Abstract:
Herbicidal composition containing 5-(N-phenylcarbamoylamino)-1,2,3-thiadiazole and either a diphenyl ether of the formula ##STR1## or an acetanilide of the formula ##STR2## in which X is chlorine, methyl or trifluoromethyl, Y is hydrogen, lower alkoxy, ethoxyethoxyethoxy or methoxycarbonyl, n is 1 to 3, R 1  and R 2  are lower alkyl and R 3  is lower alkoxy-lower alkyl. The active components display synergistic effectiveness as broad-spectrum herbicides for perennial as well as annual weeds in paddy fields. Suitable solid and liquid carrier materials for the composition include emulsifiers.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to herbicidal compositions. Of particular concern are herbicidal compositions containing two kinds of compounds as active ingredients which possess remarkable synergistic effects that cannot be expected by application of compositions containing only one or the other type of compound. 
     In recent years, many excellent herbicides have been developed and employed to provide easy and rational control of annual weeds in paddy fields. A problem has arisen due to perennial weeds, previously occurring only locally, but of late spreading extensively along with the annual weeds. Measures for combatting this are eagerly being sought. Several factors can be cited to account for the propagation of such perennials, such as changes in cultivation and seeding methods and inadequate control of the cultivations. The principal factor apparently is the continued employment, for many consecutive years, of narrow-spectrum herbicides effective against annuals but ineffective with perennials. Under the circumstances, a great need exists for the development of broad-spectrum herbicides capable of combatting perennials as effectively as annuals. 
     Japanese patent publication No. 42853/77 discloses a plant growth regulator containing 5-(N-phenylcarbamoylamino)-1,2,3-thiadiazole. This compound has the effect of inhibiting weeds. Tests on the herbicidal properties of this regulator reveal that it has the effect of controlling the growth of annual broad-leaved weeds, annual cyperaceae weeds, and perennial weeds such as Scirpus erectus when applied during the pre-germination period or in the early stage of germination of weeds in paddy fields, but that it displays inferior results with Barnyardgrass and Monochria Vaginalis, which are strong harmful weeds. Additional disadvantages include a narrow herbicidal spectrum and narrow period of application. 
     The use in combination of various herbicides has been attempted, but it is widely recognized that in almost all instances the effect is a mere sum of the results attainable by the respective herbicides used alone, or, alternatively, that the effects of the respective herbicides compensate each other. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a novel herbicidal composition not displaying the aforesaid defects, i.e., possessing a broad herbicidal spectrum effective for the eradication of both annual and perennial weeds. 
     The present herbicidal composition is characterized by containing as active components 5-(N-phenylcarbomoylamino)-1,2,3-thiadiazole and a diphenyl ether of the formula ##STR3## wherein the substituents X are the same or different and are chlorine, methyl or trifluoromethyl, Y is hydrogen, lower alkoxy, ethoxyethoxyethoxy, or methoxycarbonyl, and n is an integer from 1 to 3, or an acetanilide of the formula ##STR4## wherein R 1  is lower alkyl, R 2  is lower alkyl and R 3  is lower alkoxy-lower alkyl. 
     This composition exhibits remarkable synergism between the combined specific compounds, showing a broad herbicidal spectrum allowing for the eradication of both annual and perennial weeds. Employment of the novel herbicidal composition according to the present invention is usually before and after the transplantation of the rice into the paddy field. It is also applicable as herbicide in fields of such crops as cereals, pulses, and vegetables. Further suitable uses include fruit trees, lawns, forests, seedling fields and non-farming land. 
     The following non-limiting listing enumerates examples of compounds of formula (I) useful in herbicidal compositions according to the present invention: 
     
         ______________________________________CompoundNumber   Compound Name______________________________________1        2,4-dichlorophenyl-3&#39;-methoxy-4&#39;-nitrophenyl-    ether2        2,4-dichlorophenyl-3&#39;-ethoxyethoxyethoxy-4&#39;-    nitrophenyl ether3        2,4-dichlorophenyl-3&#39;-methoxycarbonyl-4&#39;-    nitrophenylether4        2,4,6-trichlorophenyl-4&#39;-nitrophenylether5        2-chloro-4-trifluoromethylphenyl-3&#39;-ethoxy-4&#39;-    nitrophenylether6        3-methylphenyl-4&#39;-nitrophenylether7        3,5-dimethylphenyl-4&#39;-nitrophenylether______________________________________ 
    
