Search

O objetivo deste trabalho foi avaliar o acúmulo de matéria seca e de nutrientes de plantas forrageiras consorciadas com o milho safrinha, em função da adubação nitrogenada. As espécies Urochloa brizantha cv. Marandu, U. decumbens cv. Basilisk, U. ruziziensis cv. Comum e Panicum maximum cv. Tanzânia, com semeadura em meados de março, foram avaliadas em quatro municípios paulistas, em consórcio com o milho. Utilizou-se o delineamento experimental de blocos ao acaso, com quatro repetições, em parcelas subdivididas. Nas parcelas, foram avaliados os consórcios e nas subparcelas, quatro doses de nitrogênio em cobertura (0, 30, 60 e 90 kg ha-1). Foi determinado o acúmulo de matéria seca e de nutrientes pelas plantas forrageiras em três épocas: no florescimento, na maturidade fisiológica do milho e por ocasião da dessecação das forrageiras, em outubro. O acúmulo de matéria seca das forrageiras intensifica-se após a colheita do milho safrinha. Quando as forrageiras são semeadas na entrelinha do milho, a adubação nitrogenada em cobertura não interfere no acúmulo de matéria seca e de nutrientes pelas forrageiras, e o consórcio não afeta a produtividade de grãos de milho safrinha. The objective of this work was to assess the accumulation of dry matter and nutrients in forage plants intercropped with off-season maize, as a function of nitrogen fertilization. The species Urochloa brizantha cv. Marandu, U. decumbens cv. Basilisk, U. ruziziensis cv. Comum, and Panicum maximum cv. Tanzânia, with seeding in mid-March, were evaluated in four municipalities of São Paulo, Brazil, intercropped with maize. A randomized complete block design was used, with four replicates, in split-plots. The intercropped systems were evaluated in the plots, and four nitrogen topdressing fertilization rates (0, 30, 60, and 90 kg ha-1) were evaluated in the split-plots. Forage dry matter and nutrient accumulation were determined in three stages: flowering, maize physiological maturity, and at forage desiccation, in October. Forage dry matter accumulation increases after the harvest of off-season maize. When forages are planted in the corn inter-rows, topdressing nitrogen fertilization does not influence forage dry matter and nutrient accumulation, and intercropping does not affect off-season maize grain yield.

The concept of precision conservation can be defined as a set of space technologies and other procedures linked to mappable environmental variables, which can be used to program conservation management practices for natural resources that consider the variability of these variables in space and time within of natural or agricultural systems. In this context, structural loss of soil through human activities is considered, as with a process with a spatial and temporal variation. The management of soil aggregation conditions can contribute to more regenerative and sustainable agricultural processes. It allows spatial analysis technologies through georeferenced visual indicators or even the use of systems with automatic learning, known as deep learning. In this sense, a fair visual method was developed with an analysis of fuzzy logic to classify aggregates in terms of shape, surface roughness, and biogenic structures. Thus, in a second stage, a model of the artificial neural network was developed, capable of detecting and classifying different forms of soil aggregates, thus allowing a brief discussion of the theme and its potential for application in conservation management through the analysis of aggregates via systems automatic sorting. In this way, elements are presented for the motivation of research and development in adaptive technologies in supporting decision-making that can help integrate dynamic and spatial information in the understanding of the soil’s structural condition to preserve the soil more precisely. RESUMO O conceito de conservação de precisão pode ser definido como um conjunto de tecnologias espaciais e outros procedimentos ligados as variáveis ambientais mapeáveis, que podem ser utilizadas para programar práticas de gestão da conservação recursos naturais que levam em consideração a variabilidade dessas variáveis no espaço e tempo dentro de sistemas naturais ou agrícolas. Nesse contexto, considera-se a perda estrutural do solo por meio de atividades antrópicas, como com um processo com variação espacial e temporal. A gestão da condição de agregação do solo pode contribuir para processos agrícolas mais regenerativos e sustentáveis, pois permite a utilização das tecnologias de análise espacial, por meio de indicadores visuais georreferenciados ou mesmo a utilização de sistemas com aprendizado automático, conhecidos como deep learning. Nesse sentido, foi desenvolvido um método visual justaposto com uma análise de lógica fuzzy para a classificação dos agregados quanto à forma, rugosidade superficial e estruturas biogênicas. Assim, numa segunda etapa foi desenvolvido um modelo de rede neural artificial capaz de detectar e classificar diferentes formas de agregados do solo, permitindo dessa maneira, uma breve discussão da temática e seu potencial de aplicação na gestão conservacionista por meio da análise de agregados via sistemas automáticos de classificação. Dessa maneira, são apresentados elementos para a motivação de pesquisas e desenvolvimento em tecnologias adaptativas, no apoio à decisão que possam auxiliar a integração de informações dinâmicas e espaciais no entendimento da condição estrutural do solo com a finalidade de uma conservação dos solos com mais precisão.

