WO1993006724A1

WO1993006724A1 - Improvements in or relating to agricultural chemicals

Info

Publication number: WO1993006724A1
Application number: PCT/GB1992/001815
Authority: WO
Inventors: Selwyn Everest-Todd
Original assignee: Everest Todd Research And Development Limited
Priority date: 1991-10-05
Filing date: 1992-10-05
Publication date: 1993-04-15
Also published as: GB9121215D0; AU2691092A; EP0606369A1

Abstract

The invention relates to agricultural chemicals and more specifically to disease and/or pesticidal chemicals. The invention resides in mixing the disease control and/or pesticidal material with a solvent comprising one or more alkyl naphthalenes, preferably di-isopropylnaphthalene or dimethyl naphthalene. It has been found in practice that when the mixture comprises between 10 % and 90 %, more preferably between 20 % and 50 %, of the solvent the effects of the disease and/or pesticidal material are enhanced.

Description

"IMPROVEMENTS IN OR RELATING TO AGRICULTURAL CHEMICAL"

This invention relates to agricultural chemicals and, more particularly, to disease and/or pest control chemicals, hereinafter referred to as "pesticidal materials".

Pesticidal materials are well known in the art and may be applied to the soil or growing medium, the growing crop or the harvested crop, hereinafter referred to as the "target". In the event, the manufacturer of the pesticidal material will recommend a dosage rate for the material, found by long experience to be the most desired rate.

As such the use of pesticidal materials is being restricted the recommended dosage rate should afford the user the most economical and effective use of the said material. If the target is treated with less than the recommended dosage rate the material will have a reduced effect on the control of the disease or pest.

The pesticidal material may be applied without dilution, as by a fogging or powder dispersion processing, for most uses the material is dispersed in an inert liquid carrier. such as water, to assist the uniform distribution of the material over the target. Such liquid diluents or liquid or solids carriers as have been proposed todate have simply been used to assist in the distribution of the pesticidal material and have had little, if any, effect on the pesticidal activity of the material.

Certain alkyl naphthalene have already been proposed as plant growth regulators and, like other such substituted naphthalenes, do exhibit some disease control characteristics but the present invention recognises that when mixed with another pesticidal material the disease/pesticide control obtained is greater than the combined effects of the sum total of the alkyl naphthalene and the pesticidal material for the doses used in the mixture.

It has also been proposed in the past to mix two or more pesticidal materials for a single application to the target but with such mixtures the effect of the mixture is simply the sum total of the effects of the two different materials at their respective dosage rates.

According to the present invention there is provided a method for enhancing the effect of a pesticidal material comprising the steps of of mixing the said pesticidal material with at least one alkyl naphthalene prior to application to the target.

In one em bodiment the method is characterised by the steps of of diluting the alkyl naphthalene with an emulsifying agent before mixing with the pesticidal material.

In another em bodiment the method is characterised by the steps of diluting the mixture of alkyl naphthalene and pesticidal material with an inert carrier before application to the target.

In one em bodiment the method is characterised in that the mixture is applied to the target by a fogging process.

In another em bodiment the method is characterised in that the mixture is applied to a solid particulate carrier before being applied to the target. In a further embodiment the method is characterised in that the mixture is diluted with an inert liquid and is applied to the target by a spray process.

Preferably the method is characterised by the steps of selecting one or more of the higher alkyl naphthalenes to comprise the alkyl naphthalene part of the mixture.

In one em bodiment the method is characterised by the steps of selecting dimethylnaphthalene to comprise the major constituent of the alkyl naphthalene part of the mixtiire.

In one em bodiment the method is characterised by the steps of selecting dimethylnaphthalene to comprise the sole alkyl naphthalene in the mixture.

In a further em bodiment the method is characterised by the steps of selecting di- isopropylnaphthalene to comprise the major constituent of the alkyl naphthalene part of the mixture.

In a still further em bodiment the method is characterised by the steps of selecting di-isopropylnaphthalene to comprise the sole alkyl naphthalene in the mixture.

Preferably the method is characterised in that the mixture comprises from 10% to 90% alkyl naphthalene by volume, more from 20% to 80% alkyl naphthalene by volume and for some applications from 20% to 50% alkyl naphthalene by volume.

The present invention also envisages a method for treating a crop comprising the steps of applying to the soil or growing medium for the crop, the growing crop, or the harvested crop, a mixture comprising a pesticidal material with at least one alkyl naphthalene.

The present invention also envisages an enhanced agricultural pesticidal material made by mixing a pesticidal material with an alkyl naphthalene.

