INFLUENCE OF FIVE HERBICIDES ON RHIZOBIUM-ALFALFA SYMBIOTIC NITROGEN-FIXATION
WANG Li-ping WANG Jin-xin~* SUN Ai-rui LU Mei LIU Shu-hua (College of Plant Protection,Shandong Agricultural University,Tai'an 271018,China)
The inhibitory effects of 5 herbicides:imazethapyr,clomazone,acetochlor,butralin and trifluralin on rhizobium-alfalfa symbiotic nitrogen-fixation were studied in greenhouse.The results revealed that:ima- zethapyr and clomazone had the strongest inhibitory effects,trifluralin had the lest inhibitory effects.At the dosage of 33.8 a.i.g/hm~2,imazethapyr reduced respectively fresh weight and dry weight by 67.2% and 65. 3%,trifluralin,at the dosage of 450 a.i.g/hm~2,reduced respectively fresh weight and dry weight by 33.0% and 33.3%;nodulation rate and total nitrogen content of alfalfa without herbicides were respectively 90.1% and 4.2%,at the dosage of 33.8 a.i.g/hm~2,imazethapyr reduced respectively nodulation rate and total nitro- gen content by 33.1% and 2.3%,while trifluralin,at the dosage of 450 a.i.g/hm~2,reduced respectively nodulation rate and total nitrogen content by 76.0% and 3.1%.
【CateGory Index】： S482.4;S541.9