Distribuição horizontal e vertical de fósforo em sistemas de cultivos exclusivos de soja e de integração lavoura‑pecuária‑floresta

The objective of this work was to evaluate the horizontal and vertical distribution of soil phosphorus and soybean yield in single‑crop and in integrated crop‑livestock‑forest (ICLF) systems. The evaluated treatments were: forest planted with eucalyptus; soybean crop and off-season corn intercropped with Urochloa brizantha 'Marandu'; U. brizantha pasture; ICLF system; and two control areas, with native forest and fallow. Soil samples were taken at the depths of 0–5, 5–10, 10–20, 20–30 cm for determining chemical characteristics. Evaluations were done in the second crop year after the implementation of the experiment. In the ICLF system, soil and yield were evaluated in four equidistant transects, at the center of the tree rows, and at 3, 6, 10, and 15 m from the rows on the northern and southern sides. Available P levels (Mehlich‑1) were greater at the upper soil layers, in the systems with soybean/off-season corn and ICLF. In ICLF, available P contents did not differ between the distances from the tree rows, and soybean yield did not differ from the one observed in the soybean/off-season corn system. Therefore, a two‑year ICLF is not yet capable of major interference on soil chemical characteristics and on soybean yield.O objetivo deste trabalho foi avaliar a distribuição horizontal e vertical do fósforo no solo e a produtividade de soja em sistemas de cultivos exclusivos e de integração lavoura‑pecuária‑floresta (ILPF). Foram avaliados os tratamentos: floresta plantada de eucalipto; lavoura de soja e milho safrinha consorciado com Urochloa brizantha 'Marandu'; pastagem de U. brizantha; sistema de ILPF; e duas áreas controle, com floresta nativa e pousio. O solo foi coletado nas camadas de 0–5, 5–10, 10–20 e 20–30 cm, para determinação das características químicas. As avaliações foram realizadas no segundo ano agrícola após a implantação do experimento. No sistema de ILPF, solo e produtividade foram avaliados em quatro transectos equidistantes, no centro do renque e a 3, 6, 10 e 15 m do renque, nas faces norte e sul. Os teores de P disponível (Mehlich‑1) foram maiores nas camadas superficiais do solo, nos sistemas com soja/milho safrinha e com ILPF. No ILPF, os teores de P disponível não diferiram entre as distâncias do renque das árvores, e a produtividade de soja não diferiu da observada no sistema com soja/milho safrinha. Portanto, com dois anos de implantação, o sistema ILPF ainda não é capaz de interferir marcadamente nas características químicas do solo e na produtividade da soja

Métodos de inoculação em casa de vegetação, para avaliação da resistência da soja à síndrome da morte súbita

The objectives of this work were to evaluate two greenhouse screening methods for sudden death syndrome (SDS) and to determine which one is best correlated with field resistance of soybean genotypes. The evaluations were done with three sets of genotypes that were classified as partially resistant, intermediate, and susceptible to SDS based on previous field evaluations. These three sets were independently evaluated for greenhouse SDS reactions using cone and tray inoculation methods. Plants were infected using grains of white sorghum [Sorghum bicolor (L.) Moench] infested with Fusarium solani f. sp. glycines. Foliar symptom severity was rated 21 days after emergence. The cone and field SDS ratings were significantly correlated and ranged from 0.69 for set 1 to 0.51 for set 3. Correlations of SDS ratings of genotypes between field and greenhouse tray ratings were significant for set 1 and not significant for set 2. The cone method showed the highest correlation with field results and is recommended to screen soybean genotypes for SDS resistance.Os objetivos deste trabalho foram avaliar dois métodos de inoculação, em casa de vegetação, e determinar o que apresenta maior correlação com resultados de reação à síndrome da morte súbita (SDS – "sudden death syndrome") obtidos em soja, no campo. Três grupos de genótipos, classificados previamente, em campo, como parcialmente resistentes, intermediários e suscetíveis, foram avaliados em casa de vegetação, por meio dos métodos de inoculação em cones e em bandeja. As plantas foram contaminadas com grãos de sorgo [Sorghum bicolor (L.) Moench] infestados com Fusarium solani f. sp. glycines. As avaliações dos sintomas foliares foram realizadas 21 dias após a emergência. As correlações entre os resultados pelo método de cones e os obtidos em campo foram significativas e variaram de 0,69 para o grupo 1 a 0,51 para o grupo 3. As correlações entre os resultados pelo método da bandeja e os obtidos em campo foram de 0,54 para o grupo 1, e não significativas para o grupo 2. O método de cones apresentou a maior correlação com os resultados em campo e é recomendado para avaliação de genótipos de soja quanto à resistência à SDS

Resistance of Soybean [Glycine Max (L.) Merr.] to Fusarium Solani F. Sp. Glycines: Causal Agent of Sudden Death Syndrome

