Comportamento de clones de pennisetum submetidos a períodos de restrição hídrica controlada

The experiment was conducted in a green-house of the Agronomic Institute of Pernambuco, to evaluate Pennisetum sp. clons submitted to different periods of water reposition suppression. The experimental design was completely randomized in a factorial arrangement with four Pennisetum sp. clones and four periods without water reposition (0, 7, 14 and 21 days), with three replicates. Evapotranspiration, dry matter content and production, water use efficiency, average plant height, basal tiller number, water stress symptoms, number of regrowth plants and basal tiller number after the stress were measured. A longer water suppression period affected evapotranspiration more than dry matter production, with water use efficiency being 449 and 591 g of water per g of dry matter for treatments with 21 and 0 days of irrigation suppression, respectively. Seven days without irrigation increased dry matter content from 25.11 to 53.07 and from 29.25 to 46.89 for Australiano and HV241 clons, with no significant difference (p>0.05) for the two other clons. Among the evaluated clons, Australiano and HV241 had the highest dry matter production under moderate water deficit.