Urea Phosphate Increases The Efficacy Of Glyphosate On Weed Control

Glyphosate is one of the largest uesd herbicides in the world.It has effective control on annual and perennial weeds.Glyphosate was widely used in the control of farmland,orchard and road weeds prevention.Especially in recent years,with the rapid increase of glyphosate resistance(GR)crops planting area,glyphosate dosage is also growing around the world.At the same time,there are also occurred some issues.Firstly,in order to reduce the cost of application,people found that manganese and other metal ions can significantly reduce the weed control efficacy of glyphosate when mixed glyphosate with foliar micronutrient fertilizer.Secondly,after decades of continuous use of glyphosate,glyphosate tolerance of some weeds also gradually strengthened.It lead to the dose of glyphosate becomes increasingly higher.How to improve the weed control efficacy of glyphosate and reduce the cost has great significance.Urea phosphate is a kind of new type of high efficient nitrogen and phosphorus compound fertilizer.It has obvious effect to increase cotton and rice production.It can be used with a variety of fertilizer including Fe,Zn and other mineral elements.It can also be used together with various kinds of herbicides and pesticides.This study found that urea phosphate can alleviate or even eliminated the antagonism of manganese sulfate on glyphosate.Then we found that the synergism of urea phosphate on glyphosate.These results showed as follows:Firstly,foliar spray of glyphosate in tank mixtures with manganic sulfate(MnSO4,0.1%)and urea phosphate(166 mg/L,500 mg/L and 833 mg/L)was performed on tall fescue and ryegrass.After measured some physiological indexes such as the control effect,water content,the chlorophyll,etc,we found urea phosphate can relieve the antagonism of Mn2+ on glyphosate.The 833 mg/L urea phosphate had the best effect,achieving the same control of the glyphosate.In comparison with glyphosate and Mn2+ mixture treated plants,adding urea phosphate reduced the water content of tall fescue leaf and chlorophyll content and improved the shikimic acid content and MDA content.What are the effective constituents in urea phosphate?According to experiments,we found that phosphoric acid and urea can both relieve the antagonism of Mn2+ on glyphosate.But the effect of phosphate acid was significantly better than that of urea.Meanwhile,reducing the pH value was one of the important reasons.So inferred the urea phosphate may mainly be effective through phosphate acid which reducing solution pH value.Secondly,foliar spray of glyphosate in tank mixtures with and urea phosphate(166 mg/L,500 mg/L and 833 mg/L)was performed on tall fescue,ryegrass,Eleusine indica L.,Conyza canadensis L.and Conyza bonariensis L.We found that urea phosphate can enhance weed control efficacy of glyphosate and 833 mg/L urea phosphate had the best effect.Compared with glyphosate treatment,adding urea phosphate increased the content of shikimic acid and reduced the leaf water content and chlorophyll content in different degrees.And then to explore two factors pH value and urea.We found that reducing the pH value could enhance glyphosate weed control effect.At the same time,low concentration urea(<0.5%)also promoted the weed control efficacy of glyphosate on ryegrass.Urea phosphate enhanced glyphosate weed control efficacy,therefore,may be by urea and phosphoric acid which reducing the solution pH value.Thirdly,foliar spray of glyphosate mixed with urea phosphate(166 mg/L,500 mg/L and 833 mg/L)was performed on Eleusine indica L.and Conyza canadensis L.which from the farm spraying glyphosate for years.We found 833 mg/L urea phosphate had the best effect in this experiment.Weeds showed early injure and high degree of death.In a word,this research indicates that urea phosphate can enhance the weed control efficacy of glyphosate.It can largely alleviate the antagonism of manganese fertilizer on glyphosate in GR crops production,not only for weed control,but also for nutrient supply to the GR crops.At the same time adding urea phosphate can strengthen the weed control effect or reduce the dosage of glyphosate when spraying glyphosate.