Paulo Costa Araújo

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.

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.