Abstract
Four experimental trials were carried out in order to evaluate the efficacy of different products (chemicals, resistance inducers and natural products) as well as heat air when applied to basil seeds naturally infested by Peronospora belbahrii, the causal agent of downy mildew of basil, a pathogen which is seed transmitted. Seed quality, as vigour index, was also evaluated. In general, seed treatment had a positive effect on the reduction of disease incidence and on plant biomass at the end of each trial, with very satisfactory results when disease incidence was lower than 10% and still satisfactory results with a higher disease incidence. Although many of the fungicides, resistance inducers and thyme oil treatments tested showed a significant disease reduction compared with the untreated control, the protection offered was only partial. Moreover, the effectiveness of the tested seed treatments varied considerably between the trials. The seeds treatment with heat air (65°C for 10 min) significantly reduced the number of infected plants per container. The interaction effect between the fungicides (at the lowest dosage tested, with the exception of acibenzolar-S-methyl, and dimethomorph), thyme oil and the heat air treatment was also significant. In terms of biomass, most treatments not significantly improved the fresh weight in comparison with the untreated control. The highest biomass was observed in the plots where seeds were dressed with mancozeb combined with heat air. Interestingly, thiram is also effective against other pathogens affecting basil and the thermal treatment and potassium phosphite are fully compatible with the rules of organic farming. Seed dressing represents the starting point of a full integrated approach for downy mildew management.
References
Ben-Naim, Y., Falach, L., & Cohen, Y. (2015). Resistance against basil downy mildew in Ocimum species. Phytopathology, PHYTO-11-14-0295-R.
Bennett, R. S., & Coyer, P. D. (2010). Dry heat and hot water treatments for disinfesting cottonseed of Fusarium oxysporum f. sp. vasinfectum. Plant Disease, 94, 1469–1475.
Cohen, Y., Baider, A., & Cohen, B.-H. (1995). Dimethomorph activity against oomycete Fungal Pathogens. Phytopathology, 85, 15001506.
Coosemans, J. (2004). First report of Peronospora lamii, downy mildew on basil (Ocimum basilicum) in Belgium. Parasitica, 60, 27.
Garibaldi, A., Bertetti, D., & Gullino, M. L. (2007). Effect of leaf wetness duration and temperature on infection of downy mildew (Peronospora sp.) of basil. Journal of Plant Diseases and Protection, 114, 6–8.
Garibaldi, A., Gilardi, G., & Gullino, M. L. (2014). Peronospora del basilico, fondamentale la prevenzione. Informatore Agrario, 70(33), 72–73.
Garibaldi, A., Gullino, M. L., & Minuto, G. (1997). Diseases of basil and their management. Plant Disease, 81, 124–132.
Garibaldi, A., Minuto, A., & Gullino, M. L. (2005). First report of downy mildew of basil (Ocimum basilicum) in France. Plant Disease, 89, 683.
Garibaldi, A., Minuto, A., Minuto, G., & Gullino, M. L. (2004a). First report of downy mildew of basil (Ocimum basilicum) in Italy. Plant Disease, 88, 312.
Garibaldi, A., Minuto, G., Bertetti, D., & Gullino, M. L. (2004b). Seed transmission of Peronospora of basil. Journal of Plant Diseases and Protection, 111, 465–469.
Gilardi, G., Demarchi, S., Garibaldi, A., & Gullino, M. L. (2013). Management of downy mildew of sweet basil (Ocimum basilicum) caused by Peronospora belbahrii by means of resistance inducers, fungicides, biocontrol agents and natural products. Phytoparasitica, 41, 59–72.
Gullino, M. L., Gilardi, G., & Garibaldi, A. (2009). Chemical control of downy mildew on lettuce and basil under greenhouse. Communication Agricultural and Applied Biological Sciences, 74(3), 933–940.
