Patent Publication Number: US-2005119126-A1

Title: Fine grains for controlling weeds stable to climate changes

Description:
TECHNICAL FIELD  
      The present invention relates to a technique to effectively control useless and noxious weeds growing in the living environment.  
     BACKGROUND ART  
      Exuberance of weeds brings about a decrease in yield of agricultural products or deterioration of the living environment irrespective of in an agricultural field or in a non-agricultural field. Herbicides are widely used to cope with such problems. Among them, a liquid formulation of glufosinate-ammonium (hereinafter referred to as glufosinate) is very widely used from such characteristics that it has high herbicidal effects against most plants, and when applied to soil, it will be readily decomposed or adsorbed by soil, and soon after the application thereof, new plants may be planted.  
      Further, in home gardening or the like, as a formulation which can conveniently be used, a dilute glufosinate liquid formulation which can be applied as it is, or triclopyr butoxyethyl ester or diuron formed into fine granule, is applied to foliage. JP-B-6-78204 discloses that glufosinate is added together with an adhesion aid to a mineral such as attapulgite and used as fine granule.  
      When a liquid formulation is used by a general consumer who has little experience or knowledge about the method of using the agricultural chemical, not only a trouble of diluting it will be required, but also the dilution rate or the dosage on application may likely be erred to cause phytotoxicity to nearby crop plants or to increase an environmental load due to excessive application. As a method to solve such a problem, with respect to a chemical which can be formed into a liquid formulation, a technique of direct application in the form of a diluted liquid formulation has been utilized not only for an insecticide but also for a herbicide. However, the diluted liquid formulation has had a drawback that the transportation cost or the storage cost is thereby substantially increased, since the application dose per unit area will be directly put on the distribution channel.  
      On the other hand, a method of using it in the form of a granule is advantageous in that the weight of the formulation to be applied can be reduced to a level of about one tenth of that in application of the diluted liquid formulation, and the application is also simple. However, most of the chemicals to be used in the form of granules of from 0.3 to 1.7 mm, are usually hardly absorbed from foliage. Further, even if glufosinate which is effective only when absorbed from foliage, is granulated and applied in the form of a granule, it shows no substantial effectiveness. As shown in JP-B-6-78204, it has been studied to formulate a fine granule by adding glufosinate together with an adhesion aid to a mineral such as attapulgite, thereby to improve the deposition efficiency on the foliage of plants to promote the development of the effectiveness. However, it has been difficult to obtain a stabilized effect, since the deposit of the chemical on the foliage is likely to be reduced substantially depending upon the climate conditions, such as in a case where wind is strong or in a case where the atmosphere is extremely dry. Therefore, until now, there has been no practical case wherein a fine granule of glufosinate has been practically used.  
     DISCLOSURE OF THE INVENTION  
      The present invention provides a herbicide obtained by blending to glufosinate-ammonium (ISO name: glufosinate-ammonium), one or two members selected from the group consisting of isouron (ISO name: isouron), karbutilate (ISO name: karbutilate), diuron (ISO name: diuron), tebuthiuron (ISO name: tebuthiuron), linuron (ISO name: linuron), cyanazine (ISO name: cyanazine), prometryn (ISO name: prometryn), metribuzin (ISO name: metribuzin), terbacil (ISO name: terbacil) and bromacil (ISO name: bromacil), as a photosynthesis-inhibiting herbicide (Group A); one or two members selected from the group consisting of 2,4-D (ISO name: 2,4-D), MCPA (ISO name: MCPA), mecoprop (ISO name: mecoprop), triclopyr (ISO name: triclopyr) and their salts and esters, as a phytohormone herbicide (Group B); one or two members selected from the group consisting of oxadiargyl (ISO name: oxadiargyl), carfentrazone-ethyl (ISO name: carfentrazone-ethyl), flumioxazin (ISO name: flumioxazin), bifenox (ISO name: bifenox) and pyraflufen-ethyl (ISO name: pyraflufen-ethyl), as a protoporphyrinogen oxidase-inhibiting herbicide (Group C); one or two members selected from the group consisting of diflufenican (ISO name: diflufenican), dichlobenil (ISO name: dichlobenil) and chlorthiamid (ISO name: chlorthiamid), as other herbicide (Group D); or one member selected from each of two Groups among (Group A), (Group B), (Group C) and (Group D); adding an adhesion aid, and depositing the blend on a mineral carrier having a grain size distribution of from 0.1 to 0.3 mm. By application of such a herbicide to the foliage of weeds, it has been made possible to simplify the treatment and at the same time to provide a stable herbicidal effect irrespective of the climate conditions.  
      Thus, according to the present invention, by blending to glufosinate which exhibits a herbicidal effect only when absorbed from the foliage and which shows no effect by soil treatment, not only a chemical showing the effect when absorbed from the foliage, but also a chemical which exhibits a high effect by soil treatment, may be mixed, followed by fine pulverization, it is possible to increase the deposit of granules on the foliage. The increase of the deposit on the foliage promotes the absorption of the chemical from the foliage. However, at the same time, it is considered that plant cells are withered and dead in early by glufosinate, whereby the absorption of the other chemicals mixed is promoted, and further, it serves to stabilize the effect.  
      Accordingly, the drawback of the known glufosinate fine granule, such as the decrease in the effect due to a climate change such as an extremely dried state, strong wind or strong rain, can be overcome. Further, in the case of a fine granule mixed with a chemical having a soil treatment effect, even if it fails to deposit on the foliage and falls on soil, it provides the inherent effect to bring about a further stability of the effect. 
    