The invention will now be described further by way of the following examples. EXAMPLE 1

METHOD

100 litres of di-isopropyl naphthalene (D.I.P.N.) were mixed with 5 litres of phosphate ester emulsifying agent to give a 92% wt/vol. emulsifiable concentrate (e.c.) of the D.I.P.N.

The emulsifiable concentrate of D.I.P.N. was then mixed with commercially available pesticidal materials having active ingredient (a.i.) contents as designated.

FORMULATION 1

2.71 ml. of the 92% e.c. D.I.P.N. were mixed with 20.0 ml. of + 50% a.i.Tolclofos-methyl until a uniform distribution of the ingredients was been obtained.

The formulation was then made up to 200 ml. with water. TREATMENTS

The formulation 1 was applied to 100 kg of seed tubers by means of a low volume sprayer mounted over a roller conveyor.

For comparison the commercially available + 50% a.i. Tolclofosmethyl was mixed at the standard dosage rates recommended by the manufacturers and applied to 100 kg. of seed tubers in identical manner to the application of the formulation 1.

TRIAL

Three months after application the two sets of tubers were planted in random blocks and assessed for stem canker, caused by Rhizoctonia solani, during the growing season. It should be noted that D.I.P.N. alone exhibits no chemical activity against the pathogen.

The result of the trials are shown in Table 1. TABLE 1 % disease control

Tolclofos-methyl 125 mg/kg. of tubers 68

Tolclofos-methyl 100 mg/kg/ of tubers

+ D.I.P.N. 25mg/kg. of tubers 89

From the above trial a mixture of the active chemical and D.I.P.N., including only 80% of the recommended dosage rate for the active ingredient, produced a 32% reduction in disease incident.

EXAMPLE 2

METHOD

A 92% e.c. of D.I.P.N. was prepared by the method described for Example 1.

FORMULATION 2

2.7 ml of the 92% e.c. of D.I.P.N. were mixed with 4.5 ml. of + 45% a.i. Thiabendazole.

This formulation was then made up to 200 ml with water and mixed until a uniform distribution of the ingredients was obtained.

T REATMENTS The formulation 2 was applied to 100 kg of seed tubers by means of a low volume sprayer mounted over a roller conveyor.

For comparison the commercially available + 45% a.i. Thiabendazole was mixed at the standard dosage rates recommended by the manufacturers and applied to 100 kg. of seed tubers in identical manner to the application of the formulation 2.

TRIAL

Three months after application the two sets of tubers were planted in random blocks and assessed for stem canker, caused by Rhizoctonia solani, during the growing season.

It should again be noted that D.I.P.N. alone exhibits no chemical activity against the pathogen.

The result of the trials are shown in Table 2.

TABLE 2 % disease control Thiabendazole 40 mg/kg. of tubers 57 Thiabendazole 25 mg/kg/ of tubers

+ D.I.P.N. 25mg/kg. of tubers 84

Fran the above trial a mixture of the active chemical and D.I.P.N., including only 63% of the recommended dosage rate for the active ingredient, produced a 47% reduction in disease incident.

EXAMPLE 3

METHOD A 92% e.c. of D.I.P.N. was prepared by the method described for Example 1.

FORMULATION 3

2.71 ml. of the 92% e.c. D.I.P.N. were mixed with 12.0 ml. of 25% a.i. Iprodione until a uniform distribution of the ingredients was been obtained.

The formulation was then made up to 200 ml. with water.

TREATMENTS

Tne formulation 3 was applied to 100 kg of seed tubers by means of a low volume sprayer mounted over a roller conveyor.

For comparison the commercially available + 25% a.i. Iprodione was mixed at the standard dosage rates recommended by the manufacturers and applied to 100 kg. of seed tubers in identical manner to the application of the formulation 3.

TRIAL

The result of the trials are shown in Table 3.

TABLE 3

% disease control

Iprodione 50 mg/kg. of tubers 65

Iprodione 30 mg/kg/ of tubers

+ D.I.P.N. 25mg/kg. of tubers 90 From the above trial a mixture of the active chemical and D.I.P.N., including only 60% of the recommended dosage rate for the active ingredient, produced a 38% reduction in disease incident.

EXAMPLE 4

METHOD

A 92% e.c. of D.I.P.N. was prepared by the method described for Example 1.

FORMULATION 4

TREATMENTS

The formulation 4 was applied to 100 kg of graded out seed tubers, by means of a low volume sprayer mounted over a roller conveyor three weeks after harvesting.

For comparison the commercially available + 45% a.i.

Thiabendazole was mixed at the standard dosage rates recommended by the manufacturers and applied to 100 kg. graded out seed tubers in identical manner to the application of the formulation 2.

