Ademar Pereira de Oliveira

Germinação de sementes de Mimosa caesalpiniaefolia Benth. em diferentes substratos e temperaturas

Mimosa caesalpiniaefolia Benth. is a native species from Northeast region, Brazil, which is cultivated progressively from Maranhao to Rio de Janeiro States. Its presents great potential for arborization, it surrounds it lives and wood production. The present work was realizated with Mimosa caesalpiniaefolia seeds with the objective to determine the substratum type, temperature, the middle time and the relative frequency of germination, for use as a pattern in the conduction of germination and vigor tests. It took place an experiment in the Laboratorio de Analise de Sementes do CCA-UFPB, in Areia-PB, in completely randomized design with the treatments distributed in outline factorial 4x4, temperatures (constant of 20, 25 and 30oC and alternate of 20-30oC) and substrate (seeds cowered by paper shits, seeds on paper sheets, seeds into sand and seeds into vermiculite) in four replications of 25 seeds. The following parameters were analyzed: germination and of abnormal seedlings (%) first germination count, germination speed, medium time and relative frequency of germination, fresh matter and weight of dry matter of seedlings. According the results in all substrates the temperature of 25oC was most adequate for conduction of germination and vigor tests for Mimosa caesalpiniaefolia seeds. For all temperatures utilized the best germination was observed when the seed were sowed covered bay paper shits.

Ácido sulfúrico superação da dormência de unidade de dispersão de juazeiro (Zizyphus joazeiro Mart.)

O Zizyphus joazeiro Mart. apresenta reducao sensivel no numero de individuos em seu ambiente natural devido, entre outras causas, a ocorrencia de dormencia exogena da unidade de dispersao (impermeabilidade a agua). Avaliou-se o efeito do periodo de imersao (0, 30, 60, 90, 120 e 150 min) dessas unidades de dispersao, em acido sulfurico (98 %), na emergencia e vigor das sementes (primeira contagem, indice de velocidade e tempo medio de emergencia, altura e massa seca de plantas). O experimento foi realizado em casa de vegetacao, utilizando-se o delineamento inteiramente ao acaso, com seis tratamentos e quatro repeticoes. O pre-condicionamento das unidades de dispersao de Zizyphus joazeiro Mart., em acido sulfurico concentrado, mostrou-se eficiente na superacao da dormencia dessa especie, promovendo aumento na porcentagem e velocidade de emergencia, primeira contagem de emergencia, na altura e massa seca de plantas e reducao no tempo medio para emergencia. A eficiencia do tratamento quimico com acido sulfurico concentrado depende do periodo de imersao, sendo a faixa entre 74 e 115 min mais adequada para proporcionar maiores porcentagens de emergencia e de vigor.

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.

Rendimento de feijão-caupi em função de doses e formas de aplicação de nitrogênio

The cowpea-bean, known as macassar-bean or rope-bean is one of the main crops in the Northeast region of Brazil. It is consumed either as fresh or dried beans. Cowpea is cultivated in almost all regions of the Paraiba State, representing 75% of the cultivated area with cowpea-beans. The low yield is attributed to the lack of a research program about mineral fertilization. The effect of levels and forms of nitrogen applications on yield of pods and green and dry grains of cowpea-bean, cv. IPA 206 was evaluates. The experiment was performed at the Universidade Federal da Paraiba, in Areia, Brazil, from April to August/2001, in a randomized blocks design. Treatments were distributed in a factorial scheme 5 x 2, where the first factor corresponded to nitrogen levels (0; 25; 50; 75 and 100 kg ha-1) and, the second factor, the application forms (soil and foliar application), in four repetitions. Each plot consisted of 20 plants, spaced 0.8 x 0.4 m apart. The estimated maximum pods yield (11 t ha-1), of green grains (9.3 t ha-1) and of dry grains (3.6 t ha-1) was obtained with 62, 61 and 56 kg ha-1 of nitrogen applied in the soil, respectively. With foliar applications the yield of pods (10 t ha-1), of green grains (8.4 t ha-1) and of dry grains (3.4 t ha-1) reached maximum values applying levels of 64, 63 and 59 kg ha-1 of nitrogen respectively.

Produção de alface em função de cultivares e tipos de tela de sombreamento nas condições de Mossoró

Two experiments were carried out in the Escola Superior de Agricultura de Mossoro, in Brazil. The first experiment, from October to November 1999, evaluated the performance of three lettuce cultivars grown at the nursery stage under shading and three types of polyethylene net, and the second experiment, from December 1999 to January 2000, compared the lettuce yield under shading and no shading. The experimental design in both experiments was a randomized complete block. Treatments in the first experiment were factorial combinations of three types of polyethylene net (2 x 2 mm white and green nets and half-shade black net) and three lettuce cultivars (Great Lakes, Veronica and Regina) replicated four times. Treatments in the second experiment were these three types of polyethylene net plus one where lettuce cultivar Veronica was grown under no shading (control) replicated three times. The lettuce spacing in both experiments was 0.20 x 0.20 m. The performance of lettuce was evaluated through plant height and diameter, leaf number per plant, shoot dry matter content, yield, relative growth rate, gross and net incomes and rate of return. Shading and cultivar interaction affected plant height. Plant diameter and leaf number per plant were affected only by cultivars. Shoot dry matter content and yield were affected by shading as well as cultivars. White polyethylene net shading associated with lettuce cultivar Great Lakes provided the highest economic indices when compared to no shading.

