Papers

Summary

The Cupuassu [Theobroma grandiflorum (Willd. ex Spreng.) Schum] is one of the most important fruit and popular in the Amazon. But cultivation is still limited because few agronomic information and lack of selected genetic material, in addition to the damage caused by "witches broom" are responsible for the low production. This study aimed to evaluate physiological parameters of healthy Cupuassu and infected with witches' broom. This study was conducted in Cupuassu 10 years of age intercropped with rubber (Hevea brasiliensis) with 25 years of age on the Campus of Federal University Rural of Amazonia, Belém-PA. Were measured with the aid of a diffusion porometer state stationary, brand LI-COR, Model 1600, to measure the following variables: stomatal conductance (EC); Photosynthetically Active Radiation (PAR), leaf temperature (T) and transpiration (Tr) of Relative Humidity Sheet. To determine the parameters used were 10 healthy plants and plants inoculated with 10 fungus C. perniciosa. Measuring with the porometer on abaxial surface of a leaf in the middle third of crown of each plant measured from the day 01.28.2006 on 4 consecutive days during periods of 8h, 10h, 12h, 14h and 16h. Based on the recorded data, we applied the Tukey test at 5%. And the plants infested with the witches' broom disease had lower stomatal conductance and transpiration compared to the healthy plants. And there was a significant difference only in periods of 10h and 14h.This involved directly in decrease in photosynthesis and consequently the productivity.