Joel Martins Braga Júnior

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

Substratos e temperaturas para testes de germinação e vigor de sementes de Amburana cearensis (Allemão) A.C. Smith

Amburana cearensis (Allemao) B.C. Smith is a species native to the Northeast Region of Brazil. It has been increasingly exploited for fine woodworking, perfumery and medicine, therefore the need for studies that can assist in its preservation. The objective of this work was to determine substrate type and optimum temperature for A. cearensis seed germination and vigor tests. The experiment was car ried out in complete randomized design with the treatments distributed in a 5 x 5 factorial scheme, using temperatures (constant of 20, 25, 30 and 35oC and alternate of 20-30oC) and substrates (Germitest paper , sand, vermiculite, bioplant and plantmax) with four replicates of 25 seeds each. The following parameters were analyzed: germination percentage, germination speed, length and dr y mass of seedlings. The optimum temperatur e for A. cearensis seed germination and vigor tests was 35oC, independently of the used substrates. The substrates sand and vermiculite were the most suitable for evaluation of the physiological quality of seeds.

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.

Temperaturas e substratos para germinação e vigor de sementes de Euterpe oleracea Mart.

O conhecimento das condicoes otimas para a germinacao, principalmente da temperatura e do substrato, e de fundamental importância, tendo em vista que estes fatores variam entre sementes de diferentes especies. O objetivo do trabalho foi avaliar a influencia de diferentes substratos e temperaturas para conducao de testes de germinacao e vigor de sementes de Euterpe oleracea. A pesquisa foi realizada no Laboratorio de Analise de Sementes do Centro de Ciencias Agrarias da Universidade Federal da Paraiba. Os tratamentos foram distribuidos em esquema fatorial 4 x 4, com os fatores temperaturas (20-30; 25; 30 e 35 oC) e substratos (areia, Bioplant®, Plantmax® e vermiculita) e quatro repeticoes cada. Para avaliacao do efeito dos tratamentos foram realizados testes de germinacao e vigor (indice de velocidade de germinacao, comprimento e massa seca de plântulas). As condicoes ideais para testes de germinacao e vigor em sementes de Euterpe oleracea estao em substrato vermiculita sob temperaturas de 20-30; 30 e 35 oC, areia a 30 e 35 oC, plantmax® a 20-30 oC e bioplant® a 35 oC.

Emergência de plântulas de Zizyphus joazeiro Mart (Rhamnaceae) em função de substratos

The juazeiro is a very important plant for the northeast half-barren semi-arid region, always remaining green, and being food source for the animals at during droughts. Due to the fact that the species mainly propagates by dispersion units (endocarps + seeds), the present study had as its purpose the evaluation of different types of substrates for the emergence of juazeiro seedlings. The experiment was carried out in a greenhouse at the Centro de Ciencias Agrarias of the Universidade Federal da Paraiba, in Areia-PB, Brazil. The substrates used were: Plugmix®, vermiculite, vegetal soil, vegetal soil + cattle manure (in ratios of 3:1, 1:1 and 1:3), vegetal soil + sand (in ratios of 3:1, 1:1 and 1:3), sand, sand + wood dust (in ratios of 3:1, 1:1 and 1:3), wood dust, sand + shaved wood (in the ratios of 3:1, 1:1 e 1:3), scraped wood, and sand + cattle manure (in the ratios of 3:1, 1:1 and 1:3). Through daily evaluations, the following characteristics had been determined: emergence, index of the speed of emergence, and the length and dry mass of the seedling. For the emergence of seedlings, the most efficient substrate was vegetal soil, and in terms of vigor, the greatest values were obtained in the Plugmix®, vegetal land + cattle manure in the ratios of 3:1 and 1:1 and sand substrates.

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).