Silva, LuísSmith, Clifford W.Tavares, João2010-12-222010-12-221999SILVA, L., C.W. SMITH & J. TAVARES, (1999). Essays for the control of Clethra arborea and Pittosporum undulatum. "Actas do 1º Encontro sobre Invasoras Lenhosas". SPCF/ADERE. Gerês: 143-148.http://hdl.handle.net/10400.3/7701º Encontro sobre Invasoras Lenhosas : Tema III - Estratégias de Controlo Integrado e Possibilidades de Valorização. Gerês, 16 a 18 de Novembro de 1999.Clethra arborea Aiton (Clethraceae) is a tree endemic to Madeira island and naturalised in São Miguel island (Azores). Pittosporum undulatum Ventenat (Pittosporaceae) is a tree from Australia which invaders all the Azorean islands. Several chemical formulations were tested against these invaders by cutting the trunk and applying herbicide, namely triclopyr, imazapyr and glyphosate, at several rates. For P. undulatum imazapyr was the most promising herbicide. For C. arborea good results were obtained at low rates, specially with triclopyr, which stimulated microbial growth and stump rotting. After two years, seedlings of several species were found around the treated stumps. Uprooting of saplings might complement a general control strategy.engAzorean IslandsApplying HerbicideChemical ControlClethra arborea AitonControl StrategyPittosporum undulatum Ventenatconference object