Adriana Ursulino Alves

Superação da dormência em sementes de Bauhinia divaricata L.

This study was carried out with the aim of determining the most efficient methodology to overcome dormancy in Bauhinia divaricata seeds. The 12 treatments employed were: control - intact seeds (T1); mechanical scarification with sandpaper (T2); coating cutting in the opposite side of micropylar region (T3); immersion in water and at room temperature during 24 hours (T4); immersion in water (50, 60 and 70oC) during three minutes (T5, T6 and T7, respectively); immersion in hot water (80oC) during three, six and nine minutes (T8, T9, and T10, respectively); and immersion in boiling water during one and two minutes (T11 and T12, respectively). Effects were evaluated considering emergency and vigor tests (first count, speed mean time to emergency, length and dry mass of seedlings and relative frequency emergency). The experiment was installed in greenhouse and sown was done in plastic trays containing sand. The experimental design used was a completely randomized with four replicates of 25 seeds and the averages were compared through the Tukey test, at 5% probability. The were significant differences among the treatments for all variables. The most probable cause for the dormancy is the impermeability of the seed coating and the most efficient treatment to overcome were coating cutting in the opposite side of micropylar region.

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.

Maturação fisiológica de sementes de sabiá

The objective of this research was to study the maturation process of the Mimosa caesalpiniifolia Benth. seeds. The seeds and fruits were collected from plants located, Areia County, State of Paraiba, Brazil. Were made sixteen weekly fruits and seeds harvests of starting from 105 days after anthesis in the period of August up to November, 2001. Were evaluated the fruits and, seeds dimensions, the moisture content; the fruits and, seeds fresh and dry weight mass, the germination percentage; and first germination count, length and the seedling fresh and dry weight mass. According to the obtained results, it was observed that the physiological maturity of Mimosa caesalpiniifolia occurred from 154 days after the anthesis extending up to 168. The harvesting cannot be delayed beyond 189 days after the due to a great loss of fruits and seeds caused by natural dispersion.

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.

Rendimento e qualidade fisiológica de sementes de coentro cultivado com adubação orgânica e mineral

O presente trabalho teve por objetivo avaliar a influencia de doses de materia orgânica sob a forma de esterco bovino, na presenca e ausencia de adubacao mineral, sobre o rendimento e qualidade fisiologica de sementes de coentro. Para tanto, foram conduzidos dois experimentos, um sob condicoes de campo e outro, no Laboratorio de Analise de Sementes pertencente ao Centro de Ciencias Agrarias da Universidade Federal da Paraiba, no periodo de outubro/2001 a fevereiro/2002. O experimento de campo foi instalado para avaliar o rendimento de sementes de coentro (Coriandrum sativum L.), cultivar verdao, cujos tratamentos consistiram em cinco doses de esterco bovino (0; 2,0; 4,0; 6,0 e 8kg m-2), na presenca e na ausencia de adubo mineral, em blocos casualizados, com os tratamentos distribuidos em arranjos fatorial 5 x 2, com quatro repeticoes. No experimento de laboratorio, conduzido para a avaliacao da qualidade das sementes atraves de testes de germinacao e de vigor (indice de velocidade de germinacao), os tratamentos tambem foram distribuidos em arranjos fatorial 5x2, em delineamento inteiramente casualizado com quatro repeticoes. O rendimento de sementes de coentro atinge, na presenca de adubo mineral, valor maximo estimado (3t ha-1) na dose de 5kg m-2 de materia orgânica (esterco bovino). Na ausencia de adubo mineral, o rendimento aumenta com a elevacao das doses de esterco bovino, com rendimento maximo de sementes (3t ha-1) na dose de 8kg m-2. A germinacao e o indice de velocidade de germinacao, na ausencia de adubo mineral (NPK) aumentam linearmente com elevacao das doses de materia orgânica (esterco bovino), apresentando valores maximos de 90% e 5,0, respectivamente, na dose maxima (8kg m-2). Na presenca de adubacao mineral, as doses de esterco bovino proporcionam germinacao media de 82% e indice de velocidade de germinacao de 4,5, com a dose de 8kg m-2. A qualidade fisiologica das sementes de coentro e influenciada pelas doses de esterco bovino, sendo a dose de 8kg m-2 mais adequada para aumentar a qualidade das sementes.

