Aislamiento de una cepa agresiva de Nomuraea rileyi desde larvas muertas de Anticarsia gemmatalis en Esperanza, Argentina

The biological control of agricultural pests by using differententomopathogenic microorganisms has been significantlyincreased in the last years, due to the need of reducing theamount of chemical insecticides in agricultural ecosystems.Fil: Palma, Leopoldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: del Valle, Eleodoro Eduardo. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentin

Control de plagas a partir de biomasa remanente del cultivo de brócoli y coliflor

En respuesta a la demanda de los productores se están desarrollando alternativas para el control de nemátodos parásitos de plantas y enfermedades que afectan la productividad y, especialmente, la calidad comercial de los productos obtenidos. Atento a esta situación, se están llevando adelante investigaciones sobre la posibilidad de aprovechar la biomasa remanente del cultivo de brócoli parala formación de un tipo de compostaje, obtenido por fermentación, que permita liberar compuestos bioactivos para el control de plagas y enfermedades. Esta propuesta se fundamenta en que se ha demostrado que muchas especies del género Brassica tienen actividad frente a varias especies de nematodos parásitos de plantas y hongos, sin generar consecuencias ambientales. La acción nematicida y fungicida de las brasicáceas es atribuible a la presencia deglucosinatos que son producto del metabolismo secundario de estas plantas.Fil: del Valle, Eleodoro Eduardo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Ciencias Agropecuarias del Litoral. - Universidad Nacional del Litoral. Instituto de Ciencias Agropecuarias del Litoral.; Argentina. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentin

Efecto de cadáveres de Galleria mellonella infectados con Heterorhabditis bacteriophora y Steinernema rarum, sus macerados y juveniles infectantes muertos en la supresión de Meloidogyne javanica

Nematodes of the Meloidogyne genus affect to most of crops of an economic importance in Argentina. Researches related to new control strategies are needed to reduce the damage produced by these organisms. The objective of this work was to compare the effects of Galleria mellonella cadavers infected with the Argentine isolates Heterorhabditis bacteriophora Rama Caída and Steinernema rarum NOE, cadaver macerates and dead infective juveniles (IJs) on M. javanica suppression. Experiments were performed using 24-well plates and pepper plants grown in a growth chamber. The entomopathogenic nematodes-infected G. mellonella cadavers, their cadaver macerates and dead IJs were effective in suppressing M. javanica second-stage juveniles under laboratory conditions. The use of H. bacteriophora-infected cadavers caused a significant decrease in the number of galls and egg masses on pepper plants parasitized by M. javanica, in a growth-chamber.Nematodos del género Meloidogyne afectan a la mayoría de los cultivos de importancia económica en Argentina. Investigaciones relacionadas con nuevas estrategias de control son necesarias para reducir el daño ocasionado por estos organismos. El objetivo de este trabajo fue comparar el efecto de cadáveres de Galleria mellonella infectados con los aislados argentinos Heterorhabditis bacteriophora Rama Caída y Steinernema rarum NOE, sus macerados y juveniles infectantes (JIs) muertos en la supresión de M. javanica. Las experiencias fueron conducidas utilizando placas de cultivo de 24 pozos y plantas de pimiento que crecieron en cámara de crecimiento. Los cadáveres infectados, sus macerados y JIs muertos fueron efectivos en suprimir juveniles de segundo estadio de M. javanica en las experiencias de laboratorio. En cámara de crecimiento, el uso de cadáveres infectados con H. bacteriophora causó reducción en el número de agallas y masas de huevos en plantas de pimiento parasitadas por M. javanica.Fil: Del Valle, Eleodoro Eduardo. Universidad Nacional del LitoralFil: Doucet, Marcelo Edmundo. Consejo Nacional de Investigaciones Científicas y Técnica

The status of teaching plant nematology to undergraduate agronomy students in Argentina, Chile, Paraguay and Uruguay

