Walter Esfrain Pereira

Divergência genética entre acessos e cultivares de mamoneira por meio de estatística multivariada

This work aimed to evaluate genetic divergence among castor bean (Ricinus communis L.) cultivars, in order to enable the choice of parents which make the formation of segregating populations possible. Accesses BRA 4871, BRA 2968, BRA 5550 and BRA 7722 Papo-de-gia, and cultivars BRS 188 Paraguacu, BRS 149 Nordestina, IAC-80, Mirante-10 and Pernambucana Melhorada were evaluated. Characteristics analyzed were: days to flowering, number of racemes per plant, length of pistillate region of main raceme, plant height, potential yield, and seed oil content. The genetic divergence among accesses and cultivars was studied by multivariate analysis techniques, with canonical variables and cluster analysis, making use of mean euclidean distance. Two groups were formed: group I, formed by eight genotypes; and group II, formed by one genotype, cultivar Mirante-10. In spite of being the more divergent, cultivar Mirante-10 should not be recommended for hybridization due to its low medium performance. The other cultivars also presented restrictions, as they were quite similar. The variables that more contributed to the genetic divergence were: days to flowering, length of pistillate region of main raceme, plant height, and seed oil content.

Produção do pimentão adubado com esterco bovino e biofertilizante

With the objective of evaluating bell pepper fertilized with cattle manure with and without biofertilizer, an experiment was carried out from January to June 2004, in Quarts Psamment at UFPB, Areia, PB, Brazil. The experimental design was randomized block, with three replications in sub-divided plots. The plot was constituted by 32 and the sub-plot by 16 plants, spaced at 1.00 x 0.50 m. In the plots, six levels of cattle manure (0, 10, 20, 30, 40 and 50 t ha-1) were appraised, while in the sub-plots the forms of application of the biofertilizer (with and without application of biofertilizer in the soil and spraying on the leaves) and an additional treatment with mineral and organic fertilizer. In the absence of biofertilizer, 28 t ha-l estimated level of cattle manure was responsible for maximum yield of fruits per plant (389 g) and for commercial fruits (7.8 t ha-l), while biofertilizer used in spray application, the levels of 14.5 and 14.0 t ha-l of cattle manure, respectively, promoted maximum production of fruits per plant of 485 g and maximum productivity of commercial fruits of 9.6 t ha-1. The biofertilizer presence into the soil, promoted mean production of 410 g of fruits per plant and productivity of 8.3 t ha-1 of commercial fruits, in function of cattle manure. The combination cattle manure and biofertilizer in the leaves was the best organic fertilization form in the bell pepper, with additional of 1.8 and 1.3 t ha-1 in the productivity of commercial fruits, comparing with those obtained with cattle manure and biofetilizer used in the soil, respectively. There is no significance difference among organic treatments and conventional fertilization in the bell pepper productivity.

Yield of sweet potato fertilized with cattle manure and biofertilizer.

In Northeastern Brazil, the sweet potato is cultivated in small farms, in a family farming systems, constituting themselves an alternative way for the generation of food, employment and income. This study aimed to assess the effect of cattle manure levels and biofertilizer concentrations on the sweet potato cultivar White Queen productivity. The experiment was carried out from March to September 2007 at the EMEPA Experimental Station in Lagoa Seca, Brazil. The experimental design was randomized blocks, in split split plot 6 x 4 x 2 + 1 scheme, with four replications. The plots consisted of cattle manure levels (0, 10, 20, 30, 40 and 50 t ha -1 ), the subplot of biofertilizer concentrations (0, 15, 30 and 45%) and the sub subplots consisted of methods of biofertilizer application, to the soil or leaves. Also, there was an additional control treatment using N, P and K mineral fertilizer. Commercial and total root productivity was evaluated. The levels of 30.8 and 31.2 t ha -1 of cattle manure were responsible for the highest commercial and total sweet potato root productivity (17.4 and 13.1 t ha -1 , respectively). Biofertilizer concentrations of 29 and 28%, applied to soil and to leaves provided, respectively, the greatest productivities of total roots (15.4 and 13.1 t ha -1 ), whereas concentrations of 30 and 27%, also applied to soil and leaves were responsible, respectively, for the highest commercial root productivity (11 and 9.7 t ha -1

