European Journal of Plant Pathology

, Volume 120, Issue 3, pp 211–222 | Cite as

Effect of temperature, relative humidity, leaf wetness and leaf age on Spilocaea oleagina conidium germination on olive leaves

  • Friday O. Obanor
  • Monika Walter
  • E. Eirian Jones
  • Marlene V. Jaspers
Full Research Paper

Abstract

The effects of temperature, relative humidity (RH), leaf wetness and leaf age on conidium germination were investigated for Spilocaea oleagina, the causal organism of olive leaf spot. Detached leaves of five ages (2, 4, 6, 8 and 10 weeks after emergence), six different temperatures (5, 10, 15, 20, 25 and 30°C), eight wetness periods (0, 6, 9, 12, 18, 24, 36 and 48 h), and three RH levels (60, 80 and 100%) were tested. Results showed that percentage germination decreased linearly in proportion to leaf age (P < 0.001), being 58% at 2 weeks and 35% at 10 weeks. A polynomial equation with linear term of leaf age was developed to describe the effect of leaf age on conidium germination. Temperature significantly (P < 0.001) affected frequencies of conidium germination on wet leaves held at 100% RH, with the effective range being 5 to 25°C. The percent germination was 16.1, 23.9, 38.8, 47.8 and 35.5% germination at 5, 10, 15, 20 and 25°C, respectively, after 24 h. Polynomial models adequately described the frequencies of conidium germination at these conditions over the wetness periods. The rate of germ tube elongation followed a similar trend, except that the optimum was 15°C, with final mean lengths of 175, 228, 248, 215 and 135 μm at 5, 10, 15, 20 and 25°C, respectively after 168 h. Polynomial models satisfactorily described the relationships between temperature and germ tube elongation. Formation of appressoria, when found, occurred 6 h after the first signs of germination. The percentage of germlings with appressoria increased with increasing temperature to a maximum of 43% at 15°C, with no appressoria formed at 25°C after 48 h of incubation. Increasing wetness duration caused increasing numbers of conidia to germinate at all temperatures tested (5–25°C). The minimum leaf wetness periods required for germination at 5, 10, 15, 20 and 25°C were 24, 12, 9, 9 and 12 h, respectively. At 20°C, a shorter wetness period (6 h) was sufficient if germinating conidia were then placed in 100% RH, but not at 80 or 60%. However, no conidia germinated without free water even after 48 h of incubation at 20°C and 100% RH. The models developed in this study should be validated under field conditions. They could be developed into a forecasting component of an integrated system for the control of olive leaf spot.

