid, >93% RH), then the lesions become necrotic and infect the petals (Williamson et al., 2007). The distances between production areas of cut flowers and consumer markets are long. Roses from South American countries are transported to USA or Europe, roses from Kenya and Ethiopia are transported via Western Europe to Eastern Europe and Asian countries. Currently a lot of focus is placed on flower transport by sea containers because of sustainability issues and lower costs. Even though long distance transport is carried out at low transport temperatures, Botrytis development still threatens successful transport to distant markets. This study is focused on the impact of dry and wet conditioned transport to distant markets at low temperatures and high relative humidity of three rose cultivars. The main aims of this study were: (i) to evaluate the effect of dry and wet transport on Botrytis development during the distribution and distribution plus retailer chains and its impact on vase life, and (ii) to evaluate the effect of transport time, cultivar and temperature on Botrytis development and quality of roses. Compared to previous reported studies on the subject,
∗ Corresponding author. Tel.: +31 0317 480120; fax: +31 0317 483011. E-mail address: [email protected] (H. Harkema). 0925-5214/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.postharvbio.2012.10.003
simulations of complete distribution (long transport) and distribution plus retailer chains on Botrytis incidence are considered. 2. Materials and methods 2.1. Plant material Cut flowering stems of Rosa hybrida L. cv. ‘Red Naomi!’, ‘Aqua!’ and ‘Avalanche+ ’ were obtained from commercial growers. The flowers were packed in bunches of 10 stems in polyethylene sleeves and placed in buckets containing tap water with sodium hypochlorite. Roses were transported to the laboratory the next day. 2.2. Treatments and conditions To simulate long term storage conditions at low temperatures for reefer transport, roses were dry or wet stored for 4, 7, 10, 14 and 21 days at 0.5 ◦ C and for 7 and 14 days at 2 ◦ C. Relative humidity was kept in all cases at 90–95%. Dry stored roses were packed in cardboard boxes of 160 mm × 290 mm × 960 mm. One bunch of each cultivar was independently packed in a box and filled up with dummy roses (not part of the experiment). Wet transported roses were recut and placed in buckets in Aqua Pack Boxes 570280 (Zwapak, Aalsmeer, The Netherlands). The buckets contained 2 l tap water with one Chrysal Professional 2 T bag (Chrysal International, Naarden, The Netherlands). The roses were stored in the darkness.
136
H. Harkema et al. / Postharvest Biology and Technology 76 (2013) 135–138
A
4.5 4
e
3.5
cd b
a
de
bc
3
b
a
2.5 2
B
5
flower opening (1 - 5)
flower opening (1 - 5)
5
d
cd
4.5
bc
b
4
c
3.5
ab
ab
a
3 2.5 2
0
3
6
9
12
15
transport simulaon (days) dry
water + add
0
3
6
9
12
15
transport simulaon (days) dry
water + add
Fig. 1. Flower opening at the start of vase life (A) and after 7 vase days (B). Each value represents mean of 12 replicates (4 per cultivar) at 0.5 ◦ C. Different letters on mean values stand for significant differences (p < 0.05) within each figure.
After the transport simulations, roses were recut and placed in Procona containers with a plastic collar (Pagter Innovations, Roosendaal, The Netherlands) containing tap water with Chrysal Professional 2 (1 T bag per 2 l water). To simulate chain conditions between purchasers and retailers, the roses in the Procona containers were stored for 4 days at 8 ◦ C and 80 ± 5% RH in the darkness, and subsequently for 2 days at 20 ◦ C and 60 ± 5% RH and 12/24 h light (12 mol m−2 s−1 photo synthetically active radiation (PAR)) as a simulation of retailer conditions. During the retailer simulation, the collars were removed from the Procona containers and the bunches were kept intact with the polypropylene sleeves. Then, the roses were recut to 45 cm (flower included) and the stems were placed in vases containing tap water with 10 g l−1 Chrysal Clear Professional 3 (Chrysal International, Naarden, The Netherlands). Leaves were removed until the edge of the vase. Each vase containing 10 stems were placed at 20 ◦ C and 60 ± 5% RH and 12/24 h light (12 mol m−2 s−1 PAR) to simulate vase life conditions. Seven days of vase life was chosen to evaluate the conditions of the flowers because it is the period of good quality guarantee many retailers provide. Reference flowers were placed in vases at the start of the experiment. Half of the reference vases were placed in the vase life room and the other half in a perspex box (‘hotbox’, RH 100% at 20 ◦ C).
