Effects of repeated applications of fluazifop‐butyl, haloxyfop and sethoxydim on Elymus repens in strawberries

Abstract

Summary:Fluazifop‐butyl, haloxyfop and sethoxydim with adjuvant oil were applied for three successive growing seasons to established strawberries infested with Elymus repens. The weed was virtually eradicated by three applications of haloxyfop (0.8 kg a.e. ha−1) in successive years. A similar effect was given by five applications of haloxyfop (0.4 kg a.e. ha−1) and fluazifop‐butyl (1.6 kg AI ha−1) in three growing seasons. Lower rates of haloxyfop and fluazifop‐butyl, and a high rate of sethoxydim (1.6 kg AI ha−1) applied five times were less effective, the ground cover of E. repens shoots not being reduced by the end of the experiment although weight of living rhizome was only 10‐30% of that on untreated plots.Fruit yields on treated plots generally reflected the level of E. repens control, but there was some evidence of crop phytotoxicity from herbicide treatments. During the experiment E. repens untreated plots increased from about 30‐100% ground cover and reduced yield 13, 28 and 68% in successive years compared with weed‐free plots.