Phytotoxicity of pre-emergence herbicides to peach seedlings (Prunus persica)

Abstract

Pre-emergence herbicides were tested for relative phytotoxicity to Nemaguard peach seedlings (Prunus persica) in a sand culture. Typical symptoms, phytotoxicity ratings, growth and regrowth parameters were recorded. Diuron, the mixture diuron plus terbacil (1:1), terbutryne and norflurazon were rated phytotoxic at concentrations as low as 1 mg ⁻¹ with little recovery in the regrowth. Terbacil and simazine caused moderate initial phytotoxicity at concentrations up to 3 mg l⁻¹ but the seedlings showed recovery in the regrowth. Oryzalin at 6 mg l⁻¹ and higher caused stunting of growth, especially with the regrowth, while trifluralin, pendimethalin, napropamide and prodiamine proved to be relatively safe to peach seedlings at concentrations up to 6 mg l¹.