Scientia Agrícola
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/12094
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Item Host colonization differences between citrus and coffee isolates of xylella fastidiosa in reciprocal inoculation(Escola Superior de Agricultura "Luiz de Queiroz", 2008-05) Prado, Simone de Souza; Lopes, João Roberto Spotti; Demétrio, Clarice Garcia Borges; Borgatto, Adriano Ferreti; Almeida, Rodrigo Piacentini Paes deCitrus variegated chlorosis (CVC) and coffee stem atrophy (CSA) are important diseases in Brazil associated with closely-related strains of Xylella fastidiosa, but little is know about host overlapping and importance of citrus and coffee as inoculum sources of these strains. In this study, reciprocal-inoculation experiments were performed to determine if CVC and CSA isolates are biologically similar within citrus and coffee plants. These two hosts were mechanically inoculated with a CVC and a CSA isolate of X. fastidiosa at four concentrations ranging between10 3 and 10 9 colony forming units CFU mL -1 . At two, four and eight months after inoculation, the infection efficiency and bacterial populations of the isolates in each host were determined by culturing. The CVC isolate infected both citrus and coffee plants, but developed lower populations in coffee. The CSA isolate did not colonize citrus. Inoculation of coffee plants with the CVC isolate resulted in low rates of infection and required an inoculum concentration ten-fold higher than that necessary to obtain a similar (25%) rate of infection in citrus. The relatively low infection rates and bacterial numbers of the CVC isolate in coffee plants compared with those observed in citrus suggest that coffee is not a suitable host to serve as a source of inoculum of the CVC strain for primary spread to citrus or within coffee plantations. Key words: citrus variegated chlorosis, coffee leaf scorch, inoculum concentration, bacterial population, epidemiologyItem Spatio-temporal modelling of coffee berry borer infestation patterns accounting for inflation of zeroes and missing values(Escola Superior de Agricultura "Luiz de Queiroz", 2009-01) Cárdenas, Ramiro Ruiz; Assunçã, Renato Martins; Demétrio, Clarice Garcia BorgesThe study of pest distributions in space and time in agricultural systems provides important information for the optimization of integrated pest management programs and for the planning of experiments. Two statistical problems commonly associated to the space-time modelling of data that hinder its implementation are the excess of zero counts and the presence of missing values due to the adopted sampling scheme. These problems are considered in the present article. Data of coffee berry borer infestation collected under Colombian field conditions are used to study the spatio-temporal evolution of the pest infestation. The dispersion of the pest starting from initial focuses of infestation was modelled considering linear and quadratic infestation growth trends as well as different combinations of random effects representing both spatially and not spatially structured variability. The analysis was accomplished under a hierarchical Bayesian approach. The missing values were dealt with by means of multiple imputation. Additionally, a mixture model was proposed to take into account the excess of zeroes in the beginning of the infestation. In general, quadratic models had a better fit than linear models. The use of spatially structured parameters also allowed a clearer identification of the temporal increase or decrease of infestation patterns. However, neither of the space-time models based on standard distributions was able to properly describe the excess of zero counts in the beginning of the infestation. This overdispersed pattern was correctly modelled by the mixture space-time models, which had a better performance than their counterpart without a mixture component.Item Humic substances and its distribution in coffee crop under cover crops and weed control methods(Escola Superior de Agricultura "Luiz de Queiroz", 2016-07) Martins, Bruno Henrique; Araujo-Junior, Cezar Francisco; Miyazawa, Mario; Vieira, Karen MayaraHumic substances (HS) comprise the passive element in soil organic matter (SOM), and represent one of the soil carbon pools which may be altered by different cover crops and weed control methods. This study aimed to assess HS distribution and characteristics in an experimental coffee crop area subjected to cover crops and cultural, mechanical, and chemical weed control. The study was carried out at Londrina, in the state of Paraná, southern Brazil (23°21’30” S; 51°10’17” W). In 2008, seven weed control/cover crops were established in a randomized block design between two coffee rows as the main-plot factor per plot and soil sam- pling depths (0-10 cm, 10-20 cm, 20-30 cm and 30-40 cm) as a split-plot. HS were extracted through alkaline and acid solutions and analyzed by chromic acid wet oxidation and UV-Vis spec- troscopy. Chemical attributes presented variations in the topsoil between the field conditions analyzed. Cover crop cutting and coffee tree pruning residues left on the soil surface may have interfered in nutrient cycling and the humification process. Data showed that humic substances comprised about 50 % of SOM. Although different cover crops and weed control methods did not alter humic and fulvic acid carbon content, a possible incidence of condensed aromatic structures at depth