The research was conducted under field conditions during the summer períod, to evaluate the solarization effect on purple nutsedge (Cyperus rotundus) control. The experimental design was randomized blocks with three replications. The treatments were arranged in a factorial scheme 2x 2 x 3, with two cover conditions (with and without transparent plastic sheet, 300 mm thickness), two periods of covering (vegetative and flower stages), and three cover periods (15, 30 and 60 days). The soil temperature under solarization was 43oC higher than the control, reaching more than 50oC at certain times of day. An increase of 400% was observed in the CO2 concentration in the atmosphere of solarized soil. Under these conditions the tuber sprouting was inhibited and the dry weight of all parts of the plant was decreased. The rate of tuber multiplication was decreases from 1:11 to 1:4 when the plant was covered at the vegetative stage, and to 1:9 when it was covered at the reproductive stage. A decrease of 20% in tuber viability was also observed.
Weeds; physical control; temperature; biology; reprodutive strategics