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.

Avaliação de linhagens e cultivares de feijão-caupi, em Areia, PB

Ten breeding lines and three cultivars of cowpea-bean were evaluated. The experiment was set up in Areia, Brazil, between April and July/00, in Red-yellow Latossoil. The breeding lines TE-92-199-20F; TE-90-170-29F; TE-90-170-76F; CNCX-405-17F; CNCX-409-12F; TE-90-180-10F; TE-87-108-6G, Linhagem avancada, and IPA 206, BR-03 Tracuateua, cvs., presented length and average weight of pods according to the commercial patterns and number of pods by plant according to the pattern of the species (above twenty pods). The yield of green pods, green and dry grains, obtained by the breeding lines TE-90-170-76F; CNCX-409-12F; CNC-405-17F; TE-90-180-0F; TE-87-108-6G, Linhagem avancada and IPA 206, cultivar, were superior to 5.0 t/ha for green pods, to 3.0 t/ha for green grains and to 1.2 t/ha for dry grains, considered highest for the cowpea-beans. Highest yield of green pods (6.5 and 6.5 t/ha), green grains (3.8 and 3.8 t/ha), and dry grains (1.8 and 1.8 t/ha) were obtained, respectively, with the breeding line CNCX-409-12F and IPA 206 cv.

Produção de batata-doce adubada com esterco bovino em solo com baixo teor de matéria orgânica

The influence of organic fertilization on total and commercial production of sweet potato roots, Rainha Branca cv. was evaluated. The experiment was carried out from June to October/2004, in Paraiba State, Brazil. The experimental design was of randomized blocks with six treatments (0; 10; 20; 30; 40 and 50 t ha-1 of cattle manure), in four replications. The total and commercial productions of sweet potato roots were 18.5 and 14.2 t ha-1 obtained with 32 and 30 t ha-1 of cattle manure. The cattle manure level responsible for maximum economic return of commercial roots (30 t ha-1), was equal to that which allowed maximum production, represented 100% of maximum technique efficiency, constituting an indicative of the economic viability of cattle manure application in sweet potato. The estimated cattle manure levels which resulted maximum production and economic returns for commercial roots, corresponded to 13.8 g kg-1 of remaining organic matter with the extractor. In similar soils of this study, the organic fertilization for sweet potato production can be dispensed, with remaining organic matter level higher than 13.8 g kg-1 of soil.

Produtividade da batata-doce em função de doses de K2O em solo arenoso

The response of sweet potato Rainha Branca cv., cultivated under different K2O levels was evaluated. The experiment was carried out in randomized blocks design with four replications in a Quartz psamment soil at Universidade Federal da Paraiba, Paraiba State, Brazil, from July to November/2004. The K2O levels applied were 0; 50; 100; 150; 200 and 250 kg ha-1). The plots consisted of 48 plants, spaced of 0.80x0.30 m. The maximum estimated values, 14.8 and 8.4 t ha-1 of total and commercial roots yield, were obtained with 194 and 174 kg ha-1 of K2O, respectively. However, the most economic level of commercial roots yield (6.0 t ha-1) was reached using 163 kg ha-1 of K2O. The K2O levels resulting in maximum roots yield and economic return, were correlated respectively with 125 and 121 mg dm-3 of available K with Mehlich 1 extractor. The probability for sweet potato response under potassic fertilization in similar soils will be minimized if the level of available K in the soil were superior to 121 mg dm-3. For utilized soil in this study, 163 kg ha-1 of K2O can be recommended for sweet potato fertilization.

Dormência e desenvolvimento de sementes de sabiá (Mimosa caesalpiniifolia Benth.)

The objective of this research was to study the dormancy of Mimosa caesalpiniifolia Benth. seeds during the maturation process. The seeds and fruits were collected from plants in a locality called Engenho Bujari, city of Areia, State of Paraiba, Brasil. Seed harvest extended from the 105th day after anthesis (d.a.a.) to the 210th (d.a.a.), from August 9 to November 22, 2001. The parameters evaluated were germination %, dormancy (%), vigor expressed by the first germination (%), seedling length, and seedling fresh and dry weight. It is concluded that to avoid seed dormancy in this species the collection must be done 154 d.a.a., when germination and accumulation of dry mass is maximum.