Citrus Black Spot

Salta, Salta. Asociación Argentina de Horticultura.Rybak, ASAHO. M. A., Canteros, Libro B. de I., Soliz, Resúmenes J., Hermosis, XXXII F., Benitez, R. Momento de Congreso Argentino de Horticultura. Sección FruticulturaPulverización y(FR Productos-S4). para Pag. el Control 181 de Mancha Negra en Mandarina NOVA. XXXII CongresoDepartment of PlantArgentino Pathology and Microbiology de Horticultura. 23 al 26 de septiembre de 2009 Ciudad de Guignardia citricarpa6500 Amarillo Blvd. Asci W., Amarillo, of G TXu 79106ignardia citricarpa with ascosporis. TanSalta, Spot Salta.http://sickcitrus.tamu.edu Asociación Argentina de Horticultura. ASAHO. Libro de Resúmenes XXXII Rybak M.A., Canteros B. I. Soliz J.,PLPA-Cit013-01 Benitez R., WheatCongreso Hermosis diseases Argentino F. Momento de D.Horticultura. Schultz, R. de Sección aplicación Fruticultura (FR-S4). Pag. 181 para control de Black spot con bencimidazol y aceiteCitrus Black en Spotmandarina Nova. XIXº Rybak M.A., Canteros B. I. Soliz J., Benitez R., Hermosis F. Momento de aplicación Reunión de Comunicaciones CientíficasSummary y Técnicas y Reunión de Citrus Black Spot is a fungal disease parathat causes control early fruit drop, de reduces Black yield and spot makes conthe fruit bencimidazolunfit for y aceite en mandarina Nova. XIXº fresh market. Spores produced on foliageReunión are the main inoculumde Comunicaciones source, and the movement of sick Científicas plants or y Técnicas y Reunión de Extensión.Corrientes ± Argentina.foliage FCA the means - of UNNE.dispersion. 6 y 7 de Agosto de 2008. CD The disease occurs in subtropical regionsExtensión. worldwide. In theCorrientes US, Citrus Black Spot ± isArgentina. only present in South FCA - UNNE. 6 y 7 de Agosto de 2008. CD Resumen Sanidad Vegetal _14. Florida, where it was detected in 2010.Resumen Sanidad Vegetal! _14. Symptoms of the rind (black spots, Fig. 1 & 2) make the fruits http://agr.unne.edu.ar/Extension/Res2008/SanVegetal/SanVegetal_14.pdfhttp://agr.unne.edu.ar/Extension/Res2008/SanVegetal/SanVegetal_14.pdfunfit for fresh market. Early virulent spots may Black spot affects citrus foliage and fruits. There are Frutos de Nova con diferentescoalesce to covergrados a large de portion intensidad of the fruit. Otherde black spot several fruit symptoms that may overlap. Typical symptoms include speckled blotch or false melanose symptoms consist of hard spots that begin as small where the fruit is covered by tiny spots in absence orange or red lesions with black margins and of any other symptom. Severe disease causes enlarge to become necrotic lesions. These blemishes extensive premature fruit drop.

Típicas manchasNaranja duras Valencia en mandarina Nova

Naranja Valencia

Figure 1: Typical black spots on Valencia orange, top left, and Ellendale mandarin, top right. Details of the lesions with pycnidia, in Nova mandarin (bottom, left & right) and in orange (bottom, center). Photos: Myrian Rybak. Lesiones Fig. de1. manchas Hard spots duras withcon picnidios black pycnidiaen el centro caused del tejido by necrótico Guignardia (20x) citricarpa

G. mangiferae

Fig. 1. Hard spots with black pycnidia caused by Guignardia citricarpa G. citricarpa G. citricarpa Guignardia citricarpa en CHA

CrecimientoPhyllosticta de Guignardia citricarpa en medios (imperfect diferenciales stage Cherry) agar y Oatmeal agar

G. citricarpa con un halo amarillo en medio Oatmeal Agar Frutos de mandarina Nova con síntomas de mancha negra

Phyllosticta citricarpa (imperfect stage)

Rybak, M. A., Canteros, B. I., Soliz, J., Hermosis, F., Benitez, R. Momento de Pulverización y Productos para el Control de Mancha Negra en Mandarina NOVA. XXXII Congreso Argentino de Horticultura. 23 al 26 de septiembre de 2009 Ciudad de Salta, Salta. Asociación Argentina de Horticultura. ASAHO. Libro de Resúmenes XXXII Congreso Argentino de Horticultura. Sección Fruticultura (FR-S4). Pag. 181

Rybak M.A., Canteros B. I. Soliz J., Benitez R., Hermosis F. Momento de aplicación para control de Black spot con bencimidazol y aceite en mandarina Nova. XIXº Reunión de Comunicaciones Científicas y Técnicas y Reunión de Extensión.Corrientes ± Argentina. FCA - UNNE. 6 y 7 de Agosto de 2008. CD Resumen Sanidad Vegetal _14. http://agr.unne.edu.ar/Extension/Res2008/SanVegetal/SanVegetal_14.pdf

Naranja Valencia

Guignardia citricarpa Asci of GuignGuignardiaardia citric citricarpaarpa with ascosporis. Asci of Guignardia citricarpa with ascosporis.

