GB2273444A

GB2273444A - Insecticidal treatment of banana plants

Info

Publication number: GB2273444A
Application number: GB9321623A
Authority: GB
Inventors: Richard Mclean Bull; Francois Colliot
Original assignee: Rhone Poulenc Agrochimie SA
Current assignee: Bayer CropScience SA
Priority date: 1992-10-20
Filing date: 1993-10-20
Publication date: 1994-06-22
Anticipated expiration: 2013-10-20
Also published as: AU667406B2; FR2696905B1; FR2696905A1; BR9304035A; AU4908693A; GB2273444B; GB9321623D0

Abstract

Banana plants are protected against insects by application of an effective amount of 1-[2,6-dichloro-4-CF* superscript dot; dot above *phenyl]-3-cyano-4-CF* superscript dot; dot above *SO-5-NH* subscript minus *pyrazole, e.g. to the soil, as a ring around the bases of the banana plants.

Description

PROCESS FOR THE AGROCHEMICAL TREATMENT OF BANANA PLANTS The present invention relates to a new process for the treatment of crops using an insecticidal product, and more especially to a new process for the treatment of crops of banana plants.

Crops of banana plants are the subject of attacks by insects and especially by the banana weevil, also known under the name of Cosmopolites sp.. More especially, the bases of banana plants are the subject of specific attacks by these insects, especially by Cosmopolites sordidus.

Although insecticides available on the market and in the literature are very numerous, it is found that the abovementioned problem has no satisfactory solution. Worse even than that, the insecticides which have a certain recognized effectiveness to date were organochlorinated compounds, especially chlorinated cyclodienes such as aldrin, dieldrin or HCH, which are banned or are going to be. Given that these insecticides were virtually the only effective ones, they were able to obtain dispensations authorizing their use despite the theoretical provisional ban.

These dispensations authorizing the temporary use have been renewed several times, which clearly shows the severity of the problem to be solved and the absence of a solution by means known per se. The insecticide known under the name of aldicarb has been well suggested. The latter is very effective but, for various reasons, attempts are being made to find effective solutions of another kind.

A new process for the treatment of banana plants has now been found which makes it possible to conveniently and economically solve the problems of attacks on banana plants by insects, especially attacks on the bases of banana plants.

The process according to the present invention is characterized in that there is applied, to the soil, at the base of banana plants affected by or susceptible to being affected by an attack from Cosmopolites sod., an effective amount of Product A which is 1- (2, 6-dichloro-4-CF3phenyl) -3-cyano-4-CF3SO-5- NH2pyrazole.

Product A was known, especially from European Patent Application 295117, but it was known for a wide and extensive field of the most diverse activities.

Given that the specific problem of the bases of banana plants was not in practice solved by any insecticide, a person skilled in the art had no reason to think of directing himself especially towards this Product A, more than towards other products.

Product A can be applied in the form of liquid or solid compositions. The compositions used in the invention are generally dilute compositions which comprise from 0.001 to 95 % of active material A, preferably from 0.1 to 15 % of active material. The remainder of the composition generally consists of a liquid or solid vehicle and, optionally, of adjuvants such as surface-active agents or other products. These compositions are described in general in the prior art.

The dilution can be a dilution with water or, in the case of certain granules, a dilution by an agriculturally acceptable inert solid vehicle.

According to a preferred aspect of the invention, an effective amount of the active material A, preferably in a solid or liquid formulated form, is applied to the soil at a distance of less than 1 m from the bases of the banana plants. The treatment is carried out in a ring around the bases of the banana plants, as close as possible to these bases, preferably at less than 0.4 m. In other words, the treatment is effected on the surface in the form of a crown. This crown is constituted by two concentric circles, the distance between the two circles being less than 1 m, preferably less than 0.4 m. It will be understood that the circles defining the crown do not need to be perfectly circular but with a view to regular and homogeneous distribution it is preferable to carry out the treatment inside this zone defined by two circles.The smaller of the circles has substantially the same size as that of the base of the banana plant and the larger of the circles has a radius less than 1 in greater than the radius of the smaller circle, preferably less than 0.4 m greater than the radius of the smaller circle. As already explained, the circles need not be strictly circular but their form preferably substantially follows the form of the base of the banana plant.

Among the solid formulations, the granulated formulations are the most advantageous due to their ease of use. Granules are preferred which have a size ranging from 0.5 mm to 3 mm.

According to yet another preferred aspect of the invention, an amount of active material of between 0.01 and 2 g of active material per banana plant base, preferably between 0.05 g and 0.5 g, is applied. The application is generally carried out 1 to 5 times per year, preferably 2 to 3 times.

The formulations are prepared by any means known per se, especially according to the techniques described in European Patent 295,117.

The following Examples, given as nonlimiting, illustrate the invention and show how it can be implemented.

