This research is in support of weed management programs. A field experiment was carried out in Botucatu (São Paulo, Brazil), with the objective to determine the critical period of broadleaf weed interference on soybean, using statistical procedures of regression analysis. A randomized block design was used with 3 replications. The crop was kept weed infcsted for different periods. The criticar period of weed interference determined by the Broken-Stick modo was between 21-30 days after crop emergence. Broadleaf weeds in soybeanel crops can be controled with single use of remedial methods without residual effect.
Regression models; control; weed management; ecology; Glycine max