Weed interference periods in pre-sprouted sugarcane seedlings.

The aim of this study was to determine the period prior to interference (PPI), the critical-period of interference prevention (CPIP), and the total-period of interference prevention (TPIP) in sugarcane in the pre-sprouted seedlings (PSS) system, in coexistence with Cyperus rotundus and other weeds, adopting a loss of 5% in yield. The treatments corresponded to seven coexistence periods and seven weed control periods: 0–30, 0–60, 0–90, 0–120, 0–150, 0–180, and 0–240 days after planting (DAP). The cultivar used was IACSP95-5000. Until 26 DAP, weeds did not compete with sugarcane. From 26 to 68 DAP, weeds competed with sugarcane. Thus, it is considered that from 68 DAP, weed control is no longer necessary because increased periods of control do not result in significant yield gains. The results showed a 26 days PPI, 26–68 days CPIP, and 68 days TPIP, adopting a loss of 5% in yield, for weed competition with sugarcane in the PSS system. There was a reduction of 8.22% in sugarcane yield per day of coexistence and an increase of 11.37% per day of control. [ABSTRACT FROM AUTHOR]