Phototoxicity of Two Paddy Herbicides on Tobacco and Screening of Alternative Herbicides

【Objective】To choose the safe herbicides, the field experiments were carried out.【Method】The pot experiment were conducted to study the influence on the growth of tobacco caused by two paddy herbicides. 【Result】The results indicated that Quinclorac and Bensulfuron-methyl could affected the height, leaf length and leaf width of tobacco. Quinclorac had significant effect on leaf width and made the blades to be narrow and linear with no commercial value. The inhibition rate of leaf width was up to 10% when the concentration of quinclorac in soil was 2×10-4 mg/kg. Moreover, the influence of Bensulfuron-methyl mainly included that plant dwarfed leaf number decreased and production dropped. The inhibition rate on plant height was more than 10% in case of 2×10-3 mg/kg Bensulfuron-methyl concentration in soil. 【Conclusion】The result showed that Benzoicacid could be used as alternation agent to control broadleaf weeds instead of Bensulfuron-methyl. Butachlor could control gramineous weeds instead of Quinclorac. Fluoroglycofen-ethyl could control gramineous weeds and broadleaf weeds instead of Quinclorac and Bensulfuron-methy. Thus, three herbicides (Benzoicacid, Butachlor, Fluoroglycofen-ethyl) would be used in rice filed safely and no influence on stubble crop tobacco.