101 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2005.The objective of my third study was to detect QTL conferring SDS resistance in two populations of recombinant inbred lines (RILs) populations. These populations were from the crosses PI 567374 x 'Omaha' and 'Ina' x LN91-1695. Six chromosomal regions were significantly associated with SDS resistance in the PI 567374 x Omaha population. For all regions, the beneficial alleles were derived from PI 567374. Five chromosomal regions were associated with SDS resistance in the Ina x LN91-1695 population. Two regions previously found to be associated with SDS resistance in the cultivar Essex derived the resistance from the resistant parent Ina.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Caracterização de genótipos de soja na região dos Cerrados quanto à reação à podridão vermelha da raiz, causada pelos fungos Fusarium tucumaniae e Fusarium brasiliense Reaction of soybean cultivars to the sudden death syndrome pathogens Fusarium tucumaniae and F. brasiliense

A podridão vermelha da raiz de soja vem crescendo em importância, a cada ano, no Brasil, com aumento substancial de participação nas perdas de produtividade. Na região dos Cerrados, são escassos os dados de campo sobre a reação de cultivares à doença. Assim, este trabalho teve como objetivo a caracterização, em campo, de uma série de genótipos de soja, quanto à resistência à podridão vermelha da raiz, em solos naturalmente infestados. Foram testados 71 genótipos de soja, sendo 16 do ciclo de maturação precoce, 28 do ciclo de maturação médio e 27 do ciclo de maturação tardio, em quatro localidades, no entorno do Distrito Federal. O delineamento experimental foi o de blocos ao acaso, com quatro repetições. A caracterização foi realizada por meio dos níveis de incidência e severidade dos sintomas foliares. Genótipos com altos níveis de resistência à doença foram observados nos três grupos de maturação, em cultivares e linhagens em fase final de melhoramento.Loss due to soybean sudden death syndrome (SDS) has increased considerably in Brazil in recent years. Field data on reaction of soybean genotypes to SDS infection in the Cerrados is almost nonexistent. Therefore, the objective of this work was to characterize the reaction of soybean genotypes, adapted to the Cerrados, to SDS infection on field trials in areas with natural inoculum. Seventy one soybean genotypes were used in the experiments, sixteen early season, twenty eight midseason and twenty seven late season genotypes, in field trials located in four different rural properties around Brazil's Federal District. The experimental design used was the randomized complete block, with four repetitions. The characterization was performed using the levels of disease incidence and severity of foliar symptoms Genotypes with good levels of disease resistance were observed in all three maturity groups, cultivars and lines in the final stages of development

Inoculation methods under greenhouse conditions for evaluating soybean resistance to sudden death syndrome

The objectives of this work were to evaluate two greenhouse screening methods for sudden death syndrome (SDS) and to determine which one is best correlated with field resistance of soybean genotypes. The evaluations were done with three sets of genotypes that were classified as partially resistant, intermediate, and susceptible to SDS based on previous field evaluations. These three sets were independently evaluated for greenhouse SDS reactions using cone and tray inoculation methods. Plants were infected using grains of white sorghum [Sorghum bicolor (L.) Moench] infested with Fusarium solani f. sp. glycines. Foliar symptom severity was rated 21 days after emergence. The cone and field SDS ratings were significantly correlated and ranged from 0.69 for set 1 to 0.51 for set 3. Correlations of SDS ratings of genotypes between field and greenhouse tray ratings were significant for set 1 and not significant for set 2. The cone method showed the highest correlation with field results and is recommended to screen soybean genotypes for SDS resistance

SOIL CHEMICAL ATTRIBUTES IN RESPONSE TO TREE DISTANCE AND SUN-EXPOSED FACES AFTER THE IMPLANTATION OF AN INTEGRATED CROP-LIVESTOCK-FORESTRY SYSTEM

ABSTRACT The use of trees in integrated crop-livestock-forestry systems (ICLF) allows diversifying production, increasing profitability per area, and providing a higher animal comfort. However, the influence of tree component on soil chemical attributes in this system is still little studied. This study aimed to assess the effect of trees and sun-exposed faces to solar radiation on soil nutrient availability at different distances of tree rows in an integrated crop-livestock-forestry system. This study was carried out in the northern Mato Grosso State, Brazil, in the Cerrado - Amazon Forest transition region in an ICLF with the tree component formed by three eucalyptus rows. The assessment carried out in the second year of ICLF implantation considered the effect of tree distances (3, 6, 10, and 15 m) on two sun-exposed faces to solar radiation (north and south) on the main soil chemical attributes. Soil sampling was performed at depths of 0-0.05, 0.05-0.10, 0.10-0.20, and 0.20-0.30 m. The results indicated a homogeneity of the average nutrient contents obtained in the north and south-exposed faces, as well as in the comparison of the same distances in both assessed sun-exposed faces. Effects of trees on soil chemical attributes were verified only when an isolated analysis was carried out in the north-exposed face for K and Al contents. For these attributes, the increased distance in the row was associated with a reduction in their contents in the more superficial and deeper layers, respectively. Trees do not significantly affect soil nutrient availability in the first years of ICLF implantation in systems with homogeneity of solar radiation incidence in the sun-exposed faces although there may be discrete nutrient reductions with the distance of trees

CULTIVAR RELEASE-BRS 217 Flora: Early-maturing soybean cultivar

The soybean (Glycine max L. Merr.) cultivar BRS 217 Flora was developed by Embrapa and released forproduction in the states of Goiás, Minas Gerais, Bahia, Mato Grosso and the Distrito Federal, Brazil. It is resistant to stemcanker, frog-eye leaf spot, bacterial pustule, and partially resistant to powdery mildew