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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Control Grasshoppers on Crop Land

Roney, J. N. 06 1900 (has links)
This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.
2

Traditional and geostatistical modeling of pink bollworm spatial dynamics in Arizona cotton with application to sampling and computer mapping.

Borth, Paul William. January 1987 (has links)
The within-field spatial distribution of F₁, F₂, and F₃ pink bollworm (PBW) (Pectinophora gossypiella Saunders) generations were modeled with Taylor's power law (TPL), Iwao's patchiness regression (IPR), and the geostatistical semivariogram. Kriging interpolation was used to grid data for the generation of isarithmic maps. Distributional patterns and movements within a field are displayed in a time series of three maps depicting density across the field. The sampling protocol was replicated in eight commercial cotton fields in south-central Arizona during 1985 and 1986. Permanent sample stations were situated throughout the fields on a regular grid pattern. Samples were collected during the peak larval population and handled so as to maintain the integrity of site-specific samples (spatially identified by X,Y coordinates). TPL and IPR could not be used satisfactorily to model the F₁ generation. TPL fit the observed F₂ and F₃ data better than IPR. Both methods predicted the F₂ to be more highly aggregated than the F₃. For a given precision, optimum sample size increased when TPL and IPR model parameters were incorporated into sample size formulae relative to a formula which assumed random distribution. Ninety-five percent of the modeled PBW distributions were autocorrelated in 2-dimensional space and shown to conform to regionalized variable theory by the successful application of geostatistics. The semivariogram models are in conceptual agreement with traditional models and represent a worthy alternative to traditional modeling methodology. The semivariogram models have a large nugget effect proportion (average = 67%) which, in combination with low PBW density in commercial fields, limits the applicability of geostatistics in this system. Isarithmic maps showed that F₁ larvae are either localized near a field edge or generally scattered throughout the field. No consistent inter-generational dispersal pattern was identified. The use of systematic grid sampling is most advantageous (relative to random sampling) when density and the spatial dependence of samples is high, or many samples can be taken. Systematic sampling and kriging estimation yielded more precise estimates than random sampling and classical statistics, but the advantage was buffered by low PBW densities and large nugget effect.
3

The more important crop pests of Ethiopia and their control

Bushen, Yoseph Sibba, 1929- January 1962 (has links)
No description available.
4

Embryo-larvicidal activities of lufenuron on selected lepidopteran pests

Edomwande, Emmanuel Orluchuckwu 30 June 2005 (has links)
Please read the abstract in the section 00front of this document / Thesis (DPhil (Entomology))--University of Pretoria, 2005. / Zoology and Entomology / unrestricted
5

BIOLOGICAL STUDIES OF TETRANYCHUS CINNABARINUS AND TYPHLODROMUS OCCIDENTALIS (ACARINA: PHYTOSEIIDAE) AT THREE DIFFERENT TEMPERATURE REGIMES.

NORTHCRAFT, PHILIP DODDRIDGE. January 1984 (has links)
Temperature effects on the biology of Tetranychus cinnabarinus (Boisduval) and Typhlodromus occidentalis (Nesbitt) (Acarina: Phytoseiidae) were studied in the laboratory. Temperature had a definite effect on the developmental time, longevity and survival of adult females, and duration and rate of oviposition in both T. occidentalis and T. cinnabarinus. Increases in temperature significantly decrease developmental time, pre-oviposition periods, oviposition duration and rate, and the longevity and survival rates of both adult females. However, the daily consumption rate of T. occidentalis protonymph, deutonymph and adult gravid female increased significantly with an increase in temperature. Mean generation times decreased for both mites with an increase in temperature. The intrinsic rate of natural increase rose with each temperature increase. However, the r(m) of T. occidentalis was less than that for T. cinnabarinus at all temperature regimes, and it decreased from the 26.6° C regime to the 30.5° C regime. Of the three temperatures studied, 22.7°, 26.6°, and 3.5° C, 22.7° C proved to be the optimum for the predator to maintain control over the prey.
6

Efeito do glyphosate em plantas daninhas da família poaceae submetidas a diferentes potenciais hídricos do solo /