In recent decades ‘modern’ agriculture has expanded into large areas of Latin American countries. The intensification of land use, with monocropping or fixed rotation schemes, has contributed to an increase in yield losses due to plant-parasitic nematodes. Thus, proper training in nematology for agronomists has become crucial to sustain food, fiber and bioenergy production. Through responses to a questionnaire received from nematology professors (NP) in Argentina, Chile, Paraguay and Uruguay, it has become clear that nematology teaching (NT) is unsatisfactory in many agronomy schools. Of major concern, detected by this survey 1) a relatively low degree of graduate education among NP, 2) little or no involvement of most NP in nematology research, 3) too little nematology training of the students, expressed in class-hours, in the compulsory coursework, and 4) several issues, raised by the NP, that hinder improvements in NT. In these circumstances, the authors believe that only a concerted action involving nematologists and scientific societies involved with plant protection in those countries will be able to improve NT for agronomy students in the short- to mid-term.Fil: del Valle, Eleodoro Eduardo. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Moreira Souza, Ricardo. Universidade Estadual Do Norte Fluminense Darcy Ribeiro; Brasi

Efecto de cadáveres de Galleria mellonella infectados con Heterorhabditis bacteriophora y Steinernema rarum, sus macerados y juveniles infectantes muertos en la supresión de Meloidogyne javanica

Nematodes of the Meloidogyne genus affect to most of crops of an economic importance in Argentina. Researches related to new control strategies are needed to reduce the damage produced by these organisms. The objective of this work was to compare the effects of Galleria mellonella cadavers infected with the Argentine isolates Heterorhabditis bacteriophora Rama Caída and Steinernema rarum NOE, cadaver macerates and dead infective juveniles (IJs) on M. javanica suppression. Experiments were performed using 24-well plates and pepper plants grown in a growth chamber. The entomopathogenic nematodes-infected G. mellonella cadavers, their cadaver macerates and dead IJs were effective in suppressing M. javanica second-stage juveniles under laboratory conditions. The use of H. bacteriophora-infected cadavers caused a significant decrease in the number of galls and egg masses on pepper plants parasitized by M. javanica, in a growth-chamber.Nematodos del género Meloidogyne afectan a la mayoría de los cultivos de importancia económica en Argentina. Investigaciones relacionadas con nuevas estrategias de control son necesarias para reducir el daño ocasionado por estos organismos. El objetivo de este trabajo fue comparar el efecto de cadáveres de Galleria mellonella infectados con los aislados argentinos Heterorhabditis bacteriophora Rama Caída y Steinernema rarum NOE, sus macerados y juveniles infectantes (JIs) muertos en la supresión de M. javanica. Las experiencias fueron conducidas utilizando placas de cultivo de 24 pozos y plantas de pimiento que crecieron en cámara de crecimiento. Los cadáveres infectados, sus macerados y JIs muertos fueron efectivos en suprimir juveniles de segundo estadio de M. javanica en las experiencias de laboratorio. En cámara de crecimiento, el uso de cadáveres infectados con H. bacteriophora causó reducción en el número de agallas y masas de huevos en plantas de pimiento parasitadas por M. javanica

Time Period Between Infection of Heterorhabditis baujardi LPP7 (Nematoda: Rhabditida) and Soil Application of Galleria mellonella (Lepidoptera: Pyralidae) Cadavers, Analysing Emergence of Infective Juveniles

It was evaluated the effect of different time periods between the infection and soil application of the Galleria mellonella larva cadavers, infected with Heterorhabditis baujardi LPP7, on the emergence of the infective juvenile (IJs) nematodes. The time period of six to ten days between infection and soil application resulted in higher emergence of IJs.Foi avaliado o efeito de diferentes tempos entre a infecção e aplicação no solo de cadáveres de larvas de Galleria mellonella, infectadas com Heterorhabditis baujardi LPP7, sobre a emergência de juveniles infectantes (JIs). O período de seis a dez dias entre infecção e aplicação no solo resultou em maior emergência de JIs.Fil: del Valle, Eleodoro Eduardo. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe; ArgentinaFil: Dolinski, Claudia. Universidade Estadual Do Norte Fluminense Darcy Ribeiro; BrasilFil: Barreto, Eduardo L. S.. Universidade Estadual Do Norte Fluminense Darcy Ribeiro; BrasilFil: Moreira Souza, Ricardo. Universidade Estadual Do Norte Fluminense Darcy Ribeiro; Brasi

