Alberício Pereira de Andrade

Gramíneas e leguminosas na recuperação de áreas degradadas: efeito nas características químicas de solo

Com o objetivo de avaliar a eficiencia de duas leguminosas e duas gramineas na melhoria das caracteristicas quimicas do solo (carbono orgânico, CTC efetiva e potencial e teores de P, K, Na, Ca, Mg, H + Al e pH do solo), considerando a profundidade e a posicao de coleta das amostras, foi realizado experimento com arranjo fatorial em parcelas subdivididas, utilizadas anteriormente para estudos de perdas de solos por erosao, em um Nitossolo Vermelho eutrofico textura argilosa, localizado no municipio de Alagoinha (PB). Os tratamentos utilizados constituiram-se de duas leguminosas (feijao guandu - Cajanus cajan L. e siratro - Macroptilium atropurpureum L.), duas gramineas (capim-pangola - Digitaria decumbens L. e capim-elefante - Pennisetum purpureum L.) e parcela desnuda (testemunha), com tres repeticoes. A utilizacao das leguminosas e das gramineas promoveu aumentos nos teores de carbono orgânico total e na capacidade de troca de cations; promoveu, tambem, aumento nos teores de potassio, materia orgânica e magnesio, principalmente na camada superficial. O maior acumulo de liteira foi conseguido com o capim-elefante, sendo este acumulo maior na posicao inferior das parcelas em todos os tratamentos.

Produtividade e qualidade da flor-de-seda em diferentes densidades e sistemas de plantio

Avaliou-se o efeito de dois sistemas de plantio (sem camalhao e com camalhao) e de tres espacamentos (1,0 × 1,5 m; 1,5 × 2,0 m; e 2,0 × 2,0 m) sobre a qualidade e a produtividade de flor-de-seda aos 60 dias de rebrotacao. Utilizou-se o delineamento experimental com blocos casualizados em esquema fatorial 2 × 3 (dois sistemas de manejo do solo e tres densidades de plantio) com cinco repeticoes, em parcelas subdivididas no espaco e no tempo. Plantas escolhidas aleatoriamente foram cortadas, separadas por tratamento e analisadas quanto aos teores de materia seca (MS), materia orgânica (MO), cinzas, extrato etereo (EE), proteina bruta (PB), fibra em detergente neutro (FDN), fibra em detergente acido (FDA), celulose, hemicelulose, lignina, carboidratos nao-fibrosos (CNF) e carboidratos totais (CT) e quanto a produtividade (kg MS/ha). Os sistemas de manejo do solo e as densidades de plantio nao influenciaram a composicao em MO, cinzas, FDN, EE, lignina, celulose, CNF e CT. As densidades de plantio influenciaram o teor de hemicelulose e FDA. O sistema de manejo do solo com camalhao teve efeito linear decrescente sobre o teor de PB. A maior produtividade de MS (699,72 kg/ha) da flor-de-seda foi verificada no sistema de plantio mais adensado (1,0 m × 1,5 m) e correspondeu a 6.666 plantas/ha.

Yield of bell pepper cultivated in greenhouse under different doses of nitrogen through fertirrigation

Aiming to evaluate the effect of doses of nitrogen applied via fertirrigation on the yield of bell pepper cultivated in greenhouse, this work was conducted at the Center of Agrarian Sciences - UFPB. The experiment consisted of five treatments (0, 100, 200, 300 and 400 kg ha-1 of N) and 4 repetitions. Total, commercial and non-commercial fruit yields were evaluated, and the relationship between the leaf area and the leaf area index with the yields were determined. The doses of nitrogen influenced linearly and positively the total (commercial plus non-commercial fruits) and for the commercial yield of fruits, and for non-commercial fruits of the bell pepper a quadratic function was observed. The thermal accumulation of the bell pepper to reach the phase of larger yield was of 1.668 oC, and to complete its whole phenologic cycle, 2.155 GDA were necessary. The leaf area and the leaf area index affected the total yield of fruits of bell pepper, in a linear and positive way. The leaf area index showed itself to be satisfactory for the conditions of this experiment, demonstrating that the density of the plants used was adequate.

