5,211 research outputs found

    Control of Aphids on Spring Oats and Winter Wheat With Slow Release Granular Systemic Insecticides

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    Aphid infestations (Homoptera: Aphididae) on spring oat (Avena sativa) cv. \u27Ogle\u27, and during the fall on winter wheat (Triticum aestivum) cv. \u27Clark\u27, composed mainly of Rhopalosiphum padi and Macrosiphum avenae, were reduced with applications at the 2-3 leaf stage of slow release granular formulations of acephate, carbofuran, and disulfoton, compared with carbofuran 15G and untreated controls, in field trials during 1990-1991 in northwestern Indiana. These field results corroborated those obtained by previous studies with the same formulations and dosages in the laboratory. In oat, all insecticide treatments reduced aphid populations and percent- age aphid~infested plants, with a residual action of ca. 25 d. Barley yellow dwarf virus-like visual symptoms were reduced with disulfoton. In winter wheat, the residual action of all insecticide treatments in the fall lasted up to 19 d. The carbofuran treatment on winter wheat seedlings caused earthworms to move out of the soil, where they died; an effect requirining further study. Percentage of aphid-infested plants revealed relatively Wlder differences among tratments than total number of aphids in both test crops. Predation by Coleomegilla maculata (Coleoptera: Coccinellidae) contributed to the overall reduction of spring populations of cereal aphids in wheat and oat. Aphid mummies parasitized by micro-hymenopterans were common in oat plants

    Resistance Stability of the Secondary Tiller of \u27Caldwell\u27 Wheat After the Primary Culm Was Infested With Virulent Hessian Fly (Diptera: Cecidomyiidae) Larvae

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    Secondary tiller resistance of \u27Caldwell\u27 wheat, Triticum aestivum, with the H6 gene for larval resistance to Hessian fly, Mayetiola destructor, was maintained, after the primary culm had been previously infested with virulent larvae. Earlier studies showed that a primary culm infested initially with a virulent larva allowed subsequent normally avirulent larvae to survive on that cultivar; however, in our study the resistance of secondary tillers was mainained even though the primary culm was infested earlier with virulent Hessian fly larvae. This gene stability for resistance is important for optimizing wheat yield of those cultivars that possess genes resistant to the Hessian fly that are tillering and infested with different biotypes

    A Study of the Biology of \u3ci\u3eRhopalosiphum Padi\u3c/i\u3e (Homoptera: Aphididae) in Winter Wheat in Northwestern Indiana

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    Periodic collections of the bird cherry-oat aphid, Rhopalosiphum padi, during two years revealed small populations on winter wheat in Lafayette, Indiana. The greatest numbers were found on volunteer wheat plants before planting. In the autumn, aphids were detected on one-shoot plants by mid-October and also early March. The populations remained small until mid-June. We conclude that the aphid feeding did not significantly affect the plants, but helped spread barley yellow dwarf virus

    Residual Action of Slow Release Systemic Insecticides on \u3ci\u3eRhopalosiphum Padi\u3c/i\u3e (Homoptera: Aphididae) on Wheat

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    Slow release formulations of acephate and carbofuran encapsulated in pearl corn­ starch or corn flour granules were applied to the soil at seeding time of potted \u27Caldwell\u27 wheat in the laboratory. Dosages of these insecticides were adjusted to a standard of IO kg/ha of a 10 10 granular formulation of carbofuran. The residual action of these insecticide treatments against Rhopalosiphum padi were compared with those obtained with that of carbofuran 150 at corresponding dosages and foliar sprays of solutions of acephate (25 10 EC) at 0.2 10 and carbofuran (4F) at 1.25 10, applied 12 d after seedling emergence. The residual action of carbofuran 150, which controlled R. padi since seedling emergence, lasted 28.5 d. The slow release granular formulations of carbofuran began to provide control (\u3e 50 10 aphid mortality) on days 13.3 and 17.9 after seeding. They controlled the insect until days 31.6 and 35.5 after seeding. The two corresponding granular formulations of acephate began to provide control on days 15.0 and 17.0 after seeding and con­ trolled the aphids until days 31.5 and 32.8 after seeding. The foliar sprays of acephate and carbofuran provided control for 18.3 and 36.2 d from application, respectively. The slow release granular formulations provided control of R. padi, an important vector of barley yellow dwarf virus, during early. stages of wheat development

    Determination of Frequency and Distribution of Hessian Fly (Diptera: Cecidomyiidae) Biotypes in the Northeastern Soft Wheat Region

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    Fifteen collections of Hessian flies from the northern soft winter wheat region of the United States were used to determine the composition and frequency of biotypes. The wheat cultivars \u27Seneca\u27 (H7Hs), \u27Monon\u27 (H3), \u27Knox 62\u27 (~, H7Hg), and \u27Abe\u27 (Hs) were used as differentials. Biotypes J and L replaced biotype B as the prevalent biotype in Indiana, since wheat cultivars having the Hs and the H6 genes have been grown. Biotype GP, the least virulent of any Hessian fly biotypes, was still present in New York indicating that wheat cuItivars with no genes for resistance are still being grown there. The genetic variability of Hessian fly biotypes that enables them to overcome the resistance in wheat cultivars is discussed

    Frailty criteria among older people living in the community. An update

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    IndexaciĂłn: Web of Science; Scielo; Scopus.Frailty is an important concept in aging research and care. Awareness of frailty signs allows healthcare workers to identify older adults at risk and design interventions to prevent their functional decline, therefore preventing adverse health outcomes. This literature review allows to identify predictors of frailty considering its physical, psychological and social domains. From the evidence found, it is possible to formulate a profile of fragile older people. Finally, future research should focus on the description of psychological and social fragility profiles, on the detection of persons likely to be fragile and finally to define precise instruments to detect fragile people, which should become the gold standards in future research.http://ref.scielo.org/ykbdx

    The Factors That May Predict Response to Rituximab Therapy in Recurrent Focal Segmental Glomerulosclerosis: A Systematic Review

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    Recurrence of FSGS occurs in 30–40% of allografts. Therapies for recurrence are not well established. We retrieved all published reports depicting kidney transplant recipients with focal segmental glomerulosclerosis (FSGS) recurrence, treated with rituximab, to determine factors associated with treatment response. We found 18 reports of 39 transplant recipients who received rituximab. By univariate analysis for two outcomes (no response versus any response), fewer rituximab infusions and normal serum albumin at recurrence were associated with treatment response. For 3 outcomes (no response, partial and complete remission), male gender, fewer rituximab infusions, shorter time to rituximab treatment, and normal serum albumin were associated with remission. Multivariate analysis for both models revealed that normal serum albumin at FSGS recurrence and lower age at transplant were associated with response. Rituximab for recurrence of FSGS may be beneficial for only some patients. A younger age at transplant and normal serum albumin level at recurrence diagnosis may predict response
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