Abstract
We determined the potential of using a formulated product based on Pantoea agglomerans CPA-2, either alone or in combination with heated sodium bicarbonate (SBC) solutions, to control the major postharvest diseases affecting citrus crops in the Mediterranean region. Treatments applied either individually or in combination were tested in semi-commercial and commercial trials carried out with oranges and mandarins from the Algarve, Andalusia and Catalonia. Firstly, several formulations of the biocontrol agents were tested in laboratory trials; one of them, a freeze-dried formulation of P. agglomerans strain CPA-2 called FD10-3, was chosen for combined with SBC. This formulation, applied at 2 × 108cfu ml−1 and the SBC treatment, applied at 3% 50°C for 20–40 s, demonstrated that it was possible to reduce decay development in laboratory trials. Semi-commercial applications of FD10-3 and 3% SBC solution at 50°C for 40 s showed excellent control of decay in unwounded mandarins and oranges artificially inoculated with both Penicillium digitatum and P. italicum. No rind injuries or residues attributable to hot water or SBC were observed on treated fruits. Combined treatment provided better control than the two treatments applied separately. Commercial trials demonstrated an important reduction in natural decay with the treatment of SBC 3% at 50°C for 40 s. Furthermore, bacterial-product formulation treatment significantly reduced the percentage of infected fruit and in some cases this reduction was equal to chemical treatments. Even so, no improvement in efficacy was observed with the combination of FD10-3 and SBC in the commercial test. We also assessed the ability of FD10-3 to grow at the wound site in oranges, whether alone or in the presence of SBC, and also its compatibility with standard citrus packinghouse practices.





Similar content being viewed by others
Explore related subjects
Discover the latest articles and news from researchers in related subjects, suggested using machine learning.References
Arras, G. (1993). Mode of action of an isolate of Candida famata in biological control of Penicillium digitatum in oranges fruits. Postharvest Biology and Technology, 8, 191–198.
Barkai-Golan, R., & Phillips, D. J. (1991). Postharvest heat treatments of fresh fruits and vegetables for decay control. Plant Disease, 75, 1085–1089.
Chalutz, E., & Wilson, C. L. (1990). Postharvest biocontrol of green and blue mold and sour rot of citrus fruit by Debryomyces hansenii. Plant Disease, 74, 134–137.
Costa, E., Teixidó N., Usall, J., Atarés, E., & Viñas, I. (2001). Production of the biocontrol agent Pantoea agglomerans strain CPA-2 using commercial products and by-products. Applied Microbiology and Biotechnology, 56, 367–371.
Costa, E., Usall, J., Teixidó, N., Torres, R., & Viñas, I. (2002). Effect of package and storage conditions on viability and efficacy of the freeze-dried biocontrol agent Pantoea agglomerans CPA-2. Journal of Applied Microbiology, 92, 873–878.
Droby, S., Hofstein, R., Wilson, C. L., Wisniewski, M., Fridlender, B., Cohen, L., Weiss, B., Daus, A., Timar, D., & Chalutz, E. (1993). Pilot testing of Pichia guilliermondii: A biocontrol agent of postharvest diseases of citrus. Biological Control, 3, 47–52.
Droby, S., Cohen, L., Daus, A., Weiss, B., Horev, B., Chalutz, E., Katz, H., Keren-Tzur, M., & Shachnai, A. (1998). Commercial testing of Aspire: A yeast preparation for the biological control of postharvest decay of citrus. Biological Control, 12, 97–102.
Eckert, J. W., & Eaks, J. L. (1989). Postharvest disorders and diseases of citrus fruits. In W. Reuter, E. C. Calavan & G. E. Carman (Eds.), The Citrus Industry (Vol. 5, pp. 179–260). Berkeley CA, USA: University of California Press.
El-Ghaouth, A., Smilanick, J. L., Brown, G. E., Ippolito, A., Wisniewski, M., & Wilson, C. L. (2000). Application of Candida saitoana and glycolchitosan for the control of postharvest diseases of apple and citrus fruit under semi-commercial conditions. Plant Disease, 84, 243–248.
Houck, L. G. (1967). Hot water treatments for control of Penicillium green mold of Eureka lemons. (Abstr.) Phytopathology, 57, 99.
Janisiewicz, W. J., & Bors, B. (1995). Development of a microbial community of bacterial and yeasts antagonists to control wound-invading postharvest pathogens of fruits. Applied and Environmental Microbiology, 61, 3261–3267.
Janisiewicz, W. J., & Jeffers, S. (1997). Efficacy of commercial formulation of two biofungicides for control of blue mould and grey mould of apples in cold storage. Crop Protection, 16, 629–633.
Karabulut, O. A., Lurie, S., & Droby, S. (2001). Evaluation of the use of sodium bicarbonate, potassium sorbate and yeast antagonists for decreasing postharvest decay of sweet cherries. Postharvest Biology and Technology, 23, 233–236.
Lurie, S. (1999). Postharvest heat treatments. Postharvest Biology and Technology, 14, 257–269.