    
     MODE FOR CARRYING OUT THE INVENTION  
      The amount of glufosinate to be deposited on grains of the mineral carrier is preferably from 0.3% to 3% (by weight, the same applies hereinafter unless otherwise specified) based on the grains. If the amount is smaller than the lower limit, the effect tends to decrease, and if it exceeds the upper limit, such is useless, since the deposit to plant bodies is limited.  
      The above-mentioned other herbicides to be blended are preferably from 0.01% to 3%, based on the amount of glufosinate.  
      In the production, a solid chemical may be finely pulverized and used as it is, or it may be used as dissolved in a solvent which can easily and safely be recovered. A liquid chemical such as glufosinate may be deposited as it is on a granular inorganic substance. Further, an adhesion aid may be used in combination to supplement the adhesion of the chemical or to promote the absorption from the foliage, of the chemical applied.  
      As such an adhesion aid, a high boiling point water-soluble solvent or a surfactant, such as ethylene glycol, propylene glycol, a polyethylene glycol, a polypropylene glycol, propylene glycol monomethyl ether, a polyvinyl alcohol, a polyvinyl pyrrolidone, a polyoxyethylene alkyl phenyl ether, a polyoxyethylene alkyl ether, a dialkyl sulfosuccinate, an alkylsulfonate, an alkylbenzenesulfonate, laurylsulfate, a polyoxyethylene alkylarylsulfate or a polyoxyethylene alkyl ether phosphate, may be used in combination. These adhesion aids may be used alone or as mixed. The total amount thereof is preferably from 0.5 to 10%, based on the total weight of the herbicide.  
      The granular inorganic substance to be used here may, for example, be zeolite, limestone, olivine, pumice, diatomaceous earth, calcined diatomaceous earth, bentonite, attapulgite or silica sand. However, it is not limited thereto, and any mineral may be used so long as it is a mineral which is free from breakage in the granular form and which has a nature capable of readily releasing a chemical from the grain surface. Such a carrier is used by adjusting the grain size so that the grain size distribution will be from 0.1 to 0.3 mm.  
      Referring to a specific production method, while stirring a selected finely granular mineral, a dissolved chemical or a suspended chemical and an adhesion aid are gradually added or blown and mixed thereto. After the mixing, in a case where a low boiling point solvent is used, it is removed, followed by drying and sieving to obtain grains of from about 0.1 to 0.3 mm as the product.  
      Further, when the grains having the chemical deposited tend to undergo caking, a small amount of a porous inorganic substance such as inorganic silicic acid or the like, may be added to prevent caking.  
     EXAMPLES  
      Now, embodiments of the present invention will be described with reference to Formulation Examples and Test Examples for herbicidal effectiveness.  
     Formulation Example 1  
      Preparation of 1% Glufosinate and 1% Isouron Mixed Fine Granule  