Gullino, M. L., Gilardi, G., & Garibaldi, A. (2014). Chemical and non chemical seed dressing for leafy vegetable crops. In M. L. Gullino & G. Munkvold (Eds.), Global Perspectives on the health of seeds and plant propagation material (pp. 125–136). Dordrecht, Heidelberg: Springer.
Hansford, C. G. (1933). Annual report of the mycologist. Rev. appl. Mycol., 12, 421–422.
Homa, K., Barney, W. P., Ward, D. L., Wyenaudt, C. A., & Simon, J. E. (2014). Evaluation of fungicides for the control of Peronospora belbahrii on sweet basil in New Jersey. Plant Disease, 98, 1561–1566.
ISTA (1993). International Seed Testing Association, 1993. International rules for seed testing. Seed Science and Technology 21 (Suppl.), 322 pages.
Koch, E., & Roberts, S. J. (2014). Non-chemical seed treatment in the control of seed-borne pathogens. In M. L. Gullino & G. Munkvold (Eds.), Global perspectives on the health of seeds and plant propagation material (pp. 105–123). Dordrecht, Heidelberg: Springer.
Lefort, F., Gigon, V., & Amos, B. (2003). Le mildiou s’étend. Dejà Dètecté dans des nombreux pays européens, Peronospora lamii, responsible du mildiou de basilic, a été observé en Suisse dans la région lémanique. Réussir Fruits et Légumes, 223, 66.
Lopez-Reyes, J.G., Gilardi, G., Garibaldi, A., & Gullino, M.L. (2015). Efficacy of essential oils as seed treatments against Fusarium oxysporum f. sp. basilici on basil and Fusarium oxysporum f. sp. lactucae on lettuce. Journal of Essential Oils Research. Submitted.
Martinez de la Parte, E., Pérez-Vicente, L., Bernal, B., & Garcia, D. (2010). First report of Peronospora sp. on sweet basil (Ocimum basilicum) in Cuba. Plant Pathology, 59, 800.
McGranth, M., Wyenandt, A., & Simon, J. (2010). Downy mildew wars. Am. Veg. Grow., 2, 10.
Mersha, A., Zhang, S., & Raid, R. N. (2012). Evaluation of systemic acquired resistance inducers for control of downy mildew on basil. Crop Protection, 40, 83–90.
Mersha, Z., Zhang, S., Fu, Y., Mo, X., Raid, R. N., & Hau, B. (2013). Efficacy of acibenzolar-S-methyl and β-aminobutyric acid for control of downy mildew in greenhouse grown basil and peroxidase activity in response to treatment with these compounds. Journal of Phytopathology, 161, 154–164.
Nagy, G., & Horvath, A. (2011). Occurrence of downy mildew caused by Peronospora belbahrii on sweet basil in Hungary. Plant Disease, 95, 1034.
Roberts, P. D., Raid, R. N., Harmon, P. F., Jordan, S. A., & Palmateeer, A. J. (2009). First report of downy mildew caused by a Peronospora sp. on basil in Florida and the United States. Plant Disease, 93, 199.
Thines, M., Telle, S., Ploch, S., & Runge, F. (2009). Identity of the downy mildew pathogens of basil, coleus, and sage with implications for quarantine measures. Mycological Research, 113, 532–540.
Wyenaudt, C. A., Simon, J. E., McGrath, M. T., & Ward, D. L. (2010). Susceptibility of basil cultivars and breeding lines to downy mildew (Peronospora belbahrii). HortScience, 45, 1416–141.
Acknowledgments
The research leading to these results has received funding from the European Union’s Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 311875 ‘TESTA - Seed health: development of seed treatment methods, evidence for seed transmission and assessment of seed health’.
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Gilardi, G., Pintore, I., Demarchi, S. et al. Seed dressing to control downy mildew of basil. Phytoparasitica 43, 531–539 (2015). https://doi.org/10.1007/s12600-015-0474-1
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DOI: https://doi.org/10.1007/s12600-015-0474-1