Physiological and Morphological Responses of Jatobá Submitted to Weed Competition and Glyphosate Doses

The jatobá (Hymenaea courbaril L.) occurring throughout Central America and tropical countries in South America. This specie has great potential timber, in addition to fruits, leaves and bark with medicinal properties. This study was conducted to evaluate the effect of weed competition and intoxication by glyphosate in jatobá plants. The experiment was carried out with jatobá plants in field. Eleven months after planting it was held a floristic inventory in the area. One month after thisfloristic inventory, it was installed an experimental design with six randomized blocks and six treatments: manual weeding of weeds; no manual weeding or herbicide; and four glyphosate doses, 1.25, 2.5, 3.75 and 5.00 L ha-1. At 15, 30, 45, 60 and 90 days after tratment it was carried out a photochemical efficiency analysis of photosystem II, chlorophyll indices, number of leaflets, height and stem diameter of the plants. Based on physiological variables (F0, Fm, Fv/Fm and ETR), the jatobá plants recovered 60 days after treatments. Although the jatobá plants are tolerant to glyphosate and weed competition, jatobá plants under 1.25 and 2.50 L ha-1 of glyphosate reduces the increase in height around 50%, plants under 3.75 and 5.00 L ha-1 reduces around 90% and plants under weed competition around 70%.