The sensitivity of Venturia inaequalis to anilino-pyrimidine (AP) fungicides (pyrimethanil and cyprodinil) was studied on populations sampled from apple trees with different fungicide and APs histories: 1) apple trees in uncultivated areas never exposed to fungicides (wild types), 2) commercial orchards with many years of good scab control with APs (well-controlled); 3) populations in experimental Centre where an initial good activity decreased after several years of intensive use (poorly controlled). The in vitro sensitivity tests were performed on monoconidial isolates, while those in vivo with curative or preventive applications on populations inoculated on apple seedlings. In the field, the infection on apple trees was assessed as severity of attack on leaves. The results evidenced that the sensitivity in vitro to pyrimethanil and cyprodinil showed a progressive lower reduction from wild types to well controlled, ending with poorly controlled populations. In vivo tests the same moderate decrease of sensitivity and activity (with a wide range) was more evident with curative, respect preventive applications, as noticed also with an important DMI (difenoconazole). In field trials, the populations intensively treated with APs showed, after some years, a reduction of control, that was confirmed in the following years. These activity reductions were sensibly less strong respect those evidenced by strobilurins, both in field and in vitro tests. The particular characteristic of resistance to AP fungicides is discussed.
Creemers, P., Brugmans, W. and Vanmechelen, A. (1995) The Ani-lino-Pyrimidines, an Interesting New Fungicide Family to Control Diseases in Fruit Culture. Mededelingen—Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen. Universiteit Gent (Belgium), 60, 353-360.
Moyano, C., Gomez, V. and Melgarejo, P. (2004) Resistance to Pyrimethanil and other Fungicides in Botrytis cinerea Populations Collected on Vegetable Crops in Spain. Journal of Phytopathology, 152, 484-490. https://doi.org/10.1111/j.1439-0434.2004.00880.x
Myresiotis, C.K., Karaoglanidis, G.S. and Tzavella-Klonari, K. (2007) Resistance of Botrytis cinera Isolates from Vegetable Crops to Anilinipyrimidine, Phenylpirrole, Hydroxyanilide, Benzimidazole, and Dicarboximide Fungicides. Plant Disease, 91, 407-413. https://doi.org/10.1094/PDIS-91-4-0407
Latorre, B.A., Spadaro, I. and Rioja, M.E. (2002) Occurrence of Re-sistant Strains of Botrytis cinerea to Anilinopyrimidine Fungicides in Table Grapes in Chile. Crop Protection, 21, 957-961. https://doi.org/10.1016/S0261-2194(02)00074-1
Schnabel, G. and Parisi, L. (1997) Sensitivity of Venturia inaequalis to Five DMI Fungicide, Including the New Triazole Fluquinconazole, and to Pyrimethanil. Zeischrift fur Pflanzenkrankheiten und Pflanzeschutz/Journal of Plant Diseases and Protection, 104, 36-46.
Kunz S., Lutz, Bu., Deising, H. and Mendgen, K. (1998) Assessment of Sensitivities to Anilinopyrimidine- and Strobilurin Fungicides in Populations of the Apple Scab Fungus Venturia inaequalis. Journal of Phytopathology, 146, 231-238. https://doi.org/10.1111/j.1439-0434.1998.tb04684.x
Koller, W., Wilcox, W.F. and Parker, D.M. (2005) Sensitivity of Venturia inaequalis Populations to Anilinipyrimidines and Their Contribution to Scab Management in New York. Plant Disease, 89, 357-365. https://doi.org/10.1094/PD-89-0357
Dux, H., Sierotzki, H., Meier-Runge, F. and Gisi, U. (2005) Sensitivity of Venturia inaequalis Populations to Anilinopyrimidines, DMI and QoI Fungicides. Modern Fungicides and Antifungal Com-pounds IV 2005, 45-54.
Fiaccadori, R., Cicognani, E., Collina, M. and Brunelli, A. (2007) Study on the Sensitivity of Venturia inaequalis to Anilinopyrimidine Fungicides in Italy. Proceedings of 59th Symposium on Crop Protection 2006, Ghent (B) 10.05.2007 pubbl. on “Communications in Agricoltural and Applied Biology Sciences”, Ghent University, 72, 997-1001.
Hilber, U.W. and Schuepp, H. (1996) A Reliable Method for Testing the Sensitivity of Botriotinia fuckeliana to Anilinopyrimidines in Vitro. Pesticide Science, 47, 241-247. https://doi.org/10.1002/(SICI)1096-9063(199607)47:3< 241::AID-PS410>3.0.CO;2-6
Fiaccadori, R., Cicognani, E., Alberoni, G., Collina, M. and Brunelli, A. (2011) Sensitivity to Strobilurin Fungicides of Italian Venturia inaequalis Populations with Different Origin and Scab Control. Pest Management Science, 67, 535-540. https://doi.org/10.1002/ps.2090
Fiaccadori, R., Collina, M. and Brunelli, A. (2013) Reduced Sensitivity of Venturia inaequalis to Strobilurins and Anilinopyrimidines in Italy. Integrated Protection of Fruit Crops IOBC-WPRS Bulletin, 91, 345-350.
Fiaccadori, R. (2017) Researches on Methodologies to Verify Reduced Sensitivities of Venturia inaequalis in Field to Difenoconazole and First Indications of a Survey in Italy. American Journal of Plant Sciences, 8, 2056-2068. https://doi.org/10.4236/ajps.2017.89138
Fritz, R., Lanen, C., Chapeland, F. and Leroux, P. (2003) Effect of the Anilinopyrimidine Fungicide Pyrimethanil on the Cystathionine β-Liase of Botrytis cinerea. Pesticide Biochemistry and Physiology, 77, 54-65. https://doi.org/10.1016/S0048-3575(03)00094-4