Silva Junior, Antonio Carlos da January 2018 (has links)
Orientador: Dagoberto Martins / Banca: Maria Renata Rocha Pereira / Banca: Robinson Luiz de Campos Machado Pitelli / Banca: Eduardo Custodio Gasparino / Banca: Lucas Perim / Resumo: A ação de herbicidas sobre plantas daninhas que se desenvolvem sob déficit hídrico pode ser comprometida, pois as rotas de penetração de herbicidas como o glyphosate são reduzidas em razão da menor hidratação da cutícula nessas plantas. Avaliou-se nesse estudo a eficiência de controle do herbicida glyphosate em quatro espécies de plantas da família Poaceae quando submetidas a distintos déficits hídricos. Os estudos foram conduzidos em casa-de-vegetação sendo que as espécies estudadas foram: capim-colonião (Megathyrsus maximum), capim-colchão (Digitaria nuda), capim-massambará (Sorghum halepense) e capim-braquiária (Urochloa ruziziensis). As plantas foram submetidas a três condições hídricas do solo [sem restrição hídrica (-0,03 MPa), déficit hídrico intermediário (-0,07 MPa) e alta restrição hídrica (-1,5 MPa)], aplicou-se três doses do herbicida glyphosate (0,0; 270,0 e 540,0 g e.a. ha-1) e em dois estádios fenológicos de desenvolvimento da planta (4-6 folhas e 1-3 perfilhos). O manejo hídrico teve início quando as plantas apresentaram duas folhas desenvolvidas. Foram realizadas avaliações visuais de controle aos 7, 14, 21 e 35 dias após a aplicação do herbicida; analisou-se ainda os parâmetros morfofisiológicos área foliar específica, condutância estomática e a diferença de temperatura do ambiente com a temperatura foliar no dia da aplicação do herbicida, bem como a matéria seca da parte aérea e da raiz ao final do estudo. Os resultados obtidos de controle e matéria seca fo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The action of herbicides on weeds that develop under water deficit can be compromised, the penetration routes of glyphosate herbicide are reduced due to the less hydration of the cuticle in these plants. The control efficiency of glyphosate herbicide in four species of plants of the Poaceae when submitted to different water deficits was evaluated in this study. The studies were carried out in a greenhouse and the species studied were: guineagrass (Megathyrsus maximum), naked crabgrass (Digitaria nuda), johngrass (Sorghum halepense) and congograss (Urochloa ruziziensis). In the treatments, the plants were submitted to three soil water conditions (no water deficit (-0.03 MPa), intermediate water deficit (-0.07 MPa) and high water restriction (-1.5 MPa)), three doses of glyphosate herbicide, (0.0, 270.0 and 540.0 g e.a. ha-1) and two phenological stages of plant development (4-6 leaves and 1-3 tillers). Water management started when the plants had two leaves developed. Visual evaluations were carried out at 7, 14, 21 and 35 days after application of the herbicide; the specific leaf area, stomatal conductance and the temperature difference of the environment with the leaf temperature on the day of application of the herbicide, as well as the dry matter of the aerial part and of the root were analyzed at the end of the study. The results of control and dry matter were submitted to analysis of variance by the "F" test and the means were compared by the Student "t" test (p> 0.05). T... (Complete abstract click electronic access below) / Doutor
7

Sphenophorus levis Vaurie, 1978 (Coleoptera: Curculionidae) : caracterização macroscópica e determinação de inseticida e época de aplicação para controle /

