Sensitivity to fungicides of Botrytis cinérea (Pers.) isolated from raspberry (Rubus idaeus L.)

ABSTRACT Objective: To evaluate the sensitivity of B. cinerea isolated from raspberry to nine fungicides alone and in combination with potassium silicate. Design/methodology/approach: The sensitivity of four isolates was evaluated to nine fungicides alone and combined with potassium silicate, obtained from four raspberry plantations in October 2022, which were identified as B.cinerea based on morphological, morphometric and molecular characteristics, in a previous study. In PDA culture medium modified with fungicides plus potassium silicate, B. cinerea was planted, mycelial growth and mycelial growth inhibition percentage (PICM) were evaluated. A completely randomized design with six repetitions and two controls was used, an ANOVA and a Tukey mean comparison test were performed. Results: B. cinerea isolated from CITAP showed lower growth with fluazi-nam (PICM = 100 ), while azoxystrobin presented a PICM equal to 0 , B. cinerea isolated from Paso del Cristo and Sierra Negra 2 had lower growth with fluazinam (PICM = 100), while boscalid and azoxystrobin showed a PICM equal to 0, in Sierra Negra 1 iprodione controlled B. cinerea better with a PICM equal to 100, while azoxystrobin showed a PICM equal to 0, all the isolates were sensitive when fungicides were combined with potassium silicate. Findings/conclusions: All the isolates were sensitive to the fungicides fluazinam, fenhexamid, thiophanate methyl, captan, pyrimethanil, fludioxonil and iprodione. The isolates from Sierra Negra 1 and CITAP were sensitive to boscalid, while Sierra Negra 2 and Paso del Cristo were insensitive, 100 % of the isolates were insensitive to azoxystrobin which suggests that they could be resistant, potassium silicate potentiates the effect of fungicides. Keywords: potassium silicate, isolates, mycelial growth, PICMObjective: To evaluate the sensitivity of B. cinerea isolated from raspberry to nine fungicides alone and in combination with potassium silicate. Design/methodology/approach: The study evaluates the sensitivity of four isolates obtained from four raspberry plantations in October 2022, which were identified in a previous study as B.cinerea based on morphological, morphometric and molecular characteristics, to nine fungicides alone and combined with potassium silicate. B. cinerea was planted in PDA culture medium modified with fungicides plus potassium silicate, and mycelial growth and mycelial growth inhibition percentage (PICM) were evaluated. A completely randomized design with six repetitions and two controls was used, an ANOVA and Tukey’s mean comparison test were performed. Results: B. cinerea isolated from CITAP showed lower growth with fluazinam (PICM = 100 ), while with azoxystrobin it presented a PICM equal to 0. B. cinerea isolated from Paso del Cristo and Sierra Negra 2 had lower growth with fluazinam (PICM = 100), while with boscalid and azoxystrobin it showed a PICM equal to 0. In Sierra Negra 1, iprodione controlled B. cinerea better with a PICM equal to 100, while azoxystrobin showed a PICM equal to 0. All the isolates were sensitive when fungicides were combined with potassium silicate. Findings/conclusions: All the isolates were sensitive to the fungicides fluazinam, fenhexamid, thiophanate methyl, captan, pyrimethanil, fludioxonil and iprodione. The isolates from Sierra Negra 1 and CITAP were sensitive to boscalid, while those from Sierra Negra 2 and Paso del Cristo were insensitive; 100 % of the isolates were insensitive to azoxystrobin, which suggests that they could be resistant; finally, potassium silicate potentiates the effect of fungicides

Poliextractos de plantas medicinales en bacterias asociadas a infecciones respiratorias agudas (IRAS) en pollos: Poliextratos de plantas medicinais sobre bactérias associadas a infecções respiratórias agudas em galinhas

Este trabalho de pesquisa teve como foco o desenvolvimento da formulação de um xarope à base de extratos vegetais de buganvília, canela, calêndula, eucalipto e ítamo para inibir o crescimento de S. aureus e S. pyogenes, bactérias associadas a infecções respiratórias. Determinar os metabólitos secundários nos extratos metanólicos de cada espécie, bem como avaliar a atividade antibacteriana dos extratos em xaropes, e sua capacidade antioxidante. Verificou-se que o extrato de eucalipto é o melhor para inibir as bactérias, assim como na forma de xarope, e o extrato de canela é o melhor antioxidante

