GB1561298A - Composition comprising peat and a pesticide - Google Patents

Description

(54) COMPOSITION COMPRISING PEAT AND A PESTICIDE (71) We, FISONS LIMITED, a British Company of Fison House, 9 Grosvenor Street, London, W1X OAH, do hereby de

ERRATUM SPECIFICATION NO 1561298 Page 1, below heading (52) Index at acceptance insert (72) Inventor MICHAEL JOHN RHODES THE PATENT OFFICE Bas 75717/5 1 April 1980 X OR, I wherein A is a group

or a group-SCH2CONHR, ; is selected from alkyl (notably lower alkyl, e. g. methyl, ethyl, propyl or isopropyl), alkenyl (notably lower alkenyl), alkoxyalkyl (notably lower alkoxy lower alkyl), or alkylmercaptoalkyl (notably lower alkylmercapto lower alkyl) ; R= is hydrogen or a lower alkyl or lower alkenyl radical ; R3, R, and R5 may be the same or different and each is selected from a lower alkyl group; X is oxygen or, more preferably, sulphur; and Y is a sulphur bridge or, more preferably, a direct linkage.

Preferred forms of the compound of formula I are those wherein A is a group moylmethyl)-phosphorothioate. These com pounds may be used in their commercially available forms and purity.

In its simplest form, the composition of the invention comprises particulate sphagnum and/or sedge peat which has the compound of formula I absorbed or adherent thereon, preferably, uniformly distributed throughout or upon the peat. If desired the peat particles may have been given a pretreatment, e. g. a dewaxing treatment, ammoniation or a coating with a glycol ether (notably a glycol monoethyl ether or thio ether). The peat may be in the form of milled peat particles, typically with a particle size such that substantially all the particles will pass through a mesh sieve.

Particularly preferred peat particles for present use are milled peat particles having the criteria set out in our British Patent No 1,300, 571.

The peat may also be used in the form of granules thereof, notably those which have been prepared by the processes described in our British Patents Nos. 1,048,254,1,070,641 or 1,357,001.

The peat may also be in the form of blocks, e. g. those formed by compressing or moulding peat under pressure.

The compound of formula I for present use (54) COMPOSITION COMPRISING PEAT AND A PESTICIDE (71) We, FISONS LIMITED, a British Company of Fison House, 9 Grosvenor Street, London, W1X OAH, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement :- The present invention relates to a composi- tion, its preparation and use.

The present invention provides a composition comprising peat having admixed therewith a compound of the general formula :

wherein A is a group

or a group-SCHCONHR, ; is selected from alkyl (notably lower alkyl, e. g. methyl, ethyl, propyl or isopropyl), alkenyl (notably lower alkenyl), alkoxyalkyl (notably lower alkoxy lower alkyl), or alkylmercaptoalkyl (notably lower alkylmercapto lower alkyl) ; R2 is hydrogen or a lower alkyl or lower alkenyl radical; R3, R, and R5 may be the same or different and each is selected from a lower alkyl group; X is oxygen or, more preferably, sulphur; and Y is a sulphur bridge or, more preferably, a direct linkage.

Preferred forms of the compound of formula I are those wherein A is a group

Such compounds and their preparation are described in US Patent No. 2,754,243. Particularly preferred compounds of formula I are O, O-diethyl-O- (2-isopropyl-4 methyl-6-pyrimidinyl) phosphorothioate, (hereinafter called diazinon), O, O-dimethyl S- (N-methylcarbamoylmethyl)-phosphorodithioate (hereinafter called dimethoate) O, O-dimethyl-S- (N-methylcarba moylmethyl)-phosphorothioate. These compounds may be used in their commercially available forms and purity.

In its simplest form, the composition of the invention comprises particulate sphagnum and/or sedge peat which has the compound of formula I absorbed or adherent thereon, preferably, uniformly distributed throughout or upon the peat. If desired the peat particles may have been given a pretreatment, e. g. a dewaxing treatment, ammoniation or a coating with a glycol ether (notably a glycol monoethyl ether or thio ether). The peat may be in the form of milled peat particles, rvpically with a particle size such that substantially all the particles will pass through a $"mes sieve.

