BRS Paiaguás and BRS Piatã: potential for use under water regimes in a semi-arid environment

[BRS Paiaguás e BRS Piatã: potencial para uso sob irrigação em ambiente semiárido]

ABSTRACT

This work aimed to evaluate the physiological parameters, the biomass flow, and the productive characteristics of the grasses BRS Piatã and BRS Paiaguás at different levels of water supply in the semi-arid region. The experiment was carried out in the dry season, in Sobral, Ceará State, Brazil. The following irrigation depths were used: 30, 60, 90, and 120% of ETo. The experiment was carried out in pots with a capacity of 7.5 dm³ at field level, using a 0-0.2m layer of argisol soil as substrate. As a result, the photosynthetic rate was not affected in the largest water treatments. In the biomass flow, the responses of grasses to treatments 90 and 120% of ETo were similar for the variables number of live leaves and phyllochron. Regarding the productive characteristics, pseudo-culm biomass was effective only in the treatment of 120% of ETo, while, for the efficiency of water use, in treatments 60 and 90% of ETo, the difference was effective. In conclusion, in the treatments of 60 and 90% of the ETo, it was possible to maintain good morphological characteristics of the grasses and to increase the biomass production during the dry season in the semi-arid region.

Keywords:
biomass flow; biomass production; gas exchange; irrigation depth; water use efficient