CH497844A - Pesticidal organophosphorus cpds. - Google Patents

Abstract

Pesticides for eradicating soil insects, termites and nematodes, contng. (where Hal is Br or I, X is O or S and R1 and R2 are C1-4 alkyl, or Hal is Cl, X is O or S and one of R1 and R2 is an opt. subst. group contng. a single C-atom and the other of R1 and R2 is alkyl which may be halo-subst.), together with at least one of the following carriers, solvents, diluents, dispersing agents, wetting agents, adhesives and/or fertilizers, and optionally other pesticides (herbicides, nematocides, fungicides, bactericides, insecticides). (I) are highly stable in alkaline solns. so that unlike other organophosphorus pesticides they do not lose their activity soon after application.

Description

  

  
 



  Use of trihalophenyl phosphates and thiophosphates to control soil insects, termites and nematodes
The present invention relates to the use of compounds of the formula
EMI1.1
 where Hal is chlorine or bromine, X is oxygen or sulfur and one of the two radicals R1 and R2 is an unsubstituted or substituted methyl group, while the other is a straight-chain or branched alkyl group which can be substituted by halogen, for the control of soil insects, Termites and nematodes.



   Soil insects are those representatives of insects that develop completely or partially in the ground and thereby damage living plants. Primarily harmful larvae of noctuids or tripolids, wireworms (Elateridae larvae) or grubs (larvae of Melolontha species) are to be understood. Also the suborder Gryllotalpa, z. B. the mole cricket, as well as millipedes (Juliden) fall under this term. Furthermore, soil nematodes such as Panagrellus, Ditylenchus, Heterodera, Meloidogyne and others are effectively controlled.



   Application technology, especially the formulation of the active ingredients into pesticides, is in principle part of the general knowledge of this technical branch. Details are given in the US. P. No.



  3 329 702 or Brit. P. No. 1,047,644 or Swiss Patent No. 424,359. Typical application examples can be found below.



   In general, it can be said that the active ingredients are used with at least one of the following additives: carriers, solvents, diluents, dispersants, wetting agents, adhesives and / or fertilizers, with other pesticides (herbicides, nematocides, fungicides, bactericides, insecticides ) can be added.



   In general, granules have proven particularly useful for uniform release of active ingredient in the soil.



  They are most likely to ensure that the active ingredient has a long-lasting influence on the environment without causing plant damage through overdosing in places or killing beneficial bacteria that are indirectly responsible or necessary for consistently good plant growth.



   The preparation of phosphonates of the formula I is conveniently carried out by using a phosphonic acid halide of the formula
EMI1.2
 in which R1, R2 and X have the meaning given for formula I and Y is a halogen atom, preferably chlorine, is reacted with a salt, preferably the sodium salt, of 2,5-dichloro-shalogen phenol.



  You can work in the presence or absence of solvents such as benzene, toluene, xylene, chlorobenzene, etc.



   The end products are generally oily, sometimes also crystalline, low-melting substances. These generally dissolve well in ethanol and acetone.



   The following compounds are particularly suitable as active ingredients for combating soil insects and termites, the term aryl denoting the remainder:
EMI1.3
  
EMI2.1


<tb> connection <SEP> no. <SEP> physical. <SEP> constant
<tb> <SEP> S
<tb> <SEP> 1 <SEP> HsCz-P-O-aryl-Br <SEP> nD22 <SEP> 1.5955
<tb> <SEP> oCH3
<tb> <SEP> S
<tb> <SEP> 2 <SEP> CH3-P-O-aryl-Br <SEP> m.p. <SEP> 55-56 <SEP> C
<tb> <SEP> I
<tb> <SEP> OCH
<tb> <SEP> s
<tb> <SEP> 3 <SEP> CH3-P-O-aryl-Br <SEP> m.p. <SEP> 52-54 <SEP> C
<tb> <SEP> OC3H7
<tb> <SEP> S
<tb> <SEP> 4 <SEP> CH3-P-O-aryl-Br <SEP> nD23 <SEP> 1.5892
<tb> <SEP> OC2Hs
<tb> <SEP> S
<tb> <SEP> 5 <SEP> C1CHrP-O-aryl-Br <SEP> m.p.

