Study on the improving efficacy of sethoxydim on weeds of lecithin and vitamin E and the safety to foxtail millet

The study was performed to explore the synergistic effect of adjuvants AnnGro® main components are lecithin and vitamin E on sethoxydim, and investigate the mitigation effect of AnnGro® on millet variety ‘Jingu 21’ under the stress of sethoxydim. Through pot experiment, different dosages of sethoxydim and AnnGro® mixture were sprayed at 3-5 leaves stage of ‘Jingu 21’ and Eleusine indica. The agronomic traits and photosynthetic physiological indices of ‘Jingu 21’ at 7 days and the synergistic effect of eleusine indica at 7, 15 and 30 days were measured after the mixture application. The results showed that sethoxydim significantly inhibited the plant height, leaf area, photosynthetic pigment content, and chlorophyll fluorescence parameters of ‘Jingu 21’, and the inhibitory effect was strengthened with the increase of the concentration. Under 1/8 recommended field dose, the ‘Jingu 21’ was severely damaged; under 1/2 recommended field dose, the plant height and leaf area of ‘Jingu 21’ were significantly reduced by 23.41% and 33.15% compared with control, at the same time, the photosynthetic pigment content and chlorophyll fluorescence parameters of ‘Jingu 21’ were significantly lower than control. Adding different concentrations of AnnGro® has no significant mitigation effect on the stress of low concentration of sethoxydim, but has a significant mitigation effect on the stress of high concentration of sethoxydim. AnnGro® which was diluted by 2500 times and 1/2 recommended field dose sethoxydim treatment had the best mitigation effect, which was reflected by the plant height and leaf area of ‘Jingu 21’ were increased by 16.76% and 24.94%, respectively, compared with sprying sethoxydim alone, the physiological indicators such as photosynthetic pigment content and chlorophyll fluorescence parameters were significantly higher than those of the control and other treatments at this dose. 1/8 recommended field dose sethoxydim treatment has poor control efficacy on Eleusine indica, and the plant control efficacy is almost 0. With the increase of the concentration of sethoxydim, the control efficacy on Eleusine indica was gradually increaseed. 30 days after the herbicide application, the plant efficacy and fresh weight efficacy of 1/2 recommended field dose sethoxydim on Eleusine indica were 53.33% and 73.10%, respectively. After adding AnnGro® which was diluted by 2500 times, the plant efficacy and fresh weight efficacy of Eleusine indica rose to 73.33% and 84.65% respectively. In summary, the addition of AnnGro® which was diluted by 2500 times has the potential to improve the control efficacy of sethoxydim on Eleusine indica and increase the safety of ‘Jingu 21’.