material sub-section. Opening stage indexes and Botrytis indexes were recorded for each replicate. The percentage of rejected flowers caused by Botrytis and the percentage of rejected flowers due to other symptoms were also calculated. Non-parametric Kruskal Wallis test (p < 0.05) was used to account for significant differences followed by the Mann–Whitney test to account for significant differences between treatments (p < 0.05). Statistical analysis was carried out in IBM SPSS statistics 19.
2.3. Quality assessment
The extent of B. cinerea development was dependent on the variety as demonstrated with the ‘hotbox’ experiment. Botrytis indexes of 1.6, 2.5 and 3.0 were obtained for ‘Avalanche+ ’, ‘Aqua!’ and ‘Red Naomi!’, respectively after 7 days at 20 ◦ C and 100% RH. For the same varieties, Botrytis indices after simulation of the whole distribution chain (4–14 days at 0.5 ◦ C + 4 days at 8 ◦ C + 2 days at 20 ◦ C) of 0.6, 1.0 and 1.5 were obtained. Simulation of the whole chain (4–14 days at 0.5 ◦ C + 4 days at 8 ◦ C + 2 days at 20 ◦ C plus 7 days of vase life) yielded Botrytis indexes values of 1.4, 2.1 and 3.5 for the three rose varieties analyzed. These results show that the hotbox test is a good indicator of the rate of damage due to Botrytis in long distribution chains. The effect of transport time and transport type (dry or in water + additive) on the development of Botrytis in the flowers of the three analyzed rose varieties is displayed in Fig. 2. Table 1 shows the percentage of stems that were rejected at the start of vase life and after 7 days of vase life. From Table 1 and Fig. 2 it can be inferred that transport time, transport type (dry or wet) and variety have a big effect on the extent of Botrytis damage level and thus on the number of flowers affected at the start of vase life. The most sensitive rose cultivar to Botrytis was ‘Red Naomi!’. Transport simulation
Flower opening stage, visual symptoms of Botrytis, number of bent necks, wilted flowers and number of stems with flower damage and leaf damage were determined. Quality assessment was carried out at the start of vase life (day 0) and after 7 days of vase life. A five point scale was used for the flower opening stage index: 1, firm pointed bud; 2, loose pointed bud, cylindrical; 3, half open flower; 4, open flower; 5, maximally opened flower, heart is visible. A four point scale was used for Botrytis cinerea development: 0, no visible symptoms; 1, some lesions (maximum 3 on one petal or maximum 5 on more petals); 2, larger spots on maximum one petal; 3, one brown petal, or spots on more petals; 4, at least one brown petal including the heart of the flower or more than one brown petal. Roses that scored 3 or 4 of Botrytis development were rejected. 2.4. Statistical analyses Four replicates per treatment were used. Each replicate consisted of one bunch of roses as previously described in the plant
3. Results and discussion 3.1. Flower opening The mean flowering opening index of 3 cultivars exposed to transport simulations at 0.5 ◦ C is displayed in Fig. 1. Fig. 1A shows that the flower opening at the start of vase life was not influenced by wet or dry transport. After at least 7 days of transport, roses that were kept dry developed better during vase life than flowers that were transported in water (Fig. 1B). No relevant effect on flower development was found between 0.5 ◦ C and 2.0 ◦ C (data not shown). 3.2. B. cinerea development and vase life
