Study On The Application Technology Of Ethametsulfuron In Rape Field

The weed species, abundance and their damage to the rape in Huaihua region are reported. It is found that there are 25 species for major weeds, belonging to 13families. Based on the analysis of their relative abundance and frequency, we foundthat some of the component of rape field weeds of community were Alopecurus aequalis, some of the component of rape field weeds of community were Alopecurusaequalis-Lapsana apogonoides, or Stellaria cf. uliginosa -Stellaria media , some of the component of rape field weeds of community were Alopecurus aequalis -Stellaria media -Eclipta prostrata ,or Alopecurus aequalis-Stellaria media -Stellaria cf.uliginosa were found to be the mostdominent varieties weeds in the area.This research applies ethametsulfuron mixed with clopyralid and haloxyfop-P-methyl in the weed preventing and controlling in the rape field, in order to obtain one kind of best employment dosage allocated proportion. Discovered through the research that, When 5% ethametsulfuron WP according to each Chinese acre employment dosage 6g, 9g, 12g separately mixed with 75% clopyralid SG and 10.8% haloxyfop-P-methyl EC applies in the management of weeds in the rape field with the characteristic status of wide killing grass spectral, high weeding effect, good security, quite remarkable production increase effect, very low remnant allowance in the field. These have provided the important basis for the correct reasonable use of ethametsulfuron in the weed preventing and controlling in the rape field.The relative toxicity of ethametsulfuron wae tested by bioassay using maize, radish and cucumber seed. EC50 values indicated that maize was much more sensitive to ethametsulfuron than radish and cucumber.The residue of ethametsulfuron in rape field soil were measured according to the inhibited rate of fresh weight of root by breeding maize in this kind of soil.the result showed that the residue of ethametsulfuron in rape field soil were 0.82ng/g, 3.03 ng/g, 6.71 ng/g and 8.14 ng/g after 140 days at the employment dosage were 15g/hm~2,22.5g/hm2, 30g/hm2 and 37.5g/hm2. respectively.