Alencar, Marina Aparecida Viana de. January 2016 (has links)
Orientador: Nilza Maria Martinelli / Coorientador: Marcelo da Costa Ferreira / Banca: Antonio Carlos Busoli / Banca: Ana Lúcia Benfatti González Peronti / Banca: Leila Luci Dinardo-Miranda / Banca: Fernando Cesar Pattaro / Resumo: O objetivo foi descrever características morfológicas para reconhecimento de adultos de Sphenophorus levis, e avaliar o inseticida mais adequado de acordo com a época de aplicação para o controle. Para as análises morfológicas foram coletados 20 machos e 20 fêmeas de S. levis e de Metamasius hemipterus. A caracterização macroscópica das espécies foi realizada a partir de revisão da literatura e observações adicionais de caracteres de importância taxonômica nos espécimes estudados. A eficiência de inseticidas no controle de S. levis foi avaliada em dois experimentos, um com aplicação em dezembro e outro com aplicação em junho. Foram realizados nove tratamentos, compostos por oito controles químicos e uma testemunha. Realizou-se amostragem prévia antes das aplicações, as quais foram realizadas em filete continuo, e três avaliações após a aplicação dos inseticidas, contabilizando o número de formas vivas do inseto e número de tocos totais e atacados. No final da safra foi realizado biometria e análise tecnológica. O delineamento estatístico utilizado foi em blocos ao acaso com quatro repetições, em soqueira. Os dados foram analisados a Tukey a 5% de significância. A descrição dos caracteres presentes na antena, pronoto, abdômen e forma do pigídio, foram importantes para a diagnose de cada espécie. As formas do pigídio, bem como a distribuição das cerdas no mesmo, propiciaram a determinação do sexo para ambas as espécies. Os produtos/misturas utilizados não sofreram influência da época de aplicação e não foram eficientes para o controle de Sphenophorus levis com a metodologia empregada. Faz-se necessários trabalhos com outras metodologias de aplicação para observar o efeito dos produtos/misturas utilizados / Abstract: The objective was to describe morphological characteristics for recognition Sphenophorus levis adults, as well as to assess the most appropriate insecticide according to the time of application for the control this pest. For morphological analysis were collected 20 males and 20 females of S. levis and Metamasius hemipterus. The macroscopic characterization of these species was started from literature review and additional comments from characters of taxonomic significance about the studied specimens. The efficiency of insecticides the controlling S. levis was evaluated in two experiments with application in december and the other with application in june. Were performed nine treatments, composed by eight chemical controls and a control. Was conducted previous sampling, the aplications were performed under continuous fillets. Three evaluations were carried out after the application, counting the number of insect life forms and the total number of stumps and attacked stumps. At the end of the harvest it was held biometrics and technological analysis. The design utilized was randomized block design with four replications, in ratoon. The data were analyzed by Tukey test at 5% significance. The characters present at the antenna, pronotum, abdomen, and description of the pygidium, were important for the diagnosis of each species. The pygidium form and the distribution of the bristles led to the determination of sex in both species. Products/mixtures used do not suffer from influence of application time and were not efficient for control Sphenophorus levis with the methodology employed. It is necessary, work with other application methods to observe the effect of products/mixtures used / Doutor
8

AppleMgr, a prototype decision aid for apple pest management

Haley, Sue 09 March 1990 (has links)
Computer decision aids can help integrate and apply diverse sources of information and expertise to problems of integrated pest management (IPM) in agriculture and forestry. AppleMgr combines a rule-based expert system with databases and spreadsheets in a prototype decision aid intended to be expanded and modified for use by extension workers in the Northwest U.S. The program requires an IBMcompatible microcomputer with hard disk. AppleMgr concentrates on the two most important insect pests on apple in the Northwest--codling moth, Cydia, pomonella (L.), and San Jose scale, Quadraspidiotus perniciosus Comstock, and on phytophagous mites, whose control largely depends on predators. The primary goal of AppleMgr is to demonstrate an improved process of decision making in apple IPM. AppleMgr is composed of modules for diagnosis of pest injury, identification of pest and natural enemy specimens, and management. The first two modules arrive at conclusions through backward-chaining inference from user observations. The management module uses backward chaining supplemented with external calculation programs to find the net benefit of a pesticide application. A method is included to predict yield and fruit size from crop samples. Cullage from codling moth and San Jose scale, mite effect on fruit size, probability of biological mite control and pesticide efficacy are predicted from researchers' data and estimates. Selected relative beneficial and adverse side effects of pesticides are presented in spreadsheets. An analysis of packing house records for apple crops from eight orchards at three yields using 1987 and 1988 prices and packing charges showed that net crop value varied by up to $8000 per acre. The variability in crop value and the importance of adverse side effects of pesticides suggest that the commonly-used "action thresholds" for treatment are seriously inadequate. AppleMgr may point the way toward more dynamic and realistic methods of IPM decision making. / Graduation date: 1990
9

