Effects of control periods and the presence of weeds in lettuce culture

Abstract

The effects of different control periods and the presence of weeds in lettuce, cv. Elisa, were evaluated. The treatments consisted of maintaining the culture in the presence or absence of weeds for periods of 7, 14, 21, 28, 35, 42 e 49 days after transplantation. A control period of 14 days was enough for the crop to show its productive potential. For crescent periods in the presence of weeds, the crop can live with the infesting community for a period of 28 days without yield reduction. Thus, the duration of the total period of interference prevention (TPIP) was 14 days, and the period that precedes the interference (PPI) was of 28 days, showing that just one elimination of weeds in the interval between the end of TPIP and the end of PPI, that is, between 14 and 28 days, would be enough to prevent interference.