Varabilidade temporal da precipitação pluvial: nível de nitrogênio no solo e produtividade de cultivares de girassol

With the aim of analyzing the effects caused by temporal variability of rains over sunflower (Helianthus annuus L.) tillage income and development in function of nitrogen fertilization and cultivars, experiments with sunflower tillage were performed in Alagoinha-PB in the years of 1995,1996,1998 in the municipal district of Esperanca-PB in 1998. In this occasion four levels of nitrogen were verified (0, 30, 60 and 90kg.ha-1), two cultivars (one precocious and another late) in blocks at random with four repetitions. Beyond these experiments, some data about pluvial precipitation were analyzed. During the performance of the experiments we analyzed the tillage phenological stages, biomass accumulation and income and its components. In relation to the results, was verified in Alagoinha-PB an annual average rains of this period (1981 - 1999) around 1.018,6mm. The sunflower vegetative and reproductive stages have changed according to the distribution of rains during the tillage cycle. The adopted treatment answers for tillage over the analyzed variations were depending on the distribution of rains during the tillage development stages. There was also a big variation in the tillage answers in relation to the nitrogen levels and in the cultivars in function of weather.

Espécies da Caatinga como alternativa para o desenvolvimento de novos fitofármacos

Grande parte do semiarido brasileiro encontra-se em avancado processo de degradacao e poucos estudos direcionam seu desenvolvimento em consonância com essa realidade. Diante deste contexto, foi realizado um levantamento etnobotânico, a fim de subsidiar pesquisas sobre fitofarmacos ocorrentes em especies da Caatinga. Para tal, foram aplicados questionarios a 256 familias, visando a documentar o conhecimento local referente as especies arbustivo-arboreas utilizadas como medicinais pela populacao rural do municipio de Monteiro-PB. Procurou-se, por meio do levantamento floristico de um fragmento florestal, com aproximadamente 30 anos de conservacao, verificar a distribuicao das especies citadas nas entrevistas. Constataram-se 37 especies identificadas no fragmento florestal avaliado e 38 no levantamento etnobotânico, com 14 especies em comum entre os levantamentos. As especies Myracrodruon urundeuva, Sideroxylon obtusifolium, Amburana cearensis, Triplaris gardneriana, Anadenanthera colubrina, Hymenaea courbaril e Bauhinia cheilantha apresentaram-se promissoras para pesquisas voltadas a obtencao de fitofarmacos.

Características de frutos de pimentão cultivado em ambiente protegido sob doses de nitrogênio via fertirrigação

This study was conducted at the Center of Agricultural Sciences-UFPB, from February to June 2004, aiming to evaluate the effect of applied doses of nitrogen via fertigation, on the characteristics of bell pepper fruits cultivated in greenhouse. The adopted experimental design was in randomized blocks, with five treatments (0, 100, 200, 300 and 400 kg ha-1) and 4 repetitions. Length, diameter and mean weight of fruits and number of fruits per plant were evaluated. Significant effects of the doses of nitrogen were verified on the diameter, mean weight and total, commercial and noncommercial number of fruits of bell pepper. The length of fruits of the bell pepper was not influenced by the doses of nitrogen; however, the obtained values are within the standard average for the studied variety. The maximum dose of nitrogen (400 kg ha-1) promoted an increment of 7.3 (increase of 133%) fruits considered of commercial quality in relation to the control (0 kg ha-1). The fruits recognized as noncommercial showed an excellent aspect, in their appearance and hygiene quality, with just their length and diameter below the estabilished standards.

Caracterização morfológica de frutos e sementes e desenvolvimento pós-seminal de Tamarindus indica L. - Leguminosae: caesalpinioideae

Tamarind (Tamarindus indica L.) is a fruit tree native of tropical Africa, belonging to the Leguminosae family and nowadays is spread along tropical regions of the world. Fruit and seed morphologic characterization is important for species identification and has been used in studies on seed germination and vigor. The main aim of this research work was to describe fruit, seed and seedlings morphology as well as characterizing its germination process. Fruit traits analyzed were type, color, dimensions, texture and consistency of pericarp, dehiscence and number of seeds for fruit. On the other hand, seed traits were scored as to color, dimensions, texture and consistency of the teguments, shape, edges, position of hilum and other structures and embryo characteristics. Seedlings were recorded when protophylls development had already been complete. Radicle, collect, hypocotyl, cotyledons, epicotyl and protophyll have been described and illustrated. T. indica presents an indehiscent fruit with dimensions around 7.3 and 9.2cm and containing 1-11 seeds. The embryonic axle is axial and invagined and is inserted into cotyledons. Seed germination is an epigeal-type and seedlings present protophyll composites with 6 and 9 pairs of opposing and glabrous and small leaflets.