Made available in DSpace on 2020-12-12T02:50:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-09-03 Intercropping forage grasses with upland rice is an alternative cropping system to improve agroecosystem diversification and could potentially enhance sustainability in tropical regions. However, nitrogen (N) immobilization and nutrient competition between rice and forage grasses could reduce rice grain yield and decrease overall productivity. Therefore, fertilizer N requirements of upland rice intercropped with forage grasses needs to be better defined. Field experiments were carried out during three growing seasons on a Typic Haplorthox soil in São Paulo state of Brazil. The experimental design was a randomized block design with a 3 × 4 factorial scheme with four replications. Treatments were cropping system [monocropped rice (Oryza sativa L.), rice intercropped with palisadegrass (Urochloa brizantha), and rice intercropped with guineagrass (Megathyrsus maximus) and sidedress N application rate (0, 40, 80, and 120 kg N ha−1). Intercropped grasses were sown between upland rice rows 30 days after rice emergence. On average, intercropping of rice with palisadegrass or guineagrass decreased rice shoot dry matter and grain yield by 11% and milled rice productivity by 10% compared with monocropped rice. Grain yield, grain protein, and milled productivity of rice increased as N application rate increased. Forage dry matter production (first and second cut) and crude protein (second cut) were greatest in the rice + palisadegrass intercropping system. Production of both forage grasses increased with up to 80 kg N ha−1 in the first cut and increased linearly with N in the second cut. Intercropping of rice with palisadegrass or guineagrass with 80 kg N ha−1 application resulted in the greatest land equivalent ratio (1.96 and 1.55, respectively). Relative N yield was greatest at 120 kg N ha−1 (220 and 173%, respectively). Although rice monocropping had greatest grain yield, intercropping systems with forage grasses were more favorable from both economic and environmental perspectives by enhancing plant diversification, nutrient cycling with forage grasses, land use production per unit area, and profitability throughout the year. UNESP Department of Soil Science College of Agricultural Science NIOO-KNAW Department of Microbial Ecology Netherlands Institute of Ecology USDA Agricultural Research Service NCSU Campus IAC Soils and Environmental Resources Center Instituto Agronômico de Campinas UNESP Department of Soil Science College of Agricultural Science

Glyphosate is the main tool for weed management in Brazilian citrus orchards, where weeds, such as Conyza bonariensis and Digitaria insularis, have been found with resistance to this herbicide. Field prospections have allowed the identification of a possible new case of glyphosate resistance. In this work, the susceptibility levels to glyphosate on three Amaranthus viridis L. populations, with suspected resistance (R1, R2, and R-IAC), collected in citrus orchards from the S&atilde, o Paulo State, Brazil, as well as their accumulation rates of shikimic acid, were determined. The fresh weight of the susceptible population (S) was reduced by 50% (GR50) with ~30 g ea ha&minus, 1 glyphosate, while the GR50 values of the R populations were between 5.4 and 11.3 times higher than that for S population. The LD50 (herbicide dose to kill 50% of individuals of a weed population) values of the S population were &le, 150 g ea ha&minus, 1 glyphosate, while the LD50 of the R populations ranged from 600 to 920 g ea ha&minus, 1. Based on the reduction of fresh weight and the survival rate, the R1 population showed the highest level of glyphosate resistance, which had GR50 and LD50 values of 248 and 918 g ea ha&minus, 1 glyphosate, respectively. The S population accumulated 240 &micro, g shikimic acid at 1000 &micro, M glyphosate, while the R1, R2, and R-IAC populations accumulated only 16, 43, and 33 &micro, g shikimic acid, respectively (between 5.6 to 15 times less than the S population). Enzyme activity assays suggested that at least one target site-type mechanism was involved in resistance. This result revealed the first report of glyphosate resistance in A. viridis reported in the world.