Análisis de crecimiento de epazote (Chenopodium ambrosioides L.) cultivado en invernadero

The Mexican tea (Chenopodium ambrosioides L.) is used as food, condiment and medicinal. The information related to the nutritional management of the crop production for the Mexican tea is scarce, so, the objective of the study was to determine the effect of three concentrations of the Steiner nutritive solution on the growth and production of Mexican tea grown under greenhouse. The study was conducted in Cuernavaca, Morelos, México. The genotype H-1000 (Hortaflor™) was utilized. Three concentrations of the Steiner nutritive solution (50, 75 and 100 %) were applied, to evaluate the crop growth by destructive samplings at 39, 46, 53, 60, 67 and 74 days after sowing; In each sampling the foliar area, foliar area index, fresh weight, dry matter, growth rates of the crop and absolute growth, was measured and calculated. The variables under study were performed a regression analysis with the Excel® program. In general, with the concentration of the nutritive solution at 100 %, the best results were obtained in all the evaluated variables, compared to the concentration at 75 and 50 %. The highest plant height, leaf area, dry matter, crop growth rate and fresh weight were obtained with the Steiner nutritive solution at 100 %.El epazote (Chenopodium ambrosioides L.) se utiliza como alimento, condimento y medicinal. La información sobre el manejo de la nutricional para la producción de epazote es insuficiente, por lo que, el objetivo del estudio fue evaluar el efecto de tres concentraciones de la solución nutritiva Steiner sobre el crecimiento de epazote cultivado en invernadero. El estudio se realizó en Cuernavaca, Morelos, México. El genotipo utilizado fue H-1000 (Hortaflor®). Se aplicaron tres concentraciones (50, 75 y 100 %) de la solución nutritiva Steiner para evaluar el crecimiento del cultivo mediante muestreos destructivos a los 39, 46, 53, 60, 67 y 74 días después de la siembra; en cada muestreo se midió y calculó el área foliar, índice de área foliar, peso fresco, materia seca, tasas de crecimiento del cultivo y absoluta de crecimiento. A las variables se les realizó un análisis de regresión con el programa Excel®. En general, con la concentración de la solución nutritiva a 100 % se obtuvieron los mejores resultados en las variables evaluadas, en comparación a la concentración 75 y 50 %. La mayor altura, área foliar, materia seca, tasa de crecimiento del cultivo y peso fresco se obtuvieron con la solución nutritiva Steiner a 100 %

Efectividad de fluxapyroxad + pyraclostrobin en el control de (Oidium mangiferae Berthet) en mango (Mangifera indica L.) en el estado de Morelos, México

El mango (Mangifera indica L.) es una de las frutas más demandadas en México, por su amplio valor comercial y su uso en la industria alimenticia, siendo susceptible a varias enfermedades en todas las etapas de su desarrollo. La cenicilla causada por el hongo (Oidium mangiferae Berthet) es una de las más importantes en este frutal, llegando a causar pérdidas hasta del 90% de la producción cuando incide en floración. El objetivo de este trabajo fue determinar la efectividad biológica de (fluxapyroxad + pyraclostrobin) en el control de este agente patógeno en panículas de mango, variedad “Ataulfo”. El ensayo se realizó durante el año 2019, en el estado de Morelos, México. Se efectuaron tres aplicaciones sobre el cultivo a intervalos de 7 días, comparando tres tratamientos de la mezcla fluxapyroxad + pyraclostrobin (300, 350 y 400 mL ha-1), contra un testigo regional (benomilo) 60 g 100-1 L de agua y un control sin aplicación. La severidad y efectividad biológica del producto fueron registradas durante tres evaluaciones semanales. Como resultado, todas las dosis empleadas, lograron prevenir el desarrollo de la enfermedad en la etapa de floración. La dosis de 350 mL ha-1 tuvo un control absoluto del 100%, mientras que el testigo sin aplicación llegó a alcanzar 77,64% de infección. En todos los tratamientos se alcanzaron eficiencias biológicas superiores al 96%, lo que representa una combinación eficaz para la prevención del patógeno en este frutal

