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El virus de la mancha anular del papayo es un factor limitante para la producción de papaya en Michoacán, México. Se evaluó el efecto de la aspersión semanal de los aceites minerales citrolina y Saf-T-Side® sobre la incidencia visual y serológica del virus de la mancha anular del papayo, en una plantación de papayo cv. Maradol roja en Antúnez, Michoacán. No se registraron diferencias significativas ocasionadas por las aplicaciones de aceites minerales respecto al testigo. Sin embargo, la incidencia visual y serológica exhibió resultados contrastantes a los 32 y 60 días. Las epidemias en el testigo se describieron mediante el modelo de Weibull (r2 = 0.97, c = 5.17 y b-1 = 0.013). El área bajo la curva de la enfermedad (ABCE) fue de 6087 días porcentaje y la incidencia final (Yf) de 98%. Se colectaron 309 adultos alados de 17 especies de áfidos en trampas tipo Moericke. Las trampas amarillas capturaron 60% y las verdes 40%; con diferencias significativas (P < 0.05) por especie, respecto al color de trampa. Únicamente Myzus persicae exhibió diferencia significativa en la captura de áfidos potencialmente vectores de la mancha anular del papayo, causada por el color de trampa. Con base en la incidencia de la mancha anular del papayo, M. persicae (r = 0.8), Aphis nerii (0.7) y A. spiraecola (0.7) estuvieron significativamente correlacionadas. Sin embargo, no se encontró correlación entre variables meteorológicas e incidencia.

Anthracnose, caused by Colletotrichum spp., is the most significant field and post-harvest disease of mango worldwide and is mainly controlled through the use of systemic fungicides belonging to the methyl benzimidazole carbamate (MBC) class. In Mexico, this disease in mango has been associated with at least seven cryptic species belonging to the C. gloeosporioides complex. In this study, the distribution of sensitivity to MBC (benomyl and carbendazim) and prochloraz fungicides of 101 Colletotrichum spp. isolates obtained from 101 commercial orchards in Mexico’s most important mango-producing states was determined. All Colletotrichum spp. isolates were obtained from commercial mango orchards with applications of MBC fungicides and that had not been exposed to applications of prochloraz, or any other DMI (demethylation inhibitors) class fungicide. Isolates were evaluated using an in vitro test to determine the effective fungicide concentration at which 50% of mycelial growth is inhibited (EC50) for each isolate-fungicide combination. EC50 values for benomyl and carbendazim ranged from 0.0967 to 0.3995 µg mL−1 (median = 0.1923 µg mL−1) and from 0.0880 to 0.1703 µg mL−1 (median = 0.1171 µg mL−1), respectively, while those for prochloraz ranged from 0.0066 to 0.0813 µg mL−1 (median = 0.0253 µg mL−1). Our results revealed a wide distribution in Mexico of Colletotrichum spp. isolates from mango sensitive to MBC fungicides and prochloraz. Data obtained in this study will serve as a source of comparison of the evolution of the sensitivity of Colletotrichum spp. populations obtained from mango to MBC and DMI fungicides in the future.

Colletotrichum species cause anthracnose disease in tropical and subtropical fruit crops worldwide. Mexico is the main producer and exporter of avocado (Persea americana) globally and has yearly outbreaks of anthracnose on this crop. However, which specific Colletotrichum spp. cause these outbreaks in avocado‐producing regions remain uncertain; thus, the objective of the present study was to identify the species responsible. A survey performed in six production regions of Mexico yielded 232 isolates, from which a subset of 104 strains was selected based on morphological characteristics and origin. This subset was sequenced and haplotypes were analysed in the gapdh partial gene. Finally, 31 strains were identified through multilocus phylogenetic analyses using the sequences of the internal transcribed spacer region and six loci. This study revealed the presence of two species previously reported in Mexico (C. karsti and C. godetiae), three novel records in Mexico (C. siamense, C. fioriniae, and C. cigarro), four novel records on avocado (C. chrysophilum, C. jiangxiense, C. tropicale, and C. nymphaeae), and two novel lineages (Colletotrichum sp. 1 and Colletotrichum sp. 2). C. siamense was the most prevalent, while the species reported for the first time on avocado, including the novel lineages, were the least prevalent. C. karsti was the most widespread (four regions), followed by C. siamense, C. jiangxiense, and C. chrysophilum (three regions). Pathogenicity tests showed that all species caused anthracnose on avocado fruit. These findings will be useful for improving the management of avocado anthracnose outbreaks in Mexico.

