1,593 research outputs found
Utilização do modelo ZAE/FAO para a estimativa da produtividade do sorgo em Alagoas.
O manejo adequado, como a escolha da época de plantio ou o uso da irrigação, permite o maior aproveitamento dos recursos hídricos disponíveis no ambiente. Pode-se estimar a produtividade agrícola da cultura do sorgo através de modelos, desde que calibrados, permitindo variar os manejos. Dessa forma é possível conhecer a resposta da cultura à disponibilidade hídrica de cada local e sua variação ao longo do ano. Assim o objetivo do trabalho foi calibrar o modelo ZAE, estimar a produtividade e avaliar quais as épocas de plantio com menor risco para a cultura do sorgo no Estado de Alagoas. Para calibração do modelo ZAE/FAO foram utilizados dados provenientes do Programa de Melhoramento Genético de Sorgo do Nordeste na região de Araripina ? PE, após a calibração foram simulados os cenários para as cidades de Água Branca, Arapiraca, Palmeira dos Índios e Porto de Pedras, em Alagoas, baseados na época de plantio (a cada 10 dias) x CAD do solo (30, 40 e 65 mm) X sistema de plantio (sequeiro). O modelo apresentou ótimo ajuste, com R2 = 0,87; índice de Wilmont (d) = 0,94; índice de confiabilidade (IC) de 0,87. As produtividades variaram de 1,8 a 1,9 Mg ha-¹, em Água Branca, de 3,7 a 4,1 Mg ha-¹ em Arapiraca, 1,9 a 2,0 Mg ha-¹ em Palmeira dos Índios, 2,2 a 2,3 Mg ha-¹ em Porto de Pedras, no mês de plantio mais produtivo
Polymorphism in the internal transcribed spacer (ITS) of the ribosomal DNA of 26 isolates of ectomycorrhizal fungi.
Inter- and intraspecific variation among 26 isolates of ectomycorrhizal fungi belonging to 8 genera and 19 species were evaluated by analysis of the internal transcribed sequence (ITS) of the rDNA region using restriction fragment length polymorphism (RFLP). The ITS region was first amplified by polymerase chain reaction (PCR) with specific primers and then cleaved with different restriction enzymes. Amplification products, which ranged between 560 and 750 base pairs (bp), were obtained for all the isolates analyzed. The degree of polymorphism observed did not allow proper identification of most of the isolates. Cleavage of amplified fragments with the restriction enzymes Alu I, Hae III, Hinf I, and Hpa II revealed extensive polymorphism. All eight genera and most species presented specific restriction patterns. Species not identifiable by a specific pattern belonged to two genera: Rhizopogon (R. nigrescens, R. reaii, R. roseolus, R. rubescens and Rhizopogon sp.), and Laccaria (L. bicolor and L. amethystea). Our data confirm the potential of ITS region PCR-RFLP for the molecular characterization of ectomycorrhizal fungi and their identification and monitoring in artificial inoculation programs
Feedlot pen surface greenhouse gases emissions from Nellore or Brangus bulls finished on diets with contrating fat levels.
The objective of this study was to evaluate greenhouse gases (GHG) emissions from a feedlot pen surface where Nellore and Brangus bulls were fed diets with low or high fat
Classificação climática e regionalização do semi-árido do Estado do Piauí sob cenários pluviométricos distintos.
A incorporação de cenários pluviométricos a estudos de classificação e regionalização climática torna-os mais ajustados e adequados à variabilidade natural das precipitações e às expectativas pluviométricas dos modelos numéricos de previsão climatológica em uso no Brasil. Este trabalho apresenta uma nova proposta de classificação climática e regionalização da região semi-árida do Estado do Piauí, utilizando-se o índice de umidade de Thornthwaite, obtido de balanços hídricos efetuados em diferentes cenários pluviométricos (anos secos, regulares, chuvosos e médios). O emprego de um sistema de informação geográfica permitiu a definição da percentagem da área dos municípios sob os diferentes tipos climáticos, em cada cenário pluviométrico. Foram definidos seis tipos climáticos: árido (E), semi-árido (D), sub-úmido seco (C1), sub-úmido (C2), úmido (B1) e úmido (B2), cujas áreas de ocorrência no Estado variaram de acordo com o cenário pluviométrico. A regionalização da região semi-árida (áreas com tipos climáticos E e D) apresentou ampla faixa de variação com o cenário pluviométrico e o critério de classificação climática adotado. No cenário regular, a delimitação da região semi-árida oscilou de 87,8% a 14,1% da área do Estado, abrangendo 199 e 34 municípios, respectivamente, dependendo do critério de classificação climática. A variabilidade observada, em termos de área e de número de municípios, expressa a tendência natural da variabilidade temporal e espacial da precipitação, refletida na caracterização dos cenários pluviométricos mais compatíveis com a realidade física
Correlation of shear strength and physicochemical properties as a criterion for the selection of accessions of Paspalum grasses.