Desenvolvimento e qualidade nutricional de mudas de mangabeiras cultivadas em substratos contendo fibra de coco e adubação fosfatada

In order to produce good quality seedlings it is necessary to use a mixture that presents appropriate physical, chemical and biological properties, which supplies the necessary conditions for the germination and the seedlings establishment. This experiment was carried out at the Agricultural Sciences Center, Paraiba Federal University (Brazil), whose objective was to evaluate the growth and the mineral composition of Hancornia speciosa seedlings in substrata composed by concentrations of coconut fiber from 0% to 40%, manure bovine from 0% to 25%, soil from 25% to 70%, sand 15% and triple superphosphate between 0 and 11 g dm-3. The soil and coconut fiber had beneficial effects on the H. speciosa seedlings with the increase of its concentrations in the mixture. The addition of the manure and the doses of triple superphosphate provoked a decrease in the matter and in the foliate area in the H. speciosa seedlings. There was an increase of the nutrients content in the seedlings in which there was an increase of the manure concentration in the mixture. It is recommended to use the concentrations of 14% of manure, 56% of soil, 15% of coconut fiber, 15% of sand and 4 g dm-3 of triple superphosphate, for the maximum estimated values of growth and nutritional composition.

Desidratação da polpa de tamarindo pelo método de camada de espuma

The foam-mat drying process was studied for the tamarind pulp at 50, 60, 70 and 80oC and the temperature effect on the tamarind powder were evaluated as regards to ascorbic acid content, total titratable acidity and colour, expressed by luminosity (L*) and hue (ho). For the representation of the drying process three models for thin-layer were applied and the criterion of evaluation used were the coefficient of determination (R2) and root mean square error (DQM). According to the results the temperature is a determinant parameter in the drying process, and the Midilli and Kucuk model was the best one to represent the behavior of the drying curves. The best results for ascorbic acid content, titritable acidity and colour were obtained at the temperatures of 60 and 70 oC.

Conservação pós-colheita de banana cv. nanicão climatizada e comercializada em Cuiabá - MT e região

The banana cv. Nanicao is the main cultivated and marketed in the Brazilian and world markets. Most of this banana marketed in the State of Mato Grosso comes from another States, and Mato Grosso presents edaphoclimatic conditions to be sufficient in the production of this cultivar and besides to assist other markets. The objective of this work it was to verify the conditions of the climatization of bananas cv. Nanicao and its influence in the post harvest conservation of fruits produced in Mato Grosso (MT) and coming from Santa Catarina State (SC). Twelve boxes were accompanied, weighting around 21 kg of bananas cv. Nanicao picked in the municipal district of Campo Verde-MT, in commercial orchard and also 12 boxes originated from SC. Previously of the climatization period, and during the whole period of useful life of the fruits, the temperature and relative humidity, the evolution of the coloration of the fruits and their weight loss, the total soluble solids and titratable acidity in the green and mature fruits were monitored. The largest period of useful life of banana coming from SC was verified, 3 day after the retreat of the climatization camera, turning totally yellow and with maximum values of 7,07% of loss of fruit weight. The banana cv. Nanicao produced in MT reached values of weight loss 5,69% in the 2nd day, when after that period it would not be appropriated for commercialization. The coloration of the fruits developed to yellow, and in some bunches they continued with green points, while other already began the senescence (brown points), being this smaller difference in bananas of MT, which reached a paler yellow coloration. These alterations can be related, respectively, with the lack of efficient circulation of the ethylene and the low relative humidity, around 65%, during the climatization.