      865 g of fine granular zeolite (Zeogreen fine granule No. 8, tradename of Nihon Zeolite Co., Ltd.) was charged in a speed kneader tank, and while rotating rotary vanes at a rotational speed of about 350 rpm, 55 g of 18.5% glufosinate liquid formulation (Basta liquid formulation, tradename of Aventis Crop Science Shionogi K.K.) was slowly added. Then, 10 g of isouron pulverized to at most 100 μm was slowly added. Then, a mixed liquid consisting of 20 g of dioctyl sulfosuccinate (Aerol CT-1, tradename of TOHO Chemical Industry Co. LTD.) and 30 g of ethylene glycol, was dropwise added. Then, 20 g of porous silicic acid (Carplex #80D, tradename of Shionogi &amp; Co., Ltd.) was added, followed by stirring for 5 minutes, and then grains smaller or larger than from 0.1 to 0.3 mm were removed to obtain 956 g of the desired fine granule.  
     Formulation Example 2  
      Preparation of 1% Glufosinate and 0.7% Metribuzin Mixed Fine Granule  
      848 g of fine granular zeolite was charged into a speed kneader tank, and while rotating rotary vanes at about 350 rpm, 55 g of a 18.5% glufosinate liquid formulation was slowly added. Then, 7 g of metribuzin pulverized to at most 100 μm was slowly added. Then, a mixed liquid consisting of 30 g of polyoxyethylene octylphenyl ether (Nonal 109, tradename of TOHO Chemical Industry Co. LTD.) and 30 g of ethylene glycol, was dropwise added. Then, 30 g of porous silicic acid was added, followed by stirring for 5 minutes, and then grains smaller or larger than from 0.1 to 0.3 mm were removed to obtain 965 g of the desired fine granule.  
     Formulation Example 3  
      Preparation of 1% Glufosinate and 2% Diuron Mixed Fine Granule  
      845 g of fine granular zeolite was charged into a speed kneader tank, and while rotating rotary vanes at about 350 rpm, 55 g of a 18.5% glufosinate liquid formulation was slowly added. Then, 20 g of diuron pulverized to at most 100 μm was slowly added. Then, a mixed liquid consisting of 30 g of polyoxyethylene nonylphenyl ether (Emulgen 911, tradename of Kao Corporation) and 30 g of propylene glycol, was dropwise added. Then, 20 g of porous silicic acid was added, followed by stirring for 5 minutes, and then grains smaller or larger than from 0.1 to 0.3 mm were removed to obtain 960 g of the desired fine granule.  
     Formulation Example 4  
      Preparation of 1% Glufosinate, 0.5% Metribuzin and 2% Diuron Mixed Fine Granule  
      850 g of fine granular zeolite was charged into a speed kneader tank, and while rotating rotary vanes at about 350 rpm, 55 g of a 18.5% glufosinate liquid formulation was slowly added. Then, 5 g of metribuzin and 20 g of diuron pulverized to at most 100 μm was slowly added. Then, a mixed liquid consisting of 30 g of polyoxyethylene lauryl ether (Pegunol TH-8, tradename of TOHO Chemical Industry Co. LTD.) and 20 g of polypropylene glycol, was dropwise added. Then, 20 g of porous silicic acid was added, followed by stirring for 5 minutes, and then grains smaller or larger than from 0.1 to 0.3 mm were removed to obtain 957 g of the desired fine granule.  
     Formulation Example 5  
      Preparation of 1% Glufosinate and 1% Terbacil Mixed Fine Granule  
      335 g of fine granular zeolite and 500 g of fine granular calcium carbonate (calcium carbonate fine granule #50150, tradename of Nitto Funka K.K.) were charged into a speed kneader tank, and while rotating rotary vanes at about 350 rpm, 55 g of a 18.5% glufosinate liquid formulation was slowly added. Then, 10 g of terbacil pulverized to at most 100 μm was slowly added. Then, a mixed liquid consisting of 30 g of sodium dodecylbenzenesulfonate (Neopelex F-25, tradename of Kao Corporation) and 30 g of polyethylene glycol, was dropwise added. Then, 40 g of porous silicic acid was added, followed by stirring for 5 minutes, and then, grains smaller or larger than from 0.1 to 0.3 mm were removed to obtain 951 g of the desired fine granule.  
