Weed Control Systems for Sunflowers

Abstract

The control of grasses and broadleaf weeds in sunflowers(Helianthus annuusL. ‘Peredovik’) generally was as good with one or two cultivations during the 3-year period as with chemicals applied alone or in sequence with cultivation. Plant injury was not evident from mechanical treatments or from α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin). However, plant injury occurred when plots were treated with 2-chloro-2′6-diethyl-N-(methoxymethyl) acetanilide (alachlor) plus 2,4-bis(isopropylamino)-6-(methylthio)-s-triazine (prometryne) as a preemergence application in 1 year and from postemergence applications of 2-tertiobutyl-4-(2,4-dichloro-5-isopropyloxyphenyl)-5-oxo-1,3,4-oxodiazoline (RP 17623) and 3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea (linuron) in 2 years. Seed yields from plots cultivated once were as good as yields from plots that received multiple cultivation or herbicide treatments. Other agronomic characteristics were favorable from plots that received one cultivation.