TRIAL Five months after application two sets of the tubers were stored, under identical conditions and assessed for skin spot, caused by Polyscytalum pustulans, during the storage period.

The result of the trials are shown in Table 4.

TABLE 4 % disease control

Thiabendazole 40 mg/kg. of tubers 62

Thiabendazole 25 mg/kg/ of tubers

+ D.I.P.N. 25mg/kg. of tubers 75

From the above trial a mixture of the active chemical and D.I.P.N., including only 63% of the recommended dosage rate for the active ingredient, produced a 21% reduction in disease incident.

EXAMPLE 5

METHOD

A 92% e.c. of D.I.P.N. was prepared by the method described for Example 1.

FORMULATION 5

2.71 ml. of the 92% e.c. D.I.P.N. were mixed with 10.0 ml. of 2-Amino butane.

The formulation was then made up to 200 ml. with water and mixed until a uniform distribution of the ingredients was obtained. TREATMENTS

The formulation 5 was applied to 100 kg of graded out seed tubers by means of a low volume sprayer mounted over a roller conveyor.

For comparison the 20gms of the 2-Amino butane were mixed with water to 200 ml until the 2 Amino butane was uniformly distributed throughout the water. The mixture was then applied to 100 kg. of graded out seed tubers in identical manner to the application of the formulation 5.

TRIAL

The two sets of tubers were stored, under identical conditions. Five months after application the two sets of tubers were assessed for skin spot caused by Polyscytalum pustulans during the storage period.

The result of the trials are shown in Table 5.

TABLE 5

% disease control

2-Amino butane 200 mg/kg« of tubers 76

2-Amino butane 100 mg/kg/ of tubers

+ D.I.P.N. 25mg/kg. of tubers 82

From the above trial a mixture of the active chemical and D.I.P.N., including only 50% of the recommended dosage rate for the active ingredient, produced a 8% reduction in disease incident. EXAMPLE 6

METHOD

A 92% e.c. of D.I.P.N. was prepared by the method described for Example 1.

FORMULATION 6

2.71 ml. of the 92% e.c. D.I.P.N. were mixed with 197.29 ml of water in which 5 gms of Dodine had been dissolved until a uniform distribution of the ingredients was obtained.

TREATMENT

The formulation 6 was applied to 100 kg. of seed tubers, three weeks after harvest, by means of a low volume sprayer mounted over a roller conveyor.

For comparison 5 gms of Dodine was made up to 200 ml with water and applied to 100 kg. of seed tubers, three weeks after harvest, in identical manner to the application of the formulation 6.

TRIAL

The two sets of tubers were stored at 8 degrees C for 150 days before reducing the storage temperature to 5 degrees C over 14 days - 170 days after treatment the tubers were planted and the two sets of tubers were assessed for the control of black leg caused by Ewinia spp. during the growing season.

It should be noted that D.I.P.N. alone exhibits no chemical activity against the pathogen.

The results of the trials are shown in Table 6. TABLE 6

% disease control

Dodine 50 mg/kg. of tubers 74

Dodine 50 mg/kg. of tubers

+ D.I.P.N. 25 mg/kg. of tubers 92

From the above trial a mixture of the active chemical and D.I.P.N., including the full recommended dosage rate for the active ingredient, produced a 24% reduction in disease incident.

EXAMPLE 7

METHOD

A granular formulation was prepared by incorporating a solution of a synthetic pyrethroid in D.I.P.N. with a particulate solid carrier so as to give a formulation containing 7.5 wt/wt D.I.P.N. and 2.5% wt/wt cypermethrin.

TRIAL

The granulated formulation was applied to heaps of freshly harvested potatoes, covered with grass and leaves.

After 3 months the potatoes were examined for damage and the treatment was found to have successfully prevented damage from the larve of the potato tuber moth-Ehthorimnea operculella.

EXAMPLE 8

Method A spray application of Fenpropimorph at 795 gms/hectares and D.I.P.N. at 1000 gms/hectares in water at a total volume of 400 litres/hectares was applied to - growing crop- at 3 leaf stages of winter barley. A spray application of Fenpropimorph at 795gms/hectares in water to a total volume of 400 litres/hectare was applied to the barley. The two formulations were applied to random areas of the growing crop.

RESULTS

The crop was examined for powdery mildew- Erysiphe Graminis.

The formulation containing Fenpropimorpl and D.I.P.N. gave an improved disease control of 14% and increased the yield of grain by 8% over the application of Fenpropimorph alone.

EXAMPLE 9 FORMULATION 9

A granular formulation of D.I.P.N. with an organo-iodine compound was produced by blending 96 kg. of a particulate solid carrier with

2 litres of D.I.P.N. and

2 litres of N-methyl pyrollidone (NMP) in which

250 gms of iodine have dissolved

TRIAL

The formulation 9 preparation was applied and incorporated into the top 15 cm of the land at a rate of 50 kg/hectare prior to planting cauliflowers.

