Edson de Almeida Cardoso

Superação da dormência em sementes de Caesalpinia pyramidalis Tul

n Forest species with hard seeds often cause important problems for nursery managers because their hard and water impermeable seed coats hinder and delay germination. For this reason, an experiment was carried out to determine methodologies for overcoming dormancy of catingueira seeds, under greenhouse conditions, in the Center for Agricultural Sciences, of the Federal University of ParaIba. The experiment was arranged in a complete randomized design, with four replicates of 25 seeds/treatment. Seeds were subjected to 12 treatments: control - intact seeds (T 1 ), mechanical scarification using fine sandpaper n o . 80 (T 2 ), coating cutting in the opposite side of micropylar region (T 3 ), immersion in sulfuric acid (98%) for 6, 8 and 10 minutes (T 4 , T 5 and T 6 , respectively), immersion in water at 60, 70 and 80 o C for one minute (T 7 , T 8 and T 9 , respectively), immersion in water at room temperature for 24, 48 and 72 hours (T 10 , T 11 and T 12 , respectively). The seeds

Emergência de plântulas de Erythrina velutina em diferentes posições e profundidades de semeadura

The aim of this research was to study the influence of the sowing depth and position upon seedling emergency and seed vigor of the coral tree, some germination tests were settled in sand, under protected environment. The treatments were represented by the position and depth of the seed sowings relative to the substratum, as follows: seed with the hilum turned down, upward and to the side at depths 1, 2, 3, 4 and 5cm. Each treatment consisted of four replicates with 25 seeds, and were evaluated by the following tests: emergence, first-counting vigor, emergency speed, length and dry mass of the hypocotyl and roots. According to the results for coral tree, the sowing depth should be between one and two centimeters, whereas the best position was the hilum turned down.

Rendimento de feijão-vagem em função de doses de K2O

Aiming to evaluate the effect of K2O levels on the increase of snap bean yield, an experiment was performed in Paraiba State, Brazil, in a Quartz Psamment soil. The experimental design was of randomized blocks, with six treatments (0; 50; 100; 150; 200 and 250 kg ha-1 of K2O), in four replications. Each plot contained 40 plants spaced 1.0 m x 0.2 m. Pods maximum number/plant (20 pods) and the maximum yield/plant (171 g), were obtained, respectively with 145 and 173 kg ha-1 of K2O, and pods yield reached maximum value around 25,3 t ha-1 at the level of 171 kg ha-1 of K2O. The most economic level of K2O for the production of pods was of 165 kg ha-1. The most economic level represented 96% comparing to that responsible for maximum pods production. The K2O levels that obtained maximum pods production and economic return were correlated, respectively, with 181 and 176 mg dm-3 of K available for the extractor Mehlich 1.

Lima beans production and economic revenue as function of organic and mineral fertilization

Lima beans (Phaseolus lunatus L.) are alternative food and income sources for the population of Northeastern Brazil. In this region, lima beans are consumed either as green or dry grains. However, low yields have been observed, a challenge that could be overcome by adequate organic and mineral fertilization. This work intended to assess lima beans yield, cultivar Raio de Sol, as affected by doses of cattle manure in the presence and absence of mineral NPK fertilization. The experiment was carried out at the Federal University of Paraiba, Brazil, from September, 2004 to May, 2005. The experimental design was of randomized blocks, with four replications, 40-plant plots, spaces of 1.00 x 0.50 between and within rows, respectively. Treatments were displayed in a 6 x 2 factorial, corresponding to manure doses (0, 10, 20, 30, 40 and 50 t ha-1) and presence and absence of NPK. Green and dry grain, and pod yields were analysed, as well as the economic revenue for pods and dry grains. To measure the economic efficiency, pods and dry grains were employed as the exchange units. Maximum pod yields (12.6 and 11.2 t ha-1) were achieved with 21.4 and 23 t ha-1 of manure, with and without NPK, respectively. Highest green grain yields (11.1 and 9.9 t ha-1) were obtained with 21.3 and 22.9 t ha-1 of manure, with and without NPK, respectively. The highest yield of dry grains (3.5 t ha-1) was obtained with 26.6 t ha-1 of manure combined with NPK. In the absence of NPK, the use of cattle manure resulted in an average dry grain yield of 2.0 t ha-1. The maximum economic efficiency for pod production was reached with 17 and 18.6 t ha-1 of manure, with predicted net incomes of 2.88 and 3.36 t ha-1 of pods, in the presence and absence of NPK, respectively. For dry grains, the maximum economic efficiency was achieved with 23 t ha-1 of manure, in the presence of NPK, which produced a net revenue of 2.12 t ha-1 of dry grains.