Mango malformation (Fusarium spp.) is one of most the severe diseases and is difficult to control in dry tropical areas worldwide. In Mexico, the disease reduces yields by up to 40–50%. In this study, the tolerance of two current mango cultivars (‘Ataulfo’ and ‘Haden’) and three recently introduced to Mexico (‘Rosigold’, ‘Mallika’ and ‘Nam Doc Mai’) to infection by Fusarium subglutinans (Fs) and F. mexicanum (Fm) was determined with a standardized inoculation procedure. The experiment was repeated and carried out in an experimental nursery located in Huamuxtitlan, Guerrero, Mexico, in 2015 and 2016. Each pathogenicity test was conducted on five healthy 6-month-old mango plants per cultivar by infiltration, singly and in combination, of Fs and Fm conidial suspension into the apical bud and the first three subapical (axillary) buds. The combination of Fusarium species induced higher severity (30.8%) than individual inoculation, independent of the cultivar. The incubation period before typical vegetative malformation symptoms was longer in ‘Ataulfo’ (267 d) than the rest of the cultivars (168–198 d). Comparatively, ‘Ataulfo’ also showed lower incidence (23.3%), disease severity index (3.6%), final severity (Yf = 0.6), infection rate (b−1 = 0.039) and area under the disease progress curve (AUDPC = 0.53). According to the severity scale used, ‘Ataulfo’ was tolerant, and ‘Nam Doc Mai’ and ‘Rosigold’ were susceptible, while ‘Mallika’ and ‘Haden’ were highly susceptible.

Roselle (Hibiscus sabdariffa L.) leaf and calyx spot induced by Corynespora cassiicola is one of the most important diseases that limit production, processing, and commercial use of this crop. The temporal progress of this disease was followed in four production locations in Guerrero, Mexico, during the 2014 and 2015 cycles. Disease incidence and severity were evaluated every 10 days through the 173-day production cycles. Epidemics were evaluated using the area under disease progress curves (AUDPCs) and Weibull model parameters. The highest severity and epidemic rate in calyces and leaves was registered in San Miguel, while the lowest was recorded in Xalpatlahuac in both cycles. Disease incidence in calyces was lower in Xalpatlahuac during both evaluation cycles and in leaves only in the 2015 cycle. The Weibull model properly described the epidemics (r = 0.93–0.99). The highest periods of epidemic growth in leaves were registered during flowering, development of calyces and foliar senescence; and in calyces during their physiological maturation and harvest. Severity on leaves and calyces was correlated with temperature from 20 to 30 °C (r = 0.80–1.0) and relative humidity higher than 90% (r = 0.80–1.0) (p

Phytopathogenic fungi can cause economic losses. The application of natural products from species of the genus Agave is an alternative for controlling these organisms. The present study aimed to determine the phytochemical profile of Agave angustifolia and A. cupreata extracts and to evaluate their antifungal activity against several species of phytopathogenic fungi. The aqueous extract from A. angustifolia and the acetonic extract from A. cupreata were studied. The phytochemical profile was determined by thin-layer chromatography. Mycelial growth inhibition and spore production were evaluated. Phytochemical screening revealed the presence of alkaloids, flavonoids, saponins, and triterpenes. The acetonic extract of A. cupreata inhibited 76, 60, and 59% of the mycelial growth of Lasiodiplodia viticola, Colletotrichum sp., and Epicoccum sorghinum, respectively, at 8 and 16 mg mL-1 (p?0.05), while spore production decreased by 92 and 86 % (p?0.001) for Fusarium subglutinans and Colletotrichum sp., respectively. The aqueous extract of A. angustifolia inhibited 40% of the mycelial growth of E. sorghinum at 16 mg mL-1 (p?0.05) and reduced the spore production of L. viticola by 35% (p?0.001). The results indicate that the extracts under study can be an alternative source of antifungal compounds.

