Efficacy of electrostatically charged glyphosate on ryegrass

Using a TX-VK3 spray tip attached to an electrostatic sprayer operated at 483 kPa pressure, ryegrass was sprayed with glyphosate at 0.0033 kg ae ha−1. Charge-to-mass ratio (Q/M) for the spray solution was 1.686 mC kg−1 at +10.0 kV charging voltage. Treatment efficacy was assessed using NDVI (Normalized Difference Vegetation Index) spectral reflectance values. Electrostatic charging of glyphosate significantly increased volume median diameter of spray droplets (Dv0.5 = 112.8 μm) compared to uncharged glyphosate (Dv0.5 = 106.5 μm). Ryegrass health declined 80% faster by charging the glyphosate spray solution compared to the uncharged spray.