Curso diário e sazonal do potencial hídrico foliar de mogno em sistema agroflorestal

Abstract

This study aimed to evaluate the daily and seasonal course of the leaf water potential of Mahogany (Swietenia macrophylla King) (Meliaceae) in an agroforestry system (SAF). The experiment was carried out in Swietenia macrophylla trees planted in agroforestry system installed at the Experimental Field of Embrapa Western Amazon, Manaus-AM. We evaluated the leaf water potential (ψf) of the daily and seasonal course in 2004 and 2005 through the use of pressure bomb Scholander. The results showed that the values of ψf of Swietenia macrophylla, generally speaking, were higher in the early morning and late afternoon, with a marked reduction at noon and that, in regard to seasonal precipitation, the lowest rates were reported to the less rainy season, ranging from -26bar in 2004 to -31bar in 2005. It was found that the water potential of Swietenia macrophylla in agroforestry system was significantly reduced due to the low rainfall between June and October 2005.