Pesquisa Agropecuária Brasileira
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/9886
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Resultados da Pesquisa
Item Leaf miner incidence in coffee plants under different drip irrigation regimes and planting densities(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2012-02) Assis, Gleice Aparecida; Assis, Franscinely Aparecida; Scalco, Myriane Stella; Parolin, Francisco José Toloza; Fidelis, Iraci; Moraes, Jair Campos; Guimarães, Rubens JoséThe objective of this work was to evaluate the effect of different drip irrigation regimes and planting densities on the incidence of the leaf miner, Leucoptera coffeella, in arabica coffee plants for one year. The experiment was carried out in 2008, in a complete randomized block design, in a split‐plot in time arrangement, with four replicates. The treatments consisted of four drip irrigation regimes – soil water balance, irrigations at 20 and 60 kPa soil tensions, and a nonirrigated treatment –, which were distributed at three plant densities: 2,500, 5,000, and 10,000 plants per hectare. The evaluations were made on a monthly basis between January and December 2008. The highest pest occurrence period was from August to November, a season with low‐air relative humidity preceded by a drought period. Irrigated coffee plants showed an incidence of intact mines 2.2 times lower than that of nonirrigated plants. Irrigation and increasing of plant density contribute to the reduction of coffee leaf miner occurrence.Item Toxicity of organic farming‐compatible products to the coffee leaf miner(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2013-03) Venzon, Madelaine; Krüger, Rodrigo Ferreira; Soto, Alberto; Tuelher, Edmar de Souza; Bonomo, Italo Santos; Fadini, Marcos Antonio Matiello; Fonseca, Maira Christina MarquesThe objective of this work was to evaluate the toxicity of organic farming‐compatible products to the coffee leaf miner Leucoptera coffeella. Lime sulphur, enriched Bordeaux mixture (Viça Café Plus), and the “supermagro” biofertilizer were first tested in laboratory. The most promising product was tested afterwards under field conditions. In laboratory, different concentrations of each product were applied on L. coffeella eggs and on infested coffee‐mined leaves. Only lime sulphur had ovicidal effects at an acceptable concentration (1.6%) for field applications, but no significant effect on larvae mortality was found. Enriched Bordeaux mixture and the “supermagro” biofertilizer had no effect on L. coffeella eggs and larvae. In the field trial, biweekly or monthly sprayings of lime sulphur at different concentrations caused population decrease after 30 days; however, this effect was not significant after 60 or 90 days.Item Study of simple sequence repeat markers from coffee expressed sequences associated to leaf miner resistance(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2007-03) Pinto, Fernanda de Oliveira; Maluf, Mirian Perez; Guerreiro-Filho, OliveiroThe objective of this work was to identify expressed simple sequence repeats (SSR) markers associated to leaf miner resistance in coffee progenies. Identification of SSR markers was accomplished by directed searches on the Brazilian Coffee Expressed Sequence Tags (EST) database. Sequence analysis of 32 selected SSR loci showed that 65% repeats are of tetra-, 21% of tri- and 14% of dinucleotides. Also, expressed SSR are localized frequently in the 5’–UTR of gene transcript. Moreover, most of the genes containing SSR are associated with defense mechanisms. Polymorphisms were analyzed in progenies segregating for resistance to the leaf miner and corresponding to advanced generations of a Coffea arabica x Coffea racemosa hybrid. Frequency of SSR alleles was 2.1 per locus. However, no polymorphism associated with leaf miner resistance was identified. These results suggest that marker-assisted selection in coffee breeding should be performed on the initial cross, in which genetic variability is still significant.Item Risk analysis of climate change on coffee nematodes and leaf miner in Brazil(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2008-02) Ghini, Raquel; Hamada, Emília; Júnior, Mário José Pedro; Marengo, José Antonio; Gonçalves, Renata Ribeiro do ValleThe objective of this work was to assess the potential impact of climate change on the spatial distribution of coffee nematodes (races of Meloidogyne incognita) and leaf miner (Leucoptera coffeella), using a Geographic Information System. Assessment of the impacts of climate change on pest infestations and disease epidemics in crops is needed as a basis for revising management practices to minimize crop losses as climatic conditions shift. Future scenarios focused on the decades of the 2020’s, 2050’s, and 2080’s (scenarios A2 and B2) were obtained from five General Circulation Models available on Data Distribution Centre from Intergovernmental Panel on Climate Change. Geographic distribution maps were prepared using models to predict the number of generations of the nematodes and leaf miner. Maps obtained in scenario A2 allowed prediction of an increased infestation of the nematode and of the pest, due to greater number of generations per month, than occurred under the climatological normal from 1961–1990. The number of generations also increased in the B2 scenario, but was lower than in the A2 scenario for both organisms.Item Microsatellite markers in analysis of resistance to coffee leaf miner in Arabica coffee(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2011-12) Pereira, Gabriella Santos; Padilha, Lilian; Pinho, Edila Vilela Resende Von; Teixeira, Rita de Kássia Siqueira; Carvalho, Carlos Henrique Siqueira de; Maluf, Mirian Peres; Carvalho, Bruna Line deThe objective of this work was to analyze coffee (Coffea arabica) genotypes resistant to the coffee leaf miner (Leucoptera coffeella) using microsatellite markers. Sixty‐six loci were evaluated, of which 63 were obtained from the Brazilian Coffee Expressed Sequence Tag (EST) database. These loci were amplified in bulks of individuals from F 5 progenies of 'Siriema' (C. arabica x C. racemosa) resistant and susceptible to the insect, in eight samples of C. racemosa, and in a F 6 population of 'Siriema' with 91 individuals segregating for resistance to the leaf miner. Polymorphisms were verified for two simple sequence repeat (SSR) loci in bulks of the susceptible progenies. The two polymorphic alleles were present in around 70% of the susceptible genotypes in F 5 and in approximately 90% of the susceptible individuals in F 6 . However, the polymorphic EST‐SSR markers among populations contrasting for resistance to leaf miner were not correlated to the evaluated characteristics. SSR markers show inter‐ and intraspecific polymorphism in C. arabica and C. racemosa.