RESUMEN El manchado de hojas y cálices de la jamaica, causado por Corynespora cassiicola, se considera la principal limitante fitosanitaria del cultivo de jamaica (Hibiscus sabdariffa) en el Estado de Guerrero, México, causando pérdidas significativas de la producción. Para su control, se evaluó la efectividad biológica de diversas substancias químicas (convencionales y alternativas) durante los ciclos de producción 2014 y 2015. El estudio se realizó en los municipios de Ayutla y Tecoanapa, Guerrero, bajo condiciones de campo y presión natural de inóculo. Las substancias químicas (tratamientos), se aplicaron a intervalos de 7 y 14 días. En cada tratamiento, se registró la severidad en hojas y cálices, así como el peso fresco y seco de cada unidad experimental. El ensayo se estableció bajo un diseño bloques al azar con cuatro repeticiones. Para el análisis de los datos se realizó un análisis de varianza y pruebas de separación de medias (Tukey-Kramer, α=0.05). La menor severidad de la enfermedad y mayor peso fresco y seco de cálices se obtuvo en plantas tratadas con mancozeb, clorotalonil y benomilo alternado con oxicloruro de cobre.

Mango malformation induced by Fusarium spp. is one of the most destructive diseases worldwide. The production losses vary from 50 to 80%. Mango growth is intermittent being characterized by resting periods (RP) intercalary between each vegetative flow. Each new flush promotes changes in the intensity of epidemics, but the interaction of the RPs on the pathogen virulence and pathogenesis are unknown. To provide some information about this interaction, the effect of Fusarium spp. infection on incubation periods (PI), maximum severity (Ymax) and days to maximum severity (DYmax) was compared in nursery plants of cvs ‘Mallika’ and ‘Haden’ inoculated in the resting and active early growth (juvenile) stages, using the veneer grafting technique to end the rest phase in 2016. When both cultivars were inoculated in the resting stage, at 14 and 0 incubation days before grafting (dbg), ‘Haden’ was more susceptible than ‘Mallika’ showing quicker PIs and greater DYmax and Ymax in 42, 55 and 82% respectively. Likewise, ‘Haden’ shoots inoculated during resting stages or active early growth, at 22 days after grafting (dag), had a shortest PI and DYmax values, by up to 32 and 45% respect to mature inoculated shoots that remained attached to the plant. Ymax was not affected by the phenology of the inoculated shoots and PI were higher only in shoots inoculated at 75–85 dag (P

The objective of this work was to evaluate phytosanitary strategies for the chemical control of powdery mildew (Oidium mangiferae) in mango, based on the alternation of active ingredients with different modes and sites of action, and to determine the environmental and epidemiological conditions that favor the development of the disease. The experiment was conducted in Guerrero, México, in commercial orchards, within a program for the development of fungicide spraying strategies. Epidemic curves were used on temporal analyses of the disease for: incidence; area under disease progression curve (AUDPC); severity; and conidial seasonality and its relationships with meteorological parameters. The disease was better controlled with the application of systemic fungicide followed by contact fungicide with multisite activity. The first symptoms appeared 30 days after the issuance of shoots, and the most susceptible phenological (critical) stages were at full bloom and at the onset of fruit with 8-15 mm. Optimum conditions for the development of powdery mildew, which maximizes the density of airborne spores, are temperatures higher than 30°C and relative humidity over 90%. Resumo: O objetivo deste trabalho foi avaliar estratégias fitossanitárias para o controle químico do míldio-da-mangueira (Oidium mangiferae), baseadas na alternação de princípios ativos com diferentes modos e sítios de ação, e determinar as condições ambientais e epidemiológicas que favorecem o desenvolvimento da doença. O experimento foi realizado em Guerrero, México, em pomares comerciais, no âmbito de um programa para o desenvolvimento de estratégias de pulverização com fungicida. Curvas epidêmicas foram utilizadas em análises temporais da doença quanto à: incidência; área abaixo da curva de progresso da doença (AACPD); severidade; e sazonalidade dos conídios e sua relação com parâmetros meteorológicos. A doença foi mais bem controlada com a aplicação de fungicida sistêmico seguido de fungicida de contato, com atividade multissítio. Os primeiros sintomas apareceram 30 dias após a emissão dos brotos, e os estádios fenológicos mais sensíveis (críticos) foram o de floração completa e o de frutos com 8-15 mm. As condições ótimas para o desenvolvimento do oídio, que maximizam a densidade de esporos no ar, são temperatura acima de 30°C e umidade relativa superior a 90%.

