Bioassay for Determining Sensitivity to Sulfosulfuron on Seven Plant Species

This study presents a bioassay procedure, based on the root and shoot growth parameters, for the determination of the herbicide sulfosulfuron (1-(4,6 dimethoxypyrimidin-2-yl)-3-(2-ethylsulfonylimidazo[1,2-a]pyridin-3-ylsulfonil)urea) sensitivity on seven vegetal species. Plant response to sulfosulfuron was calculated with the equations fitted to the root growth data as a function of the logarithm of the herbicide concentration by non-linear regression and was used to calculate the doses for 10, 30 and 50% inhibition of root growth (EC₁₀, EC₃₀ and EC₅₀). The results indicate that the phytotoxic effect of sulfosulfuron in all the species assayed followed the order: flax > maize > onion > vetch > lepidium sativum > tomato > barley. These species showed phytotoxicity at low levels of sulfosulfuron and flax appeared to be the most susceptible species to sulfosulfuron (0.001 mg/L).

Key Words:

• Hydroponic bioassay
• Sensitivity
• Sulfosulfuron
• Dose-response, Phytotoxicity

Notes

∗Mean values of each bioassay were analysed using ANOVA and compared by Newman Keuls multiple range test. Different letters after value, for each column, indicate differences at p < 0.05.

∗Mean values of each bioassay were analysed using ANOVA and compared by Newman Keuls multiple range test. Different letters after value, for each column, indicate differences at p < 0.05.

∗Mean values of each bioassay were analysed using ANOVA and compared by Newman Keuls multiple range test. Different letters after value, for each column, indicate differences at p < 0.05.

^aRegression Equations by Gompertz model.

^bRegression Equations by Seefeldt model.