increments in fulvic acids was observed, leading to an average decrease of 53 % in the E4 /E6 ratio. Humin carbon content increased 25 % in the topsoil, particularly under crop weed-control methods, probably due to high incorporation of recalcitrant structures from coffee tree pruning residues and cover crops.Item Bioprospecting endophytic bacteria for biological control of coffee leaf rust(Escola Superior de Agricultura "Luiz de Queiroz", 2006-01) Shiomi, Humberto Franco; Silva, Harllen Sandro Alves; Melo, Itamar Soares de; Nunes, Flávia Vieira; Bettiol, WagnerSuppression of plant diseases due to the action of endophytic microorganisms has been demonstrated in several pathosystems. Experiments under controlled conditions involving endophytic bacteria isolated from leaves and branches of Coffea arabica L and Coffea robusta L were conducted with the objective of evaluating the inhibition of germination of Hemileia vastatrix Berk. & Br., race II, urediniospores and the control of coffee leaf rust development in tests with leaf discs, detached leaves, and on potted seedling of cv. Mundo Novo. The endophytic bacterial isolates tested proved to be effective in inhibiting urediniospore germination and/or rust development, with values above 50%, although the results obtained in urediniospore germination tests were inferior to the treatment with fungicide propiconazole. Endophytic isolates TG4-Ia, TF2-IIc, TF9-Ia, TG11-IIa, and TF7-IIa, demonstrated better coffee leaf rust control in leaf discs, detached leaves, and coffee plant tests. The endophytic isolates TG4-Ia and TF9-Ia were identified as Bacillus lentimorbus Dutky and Bacillus cereus Frank. & Frank., respectively. Some endophytic bacterial isolates were effective in controlling the coffee leaf rust, although some increased the severity of the disease. Even though a relatively small number of endophytic bacteria were tested, promising results were obtained regarding the efficiency of coffee leaf rust biocontrol. These selected agents appears to be an alternative for future replacement of chemical fungicide.Item Avaliação da qualidade de frutos de café atacados por Ceratitis capitata (Wiedemann, 1824) (Diptera: Tephritidae)(Escola Superior de Agricultura "Luiz de Queiroz", 1993-07) Cividanes, F.J.; Nakano, O.; Melo, M.Foram usadas plantas de Coffea arabica L., variedade Catuaí Vermelho, localizadas no Campus da Escola Superior de Agricultura "Luiz de Queiroz" - USP, Piracicaba,SP, para avaliação dos danos que Ceratitis capitata (Wied., 1824) pode causar aos frutos do cafeeiro. Os resultados mostraram que o ataque de C. capitula não causou queda prematura dos frutos, mas aumentou a queda de cerejas e foram encontradas, fortes evidências, com base na atividade da enzima polifenol oxidase e lixiviação de potássio, que cerejas atacadas podem produzir bebida de café de qualidade inferior.Item Dispersal capacity of fruit fly parasitoid Diachasmimorpha longicaudata (Hymenoptera: Braconidae) in irrigated coffee plantations(Escola Superior de Agricultura "Luiz de Queiroz", 2016-05) Camargos, Maria Gisely; Alvarenga, Clarice Diniz; Giustolin, Teresinha Augusta; Paranhos, Beatriz Aguiar Jordão; Oliveira, Patrícia Cristina do Carmo; Rabelo, Marcelo MendesDiachasmimorpha longicaudata is an Old World parasitoid of tephritid fruit flies that was widely introduced in the Americas to control pest species such as the Mediterranean fruit fly Ceratitis capitata. Augmentative releases in irrigated coffee plantations in semiarid regions of Brazil are under consideration and dispersal capacity of D. longicaudata in this habitat are important to develop release strategies. Approximately 2,000 individuals of D. longicaudata (5 to 7 days old) were released in the center of a fruiting coffee plantation every two weeks from Dec. 2009 to Apr. 2010. Dispersal from the central release point was monitored to the north, south, east, west, northeast, northwest, southeast and southwest at 11 distances, beginning at 4.6 m and ending at 90 m from the release point. At each point, a parasitism unit (approximately 120 larvae of C. capitata in the 3rd instar wrapped in voile fabric) and 10 coffee beans were collected. The average dispersion distance and dispersion area were estimated by the model proposed by Dobzhansky and Wright (1943). The average dispersion distances were 27.06 m (as estimated by fruit collection) and 33.11 m (as estimated by oviposition traps). The average dispersion areas were 1,315.25 m2 and 1,752.45 m2 originating from the collection of beans and parasit- ism units, respectively. Cohorts of 2,000 adult D. longicaudata released at six points ha−1 are estimated to result in sufficient colonization to exert significant control of Ceratitis capitata.Item Genetic characterization of Xylella fastidiosa isolated from citrus and coffee plants(Escola Superior de Agricultura "Luiz de Queiroz", 2007-09) Miranda, Vicente Savonitti; Farias, Paulo Roberto Silva; Roberto, Sérgio Rufo; Lacava, Pedro MagalhãesThe Citrus Variegated Chlorosis and the Coffee Leaf Scorch are some of the many destructive diseases caused by Xylella fastidiosa, a gram-negative bacterium limited to the xylem of affected plants. As its genetic characterization is still not well established, different isolates of X. fastidiosa from citrus and coffee were evaluated through RAPD (Random Amplified Polymorphic DNA) technique to characterize and classify these isolates based on similarity coefficients. Sixteen isolates of