Asexual reproduction: an alternative for the propagation and conservation of papaya (Carica papaya L.) native to Guerrero, Mexico

Objective: To evaluate the effect on the rooting of Carica papaya L. cuttings using three different substrates and varying the length of the vegetative material Design / methodology / approach: A completely randomized design with a 2 × 3 factorial arrangement was used. Herbaceous cuttings of 30 and 40 cm in length were collected in March 2018, from lateral branches from native papaya plants (Carica papaya L.) from various regions of the state of Guerrero. The stakes were placed in different substrates: 1) sand, 2) Peat Moss® and 3) a mixture of sand and Peat Moss® (70:30, v / v). Sixty days after sowing, the rooting percentage, root length, plant height, stem diameter, number of leaves, crown diameter, weight of fresh biomass, weight of dry biomass, fresh weight of root and root dry weight. With the data obtained, an analysis of variances and a mean comparison test (Tukey, p?0.05) were performed. Results: The 40 and 30 cm long cuttings showed 60 and 50% rooting, respectively, being those plants where 40 cm cuttings were used, consistently taller, with a greater number of leaves, crown diameter and greater length of root. Of the three substrates used, sand was the best for the rooting of papaya cuttings, since in it plants with significantly higher fresh biomass weight were developed (p?0.05). Study limitations / implications: It is important to continue the study into the flowering and fruiting stages. Findings / conclusions: The proposed protocol allows the rooting of papaya cuttingsObjective: Evaluate the effect of three types of substrate and different shoot lengths onthe rooting of Carica papaya L. shoots.Design/ methodology/ approach: This experiment followed a completely randomizeddesign with a 2×3 factorial arrangement. Shoots of 30 and 40 cm of length werecollected in March 2018 from the lateral branches of papaya plants (Carica papaya L.)native to various regions of Guerrero. Shoots were placed in different substrates: 1)sand, 2) Peat Moss®, and 3) sand and Peat Moss® mixture (70:30, v/v). Sixty days afterplanting, rooting percentage, root length, plant height, stem diameter, number of leaves,crown diameter, biomass fresh weight, biomass dry weight, root fresh weight, and rootdry weight were evaluated. Data were analyzed through an analysis of variance and amean difference test (Tukey, p?0.05).Results: The rooting of 40- and 30-cm shoots was 60 and 50%, respectively. Plantswith the highest height, number of leaves, root length, and crown diameter derived from 240-cm shoots. Sand was the best substrate for rooting, where plants with higher freshbiomass were significantly developed.Study limitations/ implications: Continue study during the flowering and fruitingstages.Findings/ conclusions: This protocol allows the rooting of papaya shoots

Biorational and conventional insecticides efficacy to control thrips (Frankliniella occidentalis Perg.) on strawberries (Fragaria x ananassa Duch.) at Morelos state, Mexico: Spanish

Strawberry cultivation presents multiple phytosanitary limitations among which the “western flower thrips” stands out. Adults and nymphs of F. occidentalis produce severe damage to flowers and fruits, reducing the yield and quality of the product. In Mexico, thrips control is based on the use of synthetic chemical insecticides. The objective of this research was to evaluate the insecticidal effectiveness of biorational and conventional products as control alternatives and their phytotoxic effects in strawberry cultivation. The study was carried out in strawberry cv. Camino Real in flowering stage - fruiting established in open ground. A completely randomized design with seven treatments and four replications was used. Significant differences between treatments could be identified; Imidacloprid + Lambda Cyhalothrin and Bifenthrin caused the highest mortality of thrips with an efficiency of 92 and 93% respectively. Spinosad obtained good results, ranking as the second best option with 90% control efficiencies; neem extract stood out as an excellent biorational pest management alternative with 77% control efficacy in the last evaluation. No phytotoxic effects were observed from any of the treatments on the crop.Objective: To evaluate the insecticidal effectiveness of biorational and conventional products as alternatives to control thrips and their phytotoxic effects in strawberry cultivation. Design / methodology / approach: The research was carried out in strawberry cv. Camino Real during its flowering stage - fruiting established in open ground; A completely randomized experimental design with seven treatments and four replications was used. The treatments evaluated were: T1: neem oil extract, T2: paraffin oil, T3: garlic extract + hot chili pepper + cinnamon, T4: spinosad, T5: imidacloprid + lambda cyhalothrin, T6: bifenthrin, and T7: control. Applications were made weekly and the mortality evaluation was carried out by counting the number of live thrips per flower. With the obtained data, an analysis of variances and a mean comparison test (Tukey, p ≤ 0.05) were performed. Results: Significant differences between treatments could be identified (p ≤ 0.05); imidacloprid + lambda cyhalothrin and bifenthrin caused the highest mortality of thrips with 92 and 93 % efficacy, respectively. Spinosad obtained good results, ranking as the second-best option with 90 % control efficiencies; neem extract stood out as an excellent biorational pest management alternative with 77 % control efficacy in its last evaluation. No phytotoxic effects were observed from any of the treatments on the crop. Limitations on study / implications: It is important to continue the study in the laboratory to obtain the LD50 and LD90 of the management alternatives, as well as an MRL analysis of the molecules used. Findings / conclusions: The proposed protocol evidenced the efficacy of biorational and ecological thrips control treatments in intensive horticultural systems

An alternative inoculation technique of Colletotrichum gloeosporioides on mango for early anthracnose tolerance screening

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.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 4,3x10 (elevado a 6), 3,9x10 (elevado a 6) 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 (1x10 (elevado a 5) 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

Antagonismo enzimático de Trichoderma spp. sobre Fusarium oxysporum y Phytophthora parasitica en Hibiscus sabdariffa L.