Influência do tamanho e da procedência de sementes Mimosa caesalpiniifolia Benth. Sobre a germinação e vigor

Mimosa caesalpiniifolia Benth. is a native species from the Northeast region, Brazil, which has been increasingly cultivated from the States of Maranhao to Rio de Janeiro. It presents great potential for urban forestry, hedging and wood production. The present research had as objective to evaluate the influence of the provenance and seed size on the germination and vigor of Mimosa caesalpiniifolia Benth. An experiment was conducted at the Laboratory of Seed Analysis of CCA-UFPB, Areia, Paraiba State, Brazil in a completely randomized design with the treatments arranged in a 3x3 factorial, with three provenances and three size classes , four replicates of 25 seeds. The following characteristics were analyzed: 100-seed weight, seed dimensions, percentage and first counting, germination speed, length and weight of dry matter of primary root and hypocotyl and weight of cotyledon dry matter . It was verified that the germination was not influenced by seed size, however, it was influenced strongly by the provenance. The tests of first count and germination speed were not shown appropriate for seed vigor evaluation, being this better appraised by cotyledon and hypocotyl dry matter. Seed vigor was directly related with size, being thus justified the use of size classes for seedling production.

Produtividade do inhame em função de fertilização orgânica e mineral e de épocas de colheita

An experiment was carried out using Red-yellow Podzolic soil of sandy texture, in Paraiba, (Brazil), to evaluate the yield of Dioscorea cayennensis yam, cv. Da Costa cultivated with different sources and levels of organic matter and mineral fertilization (NPK). The experimental design was of randomized blocks with split-plots in a factorial scheme of 2 x 4 + 2 and four replications. In the main plots was studied the harvest time (seven and nine months after planting date (MPD)) and, in the sub-plots four levels of cattle manure (5, 10, 15, 20 t/ha) and four levels of chicken manure (2.8; 5.6; 8.4; 11.2 t/ha), associated to 100-120-60 kg/ha of N-P2O5-K2O and two additional treatments (control and isolated mineral fertilization). Organic matter, increased in 3.8 t/ha the yield of yam harvested after nine MPD. Cattle manure surpassed significantly by 1.9 t/ha the yield obtained with the addition of chicken manure, seven MPD. Nine MPD, the addition of chicken manure resulted in a significant yield increase (2.0 t/ha) when compared to treatments with addition of cattle manure. Mineral fertilization alone resulted in significant yield increases seven (7.7 t/ha) and nine (4.4 t/ha) MPD. Cattle manure (13.3 and 12.6 t/ha) plus NPK was responsible for the maximum yam yield, (18 t/ha) when harvested at seven MPD (20 t/ha), and nine MPD, while the level of 7.0 t/ha of chicken manure resulted in maximum yam yield (15 t/ha) at seven (22 t/ha) and nine MPD. Average yield when harvesting nine MPD (18.0 t/ha) surpassed significantly, in 19.5% (3.5 t/ha) the average of 14.5 t/ha obtained at seven MPD.

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.

Produção de raízes de batata-doce em função do uso de doses de N aplicadas no solo e via foliar

With the objective of evaluating the levels and application forms of nitrogen (soil and leaves) in the sweet potato Rainha Branca cv. an experiment was carried out from July to November/2003, in the Centro of Ciencias Agrarias from Universidade Federal of Paraiba, Areia, Brazil, in Quartz Psamment soil. The experimental design was randomized blocks, in a factorial scheme 5x2, with five levels of N (0, 50, 100, 150 and 200 kg ha-1), tow applications forms (soil and by foliating), in four replications. The plots with 28 plants, spaced at 0.80x0.30cm. The total and uncommercial yield of roots increased linearly in function of the levels of N applied in the soil, corresponding approximately to 45.52 and 12.64 kg ha-1, respectively to each kilogram of N. The commercial yield in function of the N levels applied in the soil, reached the maximum value of 19255 kg ha-1 with 154 kg ha-1 of N. The total, commercial and uncommercial roots yields obtained in function of the N levels applied to the leaves did not suffer significant changes with rates of 13800, 12600 and 1200 kg ha-1, respectively. The most economical N level applied in the soil related to commercial roots yield was 144 kg ha-1, with roots estimated yield of 19123 kg ha-1. The nitrogen supplied in the soil was more efficient for the sweet potato to express its maximum commercial roots yield, with increment of 6555 kg ha-1, when compared to the leaves application.

Rendimento e qualidade de raízes de batata-doce adubada com níveis de uréia

Studies with the objective of increasing yield and quality of sweet potato roots, could be an important tool to improve the socio economic condition in the northeastern area of Brazil, due to the importance of this vegetable in that area. The present work was done to evaluate the effect of urea levels on yield and quality of sweet potato cultivar Rainha Branca. The experiment was conduced from July to November/2003, in Paraiba State, Brazil. The experimental design was of randomized blocks with five treatments (0; 115; 230; 345 and 460 kg ha-1 of urea), in cover fertilization at 30 and 60 days after planting date, in four replications. Plots with 28 plants, spaced 0,80 x 0,30 m apart were used. Commercial root yield of 18.8 t ha-1 was obtained when 339 kg ha-1of urea were employed, a much better result compared to the national average of 8.8 t ha-1of commercial roots The glucose level (reducing sugars) on the sweet potato roots, increased with the increase of the urea levels, up to 187 kg ha-1of urea with a maximum of 8.7% of glucose. Starch level was reduced with increasing urea levels, with minimum percent of 57% at the level of 460 kg ha-1. However, the starch minimum level was within the range defined for this species.