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Brazil

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Segura S.,CRUCO | Andres J.,CRUCO | Fresnedo J.,CRUCO | Zavala F.,ITA 25 | And 7 more authors.
Acta Horticulturae | Year: 2012

Genetic resources information about seven Annonaceae species from Mexico were revised and linked to geography of the country. The collects of A. cherimolia, A. muricata, A. squamosa, A. reticulata, A. glabra, A. globiflora, and A. diversifolia are presented as species maps which represented regions where the climate is similar to that in sites where samples were collected. Some species showed evidence of intraspecific variation in their climatic adaptation. The eco-climatic diversity by means of cartographic representations permitted us to identify climatic particularities of these species. Complementary information about genetical resources of each species was revised focusing on studies in Mexico. Different species require different strategies to conserve and use their genetical resources. This study demonstrates how potential distribution and climatic suitability maps for Annona can complement genetic information in a way that delineates intelligent strategies for genetical resources studies by species. The research on Annona diversity in Mexico has been restructured by the Mexican Annonaceae Network (REMA) of the National System of Genetical Plant Resources and these results are expected to be a useful tool for planning collections, both ex situ and in situ conservation, breeding, and use of this group of fruit plants in the country.


Rubim R.F.,Fitotecnia | Vieira H.D.,Centro Ciencias e Tecnologia Agropecuaria | Araujo E.F.,Federal University of Viçosa | Viana A.P.,Centro Ciencias e Tecnologia Agropecuaria | Coelho F.C.,Centro Ciencias e Tecnologia Agropecuaria
Revista Brasileira de Sementes | Year: 2010

The objective of this study was to evaluate the effect of sodium hypochlorite on the removal of the parchment and the acceleration of conilon coffee seed germination. Seeds of the Vitoria cultivar were obtained from fruits harvested at the cherry stage and pulped by hand. They were dried in a forced ventilation oven until 35, 30 and 25% moisture content on a wet basis. Sodium hypochlorite solution in concentrations of 4, 5, 6 and 7% active chlorine was appliedto those seeds with parchment for periods of 3 and 6 hours. For each moisture content, there were three additional treatments consisting of seeds with parchment and seeds whose parchments had been removed mechanically and manually. The seeds were evaluated for: moisture content, germination, first count of the germination test and speed of the germination index. The experiment was a completely randomized design in a factorial 3 (degrees of water content) × 4 (concentrations of sodium hypochlorite) × 2 (time of immersion) + 9 (additional treatments) with four replications. Sodium hypochlorite at a concentration of 6% for 3 hours caused germination and a speed of germination index similar to the method of manual removal of the parchment, which is used in the laboratory. The mechanical removal of the parchment damaged coffee seeds, reducing their germination.


Madalao J.C.,Federal University of Viçosa | Pires F.R.,Federal University of Espirito Santo | Filho A.C.,Federal University of Santa Maria | Nascimento A.F.,Campus CEUNES | And 5 more authors.
Semina:Ciencias Agrarias | Year: 2012

This paper aimed to select species with potential for phytoremediation of soils contaminated with the herbicide sulfentrazone. Eight species were evaluated: Arachis pintoi, Eleusine coracana, Crotalaria spectabilis, Crotalaria ochroleuca, Cajanus cajan, Leucaena leucocephala, Stizolobium cinereum, and Raphanus sativus. The experiment was set-up inside a greenhouse, using pots with a capacity of 6dm3 filled with soil samples collected at a depth of 0-20cm. The experimental design was arranged into randomised blocks in a factorial scheme (8 × 5) with four replications, which consisted of the combination between the species and five doses of sulfentrazone (0, 200, 400, 800, and 1,600g ha-1). The herbicide phytotoxicity, plant heights, and dry masses of shoots and roots were evaluated. The species Cajanus cajan and Leucaena leucocephala had a higher tolerance to sulfentrazone up to a dose of 400g ha-1, showing minor symptoms of phytotoxicity and smaller decreases in plant heights and in dry matter accumulation, both in the shoots and roots, when compared to the control treatment, indicating, thus, the potential to be used for further studies on phytoremediation of sulfentrazone in soil.


De Freitas Costa Paiva M.R.,Fitotecnia | Da Silva G.F.,Ciencias Naturais | De Oliveira F.H.T.,UFERSA | Pereira R.G.,Fitotecnia | De Queiroga F.M.,Fitotecnia
Revista Caatinga | Year: 2012

The nitrogen (N) and phosphorus (P) generally are the two nutrients that occur in lower levels in the soil in relation to the need of the plant and are the nutrients most required by the maize crop. With the present work aimed to define the levels of N and P2O5 associated to the maximal economical of green corn in an alkaline soil of the city of Baraúna-RN. The maize hybrid AG 1051 was planted in spacing of 0.70 x 0.23 m and harvested on the condition of green corn to 75 days after planting. Were applied 17 treatments, being 16 treatments resulting from the combination between four doses of N (30, 60, 90 and 120 kg ha-1) and four doses of P2O5 (30, 60, 90 and 120 kg ha-1) and a control treatment, in which not applied any dose of these nutrients. The experimental design was in randomized blocks with four repetitions. The characteristics evaluated were: number and total weight of cobs, number and weight of marketable covered cobs and number and weight of marketable uncovered cobs. The increase of the availability of N and P in soil, as a result of fertilizing, positively influences positively the weight of green maize ears. The culture of green corn responded better to phosphorus fertilization than nitrogen fertilization, showing that in the soil of the experimental area the P was more limiting to the production than the N. Although the majority of production of marketable covered cobs has been estimated for the application of 120 kg ha-1 N + 106 kg ha-1 P2O5, the doses of maximum economic and environmental efficiency recommended were 60 kg ha-1 N + 106 kg ha-1 P2O5.


