oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Effect of Infestation of Alabama argillacea (Lepidoptera: Noctuidae) at Different Ages of Cotton Plants in Yield  [PDF]
Marcos Doniseti Michelotto, Jacob Crosariol Netto, José Fernando Grigolli, Antonio Carlos Busoli, Willians Cesar Carrega, Everton Luis Finoto, Juliana Altafin Galli
American Journal of Plant Sciences (AJPS) , 2014, DOI: 10.4236/ajps.2014.510159
Abstract:

The cotton leafworm is an important defoliating pest of cotton in Brazil, and occurs in all regions where the crop is cultivated. The purpose of this study was to evaluate the effect of larval densities of A. argillacea after different infestation periods on the yield components of four cotton cultivars. The experiment was carried out in Pindorama, SP, Brazil, in the 2008/2009 growing season. The cultivars IAC-25, DeltaOPAL, Fibermax 966 and Fibermax 993 were artificially infested with A. argillacea larvae at three times (30, 60 and 90 DAE) and four densities (0, 2, 4, and 6 larvae per plant). The average boll weight (g), fiber percentage (%), 100-seed weight (g) and yield (kg·ha-1) were evaluated. With increasing infestation density of A. argillacea, the cotton yield of the cultivars decreased. The presence of larvae significantly reduced the weight of 100 seeds of cultivar Fibermax 966. Initial infestations reduced the boll weight of IAC-25 and DeltaOPAL, while cultivars Fibermax 966 and Fibermax 993 were most affected by late infestations. Early infestation compromised fiber percentage of cultivar DeltaOPAL and late infestations were most harmful to cultivar Fibermax 966. Early A. argillacea infestation reduced the yield of DeltaOPAL, while infestations 60 DAE caused the most damage to IAC-25, and the other cultivars were not affected by the moment of infestation.

Estimate of Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) development with nonlinear models
Medeiros, R. S.;Ramalho, F. S.;Zanuncio, J. C.;Serr?o, J. E.;
Brazilian Journal of Biology , 2003, DOI: 10.1590/S1519-69842003000400006
Abstract: the objective of this work was to evaluate which nonlinear model [davidson (1942, 1944), stinner et al. (1974), sharpe & demichele (1977), and lactin et al. (1995)] best describes the relationship between developmental rates of the different instars and stages of alabama argillacea (hübner) (lepidoptera: noctuidae), and temperature. a. argillacea larvae were fed with cotton leaves (gossypium hirsutum l., race latifolium hutch., cultivar cnpa 7h) at constant temperatures of 20, 23, 25, 28, 30, 33, and 35oc; relative humidity of 60 ± 10%; and photoperiod of 14:10 l:d. low r2 values obtained with davidson (0.0001 to 0.1179) and stinner et al. (0.0099 to 0.8296) models indicated a poor fit of their data for a. argillacea. however, high r2 values of sharpe & demichele (0.9677 to 0.9997) and lactin et al. (0.9684 to 0.9997) models indicated a better fit for estimating a. argillacea development.
Estimate of Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) development with nonlinear models
Medeiros R. S.,Ramalho F. S.,Zanuncio J. C.,Serr?o J. E.
Brazilian Journal of Biology , 2003,
Abstract: The objective of this work was to evaluate which nonlinear model [Davidson (1942, 1944), Stinner et al. (1974), Sharpe & DeMichele (1977), and Lactin et al. (1995)] best describes the relationship between developmental rates of the different instars and stages of Alabama argillacea (Hübner) (Lepidoptera: Noctuidae), and temperature. A. argillacea larvae were fed with cotton leaves (Gossypium hirsutum L., race latifolium Hutch., cultivar CNPA 7H) at constant temperatures of 20, 23, 25, 28, 30, 33, and 35oC; relative humidity of 60 ± 10%; and photoperiod of 14:10 L:D. Low R2 values obtained with Davidson (0.0001 to 0.1179) and Stinner et al. (0.0099 to 0.8296) models indicated a poor fit of their data for A. argillacea. However, high R2 values of Sharpe & DeMichele (0.9677 to 0.9997) and Lactin et al. (0.9684 to 0.9997) models indicated a better fit for estimating A. argillacea development.
Distribui??o espacial de Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) em algodoeiro
Fernandes, Marcos G.;Busoli, Antonio C.;Barbosa, José C.;
Neotropical Entomology , 2003, DOI: 10.1590/S1519-566X2003000100016
Abstract: the knowledge of the dispersion pattern of the pests on a crop is fundamental for establishing an appropriated sequential sampling method. also it permits the correct utilization of control strategies and optimization of sampling techniques. the objective of this research was to determine the spatial distribution of larvae of alabama argillacea (hübner) on cotton crop, cnpa ita-90 cultivar. during the 1998/99 growing season a sampling system was applied in three experimental areas located at itamarati sul s.a. farm in the region of ponta por?, estate of mato grosso do sul, brazil. the areas measured 1 ha and contained 100 plots with 100 m2. in a weekly basis the number of small, medium and large larvae were counted on five plants per plot. the aggregation indexes (variance/mean ratio and morisita index), the chi-square test and the adjust of observed and expected values to theoretical distributions of frequencies (poisson, positive binomial and negative binomial) showed that all stages of cotton leafworm larvae were distributed according to the contagious model, fitting the negative binomial distribution during the whole period of infestation.
