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Search Results: 1 - 10 of 22520 matches for " Josimar Souza;Zinger "
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Parasitism Capacity of Trichogramma pretiosum and Trichogramma acacioi (Hym.: Trichogrammatidae) on eggs of Sitotroga cerealella (Lep.: Gelechiidae)
Pratissoli, Dirceu;Zanuncio, José Cola;Vianna, Ulysses Rodrigues;Andrade, Josimar Souza;Zinger, Fernando Domingo;Alencar, Jo?o Rafael de Conte Carvalho de;Leite, Germano Le?o Demolin;
Brazilian Archives of Biology and Technology , 2008, DOI: 10.1590/S1516-89132008000600021
Abstract: the objective of this work was to evaluate the parasitism capacity of trichogramma pretiosum riley and t. acacioi brun, moraes and soares (hymenoptera: trichogrammatidae) in eggs of the alternative host sitotroga cerealella (olivier) (lepidoptera: gelechiidae) aiming to use both species in biological control programs of nipteria panacea tierry-mieg (lepidoptera: geometridae). the parasitism rhythm and total parasitism of these parasitoid species were affected by the temperature with higher values during the first 24 h of their life. parasitism period was longer for t. pretiosum and t. acacioi at the lowest temperature.
Incidência de Colletotrichum spp. em frutos de Coffea arabica L. em diferentes estádios fisiológicos e tecidos do fruto maduro
Ferreira, Josimar Batista;Abreu, Mario Sobral de;Pereira, Igor Souza;
Ciência e Agrotecnologia , 2005, DOI: 10.1590/S1413-70542005000400022
Abstract: colletotrichum species are present in all organs of coffee trees and the importance of them is still controversial, since several populations can infect plant and cause disease or colonize plants in an endophytic form. this study was carried out with the objective to verify the presence of colletotrichum spp. in different stages of development of coffee fruits and in the exocarp plus mesocarp, endocarp and endosperm of ripe fruits. in fruits from the cultivars catuaí amarelo and vermelho, icatu, topázio, katipó, rubi, acaiá cerrado and mundo novo came from the experimental farm the of federal university of lavras, brazil. in the developing young fruits colletotrichum spp. occurred at the average incidence of 86.6%. the highest incidence, 94.4% was observed in fruits from topázio and rubi cultivars, and the lowest incidences were 72.8% and 78.4%, in fruits from icatu and mundo novo cultivars, respectively. incidence of colletotrichum spp. in the tissues of coffee berries varied according to the cultivar and the type of infected tissue. based on exocarp plus mesocarp infection, the cultivars topázio, rubi, acaiá cerrado and icatu were colonized with 84.72%, 79.16%, 77.77% and 48.6%, respectively. in relation to endocarp the maximum colonization was of 9.72% in cultivar rubi and lower percentage of colonization was observed in acaiá cerrado with 1.39%. in relation to endosperm, the maximum colonization was observed in rubi cultivar with 8.33% and lower percentage of colonization was observed in mundo novo and katipó cultivars, both with 1.39%. colletotrichum spp. was present in the seeds of all cultivars studied.
Análise da dinamica, estrutura de focos e arranjo espacial da mancha manteigosa em campo
Ferreira, Josimar Batista;Abreu, Mario Sobral de;Pereira, Igor Souza;
Ciência e Agrotecnologia , 2009, DOI: 10.1590/S1413-70542009000100003
Abstract: the aim of this study was to analyze the spatial dispersion pattern of the blister spot on coffee trees, through spatial arrangements and the analysis of the dynamics and foci structure of the disease during three consecutive years. no disease progress was observed in this area during the period of study. seedlings showing disease symptoms were found under the canopy of diseased trees, strongly indicating that the disease may be transmitted through the seeds. ten foci with 2.5 trees per focus were observed in the studied area. the foci were distributed following the plant rows with elliptical shape. unitary foci predominated in the area in 52% of the diseased trees. analyses of runs and doublets showed a random spatial pattern of the disease. these results evidenced that the blister spot occurs from isolated plants (unitary foci) and this characteristic may possibly be explained if the seeds are the main disease transmission agent (seed-plant-seed).
