WO2021005553A1

WO2021005553A1 - Novel granules and its pesticidal compositions

Info

Publication number: WO2021005553A1
Application number: PCT/IB2020/056470
Authority: WO
Inventors: L.C. Rohela; Rajesh Aggarwal
Original assignee: Insecticides (India) Limited
Priority date: 2019-07-11
Filing date: 2020-07-09
Publication date: 2021-01-14

Abstract

The present invention provides a zeolite based granular pesticidal composition which is capable of efficiently retaining various pesticides and also capable of moderately releasing said pesticides after mixing with soil to be treated.

Description

NOVEL GRANULES AND ITS PESTICIDAL COMPOSITIONS

FIELD OF THE INVENTION The present invention relates to zeolite based granules. The present invention also relates to delivery of one or more pesticides by using the zeolite based granules.

BACKGROUND OF THE INVENTION

A pesticide is a bioactive material which destroys or inhibits the pests. The general term pesticide includes insecticides, herbicides, fungicides, plant growth regulators, rodenticides and miticides.

With a greater appreciation as to environmental damage associated with pesticide usage, there are ever-increasing limitations as to the classes of chemical compounds suitable as pesticides as well as limitations how much and when those pesticides can be spread on crops. In many cases in order to ameliorate environmental damage associated with pesticide application, pesticide use is mandated during seasons when the pest lifecycle is not at the most vulnerable stage. With integrated pest management now endorsed by environmental regulatory agencies, industry associations, and entomologists, more judicious pesticide usage should be expected in the future. An ongoing problem in minimizing pesticide usage is the difficulty in delivery of a pesticide efficiently to a target plant within a large area of cultivated vegetation.

The pesticides usually formulated into various forms such as dusts, granules, wettable powders and emulsions. The spray treatments of liquid pesticides require considerable skill for application and result only in contact to exposed foliage with other surfaces receiving only indirect drainage from exposed foliage. Additionally, spray treatment tends to dissipate quickly. Due to spray atomization of liquid pesticides, a considerable amount of pesticide is lost through volatilization and wind drift and tends to be applied in greater quantities to reach pests dwelling on the underside of foliage. The net result is inefficient pesticide usage, non-target hazard effects to people, wildlife, and non-target property. Other deleterious effects of inefficient usage of pesticides include leaching through rain contact causing environmental wastewater management issues and aerosol pollution.

In view of the aforesaid, a preferred means of applying pesticides for both consumers and professional applicators is dry granules for use in the broadcast delivery of the pesticides. The dry granules are those granules which can be applied with a dry spreader or by hand to a target area and when exposed to water by way of, for example, rain or irrigation, will allow the pesticide material to migrate further away from the carrier.

Granular pesticides are important commercial products because of their ability to eliminate undesirable vegetation, diseases, insects and the like and their ease of application, either by hand or a mechanical means. The granular pesticide can be a pesticide applied to an inert material, like clay or ground com cobs, or can be a combination pesticide. These granules are often prepared from wood dust, diatomaceous earth compositions or mineral components, such as limestone or dolomite, and may contain surfactants and/or binders to aid in the disintegration and dispersion of the granules upon exposure to water In a granular form, a pesticide is impregnated into or absorbed onto an inert material or a fertilizer material. The granular pesticide product is applied to soil and/or vegetation by directly spreading pesticide granules onto the soil and/or vegetation at a suitable dosage rate.

Using granular products having particle sizes in the range of about 1 millimeter to about 10 millimeters, an operator can cover a large area with minimal distance traversed by the spreader itself while at the same time applying the granular pesticide with relative uniformity over the desired area. Unfortunately, such granular pesticides often remain in solid or semisolid form for a considerable time following application. Since the pesticide is typically bound physically within the granule, the pesticide efficacy is reduced or delayed, potentially resulting in a loss of active ingredient via volatilization or photo- degradation.

A further consequence of granular pesticide distribution is that the granules are subject to removal by plant culture operations such as mowing or aerating, or environmental factors such as wind and rain. Unintended removal is especially problematic on sloping ground where the underlying soils have low percolation rates, where ground cover is sparse, or in areas of high foot traffic. These actions contribute to a loss of uniformity in pesticide application and therefore efficacy is altered due to excessive concentration of the product within certain treated areas while other areas suffer diminished pesticide concentrations. Additionally, a long-persistent granule creates a greater likelihood that people, beneficial insects, and animals will come into physical contact with the granules, resulting in undue adverse health effects and environmental degradation.