En México, la producción de naranja es amenazada por la incidencia de enfermedades que afectan la producción. La nutrición balanceada constituye una alternativa para mantener productivos a los árboles y atenuar el daño por fito-parásitos. El objetivo del presente estudio fue evaluar el efecto de la fertilización química, orgánica y combinada tanto al suelo como foliar sobre la producción de naranjos Marrs (Citrus sinensis/C. volkameriana) con incidencia del virus tristeza de los cítricos (VTC) y Huanglongbing (HLB) confirmada por PCR. El estudio se realizó de agosto 2018 a diciembre 2019 en Cazones, Veracruz, México en una plantación comercial con árboles de seis años. Por la topografía irregular se trabajó en la parte baja y alta del terreno, en árboles con tres grados de síntomas de VTC y HLB. El diseño experimental utilizado fue bloques completos al azar en arreglo de parcelas divididas, con tres repeticiones. Las variables evaluadas fueron la incidencia de VTC y HLB, floración, número de frutos y rendimiento. La mayor incidencia de VTC (47%) y de HLB (64.7%) se encontró en la parte baja del terreno. Los árboles asintomáticos y con síntomas ligeros de ambas enfermedades presentaron mayor floración y número de frutos en la fase inicial. La fertilización química (100 N-22 P2O5-195 K2O-30 MgO) y combinada (50 % química más 10 kg de composta) aplicada al suelo, más fertilización foliar con sulfato de zinc, hierro, cobre, manganeso y bórax incrementaron la floración hasta 96 flores por m2 de dosel en la parte alta del terreno, y hasta 89 frutos por rama primaria en la fase inicial de crecimiento. El rendimiento por árbol fue muy bajo (5 a 12 kg), por efecto de una sequía atípica en la región durante la fructificación. La incidencia y severidad de VTC y HLB, aunado al estrés hídrico limitan la producción del naranjo Marrs.