Mejoramiento convergente masivo en la línea de maíz tropical T49 / Massive convergent improvement in the T49 tropical corn line

En México, mínimamente se ha trabajado el mejoramiento de líneas y excepcionalmente en el mejoramiento convergente. El objetivo de este estudio fue evaluar los cambios generados en líneas recobradas de maíz sometidas a un esquema de mejoramiento convergente masivo. El material genético estuvo constituido por una línea endogámica (T49), que se utilizó como progenitor recurrente, además, ocho líneas elites donantes (T48, GNF, B41, LT154, LT156, CML549, CML550 y CML264) con características sobresalientes en rendimiento, profundidad y tamaño de grano, aptitud combinatoria general, resistencia a enfermedades, entre otras. Se generaron dos grupos de líneas recobradas de maíz, en uno se realizaron dos retrocruzamientos y una autofecundación; el segundo grupo considero tres retrocruzamientos. Se obtuvieron cien líneas para su evaluación per se, mediante el diseño experimental de látice simple 10 x 10, en dos localidades del estado de Guerrero, en el ciclo agrícola primavera-verano 2019. Se cuantificaron las variables: rendimiento de grano, altura de planta y mazorca, calificaciones de planta y mazorca; y componentes del rendimiento. La información obtenida se sometió a análisis de varianza por localidad y combinando localidades. Con las comparaciones de medias por grupo de retrocruzas, se pudo identificar los cambios generados en las líneas recobradas respecto a la original. Los análisis de varianza por localidad mostraron diferencias estadísticas en la mayoría de las variables cuantificadas. Así mismo, el análisis combinado de localidades permitió identificar líneas sobresalientes, superiores a la línea original, las cuales pueden ser empleadas para la formación de nuevos híbridos. Al comparar los grupos de retrocruzas se determinó que las líneas donantes CML549, GNF y B41, incorporaron mayor número de características favorables a la línea original. Por otra parte, se observó que, en promedio, las líneas con tres retrocruzas fueron superiores a las líneas con dos retrocruzas más una autofecundación

Morphological and molecular characterization of Podosphaera xanthii, causal agent of powdery mildew in husk tomato and watermelon

Objective: To determine the causal agent of powdery mildew in husk tomato and watermelon, as well as its morphological and molecular characterization. Design/methodology/approach: In Iguala, Guerrero, in 2018, leaves with powdery mildew symptoms from husk tomato (Physalis ixocarpa) and watermelon (Citrullus lanatus) were collected. From two isolates (Phyxa1 and Phyxa2) of husk tomato and two of watermelon (Citrus1 and Citrus2), the morphological characterization was carried out by assembling morphological structures and visualizing them under an optical microscope. For molecular characterization, the ITS region was amplified with the use of primers ITS1 and ITS4, PCR was performed and the products obtained were sequenced in the company Macrogen®. A phylogenetic analysis was performed with the resulting sequences and they were compared with other sequences available in GenBank. Results: It was determined that there is morphological and genetic variability between isolates from husk tomato and watermelon. The largest sizes of conidiophores and conidia were from Phyxa1 and Phyxa2 isolates, the smallest sizes were recorded in Citrus1 and Citrus2. The isolates presented a tendency to group according to the host, the Phyxa1 and Phyxa2 isolates were associated with Solanacea isolates, while the Citrus1 and Citrus2 isolates were grouped with isolates of the Cucurbitaceae family. Findings/conclusions: Podosphaera xanthii was shown to be the agent associated with powdery mildew in husk tomato and watermelon. Morphological and genetic variability of P. xanthii was determined, which was associated with the host of origin.Objective: To determine the causal agent of powdery mildew in husk tomato and watermelon, as well as its morphological and molecular characterization. Design/methodology/approach: Leaves with powdery mildew symptoms were collected from husk tomato (Physalis ixocarpa) and watermelon (Citrullus lanatus) in Iguala, Guerrero, Mexico in 2018. From two isolates (Phyxa1 and Phyxa2) of husk tomato and two of watermelon (Citrus1 and Citrus2), the morphological characterization was carried out by assembling morphological structures and visualizing them under an optical microscope. For molecular characterization, the ITS region was amplified with the use of primers ITS1 and ITS4, PCR was performed and the products obtained were sequenced in the company Macrogen®. A phylogenetic analysis was performed with the resulting sequences and they were compared with other sequences available in GenBank. Results: It was determined that there is morphological and genetic variability between isolates from husk tomato and watermelon. The largest sizes of conidiophores and conidia were from Phyxa1 and Phyxa2 isolates, the smallest sizes were found in Citrus1 and Citrus2. The isolates presented a tendency to group according to the host, the Phyxa1 and Phyxa2 isolates were associated with Solanacea isolates, while the Citrus1 and Citrus2 isolates were grouped with isolates of the Cucurbitaceae family. Findings/conclusions: Podosphaera xanthii was shown to be the agent associated with powdery mildew in husk tomato and watermelon. The morphological and genetic variability of P. xanthii was determined, which was associated with the host of origin