Mexico is the seventh largest producer of jamaica (Hibiscus sabdariffa), and Guerrero State agglomerates more than 70 % of the national production. The crop presents important phytosanitary limitations, highlights the "black leg" associated with a complex of pathogens (Fusarium oxysporum and Phytophthora parasitica). Losses up to 100 % are reported in areas without phytosanitary management. Due to the nature of the consumption of the final product, it is necessary to implement ecological strategies to manage the disease. The objective of the study was to quantify the chitinases and glucanases activity of Trichoderma spp. isolates, and to evaluate their inhibitory effect in vitro on F. oxysporum and P. parasitica. Strains Ta10, Ta11, Ta6 and Ta9 of T. asperellum and Ti14 of T. inhamatum from soils cultivated with jamaica and high incidence of the pathogens were evaluated. The levels of chitinases and glucanases produced in all Trichoderma spp. were significant (P0,05), and it was found that Ta9 had the highest specific chitinase activity, and Ti14 the highest for glucanase. All the filtrates from the different isolates of Trichoderma spp. generated a substantial inhibition of mycelial growth of F. oxysporum and P. parasitica. Consistently, the strain Ta9 produced inhibition percentages greater than 90 % in both tests. A significant correlation was detected between the enzymatic activity and the inhibition of the growth of the Trichoderma spp. isolates on pathogensMéxico es el séptimo productor de jamaica (Hibiscus sabdariffa), y el estado de Guerrero concentra más del 70 % de la producción nacional. El cultivo presenta limitantes fitosanitarias importantes, destacando la “pata prieta” asociada a un complejo de patógenos (Fusarium oxysporum y Phytophthora parasitica), con pérdidas de hasta 100 % en áreas sin manejo fitosanitario. Debido a la naturaleza del consumo del producto final, es necesaria la implementación de estrategias ecológicas de manejo de la enfermedad. El objetivo del estudio fue cuantificar la actividad de quitinasas y glucanasas de aislados Trichoderma spp., y evaluar su efecto inhibitorio in vitro sobre F. oxysporum y P. parasitica. Se evaluaron las cepas Ta10, Ta11, Ta6 y Ta9 de T. asperellum y Ti14 de T. inhamatum provenientes de suelos cultivados con jamaica y alta incidencia de los patógenos. Los niveles de quitinasas y glucanasas en todos los aislados de Trichoderma spp. fueron significativos (P0,05); la cepa Ta9 mostró la mayor actividad específica de quitinasas, y la cepa Ti14 la mayor de glucanasas. Todos los filtrados provenientes de los diferentes aislados de Trichoderma spp. generaron una inhibición sustancial del crecimiento micelial de F. oxysporum y P. parasitica. De manera consistente, la cepa Ta9 alcanzó porcentajes de inhibición mayores al 90 % en ambos ensayos. Se detectó correlación significativa entre la actividad enzimática y la inhibición del crecimiento de los aislados de Trichoderma spp. sobre los agentes patógenos

An alternative inoculation technique of Colletotrichum gloeosporioides on mango for early anthracnose tolerance screening

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

EVALUATION OF TOLERANCE TO VEGETATIVE ANTRACNOSIS OF NEW MANGO GERMPLASMS IN MEXICO

Anthracnose (Colletotrichum gloeosporioides Penz.) is one of the most important diseases of mango (Mangifera indica L.) due to its wide distribution in the world and to induce severe epidemics in the vegetative and reproductive stages, causing important production losses. The objective of this research was to evaluate the tolerance to C. gloeosporioides infection in the vegetative stage of eleven new mango cultivars in Mexico with potential in the export market. Leaves of 15 days old of development were inoculated with the Gro isolate highlighted in virulence. Based on the incubation, period, incidence and severity, "Alphonse", "Neelum", "Kesar and Ivory” cultivars were low susceptibility, “Nam Doc Mai”, “Rosygold”, “Cotaxtla” were highly susceptible, and "Fairchild", "Ataúlfo Diamante", "Ataúlfo Zafiro" and "Mallika" had medium susceptibility. The longer incubation periods determined the lowest severity (r2= -0.89 and -0.90) and incidence (r2= -0.77 and -0.85). The incidence correlated positively with severity (r2= 0.86 and 0.92), both inoculation techniques (DLT and ALT) were useful to induce typical symptoms of anthracnose and to estimate the expression of virulence (incubation period, incidence and severity) of the pathogen.   La antracnosis (Colletotrichum gloeosporioides Penz.) es una de las enfermedades más importantes del mango (Mangifera indica L.) debido a su amplia distribución en el mundo y por inducir severas epidemias en etapas vegetativas y reproductiva que conllevan a importantes pérdidas de producción. El objetivo de esta investigación fue evaluar la tolerancia a la infección por C. gloeosporioides en etapa vegetativa de once nuevos cultivares de mango en México con potencial en el mercado de exportación. Se inocularon hojas de 15 días de desarrollo con el aislamiento virulento Gro. Basándose en los períodos de incubación, incidencia y severidad, los cultivares "Alphonse", "Neelum", "Kesar e “Ivory" presentaron baja susceptibilidad, "Nam Doc Mai", "Rosygold", y "Cotaxtla" fueron altamente susceptibles mientras que  “Fairchild”. “Ataúlfo Diamante”, “Ataúlfo Zafiro” y "Mallika" exhibieron susceptibilidad media. Los períodos de incubación más largos determinaron la menor severidad (r2 = -0.89 y -0.90) e incidencia (r2 = -0.77 y -0.85). La incidencia se correlacionó positivamente con la gravedad (r2 = 0,86 y 0,92), ambas técnicas (DLT y ALT) de inoculación fueron útiles para inducir síntomas típicos de antracnosis y para estimar la expresión de virulencia (período de incubación, incidencia y severidad) del patógeno