The importance of having a technique that allows an efficient expression of symptoms of anthracnose is based on the early differentiation of cultivars and the optimization of genetic, material and financial resources. The objective of this research was to generate an alternative inoculation technique for Colletotrichum gloeosporioides on mango for early anthracnose tolerance screening. On this technique was optimized some of the most relevant components such as isolate virulence, conidial density, the inoculum deposition on leaves and using of surfactants. The study was carried in Iguala, Mexico, during the production cycles 2015-2016. C. gloeosporioides was biologically and culturally characterized. Gro and Sin monosporic strains were isolated from leaves, flowers, fruits and branches with anthracnose symptoms from commercial mango orchards located in Guerrero and Sinaloa states, Mexico. These strains show mycelial growth at 2.2 and 2.1 cm of diameter per day, spore density of 4.3x106, 3.9x106 conidia/ml, germination of 27 and 26%, virulence, with incubation period 4.5 and 4.1 days after inoculation, incidence of 90 and 92% and severity of 3.2 and 3.5 cm of diameter. The highest incidence and severity values with the lowest incubation period, was obtained using Gro isolate (1x105 conidia/ml) and polyoxyethylene-20-sorbitan monolaurate as spreader-sticker inoculated on the abaxial surface on detached young leaves, 15-20 days old, with a soft brush and incubated under dark condition. This inoculation technique allowed the optimal expression of C. gloeosporioides virulence in mango leaves and could be incorporated as a tool in the early differentiation of tolerance and susceptibility among cultivars. Resumen La importancia de contar con una técnica que permita una expresión eficiente de síntomas de antracnosis se basa en la diferenciación temprana de cultivares y a la optimización de recursos genéticos, materiales y financieros. El objetivo de esta investigación fue generar una técnica de inoculación alternativa para Colletotrichum gloeosporioides en mango para la detección temprana de la tolerancia a la antracnosis. En esta técnica se optimizaron algunos de los componentes más relevantes como la virulencia de los aislamientos, la densidad de conidios, la deposición de inóculo en hojas y el uso de surfactantes. El estudio se realizó en Iguala, México, durante los ciclos de producción 2015-2016. C. gloeosporioides fue caracterizado biológica y culturalmente. Los aislamientos monospóricos Gro y Sin, fueron obtenidos de hojas, flores, frutos y ramas con síntomas típicos de antracnosis procedentes de huertos comerciales de mango ubicados en los estados de Guerrero y Sinaloa, México. Estos aislamientos presentaron un crecimiento micelial de 2,2, y 2,1 cm de diámetro por día, densidad de esporas de 4,3x106, 3,9x106 conidios/ml, germinación de 27 y 26%, virulencia, con un período de incubación de 4,5 y 4,1 días después de la inoculación, 90 y 92% de incidencia y severidad de 3,2 y 3,5 cm de diámetro. Los valores de incidencia y severidad más altos y los períodos de incubación más bajos se obtuvieron con el aislamiento Gro (1x105 conidios/ml), en un medio de monolaurato de polioxietileno-20-sorbitán sobre la superficie abaxial de hojas jóvenes desprendidas, de 15-20 días de desarrollo, con el empleo de una brocha de pelo suave e incubado en condiciones de oscuridad. Esta técnica de inoculación permitió la expresión óptima de virulencia de C. gloeosporioides en hojas de mango y podría incorporarse como una herramienta en la diferenciación temprana de la tolerancia y susceptibilidad entre cultivares.

La cenicilla del mango (Erysiphe quercicola) causa pérdidas de producción de hasta 90%, por lo que es necesario estimar la tolerancia a este patógeno en el nuevo germoplasma introducido o generado recientemente para incrementar el potencial de exportación de México. El objetivo de este estudio fue determinar la respuesta al daño por cenicilla mediante una técnica de inoculación optimizada para inducir la enfermedad en hojas adheridas de 10 cultivares de mango amarillo nuevos para México. Se evaluaron dos métodos de inoculación. El mejor fue por aspersión de conidios a concentración de 4.6 × 105 esporas mL-1, en las superficies adaxial y abaxial de las hojas, a ± 300–450 lux y suspendidos en polisorbato 20 + surfactante a base de alcoholes etoxilados al 2%. La prueba de inoculación mostró que el cv. Alphonso fue moderadamente tolerante y Neelum y Fairchild ligeramente tolerantes. En contraste, Nam Doc Mai, Rosigold, Ataulfo Zafiro, Cotaxtla y Kesar fueron susceptibles y Mallika e Ivory altamente susceptibles. Los cultivares más tolerantes presentaron valores menores de incidencia, severidad máxima, área bajo la curva del progreso de la enfermedad, tasa de infección aparente y densidad de conidios por cm2 de área foliar dañada (LSD, P ? 0.05).