Example 1 A crop of banana plants is treated one or more times per year by application of a granulated formulation of Product A. The results are recorded under the following different forms: * 1 month after the treatment, the size of the insect population in the crop of banana plants is measured in the following way: slices or sections of banana plants, with a thickness of approximately 5 cm and obtained by a transverse cut of the pseudostem of a banana plant, are deposited on the ground and distributed randomly among the banana plants; these slices constitute baits which attract the weevils (Cosmopolites sordidus); when the number of weevils under a slice is measured, a representative measurement of the size of the insect population in the crop is obtained.

* The degree of infestation, at the end of the growth cycle (first cycle for Example 1 or second cycle for Example 2) is determined as being the percentage of banana plants having at least one weevil tunnel.

* The grade of infestation, at the end of the growth cycle (first cycle for Example 1 or second cycle for Example 2). This grade is determined by interpolation between the grade 0 (complete absence of weevil tunnels) and the grade 100 (more than 90 % of the circumference of the banana plants contains at least one weevil tunnel).

The application of Product A was carried out in the following way: granules with a size of approximately 1 mm are applied to the soil on a ring with a width of approximately 20 cm surrounding each banana plant seedling. The amount of active material applied is shown in the table below.

The results shown below are observed:

Gram of Number of Number of Degree of Grade of Product A per treatments weevils infestation infestation banana plant per year per slice base 0.05 3 8 24 12 0.1 1 10 12 9 0.1 2 6 8 6 0.1 3 2 4 4 0.2 1 3 9 6 0.2 2 2 4 3 0.2 3 0 1 2 0.4 1 0 5 4 0.4 2 1 2 2 0.4 3 0 0 0 0 (control) 0 32 88 33 Example 2 The operation is carried out as in Example 1 but under different infestation conditions

Gram Gram of Number of Number of Degree of Grade of Product A per treatments weevils infestation infestation banana plant per year per slice base 0.1 2 13 22 14 0.1 3 8 10 7 0.2 1 10 16 12 0.2 2 6 6 5 0.2 3 3 4 3 0.4 1 6 6 4 0.4 2 4 2 1 0.4 3 2 2 2 0 (control) 68 98 52 The above tables show the altogether remarkable results of the application according to the invention.

Claims

1. Process for the treatment of banana plants against insects, characterized in that an effective amount of 1- (2, 6-dichloro-4-CF3phenyl) -3-cyano-4-CF3SO- 5-NH2pyrazole is applied.

2. Process according to claim 1, characterized in that the application is carried out on the soil, as a ring around the bases of the banana plants.

3. Process according to claim 1 or 2, characterized in that banana plants affected by, or susceptible to being affected by, an attack from Cosmopolites sD, are treated.

4. Process according to claim 3, characterized in that banana plants affected by, or susceptible to being affected by, an attack from Cosmopolites sordidus are treated.

5. Process according to any one of claims 1 to 4, characterized in that banana plants are treated using a solid formulated composition.

6. Process according to any one of claims 1 to 5, characterized in that banana plants are treated using a formulated composition comprising 0.001 to 95 % of 1-(2, 6-dichloro-4-CF3phenyl)-3-cyano-4-CF3S0-5- NH2pyrazole.

7. Process according to any one of claims 1 to 6, characterized in that banana plants are treated using a formulated composition comprising 0.2 to 15 % of 1- 2, 6-dichloro-4-CF3phenyl) -3-cyano-4-CF3SO-5- NH2pyrazole.

8. Process according to any one of claims 1 to 7, characterized in that there is applied to the soil, at a distance of less than 1 m from the bases of the banana plants, an effective amount of l-[2,6-dichloro- 4-CF3 phenyl]-3-cyano-4-CF3SO-5-NH2pyrazole.

9. Process according to claim 8, characterized in that there is applied to the soil, at a distance of less than 0.4 m from the bases of the banana plants, an effective amount of 1(2, 6-dichloro-4-CF3phenyl] -3- cyano-4-CF3SO-5-NH2pyrazole.

10. Process according to any one of claims 1 to 9, characterized in that between 0.01 and 2 g of 1- (2, 6-dichloro-4-CF3phenyl) -3-cyano-4-CF3SO-5- NH2pyrazole is applied per banana plant base.

11. Process according to claim 10, characterized in that between 0.05 and 0.5 g of 1-t2,6-dichloro-4- CF3phenyl) -3-cyano-4-CF3SO-5-NHyrazole is applied per banana plant base.

12. Process according to claim 11, characterized in that between 0.05 and 0.5 g of 1-t2,6-dichloro-4- CF3phenyl]-3-cyano-4-CF3SO-5-NH2-pyrazole per banana plant base is applied at least twice per year.

13. Process according to any one of the preceding claims substantially as hereinbefore described in Example 1 or 2.