Particularly preferred peat particles for present use are milled peat particles having the criteria set out in our British Patent No 1,300,573.

The peat may also be used in the form of granules thereof, notably those which have been prepared by the processes described in our British Patents Nos. 1,048,254,1,070,641 or 1, 357, 001.

The peat may also be in the form of blocks, e. g. those formed by compressing or moulding peat under pressure.

The compound of formula I for present use may be in the form of a powder, typically of mean particle size less than 1 millimetre, e. g.

0.01 to 1 millimetres, which is applied by dry mixing or as a dust or roller coating to the peat particles ; as a wettable powder containing one or more wetting agents which is applied as such or in solution, emulsion or dispersion form onto the peat particles; or in the form of a coating, e. g. in a film forming oil, wax or resin, over part or all of the peat particles.

We prefer that the composition contain at least 0. 01 parts of the compound of formula I, e. g. of dimethoate and/or diazinon, per 1,000 parts of weight of dry peat solids in the composition, notably from 0.05 to 100 parts per 1,000 parts. The above proportions are given in terms of the active ingredient.

In addition to the peat and the compound of formula I the compositions of the invention may contain other ingredients, notably diluents or carriers (e. g. sand, bark or vermiculite), plant nutrients, binders for the peat particles where a granular composition is desired, fungicides, plant growth regulants and wetting agents. Where plant nutrients are present, these may either be present as discrete solid particles which are blended in with the peat particles, as with a peat based compost; or may be incorporated into peat granules during their pre paration. Suitable plant nutrients include potassium and/or ammonium phosphates, nitrates and/or sulphates, ureaformaldehyde condensates and trace element salts and complexes, e. g. iron chelates.

The compositions of the invention may be simply prepared by mixing, e. g. dry mixing, together the desired ingredients. If need be, a fluid adhesive or coating composition may be applied to assist adherence of particles of the compound of formula I to the peat. Alternatively, a solution, emulsion or dispersion of the compound in water, other liquid carrier or a mobile oil or wax as carrier may be applied (e. g. by a dribble bar or spray) to a tumbling bed of the peat particles or granules. As indicated above the peat particles may have been given a pretreatment and this may render them suitable for roller or dust coating. If desired, the incorporation of the various ingredients may be carried out in various separate stages. Thus, peat particles could be granulated with fertilizer ingredients as in the process of our BP No 1,070,641; the granules then coated with a natural or synthetic resin (e. g. a polyethylene glycol); diazinoil and/or dimethoate applied as a dust coating to the granules; and a final coating (e. g. of a divinylpyrrolidine resin) applied to the dusted granules.

The compositions prepared as above may be given subsequent treatments, e. g. drying, before storae and/or use.

It is also within the scope of the present invention to form the compositions of the invention in situ in a peat based plant growth medium before plants are grown therein, bv applying the compound of formula I to the medium and admixing it into the medium.

This may be achieved bv dusting the surface of the medium with the compound and working the latter into the medium. Alternatively, the compound mav be used in the form of a water wettable powder which is watered into the medium after application. The compound may also be applied as a spray directly on to the medium and then worked in.

The compound of formula I is incorporated into the compositions before they are applied to plants or before plants are grown therein and acts to protect the composition and plants subsequently grown therein from pests.

The invention thus also provides a means for combatting pests at a locus which comprises applying a composition of the invention thereto or forming a composition of the invention in situ at the locus. The composition of the invention provides from 5 to 50 kgs of active ingredient of compound of formula I per hectare.

The invention will now be illustrated by the following Examples in which all parts and percentages are given by weight unless stated otherwise: Example 1.

