Luciana Rodrigues de Araújo

Resposta do coentro à adubação fosfatada em solo com baixo nível de fósforo

Coriander (Coriandrum sativum L.) is an arbustive vegetable utilized as spice in regional foods in North and Northeast Brazil. In the Paraiba State it is cultivated by small farmers and the yield of the crop is low mainly due to not well balanced mineral nutrition fertilization. The work was conducted at the Universidade Federal da Paraiba, in Areia, Brazil, from June to August 2002, to evaluate the effect of levels of P2O5 on the yield of coriander, cv. Verdao. The experimental design was randomized blocks with five treatments (0; 50; 100; 150 and 200 kg ha-1 of P2O5) and four replications. Coriander plants were spaced 25 x 5 cm and sown in plots of 2,0 m2. The applications of 93 kg ha-1 and 112 kg ha-1 of P2O5 resulted, in maximum plant height (63 cm) and in the higher production of green mass (51 t ha-1), respectively. The level of 110 kg ha-1 of P2O5 was economically the most efficient and provided a green mass yield of 50,55 t ha-1 with an increase of 15,1 t ha-1.

Initial growth in seedlings of Adenanthera pavonina L. for different substrates

Adenanthera pavonina L., a species that produces great quantities of viable seeds, is widely used in the reclamation of degraded areas. The aim was to study the effect of different substrates on the emergence and initial growth of seedlings of A. pavonina. The experiment was carried out at the Centre for Agrarian Science of the Federal University of Paraiba, in Areia, Pariba, Brazil. The experimental design was completely randomised (CRD) with the treatments composed of 14 substrates: sand, compost, fine vermiculite, sawdust, carbonised rice hull, sand + compost in a 1:1 ratio, sand + sawdust in a 1:1 ratio, sand + cured cattle manure in a 1:1 ratio, compost + sawdust in a 1:1 ratio, compost + cattle manure in a 1:1 ratio, fine vermiculite and sand in a 1:1 ratio, fine vermiculite + sawdust in a 1:1 ratio, fine vermiculite + compost in a 1:1 ratio, and fine vermiculite + cured cattle manure in a 1:1 ratio, in four replications of 25 seeds. The following were evaluated: emergence, first count, speed of emergence index, and length and dry weight of the roots and shoots. Given the results, it was found that the sand, compost and fine vermiculite substrates, as well as the mixtures of sand + compost, compost + sawdust and fine vermiculite + sawdust in a 1:1 ratio are the most efficient for promoting the emergence and initial growth of seedlings of A. pavonina.

Potencial fisiológico de sementes de Clitoria fairchildiana R. A. Howard. - Fabaceae submetidas a diferentes regimes de luz e temperatura

Clitoria fairchildiana Howard, a native of the Amazon region is widely used in reforestation programs, planting trees in the streets, public squares, roads and parking lots because of its broad and leafy canopy and its rapid growth. Thus, the objective was to study the influence of light and temperature regimes on germination and vigor of C. fairchildiana seeds. We evaluated the physiological potential of seeds under constant temperatures (25 and 30°C) and alternating (20-30°C) in different light regimes: white, green, far-red, red and darkness. The experimental design was completely randomized in a factorial 3x5, with four replications. The variables analyzed were: germination percentage, first count and germination speed index (GSI), as well as length and dry mass of shoots and primary roots of seedlings. C. fairchildiana seeds germinate in the dark and in all light regimes, regardless of the temperature used and are considered neutral photoblastic. To evaluate the effect of these seeds is recommended temperature of 30°C in the regime of white light, except for the test seedling dry weight, which indicated the green light, far-red or dark.

Substrates and temperatures in the germination of Eriotheca gracilipes seeds

The Eriotheca gracilipes (K. Schum.) A. Robyns) is a forest specie that belongs to the Bombacaceae family and is considered an endemic specie from the Brazilian savanna. The aim of this study was to evaluate the best substrate and temperature for the vigor and germination test of E. gracilipes seeds. The experiment was carried out in a randomized design with a 4 x 7 factorial, with 28 treatments with the combination of four temperatures (20; 25; 30 and 20-30 °C) and seven substrates (coarse vermiculite, medium vermiculite, sand, Basaplant®, paper towel, on and between filter papers), with 4 repetitions of 25 seeds each. It was assessed germination, first count of germination, and germination speed index. In conclusion, for germination and vigor tests of Eriotheca gracilipes seeds it is recommended the paper roll as substrate at temperatures of 20-30, 25 or 30 °C, and the Basaplant® and paper roll at the temperature of 30 °C, respectively.

Initial growth in seedlings ofAdenanthera pavoninaL. for different substrates

Adenanthera pavonina L., a species that produces great quantities of viable seeds, is widely used in the reclamation of degraded areas. The aim was to study the effect of different substrates on the emergence and initial growth of seedlings of A. pavonina. The experiment was carried out at the Centre for Agrarian Science of the Federal University of Paraiba, in Areia, Pariba, Brazil. The experimental design was completely randomised (CRD) with the treatments composed of 14 substrates: sand, compost, fine vermiculite, sawdust, carbonised rice hull, sand + compost in a 1:1 ratio, sand + sawdust in a 1:1 ratio, sand + cured cattle manure in a 1:1 ratio, compost + sawdust in a 1:1 ratio, compost + cattle manure in a 1:1 ratio, fine vermiculite and sand in a 1:1 ratio, fine vermiculite + sawdust in a 1:1 ratio, fine vermiculite + compost in a 1:1 ratio, and fine vermiculite + cured cattle manure in a 1:1 ratio, in four replications of 25 seeds. The following were evaluated: emergence, first count, speed of emergence index, and length and dry weight of the roots and shoots. Given the results, it was found that the sand, compost and fine vermiculite substrates, as well as the mixtures of sand + compost, compost + sawdust and fine vermiculite + sawdust in a 1:1 ratio are the most efficient for promoting the emergence and initial growth of seedlings of A. pavonina.

Different water volumes in the substrate and temperatures for germination of cabacinha seeds

Cabacinha (Luffa operculata) is a species that has been used empirically in folk medicine against sinusitis. The fruits have important pharmaceutical substances and studies related to its germination are not available, justifying the determination of the appropriate conditions that make possible the germination of its seeds. Thus, we evaluated the influence of different volumes of water in substrate and temperatures on germination and vigor of cabacinha. The treatments consisted of moistened substrate with water volumes equal to 2.0; 2.5; 3.0 and 3.5 times its weight of the dry paper and the seeds were kept in germination regulated at constant temperatures of 25, 30 and 35°C and 20-30°C alternating. The percentage and speed of germination, hypocotyl and roots of the plants were evaluated. The experimental design was completely randomized with treatments arranged in a 4x4 factorial (volumes of water x temperatures), in 4 replications of 25 seeds. The constant temperature of 30°C and the water volume of 2.0 times the weight of dry substrate is the best combination to lead the germination tests of cabacinha seeds.