Estudos histoplásticos da intera??o Colletotrichum gloeosporioides: cafeeiro
Pereira, Igor Souza;Abreu, Mario Sobral de;Alves, Eduardo;Ferreira, Josimar Batista;
Bragantia , 2009, DOI: 10.1590/S0006-87052009000100013
Abstract: in studies involving the interaction colletotrichum gloeosporioides - coffee trees (coffea arabica l.) there is little information regarding the pre-penetration, penetration and colonization pathways of this pathogen. the objectives of this work were: 1. to study through scanning electron microscopy (sem) the pre-penetration and penetration events of c. gloeosporioides in hypocotyls of coffee plantlets; 2. to observe the colonization of colletotrichum spp. in branches and fruits of coffee trees with blister spot symptoms. the study took place in three trials. in the first trial, it was observed and reported the pre-penetration events of c. gloeosporioides inoculated on hypocotyls of coffee cv. acaiá cerrado with and without wounds. the second trial was performed to investigate the colonization of diseased coffee branches that presented drastic wilt and local necrosis was observed. finally the third trial investigated the colonization of this pathogen in diseased coffee fruits. when c. gloeosporioides was inoculated, germination could be observed in wounded hypocotyls 6 hours after inoculation. better adhesion of conidia was evident at surface depressions of hypocotyls and germination started by emission of one or two terminal germ tubes. round or sub-round shaped apressoria appeared 12 hours after inoculation. up to 72 hours, acervula formation was not observed on inoculated tissues. the wilted branches presented colonization in the phloem and cortical tissues. in fruits at different stages of maturation, it was observed colonization in tissues near the epidermis and collapse of the stomata in the affected area.
Efeito de fungicidas e influência de fatores climáticos sobre a mancha manteigosa no cafeeiro
Ferreira, Josimar Batista;Abreu, Mario Sobral de;Pereira, Igor Souza;Fernandes, Katiucia Dias;Pereira, Ricardo Borges;
Ciência e Agrotecnologia , 2009, DOI: 10.1590/S1413-70542009000200009
Abstract: the aim of this work was to assess the effect of selected fungicides on the control of coffee blister spot in the field and to verify the climatic effects on the progress of the disease. trials were carried out with coffee plants of cultivar catucaí vermelho, approximately 8 years old. the fungicides tested were tetraconazol (1l/ha), triadimenol (12kg/ha), chlorothalonil (3kg/ha), and mancozeb (2kg/ha). climatic data were collected daily from october 2004 to may 2006. the fungicides chlorotalonil and triadimenol provided the best efficiency results on the control of the progress of die-back and the number of fruits, with an increase in the cherry production. the increase of die-back during the period from october to january was possibly induced by the rainfall. tetraconazol and mancozeb were not efficient. coffee trees affected by blister spot, even if treated with fungicides, had significant decrease in the fruit production and the untreated healthy trees had their yield 95% higher than of those treated.
Aspectos morfológicos da coloniza??o de Colletotrichum gloeosporioides em órg?os de plantas de cafeeiros e com sintomas da mancha manteigosa
Ferreira, Josimar Batista;Abreu, Mario Sobral de;Alves, Eduardo;Pereira, Igor Souza;
Ciência e Agrotecnologia , 2009, DOI: 10.1590/S1413-70542009000400003
Abstract: the aim of this work was to study the colonization of leaves, petioles, veins, branches, fruits, and peduncles by c. gloeosporioides, the causal agent of blister spot, under natural infections of cultivar catucaí vermelho in field conditions. all materials were analyzed through scanning electron microscopy. the branches and veins of coffee leaves affected by blister spot with descending death as well as hypocotyls from seedlings had their xylem, phloem and cortical cells colonized by c. gloeosporioides while fruits showing blister spot symptoms had their exocarp, mesocarp, endocarp, and endosperm tissues colonized by c. gloeosporioides.
Eventos do processo de infec??o de Colletotrichum gloeosporioides inoculados em folhas de Coffea arabica L
Ferreira, Josimar Batista;Abreu, Mario Sobral de;Alves, Eduardo;Pereira, Igor Souza;Fernandes, Katiúcia Dias;
Summa Phytopathologica , 2009, DOI: 10.1590/S0100-54052009000400004
Abstract: the present study was carried out with the objective to provide information on the pre-penetration, penetration and colonization events of isolates of colletotrichum gloeosporioides from mango and coffee, when inoculated in coffee leaves. the cultivar catucaí vermelho was used in all experiments. coffee leaves were selected, standardized and washed in sterile water. after that, circular areas of 0.5 cm in diameter were marked on the undersurface of the leaves. in the center of each circular area, 20 μl of spore suspension was deposited. one isolate from mango and two from coffee presenting blister spot were used in all trials. the time course of the experiments was 3, 6, 8, 12, 24, 36, 48, 72, 96, 144 and 240 hours after inoculation (h.a.i.). all materials were analyzed in scanning electron microscopy. the conidia of all isolates adhered more frequently on the plant tissue depressions and guard-cells forming septum before germination. the most common penetration via was the direct, although some penetration through stomata also occurred. isolates obtained from blister spot symptoms germinated on coffee leaves after 6 to 8 h.a.i., producing appressoria after 12 h.a.i., and acervuli after 96 to 144 h.a.i. the isolate from mango germinated on the coffee leaves after 6 to 8 h.a.i. and formed appressoria after 8 to 12 h.a.i., but was unable to form acervuli, bearing conidia directly from conidiogenous hypha on the mycelium.
