Francisco José Loureiro Marinho

Avaliação de genótipos de caupi sob salinidade

To assess the tolerance of 50 cowpea genotypes under salinity, experiments were conducted in greenhouse covered with fiberglass sheets. The salinity treatments applied in terms of electrical conductivity of saturation extract of soil (EC) were EC1 - 0.3; EC2 - 3.0; EC3 - 6.0; EC4 - 9.0 and EC5 - 12.0 dS m-1. The genotypes were classified for the salinity tolerance on the basis of the reduction in dry weight (%) of shoot. Under EC2, 36 genotypes were tolerant (T), 12 moderately tolerant (MT) and 2 moderately susceptible (MS); under EC3, 3 were T, 14 MT, 30 MS and 3 susceptible (S); under EC4, one was MS and 49 S and under EC5, all were S. The protein content of seed was influenced by salinity and varied with the genotype.

Germinação e formação de mudas de coqueiro irrigadas com águas salinas

The coconut cultivation is growing in the Northeast Brazil with increase in productivity under irrigated conditions. Saline waters are commonly found in this region and considering the lack of data related to salinity on dwarf-green coconut (Cocos nucifera L.), this work had the objective of evaluating the effects of the irrigation with saline waters (ECw = 2.2, 5, 10, 15 and 20 dS m-1) on the germination and the initial growth of seedlings until 120 days after sowing (phase I), extending the evaluation, later, after transplanting in the nursery, when seedlings were irrigated with water of ECw = 2.2 dS m-1, for another 120 days (phase II), studying the residual effect of the applied salinity levels in the phase I. In both the experiments a completely randomized design was used with four replications. The saline waters were prepared with the addition of commercial NaCl. In the first phase, the increment of ECw did not influence the germination significantly, which varied from 80 to 97.5%, however, it affected the germination speed and the growth of the seedlings; in the germination phase the salinity affected the total phytomass starting from 5.4 dS m-1; the root system was the most affected variable by the water salinity. In the phase II, the plants germinated under conditions of high salinity when irrigated with water of 2.2 dS m-1 maintained the rhythm of growth similar to those germinated without saline stress.

Crescimento e fenologia de espécies de Jatropha durante a estação chuvosa

Jatropha curcas L., Jatropha mollissima (Pohl) Baill and Jatropha gossypiifolia L. are Euphorbiaceae with potential for biodiesel production and use in pharmaceutical and cosmetic industries. The aim of this study was to evaluate these species in terms of growth and phenology in a field experiment. In this study an experimental design of randomized blocks was adopted. The experimental plot had 18 plants and a useful plot area of 15 m2. In the phenological studies of plants the following phases were considered: establishment/vegetative growth, flowering, fruiting and ripening/harvest. The phenological stages of the species differed chronologically. Jatropha mollissima outgrew the others in plant height, while Jatropha curcas outgrew the others in stem diameter. The highest relative growth rates in plant height occurred during vegetative growth, with the highest values being recorded in Jatropha mollissima, while the greatest relative growth rates also in vegetative growth were recorded in Jatropha curcas. The lowest relative growth rates in plant height and stem diameter of the studied species coincided with the reproductive phases.