Qualidade de frutos do coqueiro-anão verde fertirrigado com nitrogênio e potássio

Field experiments were conducted to investigate the effect of fertirrigation using nitrogen and potassium on the average weight of coconut and pH, soluble solids content, volume and electrical conductivity of coconut water. The experiment was carried out in a three-year old experimental field of green dwarf coconut (Cocos nucifera) located at Parnamirim, RN between April 2000 and May 2002. A Plan Puebla matrix was used in order to generate experimental groups with different combinations of nitrogen and potassium concentrations within a range of 135 g plant-1 year-1 to 2565 g plant-1 year-1. The statistical design consisted of randomized blocks with four replications. Nitrogen and potassium levels affected the average weight of coconut. The highest weight (2.23 kg) was reached when 881 g of nitrogen plant-1 year-1 and 1689 g of potassium plant-1 year-1 were used. Coconut water volume was also affected by both nutrients, since the maximum volume observed (417.75 mL) was found when 818 g of nitrogen plant-1 year-1 and 1487 g of potassium plant-1 year-1 were tested. Nitrogen and potassium levels also demonstrated a linear effect on the soluble solids content of coconut water, where nitrogen had a negative and potassium a positive effect on it. A negative linear effect was observed between nitrogen concentration and electrical conductivity of coconut water, while it was observed that potassium levels showed a quadratic effect on this same parameter.

Expression of Xylella fastidiosa RpfF in Citrus Disrupts Signaling in Xanthomonas citri subsp. citri and Thereby Its Virulence

Xylella fastidiosa and Xanthomonas citri subsp. citri, that cause citrus variegated chlorosis (CVC) and citrus canker diseases, respectively, utilize diffusible signal factor (DSF) for quorum sensing. DSF, produced by RpfF, are similar fatty acids in both organisms, although a different set of genes is regulated by DSF in each species. Because of this similarity, Xylella fastidiosa DSF might be recognized and affect the biology of Xanthomonas citri. Therefore, transgenic Citrus sinensis and Carrizo citrange plants overexpressing the Xylella fastidiosa rpfF were inoculated with Xanthomonas citri and changes in symptoms of citrus canker were observed. X. citri biofilms formed only at wound sites on transgenic leaves and were thicker; however, bacteria were unable to break through the tissue and form pustules elsewhere. Although abundant growth of X. citri occurred at wound sites on inoculated transgenic leaves, little growth was observed on unwounded tissue. Genes in the DFS-responsive core in X. citri were downregulated in bacteria isolated from transgenic leaves. DSF-dependent expression of engA was suppressed in cells exposed to xylem sap from transgenic plants. Thus, altered symptom development appears to be due to reduced expression of virulence genes because of the presence of antagonists of DSF signaling in X. citri in rpfF-expressing plants.

Estado nutricional de pinheira sob adubação orgânica do solo

From August 2009 to July 2010, an experiment was conducted in a sugar-apple orchard (Annona squamosa L.) in the town of Remigius PB, in order to evaluate the levels of macro and micronutrients and the leaf tissue of the plants in a soil treated with cattle manure and poultry litter. The treatments were distributed into randomized blocks, with plots split with time, three replications and two plants per plot, in a 2 × 5 × 2 factorial arrangement, corresponding to two sources of organic matter of animal origin (cattle manure and poultry litter), five doses of organic material by volume (0.0, 3.5, 5.3, 7.1 and 8.9%), and two periods of plant evaluation, 36 and 48 months after transplanting. The doses of organic material were set based on the organic-matter content of each source. With the exception of magnesium and zinc, the organic-matter sources did not differ statistically from the levels of other nutrients in the leaf dry-matter of the plants. The greatest accumulation of nutrients in the leaf dry-matter of the sugar apple was in the dosage-range of between 6.01 and 8.65% of organic matter.

Comprimento das estacas e parte do ramo para formação de mudas de pinhão-manso

Jatropha curcas is traditionally propagated by seed. However, in several situations the vegetative propagation is an important alternative and its technology needs to be developed. The objective of this study was to evaluate how the length and the portion of the branch from where the cuttings are extracted, influence the rooting and growth capacity of Jatropha cuttings. The treatments were arranged in a 3 x 4 factorial design, with three cutting positions (apical, middle and basal) and four cutting lengths (10, 15, 20, and 25 cm). A completely randomized design with four replications and ten cuttings per plot was adopted. At 70 days after planting, the cuttings were evaluated for the number of sprouts and branches, branch length, number of leaves, leaf area, number of roots, and dry mass of shoots and roots. The position from where the cuttings are extracted (apical, middle or basal) did not influence its capacity for rooting and the growth of the seedlings. The cutting length influences the initial growth, and the best growth was obtained in cuttings of around 22 cm.