     Formulation Example 6  
      Preparation of 1% Glufosinate and 1% Cyanazine Mixed Fine Granule  
      845 g of fine granular zeolite was charged into a speed kneader tank, and while rotating rotary vanes at about 350 rpm, 55 g of a 18.5% glufosinate liquid formulation was slowly added. Then, 10 g of cyanazine pulverized to at most 100 μm was slowly added. Then, a mixed liquid consisting of 30 g of sodium dodecylbenzenesulfonate and 30 g of ethylene glycol, was dropwise added. Then, 30 g of porous silicic acid was added, followed by stirring for 5 minutes, and then, grains smaller or larger than from 0.1 to 0.3 mm were removed to obtain 956 g of the desired fine granule.  
     Formulation Example 7  
      Preparation of 2% Glufosinate and 0.5% Triclopyr Butoxyethyl Ester Mixed Fine Granule  
      805 g of fine granular zeolite was charged into a speed kneader tank, and while rotating rotary vanes at about 350 rpm, 110 g of a 18.5% glufosinate liquid formulation was slowly added. Then, a mixture consisting of 5 g of triclopyr butoxyethyl ester (Zytron ester, tradename of Dow Chemical Nippon K.K.) and 30 g of propylene glycol was slowly added. Then, 20 g of dioctyl alkylsulfosuccinate was dropwise added. Then, 30 g of porous silicic acid was added, followed by stirring for 5 minutes, and then grains smaller or larger than from 0.1 to 0.3 mm were removed to obtain 962 g of the desired fine granule.  
     Formulation Example 8  
      Preparation of 1% Glufosinate, 0.25% of Oxadiargyl and 0.05% of Diflufenican Mixed Fine Granule  
      852.5 g of fine granular zeolite was charged into a speed kneader tank, and while rotating rotary vanes at about 350 rpm, 55 g of a 18.5% glufosinate liquid formulation was gradually added. Then, 25 g of a 10% oxadiargyl acetone solution and 10 g of one having a 50% diflufenican suspension diluted 10 times with water, were slowly added. Then, a mixed liquid consisting of 20 g of polyoxyethylene nonylphenyl ether, 20 g of propylene glycol monomethyl ether and 20 g of propylene glycol, was dropwise added. Then, 20 g of porous silicic acid was added, followed by stirring for 5 minutes, and then, grains smaller or larger than from 0.1 to 0.3 mm were removed to obtain 954 g of the desired fine granule.  
     Comparative Formulation Example  
      Preparation of a 1% Glufosinate Fine Granule  
      875 g of fine granular zeolite was charged into a speed kneader tank, and while rotating rotary vanes at about 350 rpm, 55 g of a 18.5% glufosinate liquid formulation was slowly added. Then, a mixed liquid consisting of 20 g of polyoxyethylene nonylphenyl ether and 30 g of ethylene glycol, was dropwise added. Then, 20 g of porous silicic acid was added, followed by stirring for 5 minutes, and then grains smaller or larger than from 0.1 to 0.3 mm were removed to obtain 950 g of the desired fine granule.  
      The herbicidal effects against plants, of the above Formulation Examples 1 to 8 and Comparative Formulation Example, were compared and studied in pots and in fields.  
     Test Example 1  
     