Made available in DSpace on 2020-12-12T01:48:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-03-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) In tropical regions, one of the primary difficulties in the sustainability of no-till systems is the maintenance of soil cover throughout the year. Intercropping corn (Zea mays L.) with tropical perennial grasses is an innovative approach to overcome this difficulty. However, the use of sidedress nitrogen (N) fertilization in this intercropping system remains incompletely studied. The effects of using sidedress N application rates (0, 50, 100 and 200 kg ha−1 N) on monocropped corn or corn intercropped with palisadegrass [Urochloa brizantha (Hochst. ex A. Rich.) R. Webster ‘Marandu’] or guineagrass [Megathyrsus maximum (Jacq.) R. Webster ‘Mombaça’] with respect to leaf nutrient concentration, agronomic characteristics, revenue and land use efficiency were investigated over three growing seasons in the Brazilian Cerrado region on a clay soil, kaolinitic, thermic Typic Haplorthox. In general, the intercropping systems of corn with palisade or guineagrass did not cause reductions in the leaf nutrient concentration, agronomic characteristics, kernels attributes, shoot dry matter and corn yield compared to that observed in the monocropped system. High sidedress N application rates promoted higher concentrations of nutrients in leaves (primarily N and P), corn yield, forage production and crude protein concentration in the off-season. Corn monocropped or intercropped with palisadegrass and guineagrass using 113, 156 and 187 kg ha−1 N resulted in the highest corn yields (9.2, 8.8 and 9.7 Mg ha−1, respectively). In addition, using these N application rates, corn intercropped with palisadegrass and guineagrass and subsequent meat production estimated on pastures resulted in the highest net profits (US$ 1196 and 1093 ha−1, respectively), whereas monocropped corn without N addition resulted in the lowest net profits (US$ 304 ha−1). Thus, forage produced during the off-season can be used for animal grazing or fodder during the dry season, increasing revenue. Corn intercropped with palisade grass with the addition of 200 kg ha−1 N resulted in a higher land equivalent ratio and relative N yield (1.21 and 123%, respectively). In summary, sidedress N fertilization in intercropped systems can increase crop and forage yields and revenue, improving land-use efficiency in tropical agriculture. São Paulo Agency of Agribusiness Technology (APTA) Department of Crop Science College of Agricultural Science São Paulo State University (UNESP) Department of Animal Nutrition and Breeding School of Veterinary Medicine and Animal Science UNESP College of Agricultural Science UNESP Corn and Sorghum Research Center Brazilian Agricultural Research Corporation (EMBRAPA) USDA – Agricultural Research Service, 3218 Williams Hall, NCSU Campus, Box 7619 Soils and Environmental Resources Center Instituto Agronômico de Campinas (IAC) Department of Crop Science College of Agricultural Science São Paulo State University (UNESP) Department of Animal Nutrition and Breeding School of Veterinary Medicine and Animal Science UNESP College of Agricultural Science UNESP FAPESP: 2003/01968-7 FAPESP: 2003/09914-3

Made available in DSpace on 2020-12-12T02:45:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01 Sewage sludge is a residual pollutant product from the treatment of urban effluent and must be adequately processed before final disposal in order to avoid environmental contamination. The use of sewage sludge in agricultural and forestry areas can improve the physical, chemical and biological properties of soil; it can also be a source of nutrients, increasing crop productivity. Accordingly, this study aimed to evaluate the growth and development of hybrid Eucalyptus urograndis (Eucalyptus grandis x E. urophylla) seedlings cultivated in soil with different doses of sewage sludge. To accomplish this, hybrid E. urograndis seedlings were cultivated for 120 days in pots containing soil (dystrophic Red-Yellow Latosol-LVA) with different doses of sewage sludge (0, 30, 60 or 90 Mg ha-1). The experiment was carried out in a randomized complete block design consisting of four treatments, three replications with four plants per replication, totaling 48 plants. Biometric, biomass and physiological variables (chlorophyll, gaseous exchange, stomatal conductance and transpiration); in addition to macro-and micronutrient contents in leaves and soils of each treatment were evaluated. The treatments with sewage sludge were statistically superior to control treatment for all variables. Therefore, we recommend the application of 60 Mg ha-1 sewage sludge for the growth of hybrid Eucalyptus urograndis seedlings. Conversely, 90 Mg ha-1 sewage sludge inhibited hybrid E. urograndis root growth. Moreover, the use of sewage sludge as organic fertilizer in tropical soils is a viable and sustainable alternative for Eucalyptus cultivation. Instituto de Botânica, Av. Miguel Stefano Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Av. Universitária Instituto Agronômico de Campinas, Avenida Luiz Pereira dos Santos Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Av. Universitária