Thus, there exists a need for granule compositions that overcomes the deficiencies of prior arts by efficient delivery of pesticides.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a granular pesticidal composition capably of efficiently retaining various pesticides and also capable of moderately releasing said pesticides after mixing with soil to be treated.

In accordance with the present invention, there is provided a zeolite based granules which are not dusty, attractive in appearance like pearl beads, can be made of any colour, easily broadcasted, not giving any toxic effects to the broadcaster etc.

In accordance with the present invention, there is provided a zeolite based granular pesticidal composition comprising bifenthrin and thiamethoxam. In accordance with the present invention, there is provided a synergistic granular composition comprising an effective amount of Bifenthrin and effective amount of Thiamethoxam.

The inventors of the present inventors have found that zeolite based granules of the present invention can efficiently retain bifenthrin and thiamethoxam and can desirably release the adsorbed bifenthrin and thiamethoxam after mixing with soil to be treated.

DETAILED DESCRIPTION OF THE INVENTION

The following is a description of embodiments of the present invention. The embodiments are in such details as to clearly communicate the invention. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention.

Unless specifically defined otherwise, all technical and scientific terms used herein shall be taken to have the same meaning as commonly understood by one of ordinary skill in the art (e.g., in agricultural chemistry, dendrimer chemistry, pesticide chemistry and formulations, and biochemistry).

Unless the context requires otherwise, throughout the specification which follow, the word“comprise” and variations thereof, such as,“comprises” and“comprising” are to be construed in an open, inclusive sense that is as“including”, but not limited to.”

As used in the description herein and throughout the claims that follow, the meaning of “a”,“an” and“the” includes plural reference unless the context clearly dictates otherwise.

In some embodiments, the numerical parameters set forth in the written description are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In accordance with an embodiment of the invention, the active ingredients/compounds used in the present invention are in the form of a free acid, salt, or an ester. The term pest is intended to cover any living organism, plant, animal or microbe, whose presence causes human discomfort, harm to agriculture, a health hazard, or cosmetic harm. The term pesticide means any chemical agent effective in pest control, that operates to control pest populations which prevents maturation or reproduction of any stage of the pest, or which kills any stage of the pest with toxic effects.

The inventors have conducted extensive studies in order to accomplish the foregoing objects and to overcome the deficiencies of prior arts, and have found out that the desired objects can be achieved by the zeolite based granules of the present invention. The zeolite based granules of the present invention possess many advantages such as low dust formation in transit and high liquid holding capacity. Due to said features, pesticides such as bifenthrin and thiamethoxam absorbed well and retained for a longer time in zeolite based granule of the present invention which resulting in better control of pests in comparison to other known granules such as bentonite and sand granules due to long residual action and others. The granule composition of the present invention can be effectively applied to soil for treatment of various pests. Examples of these pests are white grubs and termites.

The application amounts of the powdered or granular compositions of the present invention may be varied over a wide range depending upon, for example, varieties of plants to be applied, kind of pests to be controlled, extent of damages, soil conditions, seasons, and weather conditions.

In accordance with one of embodiment of the present invention, a granular composition comprising of Bifenthrin, Thiamethoxam and one or more agriculturally acceptable adjuvant selected from irisiloxane ethoxylate, dimethyl formamide and solvent CIX, wherein weight ratio of Bifenthrin to Thiamethoxam is 1:0.5.

In accordance with one of the preferred embodiment of the present invention, the Bifenthrin is present in an amount of 0.6%-l% of total weight of the composition. In accordance with one of the preferred embodiment of the present invention, the Thiamethoxam is present in an amount of 0.2%-0.6% of total weight of the composition.

EXAMPLES

The present invention now will be further illustrated by, but is by no limited to, following examples, in which all percentages and parts are expressed on a weight basis unless otherwise specified.

The chemical composition of zeolite clay used for preparation of zeolite granule is given herein below:

Process of preparation of zeolite granules Mineral lumps of zeolite clay were crushed 10 make fine powder. Powdered zeolite clay was added with required amount of water and rotated in the granulator to form round shaped granules. A dye of required colour was added and dried in rotary kiln. The dried granules were sieved to obtain uniform size granules.