         
         
           
              Pot Test 1  
              Test period: Jul. 9 to Jul. 30, 2000  
              Test site: Glass chamber in Tsukuba Bunshitsu, Hodogaya Agros Corporation  
              Test plants: Crabgrass ( Digitaria adscendens ) 
            Leaf age: 5.5     Plant height: 20 to 30 cm Greenfoxtail ( Setaria viridis )     Leaf age: 5     Plant height: 28 to 35 cm Slender amaranth ( Amaranthus viridis )     Leaf age: 4 to 4.5     Plant height: 6 to 10 cm Common lambsquater ( Chenopodium album )     Leaf age: 5     Plant height: 4 to 8 cm Common cocklebur ( Xanthium strumarium )     Leaf age: 5.3     Plant height: 14 to 20 cm    
         
              Test scale: 180 cm 2  pot, no repetition  
              Date of treatment: Jul. 9, 2000  
              Test method: The leaf surface of the test plant was wetted by an atomist spray, and each fine granule was applied on the leaf surface in an amount corresponding to 10 or 20 g/m 2 .  
              Dates of investigation: Jul. 16, and Jul. 30, 2000  
           
         
       
    
      Test results: Shown in Table 1.  
                                       TABLE 1                       Tested                   Common   common       formu-   Dose   Crab-   Green-   Slender   lambs-   cock-       lation   g/m 2     grass   foxtail   amaranth   quater   lebur                                                                                Formu-   10   6   9   7   9   9   10   8   10   8   9       lation   20   7   10   8   10   9   10   10   10   8   9       Example 1       Formu-   10   9   10   9   10   9   10   9   10   9   10       lation   20   9   10   9   10   10   10   9   10   9   10       Example 2       Formu-   10   4   9   8   10   9   10   8   10   9   9       lation   20   6   10   8   10   9   10   8   10   9   9       Example 3       Formu-   10   9   10   9   10   10   10   9   10   9   10       lation   20   9   10   9   10   10   10   9   10   10   10       Example 4       Formu-   10   5   9   6   8   8   10   8   10   7   9       lation   20   6   10   7   10   9   10   9   10   8   9       Example 5       Formu-   10   6   9   7   9   8   10   8   10   9   9       lation   20   8   10   8   10   9   10   8   10   9   9       Example 6       Formu-   10   6   9   6   9   9   10   9   10   9   10       lation   20   7   10   8   10   9   10   10   10   9   10       Example 7       Formu-   10   9   10   8   10   9   10   9   10   8   10       lation   20   9   10   9   10   10   10   9   10   10   10       Example 8       Compar-   10   6   7   6   7   5   6   6   7   6   7       ative   20   7   8   8   8   8   9   8   9   7   9       Formu-       lation       Example                 *Investigation Left: After 7 days from treatment, Right: After 21 days from treatment            *Evaluation 0: No effect to 10: Completely withered             
 
     Test Example 2  
     
         
         
           
              Pot Test 2  
              Test period: Jul. 9 to Jul. 30, 2000  
              Test site: Glass chamber in Tsukuba Bunshitsu, Hodogaya Agros Corporation  
              Test plants: Crabgrass ( Digitaria adscendens ) 
            Leaf age: 5.5     Plant height: 20 to 30 cm Greenfoxtail ( Setaria viridis )     Leaf age: 5     Plant height: 28 to 35 cm Slender amaranth ( Amaranthus viridis )     Leaf age: 4 to 4.5     Plant height: 6 to 10 cm Common lambsquater ( Chenopodium album )     Leaf age: 5     Plant height: 4 to 8 cm Common cocklebur ( Xanthium strumarium )     Leaf age: 5.3     Plant height: 14 to 20 cm    
         
              Test scale: 180 cm 2  pot, no repetition  
              Date of treatment: Jul. 9, 2000  
              Test method: Each fine granule was applied on the leaf surface of the test plant in an amount corresponding to 10 or 20 g/m 2 .  
              Dates of investigation: Jul. 16, and Jul. 30, 2000  
           
         
       