Amostragem seqüencial de Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) em algodoeiro
Fernandes, Marcos G.;Busoli, Antonio C.;Barbosa, José C.;
Neotropical Entomology , 2003, DOI: 10.1590/S1519-566X2003000100017
Abstract: an appropriated management of the cotton leafworm on cotton crop demands a sampling plan that quantifies the population density of the pest in an accurate and fast form. the objective of this research was to determine the plan of sequential sampling of alabama argillacea (hübner) on cotton crop, cnpa ita-90 cultivar. during the 1998/99 growing season a sampling system was applied in three experimental areas located at the fazenda itamarati sul s/a in the region of ponta por?, state of mato grosso do sul, brazil. each area measured 1 ha and was composed of 100 plots with 100 m2. the number of small, medium and large larvae was counted on five plants per plot, in a weekly basis. after defined that all stages of cotton leafworm larvae were distributed according to the contagious model, fitting negative binomial distribution during the whole period of infestation, a sequential sampling plan was provided, according to the sequential probability ratio test (sprt). a threshold level of two larvae per plant was assumed to trigger the sampling plan. after the data were analyzed two decision lines were indicated: the superior one, which represents the condition that the adoption of some control method is recommended, and was defined as s1= 4.8784+1.4227n; and the inferior one, representing the situation where the adoption of some control method is not recommended, defined as s0= -4.8784+1.4227n. the sequential sampling plan indicated the expected maximum number of 16 samples to determine whether or not the pest control is necessary.
Selection of Metarhizium anisopliae (Metsch.) and Beauveria bassiana (Bals.) isolates to control Alabama argillacea (Huebner) caterpillars
César Filho, Everardo;Marques, Edmilson Jacinto;Barros, Reginaldo;
Scientia Agricola , 2002, DOI: 10.1590/S0103-90162002000300008
Abstract: the cotton leafworm, alabama argillacea (huebner, 1818) (lepidoptera: noctuidae), is considered to be one of the key pests in herbaceous cotton (gossypium hirsutum l. r. latifolium hutch) cropping, with constant occurrence in all cotton-growing states of brazil. in this study metarhizium anisopliae and beauveria bassiana isolates were screened and evaluated for pathogenicity against alabama argillaceae. initially, a screening of ten isolates of each fungus in a concentracion of 108 conidia ml-1, was carried out on 3rd instar larvae of a. argillacea. further studies were conducted to determine the pathogenicity and virulence of six and seven isolates of m. anisopliae and b. bassiana, respectively, against 3rd instar larvae of a. argillacea and using the concentrations of 106, 107, 108, and 109 conidia ml-1. the experiments were carried out in recife, pe, brazil, at 27 ± 2oc, rh 70 ± 5% and a photophase of 12 hours. mortalities caused by m. anisopliae isolate at the different concentrations ranged from 4.5 to 91.2%, the highest mortality percentage being found for the isolate 1189 at 109 conidia ml-1. the isolate 645 of b. bassiana caused the highest mortality at the highest concentration, followed by isolates 634, 604, and ipa 198. the lowest lethal time for b. bassiana and m. anisopliae, was achieved by the isolates 483 (4.1 days) and 1189 (2.0 days), respectively. the isolates 1189, 1022 e 866 of m. anisopliae and 483, ipa198 and 604 of b. bassiana, at 108 e 109 conidia ml-1 are promissing for use the integrated control of a. argillacea larvae, but m. anisopliae seems more effective.
Resistência de variedades de algod?o ao curuquerê do algodoeiro Alabama argillacea Hubner (lepidoptera: noctuidae)
Junior, Arlindo Leal Boi?a;Jesus, Flávio Gon?alves de;Janini, Julio César;Silva, Anderson Gon?alves da;Alves, Gleina Costa Silva;
Revista Ceres , 2012, DOI: 10.1590/S0034-737X2012000100007
Abstract: this work aimed to test the occurrence of types of resistance in cotton varieties (gossypium hirsutum l.) including non-preference to oviposition and feeding and antibiosis to alabama argillacea (hubner, 1818), in laboratory experiments (27±2 oc, 70±10% de r.h. and photophase of 14 hours). the experiment to evaluate the non-preference for oviposition and feeding in free choice tests used a randomized block design, while the tests without free choice used a completely randomized design. to evaluate antibiosis, leaves of the varieties deltaopal, nuopal, fmt 701, fmx 910 e fmx 996 were fed to the larvae daily. the duration of each insect phase, the larvae mass in the 10th day, the pupa mass with 24 hours, the larva and pupa stage, the adult longevity, total viability and fecundity were recorded. the varieties nuopal and fmt 701 showed resistance by non-preference for feeding. the varieties nuopal, fmt 701 and fmx 910 showed resistance by antibiosis to a. argillacea.
