Levantamento da flora emergente de plantas daninhas em sistemas de cobertura do solo

Abstract

The emerging flora of seedlings and weeds in several soil cover systems was studied through: a) cover crops under no-tillage (pigpeas; brachiaria; pearl millet; gray mucuna; oats; striped mucuna; saracen wheat; crotalaria) and b) tillage systems (minimum tillage; cover removal; no-tillage on grown weeds; conventional tillage). Evaluation ofthe emerging Hora showed that among cover crops the tr eatments with pearl millet and the bracchiaria presented low monocotyledonous incidence (0.66 pi/ m2), differing however from the conventional tillage (50.33 pl/m2). The dicotyledonous occurrence was inhibited by crotalaria presence, saracen wheat and pearl millet, (1.00, 1.00, and l .33pl/m2, respectively), only oats differing within cover crops (18.66 pl/m1). The residual population of pearl millet (130.66 pl/m1) was statistically higher than residues of brachiaria. gray mucuna, andstriped mucuna (1.00, 0.00, and 0.33 pl/m', respectively). It was found that the complete soil cover was achieved with bracchíaria, which controHed weeds efficiently. Pearl miJJet and crotalaria showed good mono- and dicotyledonous control, achieving good soil cover. However, the emergence of volunteer pearl millet may pose management problems for the subsequent crop.