Determination of the critical period of weeds competitionin pepper crop (Capsicum annum, L.)

Abstract

The determination of critical period of competition between weeds and economic crops is the only efficient way to establish methods of weeds management during the time that the crop requires. To achieve this aim, was conducted a research two-year (2012-2013) at the National Institute of Agricultural Sciences, where was evaluated using a randomized block design, with treatments at 20-30-40-50-60-70 days after the transplant with and without weeds and two controls, with and without management during the whole cycle of the pepper. The dominant weeds in the system were Cyperus rotundus L., Amaranthus dubius Mart. and Portulaca oleracea L. The critical period of weed competition with the pepper crop goes from 50 to 80 days before the transplant, period during which the crop can´t miss the weed management, to guarantee good yields. The highest yields were obtained when the weeds were managed at 50, 60, 70 days and the whole cycle of crop, with 8,8; 8,3; 12,3 and 12,4 t ha^-1 respectively and the lowest yields on the same days but with the reverse treatment with 0,6; 1,0 and 0, 5 t ha^-1.