Fig. 1. Hard spots with black pycnidia caused by Guignardia citricarpa

! !

Frutos de Nova con diferentes grados de intensidadFrutos de black de Nova spot con diferentes grados de intensidad de black spot

Figure 4. Pycnidia (left) and its conidia (right). Photos: Figure 2: Hard spots on mature and green mandarin fruits. Myrian Rybak. Típicas manchas duras en mandarina Nova Photos: TípicasMyrian Rybak. manchas duras en mandarina Nova Management Causal agent • RemovalPhyllosticta of dead leaves in groves citricarpa to reduce the (imperfect stage) Black spot is caused by Guignardia citricarpa primary inoculum. (asexual stage Phyllosticta citricarpa). Spores of the • Application of fungicides. Programs with three sexual stage, ascospores, develop on dead leaves applications of Copper plus oil offer good (Fig. 3). Conidia-containing Pycnidia (asexual stage, protection. First application at 2-3 cm fruit Fig. 4) develop in the center of fruit lesions, and can diameter, second one month later (at 3-4 cm fruit be seen as small black dots (Fig. 1). The disease is diameter) and a third in another month (at 4-5 cm widespread to most humid subtropical regions of the fruit diameter). In Argentina, a post infection Lesiones de manchas duras con picnidiosworld. en el centroLesiones del tejido de manchas necrótico duras (20x) con picnidiosapplication en el centrowith Benomyl, del tejido Carbendazin necrótico (20x)or Thiophanate methyl, together with a second application at 4-5 cm fruit has resulted in good disease control. In Florida, protective treatments using either Copper, Strobilurin fungicides, G. mangiferae Mancozeb, Carbendazim G. mangiferae or Thiophanate methyl are recommended.

References

• Dewdney M.et al. 2012. Florida Citrus Pest Management Guide: Citrus Black Spot (http://edis.ifas.ufl.edu/cg088 ) Figure 3. Sexual stage fruiting body (left) and asci with • Dewdney M.et al. 2012. Citrus Black Spot (http://edis.ifas.ufl.edu/ ascospores (right). Photos: Myrian Rybak. G. citricarpapp274 ). G. citricarpa G. citricarpa G. citricarpa• Kotze, J. M. 2000. Black spot. Page 23-25. In: Compendium of Guignardia citricarpa en CHA Guignardia citricarpa en CHA Inoculum source and conditions Citrus Disease. APS Press. • Rybak, M. A. et al. 2009. Momento de Pulverización y Productos para el Control de Mancha Negra en Mandarina NOVA. XXXII Crecimiento de Guignardia en medios diferencialesAscospores areCrecimiento Cherry carried agar from de y dead GuignardiaOatmeal leaves agar into en airmedios diferencialesCongreso Argentino Cherry de Horticultura agar y Oatmeal (FR-S4). Pag. agar 181. currents. Conidia (Fig. 4) from fruit lesions are • Rybak M.A. et al. 2008. Momento de aplicación para control de Black spot con bencimidazol y aceite en mandarina Nova. XIXo disseminated by rain. Conidia and ascospores (Fig. Reunión de Comunicaciones Científicas y Técnicas y Reunión de 3) are responsible for the local spread of the disease. Extensión.Corrientes ␣ Argentina. FCA - UNNE. http:// Long distance dispersion occurs via infected nursery agr.unne.edu.ar/Extension/Res2008/SanVegetal/ SanVegetal_14.pdf stock. Under favorable conditions spores germinate • USDA Citrus Health Response Program, Black Spot http:// and infect young tissues. Although infection takes www.aphis.usda.gov/plant_health/plant_pest_info/citrus/ black_spot.shtml place in young tissues, lesions will not develop completely until fruits mature (Fig. 1 & 2).

Prepared by Dr. Diana Schultz1, Dr. Myrian Rybak 2 y Dr. Ronald D. French3 1 Plant Pathologist , Fort Myers, Florida, 2 Plant Pathologist, Instituto Nacional de Tecnología Agropecuria (INTA), Estación Experimental Agropecuaria, Cerro Azul, 3 Misiones, Argentina, Assistant Professor and Extension Plant Pathologist (Amarillo, TX) G. citricarpa con un haloTexas amarillo A&M AgriLife en Extension medio Service;Oatmeal The TexasAgar A&M System Frutos de mandarina Nova con síntomas G. citricarpa con un halo amarillo en medio Oatmeal Agar Frutos de mandarina NovaMarch con 1, 2013 síntomas The information given herein is for educational purposes only. References to commercial products or trade names are made with the understanding de thatmancha no discrimination negra is intended and de manchano endorsement negra by Texas A&M AgriLife Extension Service personnel is implied. Educational programs of the Texas A&M AgriLife Extension Service are open to all people without regard to race, color, sex, disability, religion, age, or national origin. The Texas A&M University System, U.S. Department of Agriculture, and the County Commissioners Courts of Texas Cooperating