Keywords

Cycloconium oleagina Olea europaea Peacock spot 

References

  1. Azeri, T. (1993). Research on olive leaf spot, olive knot and Verticillium wilt of olive in Turkey. EPPO Bulletin, 23, 437–440.Google Scholar
  2. Bentes, J. L. S., & Matsuoka, K. (2002). Histology of Colletotrichum guaranicola and Paullinia cupana var. sorbilis on resistant and susceptible clones. Fitopatologia Brasileira, 27, 71–77.CrossRefGoogle Scholar
  3. Bernès, J. (1923). Les parasites de l’olivier au congrès oleicole de Nice. Progrès Agriculture and Viticulture, 80, 518–524.Google Scholar
  4. Chen, S., Zhang, J., & Zhang, L. (1981). Studies on olive peacock’s eye disease. I. Biological characteristics of the pathogen. Acta Phytopathologica Sinica, 11, 37–42.Google Scholar
  5. Dzaganiya, A. M. (1967). Data on the characteristics of development of the pathogen of olive leaf spot in Georgia. Review of Applied Mycology, 46, 2788.Google Scholar
  6. Graniti, A. (1993). Olive scab: a review. EPPO Bulletin, 23, 377–384.CrossRefGoogle Scholar
  7. Guechi, A., & Girre, L. (1994). Sources of Cycloconium oleaginum (Cast.) conidia for infection of olive leaves and conditions determining leaf spot disease development in the region of Sétif, Algeria. Mycopathologia, 125, 163–171.CrossRefGoogle Scholar
  8. Jetter, R., & Schäffer, S. (2001). Chemical composition of the Prunus laurocerasus leaf surface. Dynamic changes of the epicuticular wax film during leaf development. Plant Physiology, 126, 1725–1737.PubMedCrossRefGoogle Scholar
  9. Jones, A. L., Fisher, P. D., Seem, R. C., Kroon, J. C., & DeMotter, P. J. V. (1984). Development and commercialization of an in-field microcomputer delivery system for weather-driven predictive models. Plant Disease, 68, 458–463.CrossRefGoogle Scholar
  10. Kashy, A. H., Waleed, A. L., & Lewik, J. (1991). Factors affecting conidia germination of the fungus Spilocaea oleagina the causal agent of olive peacock. Arab Journal of Plant Protection, 9, 88–93.Google Scholar
  11. Kolattukudy, P. E., Rogers, L. M., Li, D., Hwang, C. S., & Flaishman, M. A. (1995). Surface signalling in pathogenesis. Proceedings of the National Academy of Science, 92, 4080–4087.CrossRefGoogle Scholar
  12. Laviola, C. (1992). Problemi fitopatologici e difesa dell’olivo. La Difesa Delle Piante, 15, 101–114.Google Scholar
  13. Laviola, C., & Scarito, G. (1993). Observations on spore production in Spilocaea oleagina in southern Italy. EPPO Bulletin, 23, 411–416.Google Scholar
  14. López-Doncel, L. M., Viruega-Puente, J. R., & Trapero-Casas, A. (2000). Respuesta del olivo a la inoculacion con Spilocaea oleagina, agente del repilo. Boletin de Sanidad Vegetale Plagas, 26, 349–363.Google Scholar
  15. MacDonald, A. J., Walter, M., Trought, M., Frampton, C. M., & Burnip, G. (2000). Survey of olive leaf spot in New Zealand. New Zealand Plant Protection, 53, 126–132.Google Scholar
  16. MacHardy, W. E. (1996). Apple scab: biology, epidemiology, and management. American Phytopathological Society, St. Paul, MN.Google Scholar
  17. Miehle, B. R., & Lukezic, F. L. (1972). Studies on conidial germination and appressorium formation by Colletotrichum trifolii Bain & Essary. Canadian Journal of Microbiology, 18, 1263–1269.PubMedCrossRefGoogle Scholar
  18. Mijuskovic, M. (1969). Contribution to the study of harmfulness and control of Cycloconium oleaginum, the causal agent of “peacock’s eye” of olive on the Adriatic coast of Montenegro. Review of Applied Mycology, 48, 875.Google Scholar
  19. Miller, H. N. (1949). Development of the leaf spot fungus in the olive leaf. Phytopathology, 39, 403–410.Google Scholar
  20. Obanor, F. O., Walter, M., Jones, E. E., & Jaspers, M. V. (2005). Sources of variation in a field evaluation of the incidence and severity of olive leaf spot. New Zealand Plant Protection, 58, 273–277.Google Scholar
  21. Pinheiro, J. C., & Bates, D. M. (2000). Mixed-effects models in S and S-Plus. Springer, NY.Google Scholar
  22. Pinheiro, J. C., Bates, D. M., DebRoy, S., & Sarkar, D. (2004). nlme: Linear and nonlinear mixed effects models. R package version 3. The R Foundation for Statistical Computing, Vienna, Austria.Google Scholar
  23. Podila, G. K., Rogers, L. A., & Kolattukudy, P. E. (1993). Chemical signals from avocados surface wax trigger germination and appressorium formation in Colletotrichum gloeosporioides. Plant Physiology, 103, 267–272.PubMedGoogle Scholar
  24. Prusky, D., Plumbery, R. A., & Kobiler, I. (1991). The relationship between antifungal diene levels and fungal inhibition during quiescent infection of unripe avocado fruits by Colletotrichum gloeosporioides. Plant Pathology, 40, 45–52.CrossRefGoogle Scholar
  25. R Development Core Team (2004). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. Retrieved from http://www.R-project.org.
  26. Saad, A., & Masri, S. (1978). Epidemiological studies on olive leaf spot incited by Spilocaea oleagina (Cast.) Hugh. Phytopathologia Mediterranean, 17, 170–173.Google Scholar
  27. Sakamoto, Y., Ishiguro, M., & Kitagawa, G. (1986). Akaike Information Criterion Statistics. Reidel, Dordrecht, Holland.Google Scholar
  28. Salerno, M. (1966). The olive leaf spot Spilocaea oleagina (Cast.) Hugh. Considerations on biology and control. Review of Applied Mycology, 45, 184.Google Scholar
  29. Schwabe, W. F. S. (1979). Change in scab susceptibility of apple leaves as influenced by age. Phytophylactica, 11, 53–56.Google Scholar
  30. Teviotdale, B. L., Sibbett, G. S., & Harper, D. H. (1989). Control of olive leaf spot by copper fungicides. Applied Agricultural Research, 4, 185–189.Google Scholar
  31. Verona, O., & Gambogi, P. (1964). On the characteristics of oil produced by olives attacked by Cycloconium oleaginum. Agricultura Italiana, 64, 1135–1139.Google Scholar
  32. Viljanen-Rollinson, S. L. H., Gaunt, R. E., Frampton, C. M. A., Falloon, R. E., & McNeil, D. L. (1998). Components of quantitative resistance to powdery mildew (Erysiphe pisi) in pea (Pisum sativum). Plant Pathology, 47, 137–147.CrossRefGoogle Scholar
  33. Wilson, E. E., & Miller, H. N. (1949). Olive leaf spot and its control with fungicides. Hilgardia, 19, 1–24.Google Scholar
  34. Winston, P. W., & Bates, D. H. (1960). Saturated solutions for the control of humidity in biological research. Ecology, 41, 232–237.CrossRefGoogle Scholar
  35. Xu, X.-M., Butt, D. J., & Santen, G. (1995). A dynamic model simulating infection of apple leaves by Venturia inaequalis. Plant Pathology, 44, 865–876.CrossRefGoogle Scholar

Copyright information

© KNPV 2007

Authors and Affiliations

  • Friday O. Obanor
    • 1
    • 2
  • Monika Walter
    • 2
  • E. Eirian Jones
    • 1
  • Marlene V. Jaspers
    • 1
  1. 1.Bio-Protection and Ecology DivisionLincoln UniversityLincolnNew Zealand
  2. 2.HortResearchLincolnNew Zealand

Personalised recommendations