EFEITOS DOS PERÍODOS DE COMPETIÇÃO DO MATO NA CULTURA DO AMENDOIM: I. SAFRA DA SECA DE 1988A field experiment was carried out at Adamantina, State of São Paulo, Brazil, to study different periods of weed competition with peanut. The treatments were 20: with and without weed presence through the crop cycle and those resulting from factorial combinations among presence and ausence of weed in the beginning of crop and the time of weed removal - 20, 30, 40, 50, 60, 70, 80, 90 and 100 days after sowing. Each plot was constituted of four lines, with common border among experimental units, with useful area reading 6.0 m2. Weed species, occurring with higher frequencies were Cyperus lanceolatus Poir., Digitaria horizontallis Willd., Brachiaria decumbens Stapf. and Portulaca oleracea L. The weed association with the peanut crop decreased pod and kernel yields and peanut dry matter. No weed effects were observed on harvest indexes and shelling percentages in any of the studied periods. A weeding operation done eight or 73 days after sowing, for treatments without and with weeds respectively, was sufficient for obtaining peanut pod yields statistically similar to those obtained when the peanut crop was maintained without competition during all cycle.
Arachis hypogaea L.; yield