Phloeotribus pruni Wood (Coleoptera: Scolytidae) is reported for the first time associated with the collapse of peach ( Prunus persica ) trees in Coatepec de Harinas, State of Mexico, Mexico. One hundred percent incidence of collapsed trees was found in a 2 ha peach orchard. In 10 trees sampled, a mean number of 3.3 adults and 4 larvae per 25 cm2 of bark were found. Trees died 12 to 18 months after the onset of symptoms. The 100% incidence of attacked trees, and the tree death 12 to 18 months after the first detection of the insect, point out the importance of this pest. Sumario Se informa por primera vez la asociacion de Phloeotribus pruni Wood (Coleoptera: Scolytidae) con el colapso de los arboles de Durazno ( Prunus persica : Rosaceae) en Coatepec de Harinas, Estado de Mexico, Mexico. Se encontro una incidencia del cien por ciento de arboles colapsados en un huerto de 2 hectareas de melocotones. En 10 arboles muestreados, se encontro un promedio de 3.3 adultos y 4 larvas por cada 25 cm2 de corteza. Los arboles murieron 12-18 meses despues de la aparicion de los sintomas. El 100% de incidencia de arboles atacados y la muerte del arbol 12 para 18 meses despues de la primera deteccion del insecto senalan la importancia de esta plaga. View this article in BioOne

We describe Aeolothrips romanruizi sp. nova that has been recently discovered in mango orchards in the Isthmus region of Oaxaca in southern Mexico. Aeolothrips romanruizi sp. nova exhibits an ornamentation of the mesonotum and metanotum very different from others in this genus, except A. microstriatus, which is similarly ornamented; but these 2 species differ in forewing color pattern, body size and some other characters of chaetotaxy. A key to the Aeolothrips species of Central America and Mexico is provided.

This study reports for the first time the presence of citrus psorosis virus (CPsV) in Persian lime (Citrus latifolia) orchards from five counties of the Veracruz state, the main producer and exporter of this fruit in Mexico. The disease was detected in 2016 only in plants grafted on non-certified rootstocks: Volkamerian lemon, Sour orange, Swingle, C-35 and Flying Dragon.

Dieback of sapote mamey [Pouteria sapota (Jacq.) H. E. Moore and Stearn] grafts caused by Lasiodiplodia theobromae significantly reduces the success of grafting in Mexican nurseries. Semi-commercial tests were conducted in a sapote mamey nursery during two grafting seasons to evaluate the effectiveness of a physical treatment (washing) and three chemical treatments (fungicide dip) on scions. Washing reduced disease incidence up to 31 %, whereas chemical treatment reduced it up to 62 %. The combination of washing and thiabendazole dip resulted in an incidence decrease of 81 %. Twelve other fungicides were screened in vitro to evaluate mycelial growth inhibition of L. theobromae. The pre-formulated mix of cyprodinil + fludioxinil was the most effective fungicide with EC50 value of 0.0043 μg mL-1, followed by pyraclostrobin + boscalid, prochloraz and tebuconazole with EC50 values < 0.1 μg mL-1, and iprodione and thiabendazole with EC50 values < 1.0 μg mL-1. This study provides novel information about strategies for controlling L. theobromae infection during the grafting process of sapote mamey and it also showed the effectiveness of several fungicides under in vitro conditions for controlling this plant pathogenic fungus.

The temporal progress of anthracnose (Colletotrichum gloeosporioides) epidemics was studied in mango (Mangifera indica) orchards treated with fungicides from different chemical groups, mode of action, and application sequences in two regions of contrasting climates (sub-humid and dry tropics) in Guerrero, Mexico. Full flowering, initial setting, and 8-15mm Ø fruits were identified as critical stages for infection. Epidemics started 20-26 days after swollen buds, and maximum severity was attained at 40-42 days after the first symptoms were detected. The Weibull model described (r²>0.89) anthracnose epidemics in both floral and vegetative flushes. Active ingredients of different fungicide groups, mode of action, and residuality such as myclobutanil, azoxystrobin, cyprodinil+fludioxonil, quinoxyfen, and chlorotalonil + sulfur led to significantly low values (LSD30ºC (rFl=0.79-0.86; rVeg=0.80-0.95) and relative humidity > 90% (rFl=0.66-0.86; rVeg=0.67-0.94). In both regions, conidial sporulation was related to temperature >30ºC (r=0.72-0.74), relative humidity