Evaluation of some pre and postemergence herbicides for weed control in yacon

Abstract

Weed control was investigated in yacon (Smallanthus sonchifolius Asteraceae) a herbaceous perennial that produces edible tubers Eight preemergence (alachlor acetochlor simazine diuron pendamethalin dimethanamid methabenzthiazuron and metribuzin) and two postemergence (linuron and methabenzthiazuron) herbicides were evaluated in field trials at Pukekohe All preemergence herbicides except metribuzin were tolerated by yacon but the best weed control was achieved with acetochlor metribuzin and dimethanamid Weeds in the untreated control caused a 62 reduction (Plt;005) in root weight relative to acetochlor alachlor metribuzin and dimethanamid The postemergence herbicides were both phytotoxic to yacon top growth but the plants subsequently recovered and plant crown production at harvest was not reduced relative to the control (P>005)