Comportamento fisiológico de sementes de pitombeira [Talisia esculenta (A. ST. Hil) Radlk] submetidas à desidratação

Em condicoes normais, as sementes de pitombeira [Talisia esculenta (A. St. Hil) Radlk] perdem a qualidade fisiologica rapidamente, o que dificulta sua utilizacao pelos viveiristas. Em funcao da escassez de pesquisas referentes a dessecacao de suas sementes, o trabalho teve como objetivo avaliar a qualidade fisiologica de sementes de pitombeira submetidas a cinco periodos de secagem (0; 24; 48; 96 e 120 horas). O delineamento experimental foi inteiramente ao acaso, e os dados, submetidos a analise de variância e de regressao polinomial. A avaliacao do efeito dos tratamentos foi realizada atraves da determinacao do teor de agua, porcentagem de germinacao e testes de vigor (primeira contagem, indice de velocidade e tempo medio para germinacao, comprimento e massa da materia seca da raiz primaria e parte aerea). Verificou-se um teor de agua inicial de 40%, o qual foi reduzindo com os periodos de secagem; consequentemente, registraram-se as maiores porcentagens de germinacao (99%) com 53 horas de secagem. Quanto ao vigor, os maiores valores de primeira contagem (78%) e comprimento da parte aerea (11,29 cm) foram obtidos com 38 horas de secagem; ja o menor tempo medio para germinacao (17 dias) e comprimento maximo da raiz primaria (15,79 cm) ocorreram quando a secagem foi por 40 horas. Quanto ao indice de velocidades de germinacao (1,41), massa da materia seca das raizes (0,079) e parte aerea (0,229), os valores maximos foram obtidos quando as sementes foram submetidas a secagem por 44; 33 e 50 horas, respectivamente. Diante dos resultados, recomenda-se a secagem de sementes de pitombeira por ate 48 horas, como forma de garantir a germinacao e o vigor.

Métodos para quebra de dormência de unidades de dispersão de Zizyphus joazeiro Mart. (Rhamnaceae)

Z. joazeiro is a forest species of great socioeconomic importance for the Brazilian Northeast region, but of difficult germination caused by the water impermeability of dispersal units. The present study evaluated pre-germinative treatments for overcoming dormancy in Zizyphus joazeiro seeds. The experiment was carried out in greenhouse conditions at Centro de Ciencias Agrarias, Universidade Federal da Paraiba, Areia-PB, Brazil. The treatments were as follow: control (intact dispersal units), mechanical scarification with sandpaper, immersion in water at room temperature for 24, 48, 72, 96 and 120 hours, immersion in water at 70 C for three minutes and, immersion in concentrated sulfuric acid for 30, 60, 90, 120 and 150 minutes. The evaluated variables included emergence percentage, first count and emergence speed index, length and weight of plant dry matter. The treatments showing higher Z. joazeiro seedling emergence were immersion of dispersal units in cold water for 48 hours, immersion in water at 70 C for three minutes and manual scarification with sandpaper, overcoming tegument hardness in dispersal units of this species.

Profundidades de semeadura para emergência de plântulas de juazeiro

Zizyphus joazeiro Mart. is a typical Brazilian tree of the northeastern dry lands, being endemic to the Caatinga. It occurs in various states of Northeast Brazil and provides a great economic potential and importance for this semi-arid region. This study had as objective to determine the best sowing depth of Zizyphus joazeiro. In greenhouse sand substratum, with 4 replications of 25 units of dispersion each one, in the following depths (one, too, tree, four and five centimeters). It was ended that the sowing of juazeiro in nursery should be done in the depth of 1.0 to 1.6cm. The depth of 1 cm resulted in smaller time for the total germination.