     The following non-limiting listing enumerates examples of compounds of formula II: 
     
         ______________________________________8        2&#39;,6&#39;-diethyl-N--butoxymethyl-2-chloroacetanilide9        2&#39;,6&#39;-diethyl-N--propoxyethyl-2-chloroacetanilide10       2&#39;,6&#39;-dimethyl-N--isobutoxymethyl-2-chloro-    acetanilide11       2&#39;-methyl-6&#39;-tertiarybutyl-N--methoxymethyl-2-    chloroacetanilide______________________________________ 
    
     In the following, compounds 1 to 11 are the aforesaid compounds 1-11, and Compound A refers to the aforesaid 5-(N-phenyl-carbamoylamino)-1,2,3-thiadiazole. 
     The compounds of formulae I and II are all known compounds. They are known to exhibit excellent effects in the control of gramineae weeds, such as Barnyard grass, and of annual broad-leaved weeds, such as Monochoria Vaginalis, in each case when treated in the early period of their germination. However, these compounds have inferior effects with respect to perennial weeds such as Cyperus serotinus, Sagittaria pygmaea, and Scirpus erectus. 
     For purposes of application, the present herbicidal composition can be employed in any form of preparation. This would include such forms as granules, powder, wettable powder, emulsion and fine granules. Concerning the mixing ratio of the two components, it is suitable to admix 0.1 to 10 parts by weight of a compound of formula I or II, relative to one part by weight of compound A. 
     As carrier materials for the herbicidal compositions, solid carriers include talc, bentonite, clay, kaolin, diatomaceous earth, vermiculite, and calcium carbonate, among others. Effective liquid carriers include, e.g., benzene, alcohols, acetone, xylene, methyl naphthalene, dioxane, isophorone, and cyclohexanone, among others. Possible emulsifiers are, e.g., alkyl sulfuric acid esters, alkyl sulfonates, polyethylene glycol ethers and polyhydric alcohol esters, among others. 
     The novel features which are considered characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its composition and its method of use, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following are examples of formulations for the present herbicidal compositions: 
     
         ______________________________________Formulation 1: Wettable Powder______________________________________Compound A             10    partsCompound 1             20    partsdiatomaceousearth                  65    partsalkylbenzenesulfonic acidsoda                   3     partsformalin condensateof sodium naphtha-lene sulfonate         2     parts______________________________________ 
    
     These ingredients are thoroughly ground and mixed into a wettable powder. 
     
         ______________________________________Formulation 2: Wettable Powder______________________________________Compound A             20    partsCompound 8             15    partspolyoxyethylenenonyl phenol ether     2     partsclay                   63    parts______________________________________ 
    
     These ingredients are thoroughly ground and mixed into a wettable powder. 
     
         ______________________________________Formulation 3: Emulsion______________________________________Compound A       10 partsCompound 3       10 partspolyethylene glycolether surfactant 10 partscyclohexanone    30 partsxylene           40 parts______________________________________ 
    
     These ingredients are mixed into an emulsion. 
     
         ______________________________________Formulation 4: Granules______________________________________Compound A            4     partsCompound 5            7     partsligninsulfonicacid soda             6     partsbentonite             10    partsclay                  73    parts______________________________________ 
    
     These ingredients are mixed, ground and thoroughly kneaded, with water being added. Then, the resulting kneaded mixture is granulated and dried in granulated form. 
     
         ______________________________________Formulation 5: Granules______________________________________Compound A            7     partsCompound 9            7     partsbentonite             40    partsdiatomaceousearth                 46    parts______________________________________ 
    