  <SEP> 88-90 <SEP> C
<tb> <SEP> OCH3
<tb> <SEP> S
<tb> <SEP> 6 <SEP> ClCH2-P-O-aryl-Br <SEP> nD23 <SEP> 1.5943
<tb> <SEP> OC2H5
<tb> <SEP> S
<tb> <SEP> 7 <SEP> H5C ° P-O-aryl-Cl <SEP> nD22 <SEP> 1.5770
<tb> <SEP> HOLES
<tb> <SEP> S
<tb> <SEP> 8 <SEP> CH3-P-O-aryl-Cl <SEP> Sdp. <SEP> 1300 <SEP> C
<tb> <SEP> (0.001 <SEP> Torr)
<tb> <SEP> OCH3
<tb> <SEP> S
<tb> <SEP> 9 <SEP> CHs-P-O-aryl-Cl <SEP> Sdp. <SEP> 117-120 <SEP> C
<tb> <SEP> (0.03 <SEP> Torr)
<tb> <SEP> OC2H5
<tb> <SEP> 0
<tb> <SEP> 10 <SEP> CHs-P-O-aryl-Cl <SEP> Sdp. <SEP> 12010 <SEP> C
<tb> <SEP> (0.001 <SEP> Torr)
<tb> <SEP> OC2H5
<tb> <SEP> S
<tb> <SEP> 11 <SEP> ClCHP-O-aryl-Cl <SEP> nD23 <SEP> 1.5777
<tb> <SEP> OC2HÏ
<tb>
Example I.
5 parts by weight of one of the active ingredients mentioned are mixed with 95 parts by weight of calcium carbonate and ground.

  The product is used as a litter against soil insects and / or nematodes.



   Example 2
5 parts by weight of an active ingredient of the formula I are mixed with 95 parts of a powdery carrier material, e.g. B. sand or carbonate of lime, mixed and moistened with 175 parts by weight of water or isopropanol.



  The mixture is then granulated. Before granulating, the above or a more active ingredient mixture, e.g. B. from 10 parts of active ingredient and 90 parts of calcium carbonate, a multiple amount, z. B. 100 to 900 parts of an optionally water-soluble artificial fertilizer, such as. B. ammonium sulfate can be added. These granules are used to control soil insects and / or nematodes.



   Example 3
20 parts of an active ingredient and 80 parts of talc are ground to the greatest fineness in a ball mill. The mixture obtained serves as a dust against soil insects.



   Example 4
By mixing 50 parts of an active ingredient of the formula I 45 parts of xylene, 2.5 parts of a l2ithylenoxydkondensationsproduktes of an alkylphenol and 2.5 parts of a mixture of the sodium salts of dodecyloxyethylsulfuric acid, a water-emulsifiable nematocidal solution is obtained, which can also be used against soil insects every stage of development.



   Example 5
PVC boxes (17 X 10 X 5 cm) are filled with moist humus soil to just below the edge.



  4 white grubs (larvae of Melolontha melolontha) are placed in the L-2 stage around a cut potato placed in the middle. Care is taken to ensure that the larvae are evenly distributed. An active ingredient emulsion prepared according to Example 4 is sprayed onto the surface of the humus soil with a chromatography atomizer, which, converted, corresponds to a concentration of 5 kg AS / ha.



  The PVC container is covered with a second perforated hood. Care is taken to ensure that the soil is evenly moistened during the investigation period.

 

   The rating takes place after 7, 14, 21 and 28 days.



   Compound no. 10 caused complete kill after 14 days.



   Example 6
Root-knot nematodes (Meloidogyne sp) are grown on the roots of living plants in the greenhouse.



   Before application of the compound to be tested, the infected roots are left to stand for one week in sterile sandy soil for incubation. About 400 cm3 of the infected soil are placed in a plastic bag and treated with the test substance at a concentration of 4.5 kg / 0.4 ha (= 10 ppm).



   In order to ensure that the emulsifying concentrate is well distributed, the bag is shaken evenly. The contents of the bag are then placed in plastic trays and sealed. Two parallel attempts are made for each connection.

 

   Four days after the treatment, the caps are removed and 4 seeds of the cucumber plant are planted in each dish. Growth counts are made 7 days after planting. Plants with inhibited growth are replaced by overplanting after 7, 14 and 21 days.



   If the seeds show no growth after 28 days, the overplanting is stopped. If, however, growth is delayed, the plants are allowed to grow for three more weeks before the assessment is made.



   With the compounds nos. 6 and 10, no infestations, that is, no formation of plant gallons, are found after 7 weeks. This completely prevents the nematode growth.

 

Claims (1)

PATENT CLAIM Use of compounds of the formula EMI3.1 where Hal is chlorine or bromine, X is oxygen or sulfur and one of the two radicals R1 and R2 is an unsubstituted or substituted methyl group, while the other is a straight-chain or branched alkyl group which can be substituted by halogen, for the control of soil insects, Termites and nematodes.