QUANTIFICATION OF THE EMERGENT FLORA OF WEEDS IN AGRO-ECOSYSTEMS IN EDÉIA (GO)

In Edéia (GO), many of the farmers who had adopted the no-tillage system complained about the high expenses related to the control of weeds. Due to this problem, this study aimed to quantify the seedlings emergency in the beginning of the rainy season by means of comparison of agro-ecosystems in Edéia. Four of them were chosen: 1) Soy/Corn/Soy/Sorghum/Soy (area I); 2) Soy/Corn/Soy/Sorghum/Soy (area II); 3) Corn/SoylSorghum/Soy; 4) Soy/Soy/Corn/Brachiaria. The results were expressed in population of weeds by m². As far as statistical analysis is concerned, the following groups were established: the main dicotiledoneous species; the main monocotiledeneous species; the species of double cropping; the Brachiaria species. One may infer that the adopted handling in the last two years favoured certain species with detriment to others. It is necessary, therefore, to establish a rotation of cultures and herbicids in order to control the most damaging species in an effective way. KEY-WORDS: Agro-ecosystems; weeds.