     These ingredients are mixed, ground and thoroughly kneaded, with the addition of water. Then, the resulting kneaded mixture is granulated and dried in granulated form. 
     Tests have been performed establishing the useful properties of the herbicidal compositions according to the present invention. These procedures are summarized in the following examples. 
     EXAMPLE 1 
     Test of herbicidal effect toward Cyperus serotinus. 
     Wagner pots measuring one five-thousandth ar in surface area were filled with paddy field soil (all vial loam) which was submerged 3 cm deep, and five tubers of Cyperus serotinus were transplanted into each pot. Three days later, granules prepared using individually either Compound A, Compound 1, or Compound 8, and also by using them in mixture with proportionate amounts of the respective compounds corresponding to the proportions indicated in Table 1 were applied to the submerged surfaces in such manner that the dosages of the respective compounds attained the proportions shown in Table 1. On the 30th day after the treatment, the residual Cyperus serotinus plants were pulled out and measured for their dry weight. Then, the residual mass percentage (%) of Cyperus serotinus was computed by the following equation: ##EQU1## The results are given in Table 1. 
     In order to clearly establish the synergistic effects of the present herbicidal compositions, the expected residual weed mass values were determined according to Colby&#39;s equation relating to synergistic effects: ##EQU2## X(%) indicates the measured residual weed mass percentage (%) in case of independent use of the compound X, and Y(%) indicates the measured residual weed mass percentage (%) in case of independent use of the compound Y. These expected residual weed mass values are given in parentheses in Table 1. 
     Synergistic effects are established when the measured residual mass percentage (%) is less than the expected residual weed mass values (%). 
     EXAMPLE 2 
     Test of herbicidal effects on Eleocharis acicularis 
     The test was conducted under the same conditions as for Example 1, except that four roots of Eleocharis acicularis, instead of Cyperus serotinus, were transplanted into each pot. The results are shown in Table 2. 
     EXAMPLE 3 
     Test of herbicidal effects under field conditions 
     A test plot of 5 cm 2  was prepared as a paddy field and seeds or tubers of paddy field weeds such as Echinochloa crusgalli, Monocharia vaginalis, Rotala indica, Callitriche stagnalis, Cyperus difformis, Scirpus erectus, Cyperus serotinus, Eleocharis acicularis, and Eleocharis plantaginea were admixed with the soil during puddling. Subsequently, rice seedinglings in the four-leave stage were transplanted into the plot, and the soil was placed in 3 cm deep submerged condition. Four days after the rice transplantation, granules prepared by mixing miscellaneous compounds in the same manner as mentioned for Example 1 were applied to the water surface. 
     On the 40th day after the treatment, the residual weeds were pulled out and measured for dry weight, the values obtained being given in Table 3 as relative values opposed to control values. 
     The rank reading of the herbicidal effect and the damage is represented according to the following numerical scale: 
     
         ______________________________________0:     same as untreated control1-2:   effects on the plant                      slight3-4:   &#34;                   small5-6:   &#34;                   medium7-8:   &#34;                   large9-10:  &#34;                   extremely large______________________________________ 
    
     EXAMPLE 4 
     Test of herbicidal effects 
     Soil from a paddy field (alluvial loam) was used to fill a Wagner pot measuring one five-thousandth of an ar in area, and, after water introduction and puddling, the soil was sown with seeds of Echinochloa crusgalli, Monochroia vaginalis, Rotala indica, Callitriche stagnalis and Scirpus erectus, and further planted with tubers of Cyperus serotinus, parent roots of Eleocharis acicularis, and rice seedlings in the three-leave stage. The soil was then placed under water, submerged 3 cm deep. On the third day after the rice transplantation, granules prepared by mixing miscellaneous compounds in the same manner as in Example 1 were applied to the submerged surface. 
     On the 30th day after treatment a survey was conducted in the same manner as in Example 3. The results are given in Table 4. 
     
                                           TABLE 1__________________________________________________________________________Test Compounds    Compound 1        Compound 8Dosage (g/10a)    80 40  20  10  0  80  40  20  10  0__________________________________________________________________________Compound A  80    0  1   1   3   3  0   0   1   1   3    (0.6)       (1.1)           (1.7)               (3)    (1.0)                          (1.8)                              (2.4)                                  (3.0)  40    1  2   3   6   13 1   2   3   5   13    (2.)       (4.8)           (7.4)               (13.0) (4.4)                          (7.9)                              (10.4)                                  (13.0)  20    2  3   3   5   27 1   4   6   8   27    (5.4)       (10.0)           (15.4)               (27.0) (9.2)                          (16.5)                              (21.6)                                  (27.0)  10    2  3   4   11  35 3   5   10  15  35    (7.)       (13.0)           (20.0)               (35.0) (11.9)                          (21.4)                              (28.0)                                  (25.0)  0 20 37  57  100 100                      34  61  80  100 100__________________________________________________________________________ As is evident from Table 1, a noticeable synergism appears. 
    