H. Harkema et al. / Postharvest Biology and Technology 76 (2013) 135–138
Avalanche+, start vaselife
Avalanche+, vase day 7
water + add
dry
4 d
3 c
2 1
c
c
b b
a b
c a
0
Botrys index (0 - 4)
Botrys index (0 - 4)
dry
2 1
a
b
c b ab
a
a
0
0
e cde
3 2
a a
0 4 7 11 14 21 transport simulaon (days)
b a
1
a
a
Red Naomi!, vase day 7
d
b ab
0 4 7 11 14 21 transport simulaon (days)
dry Botrys index (0 - 4)
Botrys index (0 - 4)
cd
bcd ab
water + add
3
e
bc
1
Red Naomi!, start vaselife
4
water + add
4
4 7 11 14 21 transport simulaon (days)
dry
a
4 7 11 14 21 transport simulaon (days)
Botrys index (0 - 4)
Botrys index (0 - 4)
c
2
a
dry
3
a a
b
Aqua!, vase day 7
4
1
b
b
water + add
bc
c
c
3
Aqua!, start vaselife
2
water + add
4
4 7 11 14 21 transport simulaon (days)
dry
137
4 3
water + add b
a
a
a
b b a
a
2
1 0 4 7 11 14 21 transport simulaon (days)
Fig. 2. Effect of transport simulation time and transport type (dry or in water + additive) on the Botrytis index. Additive used corresponded to Chrysal Professional 2 T bags. Bars are mean values of 4 replicates. Different letters stand for significant differences (p < 0.05) within each figure.
time was positively correlated with the extent of Botrytis damage. The type of transport (dry or wet) effect on the Botrytis damage was significant (p < 0.05). Roses kept at 0.5 and 2.0 ◦ C during dry transport was less affected by Botrytis damage than those that were transported in water. In addition, dry transport of roses at low temperatures and high relative humidity had a positive effect on vase life compared to wet transport. Our findings are in agreement with the study of Faragher et al. (1984) in which Rose cv. ‘Mercedes’ was stored for 10 days at 2 ◦ C and 95% RH either in dry and wet conditions. The dry stored roses displayed a longer vase life than wet stored ones. Cevallos and Reid (2001) found no benefit of wet storage in rose ‘Ambiance’ stored for 6 days at 2.5 and 5 ◦ C but at temperatures above 5 ◦ C vase life was a slightly longer after wet
storage. Hu et al. (1998) on the contrary showed a longer vase life after 2–3 days wet storage of Rose ‘Bridal Pink’. Previous studies suggest that wet transport might be unnecessary for other species. For example, for Narcissus ‘King Alfred’ and ‘Paper White’ wet storage for 6 days at 0–10 ◦ C showed no significant benefit as well as Chrysanthemum maximum (0 ◦ C), tulips (0 ◦ C), Iris ‘Telstar’ (0–10 ◦ C) and carnation ‘Imperial White’ (0–10 ◦ C) (Cevallos and Reid, 2001). Campanula medium ‘Champion Blue’ showed no difference in the number of open flowers due to wet or dry storage of 1–3 weeks, however, at the end of vase life wet stored stems showed less senesced flowers than dry stored stems (Bosma and Dole, 2002). Matthiola incana ‘Vivas Blue’ had a longer vase life when dry stored
138
H. Harkema et al. / Postharvest Biology and Technology 76 (2013) 135–138
Table 1 Percentage of rose stems rejected due to Botrytis or other symptoms. Start of vase life
After 7 days of vase life
Stems rejected due to
Botrytis
Botrytis
TS dry or wet
Dry
Wet
Dry
Avalanche+ 4 days 0.5 ◦ C 7 days 0.5 ◦ C 7 days 2.0 ◦ C 11 days 0.5 ◦ C 14 days 0.5 ◦ C 14 days 2.0 ◦ C 21 days 0.5 ◦ C
0a 3ab 0a 0a 3ab 5ab 45d
0a 3ab 0a 20bc 25c 24c 80e
10ab 13ab 3a 20ab 8a 15ab 50cd
Aqua 4 days 0.5 ◦ C 7 days 0.5 ◦ C 7 days 2.0 ◦ C 11 days 0.5 ◦ C 14 days 0.5 ◦ C 14 days 2.0 ◦ C 21 days 0.5 ◦ C
1ab 0a 0a 0a 25cde 4ab 20bcd
2ab 11abcd 10abc 29de 61f 39e 74f