The composition of fine dried zeolite granule is given herein below:

Preparation of pesticide absorbed granules The present example pertains to combination of bifenthrin and thiamethoxam absorbed in zeolite granules. However, the art can be extended to various others insecticides, fungicides, plant growth regulators etc. The required amount of bifenthrin and thiamethoxam can be dissolved in high polarity solvents such as methanol, isopropyl alcohol, acetone, diacetone alcohol, dimethylformamide, solvent CIX, dimethylsulfoxide, 2-methoxy ethanol, 2-butoxy ethanol etc. which are compatible with the toxicants.

In the following example, dimethylformamide, solvent CIX in required proportions were used to solubilize required quantity of bifenthin and thiamethoxam. The obtained solution was mixed with ethoxylated trimethoxy siloxane and sprayed over the zeolite granules in a rotator mixer to fonn the free flowing granules. The exemplary granular composition of Bifenthin (0.8%) and Thiamethoxam (0.4%) is given herein below:

The following tests were performed in order to compare zeolite granule of the present invention with other known granules:

Attrition Test

Liquid holding capacity

The zeolite granules as chosen in the present invention has lower attrition rate as compared to other granules which means that they will form less dust and in retrospect they have lower dermal toxicity to the applicator person. In addition, said zeolite granules have higher liquid holding capacity which means it can absorb more amounts of input raw materials. Further, the zeolite granules of the present invention are almost neutral and provide more stability of the toxicants.

It has also been found that observed the stability on storage was better on zeolite granules of the present invention as compared to other mineral granules. Further, the composition of the present invention achieved better bio efficacy as compared to when bifenthrin and thiamethoxam formulated on other granules.

The observation on white grab population were recorded before application of treatments and on 60 day after application of treatments and at harvest of the crop and presented in Table 1. The results indicated that after application, all the treatments of the present composition were significantly superior over other treatment in managing white grub population in groundnut crop.

Table 1: Effect of Thiamethoxam 0.4% + Bifenthrin 0.8% GR based on per cent reduction in population of white grubs over control during Kharif.

A synergistic effect of pesticides is present when the pesticidal activity of the active compound combinations exceeds the total of the activities of the active compounds when applied individually. The expected activity for a given combination of two active compounds can be calculated as follows (cf. Colby, S.R.,“Calculating Synergistic and Antagonistic Responses of Herbicide Combinations”, Weeds 1967, 15, 20-22):

E = X + Y XY/100 X is the efficacy when active compound A is applied at an application rate of x ppm (or g/ha).

U is the efficacy when active compound B is applied at an application rate of y ppm (or g/ha),

E is the efficacy when the active compounds A and B are applied at application rates of x and y ppm (or g/ha) respectively.

The expected efficacy of Bifenthrin (100 g a.i./ha) + Thiamethoxam (93.75 g a.i.Zha)] is calculated by said Colby’s formula and following values are obtained:

Comparison of observed efficacy with calculated efficacy:

From the above data, it is evident that observed insecticidal efficacy of Thiamethoxam 0.4% + Bifenthrin 0.8% GR is giving better efficacy even at low dose [Bifenthrin (96 g a.i./ha) + Thiamethoxam (48 g a.i./ha)] in comparison to calculated insecticidal effect at higher dose [Bifenthrin (100 g a.i./ha) + Thiamethoxam (93.75 g a.i./ha)] which is indicative of unexpected efficacy/synergism.

The inventors of the present invention also experimented various solvents but success was achieved through the combination of solvents i.e. dimethyl formamide and solvent CIX to provide homogeneous distribution of toxicants on the zeolite granules. Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be readily apparent to those of ordinary skill in the art in light of the teachings of this invention that certain changes and modifications may be made thereto.

Claims

We Claim:

1 ) A granular composition compri sing:

(a) Bifenthrin;

(b) Thiamethoxam;

(c) one or more agriculturally acceptable adjuvant selected from trisiloxane ethoxylate, dimethyl formamide and solvent CIX,

wherein weight ratio of Bifenthrin to Thiamethoxam is 1:0.5.

2) The granular composition as claimed in claim 1, wherein the Bifenthrin is present in an amount of 0.6%-l% of total weight of the composition.

3) The granular composition as claimed in claim 1, wherein the Thiamethoxam is present in an amount of 0.2%~0.6% of total weight of the composition.