Los trips son una plaga de importancia económica en múltiples cultivos, entre ellos mango; altas densidades de trips causan pérdidas significativas. El manejo convencional se basa en el uso de insecticidas químicos sistémicos que acarrean inconvenientes como selección de resistencia, contaminación ambiental e intoxicaciones. El objetivo del estudio fue evaluar la efectividad insecticida de productos biorracionales, como alternativas de manejo de trips. Se utilizaron arboles de mango cv. manila en un diseño experimental completamente al azar; se aplicaron cinco tratamientos insecticidas, T1: Aceite parafínico, T2: extracto de ajo + extracto de chile picante + extracto de canela, T3: Extracto de neem + extracto de canela, T4: Extracto de aceite neem todos a 2.0 L/ha, T5: Spinetoram a 500 mL/ha y T6: testigo sin aplicación. Se realizó una evaluación previa y tres posteriores a la primera aplicación, se contabilizó y evaluó la cantidad de individuos por inflorescencia o brote vegetativo, con los datos de la fluctuación poblacional se realizó un análisis de varianza y comparación de medias (Tukey, p=0.05). Se destacó la presencia de Frankliniella invasor como especie dominante. En la primera evaluación, de manera consistente en todo el experimento Spinetoram (dosis 500 mL/ha) obtuvo las mejores eficacias de control; en la segunda y tercera fecha de evaluación T2: Extracto: ajo + chile + canela (dosis 2 L/ha) registro altos niveles de control. Aquellos tratamientos que con mezcla de extractos mantuvieron altos niveles de control. Dos aplicaciones semanales consecutivas, son suficientes para mantener bajas poblaciones de trips por 21 días.

-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%.Index terms: Mangifera indica, Oidium mangiferae, epidemics, fungicide resistance, integrated pest management, multisite fungicides. Epidemiologia e estratégias para o manejo químico do míldio-pulverulento em mangueiraResumo -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%.Termos para indexação: Mangifera indica, Oidium mangiferae, epidemia, resistência a fungicidas, manejo integrado de pragas, fungicidas multilocais.

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 (LSD<0.05%) in the Yf, AUDPC and b-1 parameters. The best strategy was to initiate a preventive treatment with a systemic ingredient, independently of its chemical group. Severity of the disease in floral (Fl) and vegetative flushing (Veg) in the sub-humid tropic was related with temperature >30ºC (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 <60% (r=0.66), severity (rFl=0.62-0.98; rVeg=0.75-0.97) and dew point <25ºC (r=0.68-0.69)

The prickly pear cactus “tuna pelona” (Stenocereus zopilotensis), is an endemic cactus species from the state of Guerrero, Mexico, it develops in semi-arid areas and has great ecological importance as it houses and forms part of the diet of multiple species in its niche. There is a constant threat to natural populations of this species due to the overexploitation of seedling collections in the f ield by unregulated trade. In order to design an alternative for the conservation management of these species, the objective of the work was to evaluate treatments for the imbibition of “hairless tuna” seeds to promote germination and the successful establishment of seedlings with economic technologies for the farmers of the area. Fruits of "tuna pelona" (S. zopilotensis) were collected, near the community of Xalitla, municipality of Tepecoacuilco de Trujano, Guerrero; the seeds were stored for 70 and 273 days after collection (dac) at room temperature in order to maintain adequate conditions for the conservation of viability until reaching dormancy. In the stored seeds, the effect of soaking treatments was evaluated: 0, 6, 12, 24 and 12 hours in water plus another treatment that consisted of immersion in a plant-based hormonal stimulant. The germination percentage per treatment was evaluated, it was found that the control treatment (zero hours in water) of seeds stored at 70 dac only obtained 2.4% of germination. The treatment of soaking in water and in the hormonal stimulant both for 6 h presented the highest germination values with 48.6 and 44.4% respectively when using seeds of 273 dac at 14 days after the application of the treatments. These results will allow the massive production of seedlings of the species for reforestation and regional marketing purposes.

México 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 (P£0,05); 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.

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.