Atributos físicos e químicos do solo de Áreas sob Pastejo na Micro Região do Brejo Paraibano

The increased intensity of land use and declining native vegetation in northeastern Brazil have led to degradation of natural resources and in particular to the decline of soil fertility.The present study aimed to assess changes in soil physical and chemical properties in secondary areas of native forest and pasture in the microregion of swamp Paraiban. Three areas were selected in the Engenho Mineiro property, whose land area was classified as Alfissol, and represented by pasture grass Brachiaria ssp which is being explorated for over 25 years with clear signs of degeneration and the other by a area of secondary native forest. The design was completely randomized in a split-plot with five replications. Soil samples were collected from 0-10, 10-20 and 20-30cm. Due to the unevenness of the area proceeded collect in line in curve level, 10.0m apart from each other. The physical attributes evaluated were: bulk density and particle, total porosity, degree of flocculation, and totality native clay, degree of flocculation, aggregate dry and wet mean weight diameter and determination of the distribution of macro and micro aggregates separated by dry and wet. For the chemical attributes were determined pH values in water and calcium, magnesium, phosphorus, potassium, aluminum, hydrogen + aluminum, and organic matter (OM) for the areas and depths studied. The soils of, in general, showed low fertility. From the results, it was found that changes in the the original coverage cause an increase in pH and reduction in organic matter content. The area cultivated with pasture presented higher values of soil density, density of particles and reduction of total porosity. The change in the vegetation cover influenced the values of macro and micro aggregates in the studied environments. The use of segmentation by the toposequence positions in the landascape, use and depths, to the determine soil degradation, was efficient in evaluating the different depths of it. The management system used causes changes in the soil physical and chemical attributes that contribute to the process of soil degradation.

Emissão/abscisão de estruturas reprodutivas do algodoeiro herbáceo, cv. CNPA 7H: efeito do estresse hídrico

O presente estudo foi conduzido no periodo de julho a dezembro de 1998, em galpao coberto, no DSER/CCA/UFPB, municipio de Areia, PB, com o objetivo de se avaliar o efeito dos niveis de agua disponivel no solo (AD) (20, 40, 60 e 80%) sobre a emissao/abscisao de estruturas reprodutivas do algodoeiro herbaceo, cv. CNPA 7H; utilizou-se delineamento experimental inteiramente casualizado, com quatro tratamentos e tres repeticoes, em tres epocas de amostragem. O crescimento vegetativo e o reprodutivo, aumentaram com os niveis de AD no solo, sendo a menor media de altura de plantas (34,5 cm), area foliar (633,05 cm2), acumulacao de fitomassa da parte aerea (9,04 g), botoes florais (4,67), flores (3,50), macas (2,33) e capulhos (1,33) por planta, observada no tratamento com o nivel de 20% da AD e a maior, 74,33 cm, 2.634,81cm2, 24,86 g, 9,67, 7,0, 6,0 e 4,3 por planta, respectivamente, no tratamento com o nivel de 60% da AD. Apesar do estresse hidrico ter afetado (p<0,05) quantitativamente o aumento da emissao e abscisao de estruturas reprodutivas do algodoeiro, existe uma inter-dependencia entre essas estruturas, independente do nivel de estresse hidrico a que foi submetido; assim, o aumento ou reducao do numero de botoes florais retidos culmina com o de flores, macas e capulhos de forma sucessiva, mantendo uma proporcionalidade padrao.

Perfil fermentativo e composição bromatológica de silagens de sorgo em função da adubação nitrogenada

Two experiments were conducted to evaluate the fermentation characteristics and chemical composition of sorghum silage. In the first experiment the fermentative profile of sorghum silages in response to nitrogen fertilization was evaluated using a completely randomized design, in split-plot scheme with five doses of nitrogen (in the plot) and six opening times (in the subplot). The nitrogen levels were 0; 50; 100; 150 and 200kg/ha and the opening times were: 1; 3; 7; 14; 28and 49 days after ensiling. In the second experiment the variations in the chemical composition of sorghum silages was evaluated. The experimental design was randomized blocks with five repetitions, and the treatments consisted on the same levels of fertilization of first experiment. Dry matter increased linearly with the nitrogen and the fermentation period. The pH increased linearly as a function of nitrogen and showed a quadratic response as a function of fermentation period. The N- NH3 values showed a quadratic response both to nitrogen as for the opening day. Organic matter increased linearly and mineral matter decreased. Lignin responded linearly to increasing nitrogen fertilization. The hemicellulose decreased linearly. The dry matter, pH and ammonia values show efficacy in the silage fermentation process independent of nitrogen level used. The use of fertilizer is an interesting practice, which increases plant productivity without changing the chemical composition of the silage. Nevertheless, for the most economic treatment, is indicated the use of 150kg of nitrogen per hectare.