Made available in DSpace on 2018-12-11T16:52:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-08-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The objective of this work was to evaluate the genetic parameters and estimate genetic gains in two populations of Hevea brasiliensis. The first population of the study is originated from the primary forest of Rio Branco – Acre (wild population – PS), and the other population is originated from clonal matrices (improved population – PM). Thirty-seven progenies were evaluated at 23 years for PS. For PM, 31 progenies at eight years of age were evaluated for growth traits and dry rubber yield. Estimates of the genetic parameters were made using the univariate linear mixed-model additive model REML/BLUP and gains in selection by the Multi-Effects Index (MEI) method. The selection strategies of 50%, 40% and 22% of individuals for the character of dry rubber yield (PBS) and stem perimeter (PAP) using the multi-effects index revealed high and low selection gains in both populations. For MP, the strategy of selection between and within progenies was more appropriate and for PS, the individual selection. The gains obtained in the selection were 54% for the PBS character in the improved population of 0.46% for the PAP character for the wild population. Universidade do Estado de Mato Grasso/UNEMAT, CP 08, Rua Prof. Dr. Renato Figueiro Varella Faculdade de Filosofia Ciências e Letras de Ribeirão Preto/USP Faculdade de Engenharia de Ilha Solteira/UNESP Instituto Agronômico de Campinas/IAC Faculdade de Engenharia de Ilha Solteira/UNESP

Made available in DSpace on 2018-12-11T17:25:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-08-22 Brazil is the largest producer of oranges (Citrus sinensis) in the world. The nutrient management of tree orchards is designed from experiments with a limited number of varieties. This knowledge is transferred to other varieties by diagnosing tissue nutrient composition and tree demand. Compositional data analysis has been first applied to tissue analysis of agricultural crops using centered log ratios with compositional nutrient diagnosis (CND-clr). The isometric log ratio (ilr) transformation is a new approach based on binary nutrient ratios and the principle of orthogonality (CND-ilr). We analyzed eleven nutrients: nitrogen (N), sulfur (S), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), boron (B), copper (Cu), zinc (Zn), manganese (Mn), and iron (Fe) in leaf tissue samples across 108 commercial plots (thirty-one grow Valencia, twenty-two Hamlim, twenty Pera, and thirty-five Natal). Nutrients were partitioned between macro- and micronutrients as well as anionic and cationic species. The effect size of varieties over Valencia was quantified by the mean and standard deviation of ilr values across ilr coordinates. Specific varietal nutrient profiles and ilr norms were defined. The nutrient profile of orange varieties could be classified into homogeneous groups to take advantage of fertilizer trials conducted on varieties of the same group. The Aitchison distance and a perturbation vector could be instrumental for diagnostic purposes and nutrient management. Universidade Estadual Paulista “Júlio de Mesquita Filho,” Instituto Agronômico de Campinas IAC / Centro de Citricultura Sylvio Moreira Université Laval / ERSAM Departamento des Sols et de Génie Agroalimentaire UNESP Departamento de Solos e Adubos Universidade Estadual Paulista “Júlio de Mesquita Filho,” UNESP Departamento de Solos e Adubos

Hevea brasiliensis is a native species of the Amazon Basin of South America and the primary source of natural rubber worldwide. Due to the occurrence of South American Leaf Blight disease in this area, rubber plantations have been extended to suboptimal regions. Rubber tree breeding is time-consuming and expensive, but molecular markers can serve as a tool for early evaluation, thus reducing time and costs. In this work, we constructed six different cDNA libraries with the aim of developing gene-targeted molecular markers for the rubber tree. A total of 8,263 reads were assembled, generating 5,025 unigenes that were analyzed; 912 expressed sequence tags (ESTs) represented new transcripts, and two sequences were highly up-regulated by cold stress. These unigenes were scanned for microsatellite (SSR) regions and single nucleotide polymorphisms (SNPs). In total, 169 novel EST-SSR markers were developed; 138 loci were polymorphic in the rubber tree, and 98 % presented transferability to six other Hevea species. Locus duplication was observed in H. brasiliensis and other species. Additionally, 43 SNP markers in 13 sequences that showed similarity to proteins involved in stress response, latex biosynthesis and developmental processes were characterized. cDNA libraries are a rich source of SSR and SNP markers and enable the identification of new transcripts. The new markers developed here will be a valuable resource for linkage mapping, QTL identification and other studies in the rubber tree and can also be used to evaluate the genetic variability of other Hevea species, which are valuable assets in rubber tree breeding. Electronic supplementary material The online version of this article (doi:10.1007/s11032-014-0095-2) contains supplementary material, which is available to authorized users.