Emergência e crescimento inicial de plântulas de Peltophorum dubium (Spreng.) Taubert sob diferentes substratos

This work carried out to determine substrate for germination and vigor tests of Peltophorum dubium (Spreng.) Taubert seeds. The experiment was carried out in a greenhouse of the Laboratory of Vegetal Ecology of the Centro de Ciencias Agrarias of the Universidade Federal da Paraiba, Northeast Brazil. Were compared the substrates sand (T 1 ); sand + vermiculite in the ratio of 1:1 (T 2 ), 3:1 (T 3 ) and 1:3 (T 4 ); vegetal soil (T 5 ), vegetal soil + sand in the ratio of 1:1 (T 6 ), 3:1 (T 7 ) and 1:3 (T 8 ), vegetal soil + vermiculite in the ratio of 1:1 (T 9 ), 3:1 (T 10 ) and 1:3 (T 11 ), vermiculite (T 12 ), bioclone® (T 13 ), bioplant® (T 14 ) and plugmix® (T 15 ). The design used was entirely randomized wi th 15 treatments (substrates) and four repetitions of 25 seeds. The evaluation was made through the determination of: percentage of emergency, first counting, index of speed, average time and relative frequency of emergency, length and dry mass of the root and aerial part of seedlings. The results evidenced that the substrates pure commercial vermiculite, bioclone®, bioplant® and plugmix®, well as the mixture sand + vermiculite in the ratio of 3:1, vegetal land + sand in the ratio of 1:1 and vegetal soil + vermiculite in the ratio of 1:3 are less efficient for conduction of germination tests with seeds of P. dubium, while the substrate sand + vermiculite in the ratio of 3:1 is most efficient in detecting differences of vigor in the seeds of the different treatments.

Germinação e vigor de sementes de Bauhinia divaricata L.

The Bauhinia divaricata is an arboreal species with high ornamental and economical value and distributed throughout Brazil. It is propagated by seeds, from which germination needs more investigation. So, this study was carried out at the Seed Analysis Laboratory pertaining to CCA-UFPB - Areia, in BOD-type chambers with 8h photoperiod in order to determine the most adequate substratum and temperature for evaluating the germination and vigor of the Bauhinia divaricata seeds. The entirely randomized experimental design in the factorial scheme 3 x 5 was used. The factors were constituted by constant temperatures of 25 and 30°C and alternate 20-30°C, as well as substrata between paper, on paper, paper roll, among sand and among vermiculite, in four replicates of 25 seeds. The following variables were analyzed: percent germination, first counting, germination index and dry matter of the plantlets. The 25°C temperature and the substrata between paper, on paper and paper roll showed to be adequate to the test for germination and vigor of the Bauhinia divaricata seeds. The lowest germination percentages and the seed vigor levels occurred in the sand substratum at three temperatures (20-30, 25 and 30°C).

Manejo da adubação nitrogenada paraa batata-doce: fontes e parcelamento de aplicação

Com o objetivo de avaliar o rendimento da batata-doce [Ipomoea batatas (L.) Lam.], cultivar Rainha Branca, submetida a fontes e parcelamentos da aplicacao de 80 kg ha-1 de nitrogenio, instalou-se um experimento, no periodo de abril a agosto de 2007, na Universidade Federal da Paraiba, em Areia. O delineamento experimental utilizado foi o de blocos casualizados, em esquema fatorial 2 x 7, com duas fontes de nitrogenio (ureia e sulfato de amonio) e oito de epocas parcelamentos da aplicacao (100% no plantio; 100% aos 30 dias apos o plantio (DAP); 100% aos 60 DAP; 50% no plantio e 50% aos 30 DAP; 50% no plantio e 50% aos 60 DAP; 50% aos 30 e 50% aos 60 DAP; 33% no plantio, 33% aos 30 e 33% aos 60 DAP), com quatro repeticoes. Foram avaliados o peso medio de raizes comerciais, a producao e o numero de raizes comerciais por planta e as produtividades total e comercial de raizes de batatadoce. O maior peso medio de raizes comerciais (294 g) foi obtido com o parcelamento do N, como ureia, 50% no plantio e 50% aos 30 DAP. O parcelamento de N 33% no plantio, 33% aos 30 DAP e 33% aos 60 DAP na forma sulfato de amonio foi responsavel pela maior producao de raizes comerciais por planta (337 g). Para o numero de raizes comercias e as produtividades total e comercial, o N na forma de sulfato de amonio parcelado 33% no plantio, 33% aos 30 DAP e 33% aos 60 DAP proporcionou os maiores valores, 1,50 raizes, 30,5 e 28,4 t ha-1, respectivamente.