A compost may be prepared as follows: Milled peat (particle size 1.5 to 9mm, moisture content 60 /) is dry mixed with N, P and K plant nutrients This compost is then tumbled in a rotating pan mixer and diazinon is applied by sprays ring an aqueous suspension of the liquid diazinon available under the Trade Name of Diazito ! Liquid (20-'1, a/i in water) onto the tumbling particles The diazinon was applied at a rate of 0.5 parts per 1000 parts of dry peat solids.

Example 2.

A compost may be prepared as follows: Milled peat (particle size 1.5 to 9 mm, moisture content 60%) is dry mixed with N, P, K plant nutrients. An aqueous solution of the wettable dimethoate powder available under the Trade Name of Rogor 20W (20% a/i in water) is sprayed on to the tumbling particles during the mixing of the peat and the plant nutrients. The dimethoate is applied at a rate of 0.5 parts per 1000 parts of dry peat solids.

The above composts are suitable for use in the loose state or in forming peat blocks for the growth of lettuces. The presence of the diazinon or dimethoate will protect the lettuce seedlings against aphids, root aphids, root maggots and sciarid flies, Surprisngly, the compositions of the invention are storage stable and retain rher pesticidal activity after storage for several weeks even though peat is an acidic material and the compounds of formula I have been found to be unstable when used in combination with acidic materials.

Claims (19)

WHAT WE CLAIM IS :-

1. A composition comprising peat admixed with a compound of the general formula:

wherein A is a group

or a group R. HNCOCH. S- ; R, is selected from alkyl, alkenyl, alkoxvalkyl, or alkylmer- capto-alkyl ; R2 is hydrogen or a lower alkyl or lower alkenyl radical; R3, R, and R; may be the same or different and each is selected from a lower alkyl group; X is oxygen or sulphur; and Y is a sulphur bridge or a direct linkage.

2. A composition as claimed in claim 1 wherein X is sulphur.

3. A composition as claimed in claim 1 wherein the compound of formula 1 is selected from O, O-dimethyl-S- (N-methxlcarba- moylmethyl)-phosphorodithioate, O, O-di- methyl-S- (N-methvlcarbamoylmethyl)- phosphorothioate and O, O-diethyl-Ó- (2-isopropyl-4-methyl-6-pvrimidinyl) phosphorothioate.

4. A composition as claimed in any of the preceding claims wherein the peat is milled sphagnum and/or sedge peat.

5. A composition as claimed in claim 4 wherein the peat is a peat as claimed in BP 1300573.

6. A composition as claimed in any one of claims 1 to 3 wherein the peat is in the form of peat granules.

7. A composition as claimed in claim 6 wherein the granular peat has been prepared by a process as claimed in and one of BP Nos. 1,048,254,1,070,641 or 1,357,001.

8. A composition as claimed in any one of the preceding claims wherein the compound of formula 1 has a mean particle size of less than 1 millimetre.

9. A composition as claimed in any one of the preceding claims wherein the compound of formula 1 is present in from 0.01 to 100 parts per 100 parts by weight of dry peat solids.

10. A composition as claimed in any of the preceding claims wherein plant growth nutrients are also present.

11. A composition as claimed in 1 substantially as hereinbefore described.

12. A composition as claimed in claim 1 substantially as hereinbefore described in either of the Examples.

13. A method for preparing a composition as claimed in any one of the preceding claims which comprises mixing together the ingredients.

14. A method as claimed in claim 13 wherein a solution, emulsion or dispersion of the compound of formula I is applied to a tumbling bed of peat particles or granules.

15. A method as claimed in claim 14 wherein the peat granules have been prepared by a process as claimed in BP 1,070,641.

16. A method as claimed in claim 13 wherein the compound of formula I is admixed with a peat based plant growth medium before plants are grown therein to form a composition as claimed in claim 1 in site.

17. A method as claimed in claim 13 substantially as hereinbefore described.

18. A method as claimed in claim 13 substantially as hereinbefore described in either of the Examples.

19. A method for combatting pests at a locus which comprises applying a composition as claimed in any one of claims 1 to 12 or produced by a method as claimed in any one of claims 13 to 15 and 17 or 18 to the locus.