The growth of Senna obtusifolia was studied under greenhouse conditions. The plants grew in 6 1 pots, filled with sand and irrigated with complete Hoagland's solution twice a day. The growth of the plant was evaluated from 21 to 161 days aft er the emerge nce (D.A.E.), at 14 days intervals. Results evidenced that plants of Senna obtusifolia accumulated the maximum amount of dry matter at 147 D.A.E. The greast intensity of growth occurred from 21 to 63 D.A.E. evaluation. From 63 D.A.E. all the plants had flowered . From the emergence to 63 days, the highest amount of dry matter was partitioned in the roots. Form this evaluation to the end of the cicle of sicklepod, the majority of the dry matter was partitioned to stems. The relative growth decreased quickly until 63 days , maintaining a low and cons tant rate until the end of expe rimental period. This growth paramet er was strongl y influenced by the net assimil ation rat e, which was steady aft er 91 days , probabl y to due the plant selfshading. The leaf area grew vast ly until 35 days and became steady 119 days aft er the plant emergence. Senna obtusifolia showed lower initial growt h rates compared to other weed species. Thus, the Senna obtusif olia species can be caracterized as late infestant plants.
Growth analysis; weed; Senna obtusfolia