Concentrations of phytohormones (ng/g fresh weight) in cotton, corn, and tomato plants exposed to neonicotinoid insecticide.

<p>U: Untreated, N: Neonicotinoid insecticides thiamethoxam (cotton), clothianidin (corn), and imidacloprid (tomato). Four-week old plants were used in the experiment. Tomato plants were treated with soil applications of imidacloprid seven days prior to the experiment. Means were compared using ANOVA (<i>F</i> statistic) or non-parametric Kruskal-Wallis test (<i>X²</i> statistic).