X. fastidiosa were used on this trial, obtained from citrus, coffee and almond. The genetic polymorphism evaluation was performed using six arbitrary 10-base primer pairs. It was possible to establish a dendogram in which the isolates were classified into five groups (A, B, C, D and E). A prevalence of citrus isolates in groups A and D was observed. In groups B and C, there was a prevalence of coffee isolates meanwhile the group D consisted of the almond isolate, solely.Item Molecular identification of Aspergillus spp. isolated from coffee beans(Escola Superior de Agricultura "Luiz de Queiroz", 2005-01) Magnani, Marciane; Fernandes, Thiago; Prete, Cássio Egidio Cavenaghi; Homechim, Martin; Ono, Elisabete Yurie Sataque; Vilas-Boas, Laurival Antonio; Sartori, Daniele; Furlaneto, Márcia Cristina; Fungaro, Maria Helena PelegrinelliSome species belonging to the genus Aspergillus are potential producers of ochratoxin A (OA), a mycotoxin with nephrotoxic, immunosuppressive, teratogenic and carcinogenic effects. The aim of the present study was to identify the species of Aspergillus that contaminate the inside of coffee beans collected in the stage of maturation and drying, from 16 producing areas located in the northern region of the State of Paraná, in the South of Brazil. A total of 108 isolates of Aspergillus spp. was identified at the species level, by sequencing the internal transcribed spacer (ITS1-5.8S-ITS2) of ribosomal DNA (rDNA). The results revealed the presence of potentially ochratoxigenic species in 82% of the geographic regions studied, among which Aspergillus niger was the species most frequently detected, followed by A. ochraceus and A. carbonarius. The presence of A. carbonarius in immature coffee fruits harvested from trees is reported for the first time.Item Life table of Hypothenemus hampei (Ferrari) in relation to coffee berry phenology under Colombian field conditions(Escola Superior de Agricultura "Luiz de Queiroz", 2010-11) Ruiz-Cárdenas, Ramiro; Baker, PeterThe overlap of generations of coffee berry borer (CBB), Hypothenemus hampei (Ferrari) under field conditions in countries like Colombia hinders the construction of life tables by the sampling of natural populations. In this paper, a field methodology to carry out regular measurements of CBB cohorts inside coffee berries of different ages until harvest, both in coffee trees and in infested berries placed on the ground, is developed and used to compare the life history parameters of CBB. Populations with berries at six ages in three experimental stations (without CBB control) and in a commercial farm in Colombia (with chemical CBB control regularly carried out) were used. The duration of the pre-oviposition period as well as the mortality and survival rates of founder females and the proportion of founders leaving infested berries were strongly influenced by the consistency of berries, with optimum conditions for CBB reproduction as from 120-150 days after flowering. No differences were found between stations for the number of CBB developmental stages; but they had larger values than the commercial farm. The latter also had more than twice the average rate of founders leaving infested berries recorded in the stations. Survival functions (cumulative probabilities of survival) for the pest differed among treatments and between the plant and ground micro-environments. Age of berries at infestation was positively related to the intrinsic rate of increase of borer population; whilst generation time and doubling time were inversely related. No differences were found between sites for the main demographic parameters of the pest.Item Brachiaria decumbens supresses the initial growth of Coffea arabica(Escola Superior de Agricultura "Luiz de Queiroz", 2004-11) Dias, Guilherme Faus da Silva; Alves, Pedro Luís da Costa Aguiar; Dias, Tomás Carneiro de SouzaBrachiaria decumbens vem se tornando uma das plantas daninhas mais freqüentes na infestação de cafezais em formação, pois além de sua elevada agressividade e dificuldade de controle, está ocorrendo expansão das áreas cafeeiras para locais anteriormente ocupados por pastagens. Objetivou-se neste trabalho avaliar os efeitos desta planta daninha, em densidades crescentes, sobre o desenvolvimento inicial de mudas de café (Coffea arabica L. cv. Catuaí Amarelo). O experimento foi conduzido em condições semi-controladas, sem limitação de água. Uma muda de café foi transplantada em caixa de amianto com capacidade para 70 L, preenchida com terra coletada da camada arável de um Latossolo Vermelho. Os tratamentos constaram de diferentes densidades de transplante de capim-braquiária, a saber: 0, 4, 8, 12, 16, 20, 24, 36, 48 e 60 plantas m - 2. O ensaio foi conduzido por um período experimental de 120 dias após o plantio (DAP). Todas as características analisadas foram afetadas negativamente pela interferência da planta daninha, mas as que se mostraram mais sensíveis a essa interferência foram à área foliar e a biomassa seca das folhas. Houve redução de 41,8% na área foliar do cafeeiro quando conviveu com o capim-braquiária a partir da densidade de 8 plantas m - 2, chegando a 68,7% na densidade de 60 plantas m -2 . Também a partir da densidade de 8 plantas m -2 , a redução na biomassa seca das folhas em relação à testemunha foi de 41,4% e na densidade de 60 plantas m - 2 chegou a 72,8%. Brachiaria decumbens, a partir da densidade de 8 plantas m - 2, interfere negativamente sobre as mudas de café até os 120 DAP.