<p><strong>Background:</strong> Mexico is the seventh largest producer of jamaica in the world, Guerrero represents the entity with the largest area planted and produces &gt;60% of the country's jamaica. The crop has numerous phytosanitary limitations, among which the chalice staining associated with a fungal complex stands out. The main damage occurs in flowering, reporting losses of 50 to 100% in areas without adequate phytosanitary management. The use of strains of <em>Trichoderma</em> spp. with antagonistic capacity, it represents a viable ecological alternative for the ecological management of the disease. <strong>Objective:</strong> to identify native strains of <em>Trichoderma </em>spp. and to evaluate its antagonistic capacity in vitro on important phytopathogenic fungi in the cultivation of hibiscus. <strong>Methodology</strong>: the research was developed in the 2018-2019 cycle in the Microbiology Laboratory of the Faculty of Agricultural and Environmental Sciences of University of Guerrero, Iguala, Guerrero. Systematic soil samplings were carried out in jamaica producing areas in Tecoanapa, Guerrero. The isolates were obtained by serial decimal dilutions and consecutive re-isolates until obtaining pure monosporic colonies. The isolates generated were identified morphologically and molecularly. The antagonistic capacity in vitro of each Trichoderma isolate was evaluated against purified monosporic strains of <em>Phytophthora parasitica, Fusarium oxysporum, Corynespora cassicola </em>and<em> Coniella diplodiella</em>. A completely randomized design was established with four repetitions per interaction, an analysis of variances and multiple comparison of means (Tukey, p &lt;0.05) of the variables was performed: percentage of radial growth inhibition (PICR), days until first contact between hyphae (DCH) and area of intersection. Four isolates of <em>Trichoderma </em>spp. with particular morphological and growth characteristics. <strong>Results:</strong> with the help of the keys of Barnett and Hunter (1998) and Samuels (2006), and the sequences resulting from the molecular tests, it was possible to identify with 99% similarity to <em>T. virens</em> and <em>T. longibrachiatum</em> as Trichoderma species dominant in soils of jamaica producing areas of Guerrero. The results indicated that all the isolates significantly reduced the size of the colonies of the phytopathogens; the Tl4 isolates consistently presented the highest PICRs (75-95%); <em>Phytophthora parasitica</em> was the organism for the most part, and <em>Coniella diplodiella</em> presented the greatest resistance to invasion by antagonist agents. Isolate Tl4 was identified as the one that most inhibited the development of all pathogenic agents (89.25%). In dual confrontations, the hyphae of both microorganisms made contact at 3.25 days after sowing on average. Isolate Tl4 (<em>T. longibrachiatum</em>) was identified as the one with the highest levels of interaction zone and based on the linear regression analysis and Pearson's correlation coefficient, a wide relationship between the zone area of interaction and the percentage of inhibition of the control agents. <strong>Implications:</strong> It is proposed to continue the study in the field phase, incorporating what was obtained in an integrated pest management (IPM) system. <strong>Conclusions:</strong> these results contribute to the agronomic management of jamaica in the region as a precedent in the search for alternatives for managing diseases with low environmental impact, also contributing to the determination of the etiology of the disease.</p>

<p><strong>Background:</strong> mango is cultivated in most tropical and subtropical regions of the world, it is estimated that there are more than a thousand cultivars, so its regional characterization represents a priority in countries such as Mexico, which holds the first place for export. <strong>Objective: </strong>the objective of the present study was to identify biochemical characteristics (photosynthetic pigments, type and proportion of carbohydrates) of eight recently introduced cultivars and two new selections in Mexico. <strong>Methodology: </strong>by spectrophotometric analysis, the concentrations of total sugars, reducing sugars and starches were evaluated, as well as the content of chlorophylls a, b and carotenoids of the cultivars 'Nam Doc Mai', 'Rosygold', 'Mallika', 'Ivory', 'Alphonse', 'Neelum', 'Fairchild', 'Kesar', 'Ataúlfo Diamante' and 'Ataúlfo Zafiro'. <strong>Results: </strong>in the case of total and reducing sugars, the cultivars ‘Kesar’, ‘Nam Doc Mai’, ‘Ivory’, ‘Mallika’ and ‘A. Zafiro' (0.42, 0.34, 0.34, 0.33, and 0.32 mg*g^-1 pf^-1) presented the highest values (respectively), the starch content was very heterogeneous and 'Rosygold' (0.36 mg*g^-1 pf^-1) was identified as cultivar with higher levels. The results showed ‘Ivory’ (0.64, 0.59, 0.27 mg*g^-1 pf^-1) as the cultivar with the highest concentration of chlorophyll <em>a</em>, <em>b</em> and carotenoid photosynthetic pigments respectively. Based on the correlation analysis (r), a certain dependence could be observed between total and reducing sugars (r= 0.70), total sugars and starches (r= 0.76), reducing sugars and starches (r = 0.79). In the case of photosynthetic pigments, a close relationship between chlorophylls <em>a</em>, <em>b</em> and carotenoids was identified (r= 0.99); In the photosynthetic carbohydrate / pigment interaction, a significant correlation was observed between total sugars and chlorophylls <em>a</em> (r= -0.80), <em>b</em> (r= -0.80) and carotenoids (r= 0.82). The close relationship found between reducing sugars and chlorophyll <em>a</em> (r= 0.60), chlorophyll <em>b</em> (r= 0.99) and carotenoids (r= 0.99) stood out. <strong>Implications:</strong> it is necessary to continue the study in floral and fruiting stages to have a complete profile of the cultivars. <strong>Conclusion: </strong>these results will contribute in future agronomic studies of these varieties in the region in order to analyze their relationship with parameters such as yield and nutritional content of fruits.</p>