McGuire, M. G. (1994). Application of Candida guilliermondii in commercial citrus coatings for biocontrol of Penicillium digitatum on grapefruits. Biological Control, 4, 1–7.
Nunes, C., Usall, J., Teixidó, N., & Viñas, I. (2001). Biological control of postharvest pear diseases using a bacterium Pantoea agglomerans CPA-2. International Journal of Food Microbiology, 70, 53–61.
Nunes, C., Usall, J., Teixidó, N., Fons, E., & Viñas, I. (2002). Postharvest biological control by Pantoea agglomerans (CPA-2) on Golden Delicious apples. Journal of Applied Microbiology, 92, 247–255.
Obagwu, J., & Korsten, L. (2003). Integrated control of citrus green and blue molds using Bacillus subtilis in combination with sodium bicarbonate or hot water. Postharvest Biology and Technology, 28, 187–194.
Palou, L., Smilanick, J., Usall, J., & Viñas, I. (2001). Control of postharvest blue and green molds of oranges by hot water, sodium carbonate, and sodium bicarbonate. Plant Disease, 85, 371–376.
Palou, L., Usall, J., Muñoz, J. A., Smilanick, J., & Viñas, I. (2002). Hot water, sodium carbonate, and sodium bicarbonate for the control of postharvest green and blue molds of clementine mandarins. Postharvest Biology Technology, 24, 93–96.
Plaza, P., Usall, J., Teixidó, N., & Viñas, I. (2003). Effect of water activity on germination and growth of Penicillium digitatum, P. italicum and Geotrichum candidum. Journal of Applied Microbiology, 94, 549–554.
Porat, R., Daus, A., Weiss, B., Cohen, L., Fallik, E., & Droby, S. (2000). Reduction of postharvest decay in organic citrus fruit by a short hot water brushing treatment. Postharvest Biology Technology, 18, 151–157.
Porat, R., Daus, A., Weiss, B., Cohen, L., & Droby, S. (2002). Effects of combining hot water, sodium bicarbonate and biocontrol on postharvest decay of citrus fruit. Journal of Horticultural Science and Biotechnology, 77, 441–445.
Schirra, M., & D’hallewin, G. (1997). Storage performance of ‘Fortune’ mandarins following hot water dips. Postharvest Biology and Technology, 10, 229–238.
Schirra, M., D’hallewin, G., Ben-Yehoshua, S., & Fallik, E. (2000). Host-pathogen interactions modulated by heat treatment. Postharvest Biology and Technology, 21, 71–85.
Smilanick, J. L., & Denis-Arrue, R. (1992). Control of green mold of lemons with Pseudomonas species. Plant Disease, 76, 481–485.
Smilanick, J. L., Margosan, D.A., & Henson, D. J. (1995). Evaluation of heated solutions of sulphur dioxide, ethanol, and hydrogen peroxide to control postharvest green mold of lemons. Plant Disease, 79, 742–747.
Smilanick, J. L., Mackey, B. E., Reese, R., Usall, J., & Margosan, D. (1997). Influence of concentration of soda ash, temperature, and immersion period on the control of postharvest green mold of oranges. Plant Disease, 83, 139–145.
Smilanick, J. L., Margosan, D., Milkota, F., Usall, J., & Michael, I. (1999). Control of citrus green mold by carbonate and bicarbonate salts and the influence of commercial postharvest practices on their efficacy. Plant Disease, 81, 379–382.
Smilanick, J. L., Sorenson, D., Mansour, M., Aieyabei, J., & Plaza, P. (2003). Impact of a brief postharvest hot water drench treatment on decay, fruit appearance, and microbe populations of California lemons and oranges. HortTechnology, 13, 333–338.
Teixidó, N., Usall, J., Palou, L., Asensio, A., Nunes, C., & Viñas, I. (2001). Improving control of green and blue molds of oranges by combining Pantoea agglomerans (CPA-2) and sodium bicarbonate. European Journal Plant Pathology, 107, 685–694.
Viñas, I., Usall, J., Nunes, C., & Teixidó, N. (2001). Nueva cepa de la bacteria Pantoea agglomerans y su utilización como agente de biocontrol de las enfermedades fúngicas de postcosecha de frutas. PCT/ES00/00101.
Acknowledgements
The authors are grateful to the European Community (QLK5-1999-01065) and the FCT of Portugal (SFRH/BPD/11517/2002) for their financial support, and to the Agrofruit Export (Tarragona, Catalonia, Spain), Rio Tinto Fruit (Huelva, Andalusia, Spain) and Tavifruta (Portugal) packinghouses for their technical assistance in commercial trials.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Torres, R., Nunes, C., García, J.M. et al. Application of Pantoea agglomerans CPA-2 in combination with heated sodium bicarbonate solutions to control the major postharvest diseases affecting citrus fruit at several mediterranean locations. Eur J Plant Pathol 118, 73–83 (2007). https://doi.org/10.1007/s10658-007-9120-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10658-007-9120-1