Estimación de parámetros genéticos en cruzas intervarietales de maíz para la región semicálida de Guerrero.

La orografía y agroecología del estado de Guerrero es muy diversa. En las áreas de altitud intermedia (1200 a 1700 m) prácticamente no se siembran con variedades mejoradas de maíz, debido a su limitada adaptación a las condiciones climáticas y edáficas; por lo que, prevalece la siembra de poblaciones nativas. En las áreas semicálidas se ha seleccionado germoplasma subtropical local; paralelamente, en Valles Altos se aplicó selección para adaptación en cuatro poblaciones tropicales durante 10 años. Con estas siete poblaciones progenitoras se generaron 12 cruzas intervarietales (CI) en arreglo factorial, con el propósito de valorar los avances del mejoramiento genético y detectar alguna CI de valor comercial. Las CI, sus progenitores y testigos se evaluaron bajo diseño experimental, durante los ciclos agrícolas Verano-Otoño de 2004 a 2008, en 16 ambientes de altitud intermedia. La información para rendimiento se analizó bajo el diseño de bloques completos al azar por localidad y combinando localidades, considerando sólo 20 variedades, incluyendo a la variedad local. Se estimaron los efectos de aptitud combinatoria general (ACG) y específica (ACE), y heterosis; se practicó el análisis de parámetros de estabilidad y el de efectos principales aditivos e interacción multiplicativa (AMMI). Se estableció un experimento en el 2009 para valorar atributos agronómicos. Se detectaron diferencias altamente significativas entre variedades para rendimiento de grano (t ha-1). Las variedades subtropicales per se fueron superiores a las tropicales adaptadas a Valles Altos pero estas fueron mejores en otros atributos agronómicos. Los progenitores masculinos VE-1 y VE-3 presentaron efectos de ACG positivo, estabilidad y consistencia a través de ambientes; además, aportaron mejor peso y diámetro de mazorca, y los femeninos SINT-3-HE y VS-529 mostraron efectos de ACG positivo y fueron inconsistentes, ambos contribuyeron en obtener una mejor sanidad de planta y mazorca. La variedad local compitió con las CI pero su rendimiento de grano fue inconsistente y tuvo problemas de acame. En particular, las cruzas intervarietales VS-529 x VE-1 y VS-529 x VE-3 fueron las que expresaron mejor rendimiento de grano, características agronómicas y menor interacción con los ambientes. _______________ ESTIMATION OF GENETIC PARAMETERS IN INTERVARIETAL CROSSES OF MAIZE FOR THE SEMIWARM REGION OF GUERRERO. ABSTRACT: Orography and agroecology in the state of Guerrero are highly diverse; in intermediate altitudes (1200 to 1700 masl) the use of commercial varieties of maize is practically inexistent, due to limited adaptation to climatic and edafic conditions; thus, use of native maize populations prevails. In the semiwarm areas genetic improvement with subtropical germplasm has been practiced; on the other hand selection for adaptation to the highland planted (2250 masl) have been applied on four tropical populations of maize for 10 years. With seven parental populations, 12 intervarietal crosses (CI) were obtained under factorial array, in order to assess gains due to genetic improvement, and to detect some CI with commercial value. CI, their parental populations and the local landrace were agronomically evaluated in years 2004 to 2008, in a total of 16 environments of intermediate altitude. Grain yield information was analyzed as a complete blocks design, by locality and combined through locations. General (ACG) and specific (ACE) combining ability effects, and heterosis were estimated. Besides, analyses of stability parameters, and the one of additives and multiplicative interaction effects (AMMI) were applied. Another experiment was carried out in order to asses other agronomic traits. Differences among varieties for grain yield (t has-1) were highly detected. Subtropical varieties per se over yielded to the tropical ones with selection under highland conditions. Male parental populations VE-1 and VE-3 showed ACG positive effects, were stable and consistent through environments; in addition, they contributed to a better weight and ear diameter; and the females SINT-3-HE and VS-529 showed also ACG positive effects and were inconsistent; but both contributed in obtaining a better plant and ear health. The local landrace showed in several cases as good grain yield as CI but inconsistent through locations and had problems of lodging. In particular, intervarietal crosses VS-529 x VE-1 and VS-529 x VE-3 expressed better grain yield, agronomic characteristics and lesser interaction with environments.Tesis (Doctorado en Ciencias, especialista en Genética).- Colegio de Postgraduados, 2010.Consejo Nacional de Ciencia y Tecnología (CONACyT)