    
      Test results: Shown in Table 2.  
                                       TABLE 2                       Tested                   Common   common       formu-   Dose   Crab-   Green-   Slender   lambs-   cock-       lation   g/m 2     grass   foxtail   amaranth   quater   lebur                                                                                Formu-   10   4   7   4   7   5   8   6   8   5   7       lation   20   6   9   5   8   7   9   7   9   6   9       Example 1       Formu-   10   5   8   5   7   7   8   6   8   6   7       lation   20   6   8   5   9   8   9   7   10   6   9       Example 2       Formu-   10   3   6   3   7   4   7   4   8   5   7       lation   20   5   9   4   8   4   9   4   9   5   8       Example 3       Formu-   10   6   8   5   8   7   8   6   8   6   8       lation   20   7   9   6   9   6   9   7   9   7   9       Example 4       Formu-   10   3   6   4   5   5   7   6   7   5   8       lation   20   6   9   5   9   6   9   7   9   6   9       Example 5       Formu-   10   3   6   4   7   5   7   4   8   5   8       lation   20   6   10   5   9   6   9   5   9   6   9       Example 6       Formu-   10   3   6   4   6   5   8   5   9   4   8       lation   20   5   8   5   7   7   10   7   9   6   9       Example 7       Formu-   10   4   6   3   8   5   8   6   9   5   7       lation   20   5   8   4   9   6   9   6   10   5   9       Example 8       Compar-   10   2   3   3   4   4   6   3   4   4   5       ative   20   2   3   4   5   5   6   6   7   5   6       Formu-       lation       Example                 *Investigation Left: After 7 days from treatment, Right: After 261 days from treatment            *Evaluation 0: No effect to 10: Completely withered             
 
     Test Example 3  
     
         
         
           
              Field test  
              Test period: Jun. 16 to Aug. 20, 2001  
              Test site: Within Shimozuma Hosenku, Kanto Railway  
              Test plants: Crabgrass ( Digitaria adscendens ) 
            Plant height: 20 to 30 cm Greenfoxtail ( Setaria viridis )     Plant height: 20 to 30 cm Tall Goldenrod ( Solidago altissima )     Plant height: 30 to 40 cm Common horsetail ( Equisetum arvense )     Plant height: 15 to 20 cm Common chickweed ( Stellaria media )     Plant height: 15 to 20 cm    
         
              Test scale: 10 m 2 /section, repeated twice  
              Date of treatment: Jun. 16, 2001  
              Test method: After three weeks from mowing, in the morning after a rainy day, each fine granule was applied in an amount corresponding to 20 g/m 2  on the foliage.  
              Dates of investigation: Jun. 23 and Jul. 16, 2001  
           
         
       
    
      Test results: Shown in Table 3.  
                                       TABLE 3                                       Tall               Tested   Dose   Crab-   Green   Golden-   Common   common       formulation   g/m 2     grass   foxtail   rod   horsetail   chickweed                                                                                Formulation   20   8   9   6   10   8   9   10   10   8   9       Example 1       Formulation   20   10   9   10   9   9   10   10   9   10   10       Example 2       Formulation   20   6   8   5   9   7   9   7   9   8   10       Example 3       Formulation   20   10   9   10   9   9   10   10   10   10   10       Example 4       Formulation   20   10   9   10   10   9   10   10   10   10   10       Example 5       Formulation   20   9   10   7   9   8   10   10   10   10   10       Example 6       Formulation   20   7   8   6   8   9   10   9   10   10   10       Example 7       Formulation   20   9   9   8   10   9   10   10   10   10   10       Example 8       Comparative   20   4   4   3   4   5   6   7   8   7   8       Formulation       Example                 *Investigation Left: After 7 days from treatment, Right: After 261 days from treatment            *Evaluation 0: No effect to 10: Completely withered             
 
      As is evident from the foregoing Test Examples, the fine granule prepared by using glufosinate alone will have its deposition on the foliage limited by a climate condition such as humidity, whereby its effect deteriorates. On the other hand, according to the present invention, a finely granulated chemical which is mainly used for soil treatment is blended to glufosinate and formed into a fine granule, whereby the deterioration of the effect of glufosinate due to a change of the climate, can be prevented.  
     INDUSTRIAL APPLICABILITY  
      The change in the effect of the glufosinate fine granule due to the climate conditions, can be avoided.