     
                                           TABLE 2__________________________________________________________________________Test compounds    Compound 1        Compound 8Dosage (g/10a)    80 40  20  10  0  80 40 20  10  0__________________________________________________________________________Compoumd A  80    0  1   2   3   7  0  0  1   1   7    (0.7)       (1.7)           (4,3)               (3.5)  (0.5)                         (1.3)                            (2.4)                                (4.3)  40    0  1   4   3   15 0  0  3   2   15    (1.5)       (3.6)           (9.2)               (11.7) (1.1)                         (2.9)                            (5.1)                                (9.2)  20    2  3   6   11  26 0  1  3   8   26    (2.6)       (6.2)           (15.9)               (20.3) (1.8)                         (4.9)                            (8.8)                                (15.9)  10    3  5   10  14  51 1  2  4   7   51    (5.1)       (12.2)           (31.1)               (39.8) (3.6)                         (9.7)                            (17.3)                                (31.1)  0 10 24  61  78  100                      7  19 34  61  100__________________________________________________________________________ As is evident from Table 2, a noticeable synergism appears. 
    
     
                                           TABLE 3__________________________________________________________________________Herbicidal effects toward various weeds under field conditions         Annual Weeds            Perennial Weeds      harmTest Compounds/Dosage         Echinochloa               Monochoria                     other broad                            Cyperus                                 Scirpus                                     Cyperus                                          Eleocharis                                                Eleocharis                                                      to rice(g/10a)       crusgalli               vaginalis                     leaved weeds                            difformis                                 erectus                                     serotinus                                          acicularis                                                plantaginea                                                      planted__________________________________________________________________________Com-    25 --     0     1     7      8    3   3    2     3     0pound    50        1     3     9      10   4   6    2     6     0A   100       3     6     10     10   5   6    4     7     0    200       5     6     10     10   5   7    5     7     0Com-    25 Com-      50 10    9     9      10   8   8    8     6     0pound    50 pound      50 10    9     10     10   9   10   9     9     0A   100  1   100         10    10    10     10   10  10   10    10    0--     Com-      50 9     6     9      10   1   1    0     0     0  pound      100         10    8     8      10   0   1    0     0     0  1   200         10    10    9      10   3   1    0     0     0Com-    50 Com-      50 10    10    10     10   10  10   9     10    0pound    100  pound      100         10    10    10     10   10  10   10    10    0A      8--     Com-      50 9     7     9      10   4   1    2     0     0  pound      100         10    9     9      10   6   2    3     0     0  8--     --     0     0     0      0    0   0    0     0     0__________________________________________________________________________ 
    