Cruzas intervarietales de maíz para la región semicálida de Guerrero, México

The topography and agro-ecology of the Guerrero State is diverse and in agricultural areas of intermediate elevation (1 200 to 1 700 m), almost no improved varieties are planted, due to unfavorable climatic and soil conditions, so it is difficult to establish a maize breeding program for every ecological niche. In these regions, the stability of 25 maize varieties was examined, during five summer-autumn crop seasons from 2005 to 2009; aiming to identify an intervarietal cross that was stable, consistent and with good yield potential through the environments. The data was analyzed in 20 varieties, using a randomized complete block design with three replications by location and combining locations. Using this information, the stability parameters proposed by Eberhart and Russell, and described by Molina were estimated, also the additive main effects and multiplicative interaction model (AMMI) was applied. The V15 and V16 male parents showed stability and consistency through the environments, a similar behavior was shown by V3, V7 and V9 intervarietal crosses, they were also outstanding in grain yield, V11 was consistent and showed greater production potential in unfavorable environments. Intervarietal crosses V1, V4, V6, V10, farmer's local variety V13 and female parents V17, V18 and V20, showed good response infavorable environments but were also inconsistent. The two methods used, showed similar results, so, it was possible to select three varieties by its grain yield potential, stability, and consistency in environments.La orografía y agroecología del estado de Guerrero es muy diversa y en las áreas agrícolas de altitud intermedia (1 200 a 1 700 m), prácticamente no se siembran variedades mejoradas, debido a condiciones climáticas y edáficas poco favorables, por lo que dificulta establecer un programa de mejoramiento genético de maíz para cada nicho ecológico. En estas regiones se examinó la estabilidad de 25 variedades de maíz, durante cinco ciclos agrícolas verano-otoño de 2005 a 2009; con el propósito de identificar una cruza intervarietal estable, consistente y con buen potencial de rendimiento a través de ambientes. La información se analizó en 20 variedades, usando un diseño de bloques completos al azar con tres repeticiones por localidad y combinando localidades. Con esta información se estimó los parámetros de estabilidad propuestos por Eberhart y Russell y descritos por Molina; además se aplicó el modelo de efectos principales aditivos e interacción multiplicativa (AMMI). Los progenitores masculinos V15 y V16 mostraron estabilidad y consistencia a través de ambientes; similar comportamiento mostraron las cruzas intervarietales V3, V7 y V9, además fueron sobresalientes en rendimiento de grano; V11 fue consistente y mostró mayor potencial productivo en ambientes desfavorables. Las cruzas intervarietales V1, V4, V6, V10, la variedad local del agricultor V13 y los progenitores femeninos V17, V18 y V20, mostraron buena respuesta en ambientes favorables pero fueron inconsistentes. Los dos métodos usados registraron resultados semejantes, por lo que fue posible seleccionar tres variedades por su potencial de rendimiento de grano, estabilidad y consistencia en los ambientes

