Riselane de Lucena Alcântara Bruno

Efeitos de substratos e das dimensões dos recipientes na qualidade das mudas de Tabebuia impetiginosa (Mart. Ex D.C.) Standl.

A crescente demanda por mudas de especies florestais nativas tem exigido pesquisas relacionadas com o uso de substratos e recipientes, capazes de proporcionar mudas que apresentem elevadas taxas de crescimento inicial e de sobrevivencia apos o plantio. Este trabalho objetivou avaliar a producao de mudas de Tabebuia impetiginosa (Mart. ex D.C.) Standl (ipe-roxo), em condicoes acessiveis aos pequenos e medios produtores rurais. O ensaio foi instalado em area experimental localizada no Departamento de Fitotecnia (CCA/UFPB), em Areia, PB. O delineamento utilizado foi em blocos ao acaso, com 14 blocos. Os tratamentos consistiram da combinacao dos substratos: S1 - terra de subsolo e S2 - terra de subsolo + composto orgânico e de sacos de polietileno preto nas seguintes dimensoes: I - 20 x 36,5 cm; II -15 x 32 cm; III - 13 x 25,5 cm; e IV - 13,5 x 19 cm. Para todas as variaveis estudadas, o recipiente I e o substrato S2 sobressairam em relacao aos demais. Entretanto, considerando a diferenca entre os resultados e a demanda de substrato e mao-de-obra exigida, no primeiro caso recomenda-se o recipiente II com o substrato S2, para a producao de mudas dessa especie.

Vigor de sementes armazenadas de ipê-amarelo Tabebuia serratifolia (Vahl.) NICH

This work aimed to determine the best conditions and storage periods adapted to the types of conservation of seed vigor for yellow-ipe. The experiment was conducted at the Laboratory of Analysis of Seeds - CCA/UFPB, using an entirely randomized design. The treatments consisted of yellow-ipe seeds packaged in (paper and polyethylene bags, three storage conditions (chamber, room temperature and humidity conditions and refrigerator) and six storage periods (0, 30, 60, 90, 120 and 150 days). The evaluated characteristics were: moisture content, Germination Speed Index (GSI), seedling length, and seedling dry matter. The results of GSI, seedling length and seedling dry matter were subjected to the analysis of polynomial regression. The yellow-ipe seeds packaged in paper bags presented higher moisture content along the storage in the chamber and room temperature and humidity conditions. In general, the seeds kept in paper packaging and polyethylene bags and stored in room temperature and humidity conditions lost the vigor more quickly along the storage.

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.

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.

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.

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.

TEMPERATURAS E SUBSTRATOS NA GERMINAÇÃO DE SEMENTES DE Caesalpinia pyramidalis TUL. 1

Caesalpinia pyramidalis Tul. is a forest species from the Caesalpiniaceae family, considered endemic to the Caatinga biome and the objective of this study was to evaluate the effects of temperature and substrate on its seed germination. The experimental design was completely randomized with a 5 x 4 factorial, totaling 20 treatments, consisting of combinations of five temperatures (25, 30, 35, 20-30 and 20-35 oC) and four substrates (sand, vermiculite, coconut fiber and paper towels), with four replications of 25 seeds each. The parameters evaluated were germination, first germination count, germination speed index and seedling length and dry matter weight. The temperatures of 20-30 and 20-35 oC and the sand and vermiculite substrates were suitable for evaluating the germination of C. pyramidalis seeds.

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