Ecologia da paisagem e controle de pragas agrícolas /

Garcia, Adriano Gomes. January 2014 (has links)
Orientador: Paulo Fernando de Arruda Manera / Banca: Wesley Augusto Conde Godoy / Banca: Carlos Roberto Padovani / Resumo: / Abstract: / Mestre
10

Metodologias de aplicação de sulfonamida heterocíclica no controle de Meloidogyne javanica e Pratylenchus brachyurus em soja /

Oriani, Eduardo Elias. January 2015 (has links)
Orientador: Pedro Luiz Martins Soares / Banca: Rita de Cássia Panizzi / Banca: Sílvia Renata Siciliano Wilcken / Resumo: Os problemas com nematoides aumentaram significativamente nas áreas de cultivo de soja e práticas de redução populacional são fundamentais para minimizar as perdas na produtividade. Três metodologias de aplicação, utilizando a nova sulfonamida nematicida, para controle do M. javanica e P. brachyurus em soja foram avaliadas: 1) aplicação no sulco de plantio sobre as sementes, 2) aplicação em área total 5 dias antes do plantio, 3) aplicação no sulco de plantio sobre as sementes, e mais uma aplicação complementar 20 dias após a emergência (DAE) em área total. Foram avaliados: i) número de plantas por metro linear (14 DAE); ii) altura das plantas e massa fresca da parte aérea (45 e 90 DAE); iii) população de diferentes estádios de desenvolvimento de nematoide (ovos, juvenis e adultos) nas raízes (45 e 90 DAE); iv) índice de galhas (45 e 90 DAE); v) produtividade. Dentre as metodologias testadas, a aplicação da sulfonamida nematicida aplicada no sulco de plantio sobre as sementes apresentou redução populacional de M. javanica aos 45 DAE na dose de 1.500 g i.a/ha e na dose de 2.000 g i.a/ha foi detectada redução populacional aos 90 DAE. Essa metodologia não mostrou efeito sobre P. brachyurus nas doses testadas. A segunda metodologia, com aplicação da sulfonamida, em área total 5 dias antes do plantio, reduziu a população de M. javanica aos 90 DAE nas doses de 500 e 1.500 g i.a/ha. Essa metodologia também reduziu a população de P. brachyurus aos 45 DAE na dose de 1.500 g i.a/ha. A terceira metodologia, com aplicação da sulfonamida nematicida no sulco de plantio (150 g i.a /ha) e mais uma aplicação complementar em área total 20 DAE (750 g i.a /ha) reduziu significativamente a população de M. javanica até 45 DAE e reduziu as galhas até 90 DAE. Essa metodologia não... / Abstract: Problems with nematodes have been increasing on soybeans fields. Programs for nematode population reduction are essential to reduce yield losses. Three application methodologies, using the novel sulfonamide nematicide, were tested to control M. javanica e P. brachyurus in soybean: 1) furrow application at sowing planting 2) broadcast application in the total area 5 days before planting, 3) furrow application at sowing and an additional total area application 20 days after emergence (DAE). Evaluations consisted in: i) number of plants per linear meter (14 DAE); ii) plants height and fresh weight of shoots (45 and 90 DAE); iii) nematode population of different developmental stages (eggs, juveniles and adults) in the roots (45 and 90 DAE); iv) gall index (45 and 90 DAE); v) yield. Among tested methodologies, sulfonamide nematicide furrow application at sowing presented M. javanica population reduction 45 DAE with 1.500 g a.i/ha and with 2.000 g a.i/ha was detected population reduction 90 DAE. This methodology did not reduce P. brachyurus population in any of the doses tested. The second methodology, with application in the total area 5 days before planting, reduced M. javanica population with 500 and 1.500 g a.i/ha 90 DAE. This methodology also reduced P. brachyurus with 1.500 g a.i/ha 45 DAE. The third methodology, sulfonamide nematicide furrow application at sowing (150 g a.i/ha) and an additional total area application 20 DAE (750 g a.i/ha) significantly reduced M. javanica population until 45 DAE and showed gall index reduction until 90 DAE. This methodology also did not have any effect on P. brachyurus population in any of the doses tested. In all methodologies tested the sulfonamide did not show negative crop response, did not increase the plant height, fresh weight and yield / Mestre

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