Análisis de crecimiento de epazote(Chenopodium ambrosioides L.) cultivado en invernadero

"The Mexican tea (Chenopodium ambrosioides L.) is an aromatic and medicinal plant. Information on its growth dynamics and mineral nutrition for its production is insufficient, therefore, the objective of the study was to evaluate the effect of three conc

Effect of agronomic characteristics of hybrid and Creole corn using native plant growth-promoting bacteria to reduce the production cost: Effect on the agronomic characteristics of hybrid and criollo corn using native plant growth-promoting bacteria as a low-cost production alternative: A rural experience in southern México.

The use of chemical fertilizers has generated an increase in environmental pollution. However, biofertilizers are profitable, improve soil conditions, leading to an increase in growth and yield of crops of economic interest for small and large producers, in this sense, contributing to environmental pollution by agrochemicals is a challenge for the 2030 agenda, where inoculation with plant growth promoting bacteria (BPCV) native to the genus Rhizobium sp., Azospirillum sp. and Azotobacter sp., are a solid ecological alternative and increase in production and cost reduction. The main objective of the research was to design and evaluate an environmentally friendly biofertilizer based on BPCV, evaluating the agronomic characteristics of two corn genotypes, hybrid A7573 C/Acceleron and Criollo under a randomized complete block experimental design with nine treatments and four replicates, water and fertilizer were used as controls under irrigation conditions and production costs were analyzed. The agronomic variables evaluated were: plant height (ADP), stem diameter (DDT) and leaf area (AF). At physiological maturity, ear row number (NHMZ), ear length (LDMZ) and grain yield in t ha-1 were evaluated, and yield and production costs were analyzed. The results indicated a positive response to inoculation with BPCV in corn. The yield of hybrid A7573 C/Acceleron T7 with 7.6 t ha-1, T6, with 7.2 t ha-1 and finally T2 with only 6.9 t ha-1, while with creole corn of the olotillo race, yields were obtained in the T6 treatment with 4. 4 t ha-1, T2 4.1 t ha-1 and T8 3.8 t ha-1 respectively and the production costs in all treatments were profitable, highlighting those inoculated with BPCV and with a free net profit of $10,219.00. The results show that the use of BPCV have greater effectiveness in all agronomic variables and better yields because they are adapted to the environmental and soil conditions, being an excellent alternative to the use of fertilizers and above all decrease the costs for corn production in rural communities.  Objective: To design and to evaluate an environmentally-friendly biofertilizer based on plant growth-promoting bacteria (PGPB), assessing the agronomic characteristics of two genotypes of C/Acceleron A7573 hybrid and Creole corn. Design/methodology/approach: A biofertilizer based on PGPB was designed and assessed in a completely random experimental block design with nine treatments and four repetitions in C/Acceleron A7573 hybrid and Creole corn in a plot at El Pericón, municipality of Tecoanapa, Guerrero, Mexico. The microorganisms Rhizobium sp., A. brasilense and A. vinelandii were used. Results: The use of PGPB has greater effectiveness in all the agronomic variables and better yields because they are adapted to the environmental and soil conditions, with it being an excellent alternative to the use of fertilizers. Limitations on study/implications: The demonstrative experimental plot had 5000 m2 and it was the main limitation. Findings/conclusions: Bacteria of the genus A. brasilense YOM9 and A. vinelandii YOC4 contributed to the higher yield of the C/Acceleron A7573 hybrid corn seed, and Rhizobium sp R01 and A. vinelandii YOC4 in the Creole grain of the olotillo race compared to the T9 fertilizer and the absolute control. A biofertilizer for corn is obtained based on results from this study, as an ecotechnology based on PGP