The present study aimed to evaluate the application of shear strength and its correlations with leaf blade morphological and chemical variables as a tool capable of detecting differences between species and accessions of the genus Paspalum in the early stages of a forage plant breeding programme. A total of 13 Paspalum accessions from two species (Paspalum atratum and Paspalum regnellii) were subjected to analyses of shear strength, which also analysed the neutral detergent fibre, acid detergent fibre, lignin, and digestibility. Morphological measurements were also performed to standardize the shear strength per unit of leaf tissue. The experimental design consisted of complete randomized blocks, with four replications and eight cuts performed over 2 years. Shear strength was evaluated for its potential usefulness for detecting differences between accessions of the same species and the correlations of accessions. It was possible to use the shear strength measured with the texturometer to detect differences between species and accessions of the Paspalum genus. The results showed significant correlations of shear strength and neutral detergent fibre (r = 0.49), and negative correlations were found between digestibility and shear strength (r = -0.55). These correlations were maintained when the strength variables were standardized according to the morphological variables. Thus, shear strength can be used in the initial stages of the selection of species of the genus Paspalum
Analysis of volatiles of rose pepper fruits by GC/MS: drying kinetics, essential oil yield, and external color analysis
Condiments and culinary supplements are subjected to long-term storage and may undergo physical, chemical, and biological
changes that can influence their quality. )us, the objective of the present study was to analyze the drying kinetics of rose pepper
(Schinus terebinthifolius Raddi) fruits in an oven with forced air circulation at different temperatures, namely, 45, 55, 65, and 75°C,
and determine the effective diffusion coefficient and activation energy using different mathematical models. Furthermore, the
effects of the different drying temperatures were analyzed for external color parameters and yield of essential oil contents by gas
chromatography coupled to a mass spectrometer. Of the ten models used for fitting, )ompson’s model was one with the best
fitting to represent the drying of rose pepper fruits. )e diffusion coefficient increases with the elevation of drying air temperature,
described by the Arrhenius equation, with activation energy of 53.579 kJ·mol− 1. )e color of the fruits decreased in lightness (L∗)
with the increase in temperature. Of the thirty-eight terpenes identified, α-pinene and cis-ocimene were the most abundant, with
the overall highest yield being found at a drying temperature of 45°C.)e authors acknowledge the Laboratory of Post-Harvest of
Plant Products, Laboratory of Natural Products, CAPES,
FAPEG, FINEP, CNPq, CONAB, and IF Goiano, Campus of
Rio Verde, for the indispensable financial support to conduct
this study. )e authors are also grateful to the Foundation
for Science and Technology (FCT, Portugal) for
financial support through national funds FCT/MCTES to
CIMO (UIDB/00690/2020). L. Barros acknowledges FCT,
P.I., for the national funding through the institutional scientific
employment program contract. M. Carocho acknowledges
FCT for the individual scientific employment
program contract CEECIND/00831/2018. )is work was
funded by the European Regional Development Fund
(ERDF) through the Regional Operational Program North
2020, within the scope of Project NORTE-01-0247-FEDER-
113508: Bio4Drinks®, which T. Finimundy acknowledges.info:eu-repo/semantics/publishedVersio
Zoneamento de aptidão e de risco climático para a cultura da mamona no Estado do Maranhão.
Introdução; Metodologia; Zoneamento de aptidão agroclimática; Zoneamento de risco climático; Indicações do Zoneamento de Aptidão Agroclimática e de Risco Climático; Zoneamento de aptidão agroclimática; Zoneamento de risco climático; Conclusões.bitstream/item/37182/1/Doc93.pd
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