Plants of Guazuma ulmifolia Lam. (4 month-old) and Sesbania virgata (Cav.) Pers. (2 month-old) were submitted to flooding in order to assess sprouting and elongation of the stem of these species, and to examine the effect of ethylene and kinetin in theses processes. The plants were submitted to flooding or maintained in dry soil for a period of 100 days and also together with: Ethrel, Ethrel with 6-BA, 6-BA or silver nitrate. Plants of G. ulmifolia sprouted after a short period of flooding, and the application of Ethrel and of Ethrel and 6-BA, in addition to the conditions of flooding, prompted the emergence of a greater number of branches than the other treatments. The application of silver nitrate, in flooded plants of G. ulmifolia, inhibited the development of lateral branches. In S. virgata, plants that received the application of 6-BA, on substrate drained or flooded, had a larger number of branches than the other treatments. Plants of G. ulmifolia and S. virgata showed a decrease in stem elongation as lateral branches were formed. The two species showed different tolerance mechanisms that contributed to their survival under conditions of prolonged flooding.
6-BA; branching; ethylene; hypoxia