Fertility life table of Trichogramma pretiosum and Trichogramma acacioi on eggs of Anagasta kuehniella at different temperatures
Pratissoli Dirceu,Zanuncio José Cola,Vianna Ulysses Rodrigues,Andrade Josimar de Souza
Pesquisa Agropecuária Brasileira , 2004,
Abstract: Species of the Trichogramma genus are among the most important ones for biological control. The objective of this research was to evaluate parasitism potential of two species of Trichogramma on eggs of Anagasta kuheniella through life fertility table, at temperatures between 15oC and 35oC. These species were collected in the State of Espírito Santo parasitising eggs of the avocado defoliator Nipteria panacea. Trichogramma pretiosum and T. acacioi showed adequate reproductive potential between 15oC and 35oC which indicates possibilities of using them in biological control programs in avocado plantations.
Sensibilidade de Colletotrichum gloeosporioides (mancha manteigosa do cafeeiro) a diferentes concentra es de fungicidas Sensibility of Colletotrichum gloeosporioides (coffee blister spot) to different fungicide concentrations
Josimar Batista Ferreira,Mario Sobral de Abreu,Igor Souza Pereira,Katiucia Dias Fernandes
Ciência e Agrotecnologia , 2009, DOI: 10.1590/s1413-70542009000700059
Abstract: Com o objetivo de avaliar a eficiência de alguns fungicidas sobre Colletotrichum gloeosporioides, agente etiológico da mancha manteigosa do cafeeiro (Coffea arabica L.), testes in vitro foram conduzidos no Laboratório de Diagnose e Controle/UFLA. Utilizou-se o método de incorpora o de fungicidas ao meio de cultura MEA 2% para a avalia o da inibi o do crescimento micelial e em lamina escavada contendo água com fungicida para a germina o de conídios. Os fungicidas, tetraconazol, triadimenol, chlorotalonil e mancozeb foram testados quanto à inibi o do crescimento do micelial (nas concentra es de 1, 5, 10, 25, 50, 100, 500 e 1.000 mg L-1) e quanto à inibi o da germina o de conídios (nas concentra es de 1, 5, 10, 25, 50 e 100 mg L-1). Os fungicidas tetraconazol e triadimenol apresentaram alta eficiência na inibi o do crescimento micelial. Os fungicidas chlorotalonil e mancozeb mostraram baixa eficiência e ineficiência, respectivamente. Quanto à germina o dos conídios, os fungicidas que demonstraram maior eficiência em baixas concentra es foram o chlorotalonil e o tetraconazol. With the aim of assessing the effect of selected fungicides on Colletotrichum gloeosporioides, the cause of coffee blister spot, in vitro tests were carried out in the Laboratory of Diagnosis and Control/UFLA, Federal University of Lavras, Brazil. In the in vitro experiments the fungicides were incorporated into malt extract medium (MEA 2%) to evaluate the effect on the fungus growth rate, and concavity slides containing water plus fungicide to assess the conidia germination. The fungicides tetraconazol, triadimenol, chlorothalonil and mancozeb were tested on the mycelial growth inhibition (in the concentrations of 1, 5, 10, 25, 50, 100, 500 and 1.000 mg L-1) and on the inhibition conidia germination (in the concentrations of 1, 5, 10, 25, 50 e 100 mg L-1). The fungicides tetraconazol and triadimenol showed high efficiency on the mycelial growth inhibition. Chlorotalonil and mancozeb showed low efficiency and inefficiency, respectively. As to the germination of conidia, chlorothalonil and tetraconazol demonstrated to be more efficient in low concentrations.
On the Structure of Certain Natural Cones over Moduli Spaces of Genus-One Holomorphic Maps
Aleksey Zinger
Mathematics , 2004,
Abstract: We show that certain naturally arising cones over the main component of a moduli space of $J_0$-holomorphic maps into $P^n$ have a well-defined euler class. We also prove that this is the case if the standard complex structure $J_0$ on $P^n$ is replaced by a nearby almost complex structure $J$. The genus-zero analogue of the cone considered in this paper is always a vector bundle. The genus-zero Gromov-Witten invariant of a projective hypersurface is the euler class of such a vector bundle. As shown in a separate paper, this is also the case for the "genus-one part" of the genus-one GW-invariant. The remaining part is a multiple of the genus-zero GW-invariant.
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