30abc 21ab 15a 34abc 59def 34abc 43bcd
Red Naomi 4 days 0.5 ◦ C 7 days 0.5 ◦ C 7 days 2.0 ◦ C 11 days 0.5 ◦ C 14 days 0.5 ◦ C 14 days 2.0 ◦ C 21 days 0.5 ◦ C
0a 3a 0a 10a 18ab 18ab 100f
3a 35bc 40c 53cd 70de 78e 100f
93ab 88ab 85ab 100b 88ab 78a 100b
Other symptoms Wet
Dry
Wet
25ab 33bc 20ab 70de 88ef 72e 98f
0a 3a 0a 3a 5a 3a 8a
0a 0a 3a 5a 3a 8a 0a
49cde 72fg 49cde 88g 88g 68efg 89g
4a 21ab 15ab 26b 18ab 15ab 58c
3a 10ab 13ab 10ab 5a 18ab 9ab
0a 0a 0a 0a 3a 0a 0a
3a 0a 0a 0a 3a 0a 0a
93ab 100b 100b 100b 85ab 100b 100b
The statistical analysis was carried out independently for each rose variety at the start of vase life and after 7 days of vase life for the different response variables (Botrytis and other symptoms). Different letters stand for significant differences among the different treatments (p < 0.05).
compared to wet stored for 2 weeks at 2 ◦ C (Regan and Dole, 2010). 4. Conclusion Transport of roses in water or wet transport at low temperatures is not necessary and even it can have a negative impact on the quality of the product compared to dry transport at low temperatures and high relative humidity conditions. Weight loss of flowers during transport at low temperatures will not be highly affected due to the low vapor pressure deficit in the surrounding air. The preconception that flowers need to be transported in water (wet transport) should be reconsidered, in particular for species that are susceptible to Botrytis. These results showed that Botrytis development can be substantially reduced in three varieties of roses by using dry transport at low temperatures and high relative humidity. Transport and handling costs in addition can be substantially reduced. Acknowledgements The experiments were part of the research project ‘Containerisation and Conditioning in Ornamental Produce Chains (CoCoS)’. The
project was initiated by the Association of Wholesale Trade in Horticultural Products in the Netherlands and financed by the Dutch Horticultural Board. We would like to thank Dr. Roberto Molteni and Dr. Eric Boer for their help with the statistical analysis. References Bosma, T., Dole, J.M., 2002. Postharvest handling of cut Campanula medium flowers. HortScience 37, 954–958. Cevallos, J.C., Reid, M.S., 2001. Effect of dry and wet storage at different temperatures on vase life of cut flowers. HortTechnology 11, 199–202. Faragher, J.D., Mayak, S., Tirosh, T., Halevy, A.H., 1984. Cold storage of rose flowers: effects of cold storage and water loss on opening and vase life of ‘Mercedes’ roses. Scientific Horticulture 24, 369–378. Hu, Y., Doi, M., Imanishi, H., 1998. Improving the longevity of cut roses by cool and wet transport. Journal of the Japan Society for Horticultural Science 67, 681–684. Kerssies, A., Bosker-van Zessen, A.I., Frinking, H.D., 1995. Influence of environmental conditions in a glasshouse on conidia of Botrytis cinerea and on post-harvest infection of rose flowers. European Journal of Plant Pathology 101, 201–216. Pie, K., De Leeuw, G.T.N., 1991. Histopathology of the initial stages of the interaction between rose flowers and Botrytis cinerea. Netherlands Journal of Plant Pathology 97, 335–344. Regan, E.M., Dole, J.M., 2010. Postharvest handling procedures of Matthiola incana ‘Vivas Blue’. Postharvest Biology and Technology 58, 268–273. Williamson, B., Tudzynski, B., Tudzynski, P., van Kan, J., 2007. Botrytis cinerea: the cause of grey mould disease. Molecular Plant Pathology 8, 561–580.