     
                                           TABLE 4__________________________________________________________________________Test results concerning herbicidal effect                     annual       Eleo-                                      Harm                     broad   Gyperus                                  charis                                      to               Echinochloa                     leaved                         Scirpus                             sero-                                  aclcu-                                      riceTest Compoumds/Dosage (g/10a)               crusgalli                     plants                         erectus                             tinus                                  laris                                      plan__________________________________________________________________________Compound A  5    --      0     9   3   4    3   0  10           3     9   4   5    5   0  20           7     10  5   7    6   0--        Compound 1            5  10    10  2   0    1   1            10 10    10  3   0    2   1            20 10    10  4   2    4   1Compound A  5  Compound 1            5  10    10  7   7    7   1  5         10 10    10  9   8    7   1  10        5  10    10  8   8    7   1  10        10 10    10  10  10   9   1--        Compound 2            5  9     10  3   1    1   1            10 9     10  4   1    3   1            20 10    10  5   3    4   1Compound A  5  Compound 2            5  8     10  8   8    9   1  5         10 10    10  8   9    9   1  10        5  10    10  9   10   10  1  10        10 10    10  9   10   10  1--        Compound 3            5  9     10  3   1    2   1            10 10    10  5   3    3   1            20 10    10  7   3    4   1Compound A  5  Compound 3            5  9     10  10  8    8   1  5         10 10    10  10  8    8   1  10        5  9     10  10  10   10  1  10        10 10    10  10  10   10  1--        Compound 4            10 9     9   2   0    1   1            20 10    10  3   1    1   1            40 10    10  5   1    2   1Compound A  5  Compound 4            10 9     10  9   6    7   1  5         20 10    10  10  8    8   1  10        10 8     10  7   7    8   1  10        20 10    10  9   8    9   1  20        10 10    10  10  9    9   1  20        20 10    10  10  9    10  1--        Compound 5            2.5               3     10  3   1    2   1            5  10    10  5   1    3   2            10 10    10  7   3    4   2Compound A  2.5     Compound 5            2.5               7     10  10  6    8   1  5         2.5               7     10  9   6    9   1  5         5  10    10  10  8    9   1  5         10 10    10  10  8    10  2  10        2.5               10    10  10  9    10  1  10        5  10    10  10  10   10  1  10        10 10    10  10  10   10  1--        Compound 6            15 0     3   1   0    0   0            30 0     7   3   0    0   0            60 1     9   4   0    0   0Compound A  10 Compound 6            15 2     9   6   6    7   0  10        30 5     10  8   6    6   0  20        15 8     10  9   8    8   0  20        30 8     10  10  9    9   0--        Compound 7            15 0     0   0   0    0   0            30 0     2   0   0    1   0            60 3     9   5   1    1   0Compound A  10 Compound 7            15 5     9   7   6    7   0  10        30 6     10  8   7    6   0  20        15 9     10  9   8    7   0  20        30 9     10  10  10   10  0--        Compound 8            2.5               9     4   3   0    1   0            5  10    7   5   1    1   0            10 10    7   7   2    2   0Compound A  2.5     Compound 8            2.5               9     9   9   6    8   0  5         2.5               10    10  7   6    9   0  5         5  9     10  10  8    6   0  5         10 10    10  9   8    9   0  10        2.5               10    10  8   8    7   0  10        5  10    10  9   9    9   0  10        10 10    10  10  10   10  0--        Compound 9            2.5               9     4   3   1    2   0            5  10    6   6   1    2   0            10 10    7   7   3    3   0Compound A  2.5     Compound 9            2.5               9     9   9   6    8   0  5         2.5               9     10  8   7    8   0  5         5  10    10  9   8    9   0  5         10 10    10  10  9    9   0  10        2.5               10    10  9   9    7   0  10        5  10    10  10  10   10  0  10        10 10    10  10  10   10  0--        Compound 10            2.5               9     7   2   0    1   0            5  9     8   3   0    1   0            10 9     9   5   2    2   0Compound A  2.5     Compound 10            2.5               9     9   10  6    7   0  5         2.5               10    10  9   6    6   0  5         5  9     10  9   7    6   0  5         10 10    10  10  7    7   0  10        2.5               10    10  9   8    6   0  10        5  10    10  10  9    9   0  10        10 10    10  10  10   10  0     Compound 11            2.5               10    3   3   0    1   0            5  10    2   5   2    3   0            10 10    7   7   2    4   0Compound A  2.5     Compound 11            2.5               10    9   10  6    7   0  5         2.5               10    10  9   6    6   0  5         5  10    10  10  7    7   0  5         10 10    10  10  7    8   0  10        2.5               10    10  9   9    7   0  10        5  10    10  10  9    9   0  10        10 10    10  10  10   10  0--          --      0     0   0   0    0   0__________________________________________________________________________ 
    
     As explained and exemplified above, the combination of 5-(N-phenylcarbamoylamino)-1,2,3-thiadiazole with a compound of the aforesaid formula I or II results in considerable synergistic action with respect to perennial weeds such as Cyperus serotinus, Eleocharis acicularis, and Eleocharis plantaginea, that cannot be sufficiently controlled by the respective ingredients used alone. The combinations are additionally remarkably effective with annual weeds which can be sufficiently controlled by the respective ingredients used alone at their usual dosages. 
     Combined use of these compounds according to the present invention presents the advantages of increased herbicidal effectiveness, broadened herbicidal spectrum, extended period for residual effect, expanded suitable application period, and increased selectivity between crops and weeds, each of which aspects is recognized as being a matter of great agricultural importance. 
     It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of herbicidal compositions differing from the types described above. 
     While the invention has been illustrated and described as embodied in a herbicidal composition having as active components 5-(N-phenylcarbomoylamino)-1,2,3-thiadiazole and a diphenylether of formula I or an acetanilide of the formula II, it is not intended to be limited to the details described, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. 
     Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.