Made available in DSpace on 2022-04-29T07:26:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-01-01 The experiment was carried out under greenhouse conditions to evaluate the effects of macronutrient omission, nutritional status, and development on peanut (Arachis hypogaea L.), as well to describe nutritional deficiency symptoms. The experiment was arranged in a completely randomized design with three replications and seven treatments, corresponding to a complete nutritive solution and individual omission of N, P, K, Ca, Mg, and S. The peanut plants cultivar Runner IAC 886 were grown in a Hoagland & Arnon nutrient solution in 5dm 3 pots. Plant height, stem diameter, leaves number, SPAD index, dry mass of aerial part, root, and hole plant, as well the nutritional disorder description were evaluated. The omission of K, Ca, N, P and Mg showed the higher growth limiter to the peanut growth, reducing considerably the plant height, stem diameter, number of leaves and also reducing the peanut dry mass production. Nutritional deficiency symptoms of each nutrient were observed. Macronutrient levels observed in peanut plants were, respectively to the control and to the treatment with nutrient omission were: N = 19.0 - 12.2, P = 4.07 - 1.1, K = 27.9 - 4.7, Ca = 10.4 - 1.6, Mg = 6.2 - 0.96, S = 1.2 - 0.7 g kg-1. Pós-Graduando em Agronomia (Produção Vegetal), Depto. de Solos E Adubos, UNESP Depto. de Solos E Adubos, Faculdade de Ciências Agrárias E Veterinárias, UNESP Pós-Graduandos em Agronomia (Ciência do Solo), Depto. de Solos E Adubos, UNESP Doutoranda em Agricultura Tropical E Subtropical, Instituto Agronômico de Campinas (IAC) Depto. de Ciências Exatas, Faculdade de Ciências Agrárias E Veterinárias, UNESP Pós-Graduando em Agronomia (Produção Vegetal), Depto. de Solos E Adubos, UNESP Depto. de Solos E Adubos, Faculdade de Ciências Agrárias E Veterinárias, UNESP Pós-Graduandos em Agronomia (Ciência do Solo), Depto. de Solos E Adubos, UNESP Depto. de Ciências Exatas, Faculdade de Ciências Agrárias E Veterinárias, UNESP

Made available in DSpace on 2021-07-14T10:37:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-06. Added 1 bitstream(s) on 2021-07-14T11:34:43Z : No. of bitstreams: 1 S0103-84782005000300005.pdf: 176140 bytes, checksum: 81d4b33eb147955533f381c34b51f582 (MD5) A enzima redutase de nitrato (EC 1.6.6.1) é a principal enzima responsável pela assimilação de nitrogênio pelas plantas e tem a atividade fortemente afetada pela disponibilidade de água no solo, por isso é usada como variável na avaliação das plantas em diferentes condições ambientais. Assim, este estudo teve como objetivo a padronização de metodologia para avaliação in vivo da atividade da redutase de nitrato em folhas e raízes de pupunheira com nove meses e um ano. As mudas foram cultivadas em casa de vegetação, e os ensaios realizados de acordo com método clássico de análise in vivo. O delineamento experimental foi inteiramente casualizado, com seis repetições. A atividade máxima da enzima em folhas foi obtida com tempo de incubação ao redor de 60 minutos, pH do meio de reação em torno de 7, temperatura de 35 a 37°C e concentração de nitrato entre 28 a 30mmolL-1. A atividade desta enzima foi maior em plantas com nove meses de idade. As folhas mostraram maior atividade da enzima quando comparadas com as raízes. A atividade da enzima redutase de nitrato variou ao longo do dia, com máxima obtida às 10:00 horas, mostrando a influência do período luminoso e do estado hídrico da planta. The nitrate reductase enzyme (EC 1.6.6.1) is the main responsible enzyme for the assimilation of nitrogen by plants and its activity is strongly affected by the soil water availability. This feature allows the use of this enzyme to evaluate plants in different environmental conditions. The objective of this study was to standardize the methodology to evaluate in vivo the nitrate reductase activity in leaves and roots of nine months and one year old peach palms (Bactris gasipaes). The plants were cultivated in a nursery and the essays were conducted according to the classical method of in vivo analyses. The experimental design was entirely randomized with six repetitions. The results showed that maximum nitrate reductase activity for leaves was obtained with an incubation time of 60 minutes, pH 7, temperatures from 35 to 37°C and, nitrate concentrations between 28 and 30mmol L-1. The nitrate reductase enzyme activity was higher in nine months than in one year old palms. The peach palm leaves showed higher enzyme activity than roots. The nitrate reductase activity varied during the day, with maximum activity at 10:00 hs, indicating an influenceby light and leaf water potential. Universidade Federal da Bahia Instituto Agronômico de Campinas, Centro de Ecofisiologia e Biofísica Universidade Estadual Paulista de Botucatu, Departamento de Botânica Instituto Agronômico de Campinas, Centro de Horticultura Universidade Estadual Paulista de Botucatu, Departamento de Botânica