Teofilo T.M.S.,Agricola Famosa | Freitas F.C.L.,Dep. de Ciencias Vegetais | Medeiros J.F.,Dep. de Ciencias Ambientais | Fernandes D.,Fitotecnia | And 3 more authors.
Planta Daninha | Year: 2012

The objective of this work was to evaluate the effect of the conventional and no-tillage systems and weed management strategies on water use efficiency in melon crop (Cucumis melo). Thus, an experiment was carried out in a randomized block design in split-plots in Mossoró-RN. The plots were constituted of two tillage systems (conventional and no-tillage) and the sub-plots of three weed management systems (plastic mulch, weeding, and no weeding). Density and dry weight of the weeds at 30 days after transplanting, commercial and total yield and daily consumption of water were evaluated. Irrigation management was performed by the characteristic soil water curve for each cropping system at 15 and 30 cm of depth and water control by daily reading a set of tensiometers installed to keep the soil above 75% of field capacity. Water use efficiency (USA), given in kg of fruit per m3, was determined based on the crop's yield and water consumption. It was found that the no-tillage system reduced weed density and dry matter in 86.7 and 61%, respectively, compared to conventional tillage, and weed interference reduced commercial yield by 100% under conventional tillage and 36.5% under no-tillage. Soil with plastic mulch under no-tillage and conventional systems, and straw mulching under no-tillage reduced water consumption by 23% (388.8 m3 ha-1), 21% (363.0 m3 ha-1) and 13% (215.0 m3 ha-1), respectively, compared to the weeding treatment under conventional tillage. Soil with plastic mulch under the two tillage systems, or straw mulching under no-tillage increased the efficiency of water use from the ground without cover. In the no-weeding treatment under conventional tillage, weed interference caused total productivity loss and increased water consumption by 9.6%.


Petter F.A.,Federal University of Mato Grosso | Alves A.U.,Federal University of Piauí | Da Silva J.A.,Fitotecnia | De Almeida Cardoso E.,Federal University of Paraiba | And 3 more authors.
Semina:Ciencias Agrarias | Year: 2014

Cultural practices affect the production and physiological quality of soybean seeds, however the Cerrado these studies are still scarce. Therefore, this study aimed to evaluate the production and physiological quality of soybean seeds (cv. Monsoy 9350) in Piauí Cerrado under the influence of times and doses of potassium. We used a randomized block design in a factorial design, the treatments consisted of the combination of five doses of potassium (30 60, 90, 120 and 150 kg K2O ha-1) + aditional treatment (zero kg ha-1) applied four times: I. 100% at planting; II. 50 % at planting and 50% at 30 days after sowing (DAS); III. 100% at 30 DAS; IV. 50% at 20 DAS and 50% at 40 DAS, with four replications. The yield and harvest index of grain, thousand seed weight, seedling length, seedling dry weight, rate of germination, germination and first count. Regardless of the applied dose, there was no effect of application times on the parameters evaluated. Except for the germination and germination speed index, all other parameters were significantly influenced by K rates. The length and seedling dry weight increased with the increasing use of K, showing greater seed vigor. Doses of 80 to 95 kg ha -1 K2O provide the best results for all parameters evaluated.


da Silva E.C.,Federal University of Säo João del Rei | Maciel G.M.,Fitotecnia | da Alvarenga P.P.M.,Federal University of Alfenas | de Paula A.C.C.F.F.,Instituto Federal Of Educacao
Bioscience Journal | Year: 2011

This work was carried out at the Horticultural Section and Experimentation of the José do Rosário Vellano University - UNIFENAS, during the year of 2005. The objective was to evaluate carotenoid content in tomato fruit of industrial tomato plants in relation to potassium and phosphorus concentrations. The experimental design was randomized complete blocks distributed on a 2 x 3 x 3 factorial model containing three replicates: two tomato plant genotypes (1095 and 1570), three K2O concentrations (45, 90 and 180 kg ha-1) and three P2O5 concentrations (40, 80 and 160 kg ha-1). The characteristics evaluated were: lycopene and carotene contents and total sugar in the ripe fruits. The phosphorus and potassium concentrations did not influence significantly B-carotene, lycopene and total sugar in genotypes. Significant differences in the tenors of B-carotene between the genotypes had occurred.


Carvalho D.F.,Federal Rural University of Rio de Janeiro | De Oliveira A.D.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária | Pereira J.B.A.,Fitotecnia
Semina:Ciencias Agrarias | Year: 2011

This study was carried out at SIPA (Integrated Agroecological Production System), in Seropédica, RJ, Brazil, with the objective of generating models for characterizing variation and evolution of leaf area index (LAI) and total dry mass of Bell pepper as a function of degree days. Experimental design was of plots split in time, with three replications. The matematical models obtained by regression analysis on the basis of the significance of the coefficients, the F value in the variance analysis of regression, and higher determination coefficient (R 2). Based on adjusted curves for LAI and dry mass and in their respective maximum values degree days is a viable methodology for determination of crop phenological stages. The values of LAI and biomass accumulated by the plants were not significantly different between tillage systems. Bell pepper needed a total of 1533 degree days for completing its productive cycle, with maximum dry mass accumulation occurring at 1059 and 1148 degree days for conventional and no till cropping, respectively.

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