Herbicide drift vs. crop resilience – the influence of micro-rates

Abstract

A greenhouse study was conducted to test the effects of low herbicide dose exposure on different crops measuring visible damages, plant height, leaf area, and dry matter. Seven crops were tested: lettuce (Lactuca sativa L.) cv. Novosadska majska maslena, oil pumpkin (Cucurbita maxima Duch) cv. Olivija, oilseed rape (Brassica napus L.) cv. NS Ras, pepper (Capsicum annuum L.) cv. Kurtovska kapija, soybean (Glycine max (L.) Merr) cv. ZP Laura, sunflower (Helianthus annuus L.) cv. NS Kruna, and tomato (Solanum lycopersicum L.) cv. Dunavski Rubin. Herbicide dicamba in the range of 0.14 to 1 155.6 g a.i. (active ingredient)/ha inhibited biomass, height, leaf area, and visual injury of all crops, while glyphosate doses from 0.48 to 3 840 g a.i./ha also reduced the growth of all tested species. A rate of 116 g a.i./ha mesotrione was needed to reach 80% visual injury in oilseed rape, while the same effects on lettuce only required 1.8 g a.i./ha of mesotrione. Tomato and oil pumpkin were also sensitive to low mesotrione doses, where only 1.3 g and 0.5 g a.i./ha of mesotrione was needed for 80% of biomass reduction, respectively. Lettuce was the most sensitive crop of all tested species; biomass was reduced by 80% by dicamba, glyphosate, mesotrione, and nicosulfuron at the low rates of 33 g a.i./ha, 19 g a.i./ha, 1.25 g a.i./ha, and 2.7 g a.i./ha, respectively. Among all herbicides, visible injuries were detected in dicamba at the lowest rates. Soybean was the most tolerant of glyphosate, mesotrione, and nicosulfuron. Based on the available literature and obtained results, herbicide off-target movement must be mitigated to maximise herbicide efficacy and decrease the negative influence on susceptible plants and the environment.