Abstracts |
Pot experiment was conducted to investigate the effect of herbicides on biomass of maize and on infection rate and hyphal enzyme activity of arbuscular mycorrhizal fungi (Glomus intraradices and G. etunicatum). The dosages of herbicides applied in the pots were the same as in the fields. The results showed that the herbicides (acetochlor, butachlor, glyphosate-isopropylammonium, aventis, dicamba, and fluroxypyr) showed significant impacts on biomass of maize, infection rate of AM mycorrhizal fungus, and hyphal enzyme activity of alkaline phosphatase (ALP) and succinate dehydrogenase (SDH), and amount of AM mycorrhiza fungal hypha in the soil. Samples collected at the 10th week showed that aventis had the greatest impact on biomass of the maize (21.1-31.3 g), and glyphosate-isopropylammoniun had the least (59.7-65.5 g), while the biomass in the control treatment was 85.4-95.7 g. In terms of impact on infection rate, butachlor ranks first (with infection rate of 13.7-18.1%) among the six herbicides, and fluroxypyr the last (30.4-36.6%), while the infection rates in the control were 63.0-88.2%. Butachlor showed the greatest impact on ALP and SDH activities of AM mycorrhizal fungal hypha (ALP 8.1-10.4% and SDH 10.6-14.6%), and fluroxypyr the least (ALP 17.0-20.6% and SDH 23.1-28.2%), whereas the control showed 38.0-50.3% and 49.7-72.4%, respectively. In addition, herbicides significantly affected the total amount of the hyphae of AM mycorrhizal fungus in the soil.. |