Eugênio Celso Emérito Araújo

Tolerância ao déficit hídrico em genótipos de feijão-caupi

ABSTRACT The objective of this study was to evaluate physiological and productive characteristics of cowpea underwater deficit and total irrigation, under soil and climate conditions of Teresina, Piaui State, in 2008. Thestomatal conductance, leaf water potential, leaf temperature and grain yield of twenty cowpea cultivarswere evaluated. Two experiments were carried out in a randomized block design with 20 treatments andfour replications, one under water deficit during the reproductive phase and another one under totalirrigation. The water deficit was obtained applying half of the water depth required by cowpea. The waterdeficit reduced 72% of the stomatal conductance, 40% the leaf transpiration, 62% of the leaf waterpotential, 60% of the grain yield and increased 11.7% the leaf temperature. Under water deficit, 13genotypes produced above average (466 kg ha -1 ), and BRS-Paraguacu, Pingo-de-ouro-1-2 andPingo-de-ouro-2 presented the best grain yield with712 kg ha -1 , 667 kg ha -1 and 642 kg ha

VARIABILIDADE DE CARACTERíSTICAS FÍSICAS E QUÍMICAS DE FRUTOS DE GERMOPLASMA DE BACURI DA REGIÃO MEIO-NORTE DO BRASIL

ABSTRACT – The objective of this study was to evaluate physical and chemical characteristics of bacury fruits collected fromselected plants of occurrence in the Mid-North region. The following fruit characteristics were analysed: length e width; averageweight; average polp weight; length to width ratio; peel thickness; percentage of peel; percentage of polp; percentage of seed; numberof seeds/fruit; number of partenocarpic section/fruit; total soluble solids content; titratable acidity, and total soluble soli ds content totitratable acidity ratio. Fruits were collected from 26 selected plants mapped in nine locations in Piaui and Maranhao States. Physicaland chemical fruit characterizatics were evaluated at the Plant Physiology Laboratory of Embrapa Meio-Norte, in Teresina, PI, Brazil.Fruit samples used varied in size according to the availability of fruit production from each selected plant. The variance analysisindicated significant effects for collect local and selected plants for all characteristics analysed, except for the number of partenocarpicsection/fruit for which did not have local effect. Average fruit weight and average polp weight; average fruit weight and fruit width;average polp weight and fruit width; fruit length and peel thickness; fruit length and percentage of peel; peel thickness and p ercentageof peel; and average fruit weight and fruit length showed high values for phenotypic correlations (r

Estimativa da área foliar da mangueira (Mangifera indica L.) cvs. Tommy Atkins e Haden, utilizando dimensões lineares

Reports on leaf area estimation in mango is rare and with little convergent results. The objective of this work was to determine the equations that best describe the relationship among the linear dimensions (length and maximum width) and the leaf area (LA) of mango cvs Tommy Atkins and Haden, allowing the fast and non-destructive estimation of the leaf area just using the length (L), the maximum width (W), or both. The leaf area of mango can be obtained multiplying the product of the length for the width, and by the factor 0,74 (in Tommy Atkins cultivar) or by 0,78 (in Haden cultivar), as well as using the equations: LA = 4,96349 L - 33,429 (R2=0,86); LA = 17,02964 W - 18,88065 (R2=0,85) and LA = 0,73499 (LxW) + 0,59459 (R2=0,92) in Tommy Atkins cultivar or LA = 5,35282 L - 33,17061(R2=0,88); LA = 19,09951W - 24,61777(R2=0,89) and LA = 0,76015(LxW) + 0,43257(R2=0,99) in Haden cultivar.

A cultura da manga sob diferentes regimes de profundidades do lençol freático em condições subúmidas

O conhecimento dos criterios agronomicos de drenagem para a cultura da manga e fundamental na elaboracao de sistemas de drenagem para areas com essa cultura e permite antecipar o seu comportamento sob diferentes niveis de drenagem do solo . O trabalho teve por objetivo avaliar as condicoes de aeracao e umidade do perfil de um solo arenoso (areia franca) sob diferentes regimes de profundidades do lencol freatico, para determinacao de criterios de drenagem para a cultura da manga, cultivar Keitt. O experimento seguiu um delineamento inteiramente casualizado, com quatro tratamentos (regimes de profundidades do lencol freatico as distâncias do dreno de 3,5 m; 10,5 m; 17,5 m e sem presenca de lencol freatico) e cinco repeticoes. As profundidades do lencol freatico e os teores de agua no perfil do solo em cada tratamento foram monitorados durante os periodos chuvosos, em tres anos consecutivos (1997-1999). Nao houve diferenca significativa entre as produtividades da cultura nos tratamentos. As diferencas nas profundidades do lencol freatico, nos tratamentos com drenagem, nao foram suficientes para diferenciar o estado da agua no solo nesses tratamentos. O lencol freatico, na profundidade media de 1,0 m, durante os cinco ou seis meses de periodo chuvoso, com recargas temporarias atingindo profundidades proximas da superficie do solo, seguidas de rebaixamento imediato do lencol freatico, nao foi suficiente para afetar o desenvolvimento e a produtividade da manga.

Cr/Al Oxide as Solid Acid Catalyst to Afford Babassu Biodisel

2g -1 ), pore size (7.0 µm), total acidity (182.28 µmol g -1 ), wherein Bronsted sites are the most active. Powder X-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) show three phases of the catalyst (Cr2O3/Na2Cr2O3/Al2O3), 0.25:0.25:0.50, respectively. The reaction reached conversion about 98.6% under the conditions: alcohol/oil molar ratio (24:1), catalyst to oil mass ratio of 3.0%, 15 h and 70 oC. The turnover frequency (TOF) found was 24.5 × 10 -4 s -1 . Kinetic of the reaction was researched over a temperature range of 60-80 oC. A pseudo first-order model was proposed with the activation energy (Ea) of 49.18 kJ mol -1 . CRAL is active in the biodiesel production for just one cycle, because in the second one it loses its activity. The leaching of catalyst is about 13%, demonstrating that the catalyst is not totally heterogeneous.