A granular formula, without D.I.P.N. produced by blending 98 kg. of particulate solid carrier with 2 litres of N-methyl pyrollidone, in which 250 gms of iodine had been dissolved, was also applied, and incorporated into top 15 cm of the land, at a rate of 50kg/ hectare prior to planting the cauliflowers.

The formulation incorporating the D.I.P.N. and the formulation without D.I.P.N. was applied to random blocks of 100 plants spaced at 50 cm along the rows with the rows 1 metre apart.

RESULTS

The crop was examined for clubroot caused by Plasnodiophora brassicae and the results obtained are shown in Table 9. TABLE 9

Treatment No. of infected plants Yield

dosage rate/ per plot heads/plot

hectare of a.i.

1 D.I.P.N. 0.98kg. 80 27

2 NMP 1.0 kg + 23 79

iodine 0.125 kg.

3 D.I.P.N. 0.98kg 18 87

NMP 1.00kg

iodine 0.125kg

4 Untreated 76 26

EXAMPLE 10

An emulsifiable concentrate was prepared using an isomeric mix of diinethylnaphthalenes

FORMULATION 10 Mixtures of between 0.5 to 2.0 litres of the isomeric mix of dimethylnaphthalenes were mixed with 500 gms of Fenpropimorph.

TREATMENTS

When the dimethylnaphthalene mix alone was applied to crops of barley at the 1st to 2nd leaf stage at dosage levels equivalent to 0.5 to 2.0 litres per hectare the level of powery mildew was significantly reduced.

Application of similar dosages when the crop was at the 5 to 7 leaf stage increased tillering, adventitous rooting, plant vigour and subsequent yield but did not effect powdery mildew infection.

For comparison Fenpropimorph was applied to the barley at the 5 leaf stage at a dosage rate of 795 gms per hectare.

The formulation 10 was then applied per hectare to the barley at the 5 leaf stage.

RESULTS

The barley treated with the formulation 10 showed a control of powdery mildew 12% better than the Fenpropimorph alone.

Claims

1. A method for enhancing the effect of a pesticidal material comprising the steps of mixing the said pesticidal material with at least one alkyl naphthalene prior to application to the target.

2 A method according to claim 1, characterised by the steps of diluting the alkyl naphthalene with an emulsifying agent before mixing with the pesticidal material.

3. A method according to claims 1, or 2, characterised by the steps of diluting the mixture of alkyl naphthalene and pesticidal material with an inert carrier before application to the target.

4. A method according to any one of claims 1, 2 or 3, characterised in that the mixture is applied to the target by a fogging process.

5. A method according to any one of claims 1 to 3, characterised in that the mixture is applied to a solid particulate carrier before being applied to the target.

6. A method according to any one of claims 1, 2 or 3, characterised in that the mixture is diluted with an inert liquid and is applied to the target by a spray process.

7. A method according to any one of the preceding claims characterised by the steps of selecting one or more of the higher alkyl naphthalenes to comprise the alkyl naphthalene part of the mixture.

8. A method according to any one of the preceding claims characterised by the steps of selecting dimethylnaphthalene to comprise the major constituent of the alkyl naphthalene part of the mixture.

9. A method according to any one of the preceding claims, characterised by the steps of selecting dimethylnaphthalene to comprise the sole alkyl naphthalene in the mixture.

10. A method according to any one of claims 1 to 7 inclusive, characterised by the steps of selecting di-isopropylnaphthalene to comprise the major constituent of the alkyl naphthalene part of the mixture.

11. A method according to any one of claims 1 to 7 inclusive, characterised by the steps of selecting di-isopropylnaphthalene to comprise the sole alkyl naphthalene in the mixture.

12. A method according to any one of the preceding claims characterised in that the mixture comprises from 10% to 90% alkyl naphthalene by volume.

13. A method according to any one of the preceding claims characterised in that the mixture comprises from 20% to 80% alkyl naphthalene by volume.

14. A method according to any one of the preceding claims characterised in that the mixture comprises from 20% to 50% alkyl naphthalene by volume.

15. A method for treating a crop comprising the steps of applying to the soil or growing medium for the crop, the growing crop, or the harvested crop, an enhanced pesticidal material made in accordance with the method set forth in any one of claims 1, 2 or 3, or claims 7 to 14 inclusive.

16. An enhanced agricultural pesticidal material made by the method set forth in any one of claims 1, 2, or 3, or claims 7 to 14, inclusive.