Efecto de las poblaciones de Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) en cultivos de algodón a dos distanciamientos
Helman, SA;Beltran, RE;Garay, F;Ra?a, E;
Neotropical Entomology , 2011, DOI: 10.1590/S1519-566X2011000200015
Abstract: the objective of this research was to evaluate the incidence of damage by the leafworm alabama argillacea (hübner) on yields of cotton grown under rows spaced 0.38 m and 0.76 m at the irrigation area of santiago del estero, argentina. the period evaluated was extended from first flower to first open boll. treatments were t1 - without control of larvae, t2 - with control of larvae, t3 - control since first flower to the end of effective blooming, and t4 - with larval control since the end of effective blooming to first open boll. the effect of injuries on the crop was evaluated trough boll cotton yield. larvae were sampled in a weekly basis and insects were present from the first flower until harvest. populations of a. argillacea decreased crop yields in the two distances tested, by decreasing the weight or number of open bolls.
Biologia de Podisus nigrispinus predando lagartas de Alabama argillacea em campo
Oliveira, José Eudes Moraes de;Torres, Jorge Braz;Carrano-Moreira, Alberto Fábio;Ramalho, Francisco de Sousa;
Pesquisa Agropecuária Brasileira , 2002, DOI: 10.1590/S0100-204X2002000100002
Abstract: nymphal development, reproduction and predation rate of podisus nigrispinus (dallas) (heteroptera: pentatomidae) deprived of prey or preying upon alabama argillacea (huebner) (lepidoptera: noctuidae) were studied on cotton plants in field. nymph and adult bugs were isolated by an organdie bag attached on cotton leaf and were deprived of prey or fed with two caterpillars of 70±10 mg every 1, 3 and 6 days. after the third instar the developmental time was delayed with food intervals. nymphs deprived of prey reached the third instar with 16.7% survivorship, but 100% died at this stage. nymphs feeding either daily or every three days showed survivorship superior to 60% and higher than those fed every six days. predation of a. argillacea available daily was 12.7 and 13.2 caterpillars per nymphs when originated males and females, respectively. additionally, females of p. nigrispinus preyed in mean 54.7 caterpillars. females fed daily showed higher fecundity but pre-oviposition, reproductive and longevity periods were similar to the other feeding intervals. the dairy predation rate for nymphs and adults was 0.7 and 1.1 caterpillars per day; thus the availability of two caterpillars per day was in excess. the nymphal development and reproduction of p. nigrispinus were affected by food availability at three and six day's intervals.
Biological aspects and predatory capacity of Podisus nigrispinus (Dallas) (Hemiptera: Pentatomidae) fed on Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) reared on cotton genotypes
Santos, Terezinha Monteiro dos;Boi?a Jr., Arlindo Leal;
Scientia Agricola , 2002, DOI: 10.1590/S0103-90162002000400008
Abstract: host plants may influence indirectly biological characteristics of predators, on a positive or negative way, poiting out the importance of studies evaluating the effect of cultivars on the third trophic level. this study evaluates the biological aspects and predatory capacity of podisus nigrispinus adults fed alabama argillacea larvae reared on cotton genotypes. the predator was fed daily with fourth instar larvae reared on leaves of the following genotypes cnpa precoce 1 (hirsute), cnpa 9211-31 (high gossypol level), cnpa 9211-41 (medium gossypol level) and gl2 gl3 (gossypol glandless). the pre-oviposition, oviposition and post-oviposition periods and the oviposition capacity of p. nigripinus were not affected when preyed on cotton leafworms reared on the listed cotton genotypes. mean weight of predator females was higher (126.2 mg) when they fed on a. argillacea reared on gl2 gl3 cotton leaves, in comparison to the observed weight (96.2mg) of p. nigripinus females fed on larvae reared on cnpa 9211-41. longevity of p. nigrispinus ranged 30.7 to 31.5 days for females and 38.0 to 66.3 days for males. p. nigrispinus females preyed 125.2 to 184.0 a. argillacea larvae during its adult stage, while adult males preyed 135.7 to 205.0 leafworms. using plant resistance in association with p. nigrispinus is viable to control a. argillacea, because resistant genotypes do not influence negatively the biological characteristics of the predator.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.