Effects of insect cadavers infected by Heterorhabditis bacteriophora and Steinernema diaprepesi on Meloidogyne incognita parasitism in pepper and summer squash plants

E. E. Del Valle, P. Lax, J. Rondán Dueñas, and M. E. Doucet. 2013. Effects of insect cadavers  infected  by  Heterorhabditis  bacteriophora  and  Steinernema  diaprepesi  on Meloidogyne incognita parasitism in pepper and summer squash plants.  The effects of insect cadavers infected with three isolates of Heterorhabditis bacteriophora and one isolate of Steinernema diaprepesi on a population of Meloidogyne incognita  in  pepper  (Capsicum  annuum)  and  summer  squash  (Cucurbita  maxima)  were evaluated in greenhouse experiments carried out in Santa Fe (Argentina). Insect cadavers were obtained for the experiments from last instar larvae of Galleria mellonella and Tenebrio molitor  that had  been  infected  with  entomopathogenic nematodes.  Two  six-day-old  insect cadavers per pot were placed below the soil surface, and the soil was inoculated with 100 second-stage juveniles of M. incognita. Sixty days after inoculation, the following parameters were recorded for each plant: number of leaves; dry weight of aerial parts; numbers of galls, egg masses and eggs; and numbers of galls, egg masses and eggs g -1  of root fresh matter. In pepper, the only variable affected by the infected cadavers with respect to control was the number of eggs in the treatment involving T. molitor cadavers infected with the H. bacteriophora isolate Rama  Caída.  In  summer  squash,  several  treatments  using  infected  cadavers  resulted  in  a decrease in the numbers of galls and egg masses. Only the treatment involving G. mellonella cadavers infected with the H. bacteriophora isolate Rama Caída proved to be efficient in reducing the number of M. incognita eggs. Our results indicated that the application of insect cadavers infected with the entomopathogenic nematodes studied might reduce M. incognita damage in pepper and summer squash plants.Fil: del Valle, Eleodoro Eduardo. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina;Fil: Lax, Paola. Consejo Nacional de Invest.cientif.y Tecnicas. Centro Cientifico Tecnol.conicet - Cordoba. Instituto de Diversidad y Ecologia Animal; Argentina;Fil: Rondan Dueñas, Juan. Provincia de Cordoba. Ministerio de Ciencia y Tecnica. Centro de Excelencia En Productos y Procesos de Cordoba; Argentina;Fil: Doucet, Marcelo Edmundo. Consejo Nacional de Invest.cientif.y Tecnicas. Centro Cientifico Tecnol.conicet - Cordoba. Instituto de Diversidad y Ecologia Animal; Argentina

Isolation of atmospheric nitrogen-free fixing bacteria from the endorhizosphere of Helianthus tuberosus and Smallanthus sonchifolius

The objective of the work was to determine the presence of fixing bacteria free of atmospheric nitrogen in the endorhizosphere of topinambur (Helianthus tuberosus) and yacón (Smallanthus sonchifolius), cultivated in the Central Valley of the Province of Catamarca. Roots of each species were collected and the technique proposed by Döbereiner et al. for the isolation of N-free endorrhizospheric fixing bacteriatwo, Azospirillum sp. The isolates obtained were morphologically and physiologically characterized, and three different morphotypes of each plant species were selected for molecular identification.Eleven autochthonous fixative microorganisms free of atmospheric nitrogen present in the endorhizosphere of the crops under study were described, 6 in topinambur and 5 in yacón. All isolates belonging to the genus Pseudomonas. In topinambur, Pseudomonas sihuiensis and in yacón of Pseudomonas alcaligenes, P. resinovorans and P. sihuiensis. The isolation of autochthonous nitrogen-free bacteria native to P. sihuiensis, P. alcaligenes and P. resinovorans is reported for the first time in the endorhizosphere of topinambur (H. tuberosus) and yacón (S. sonchifolius), cultivated in soils of the Central Valley of the Province of CatamarcaFil: Di Barbaro, Maria Gabriela. Universidad Nacional de Catamarca. Facultad de Ciencias Agrarias; ArgentinaFil: del Valle, Eleodoro Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: Brandán de Weht, Celia. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; Argentin

Susceptibility of Spodoptera frugiperda and Helicoverpa gelotopoeon (Lepidoptera: Noctuidae) to the entomopathogenic nematode Steinernema diaprepesi (Rhabditida: Steinernematidae) under laboratory conditions

Spodoptera frugiperda Smith and Helicoverpa gelotopoeon (Dyar) are important agricultural pests ofseveral crops. The aim of the present work was to evaluate the susceptibility of larvae of both insects to an isolate of Steinernema diaprepesi Nguyen & Duncan under laboratory conditions, as well as the capacity of the nematode to multiply on the lepidoterans. Larvae (n = 15) were exposed to 0 (control), 50, and 100 infective juveniles (IJs) per Petri dish. Mortality was evaluated every 24 h during 6 d, and emerging IJs were counted. Mortality of S. frugiperda was 93% and 100% with 50 and 100 IJs dosage, and 87% and 93% in H. gelotopoeon, respectively. The production of IJs was significantly different between doses (P ≤ 0.05) for S. frugiperda (11 329 with 50 IJs vs. 27 155 with 100 IJs) but not for H. gelotopoeon 19 830 vs. 26 361, respectively). This is the first study evaluating the susceptibility of these lepidopterans to S. diaprepesi. These results encourage the possibility of using this nematode for biological control of both pests.Fil: Caccia, Milena Guadalupe. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; ArgentinaFil: del Valle, Eleodoro Eduardo. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: Doucet, Marcelo Edmundo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; ArgentinaFil: Lax, Paola. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; Argentin

Evaluation of the Effect of Azospirillum brasilense and Mycorrhizal Fungi of the Soil in Yacon Grown in a Greenhouse

In order to evaluate the effect of Azospirillum brasilense and mycorrhizal fungi in the soil on the nutrition of the yacon crop (Smallanthus sonchifolius [(Poeppig & Endlicher) H. Robinson]), determinations of agronomic parameters and the health status of the plants were carried out, under greenhouse conditions. The tests were carried out at the time of the implantation of the culture: the propagules were inoculated with A. brasilense and with native mycorrhizal fungi, generating four treatments, including the control and the co-inoculation of the consortium of the microorganisms under study (T0: control or control without inoculation; T1: inoculation with native A. brasilense; T2: inoculation with native mycorrhizal fungi and T3: joint inoculation with A. brasilense and native mycorrhizal fungi. The results indicate that co-inoculation with A. brasilense and native mycorrhizal fungi increased plant growth in height, leaf area, biomass, dry matter and yields significantly in greenhouse production. It was determined that the application of the selected microorganisms has a plant growth promoting effect, increasing growth and productivity, greenhouse grown yacón.Fil: Di Barbaro, Maria Gabriela. Universidad Nacional de Catamarca; ArgentinaFil: Andrada, Horacio Enrique. Universidad Nacional de Catamarca; ArgentinaFil: del Valle, Eleodoro Eduardo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Ciencias Agropecuarias del Litoral. - Universidad Nacional del Litoral. Instituto de Ciencias Agropecuarias del Litoral.; Argentina. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: Brandan, Celia Ines. Universidad Nacional de Tucumán; Argentin