EP1816907A2

EP1816907A2 - Method for control of soil pests of trans-planted crops

Info

Publication number: EP1816907A2
Application number: EP05848867A
Authority: EP
Inventors: Jean Leblanc; Michel Sarazin; Marc Hullebroeck; Jos Van Ast
Original assignee: FMC Corp
Current assignee: FMC Corp
Priority date: 2004-12-01
Filing date: 2005-12-01
Publication date: 2007-08-15
Also published as: EP1816907A4; WO2006060551A2; WO2006060551A3

Abstract

Pyrethroids are useful in a method for protecting an underground germplasm part of a trans-planted crop against attack by a soil pest. Of particular interest is the use of bifenthrin for protecting an underground germplasm part of a trans-planted crop by contact and repellant activity against attack by a soil pest.

Description

METHOD FOR CONTROL OF SOIL PESTS OF TRANS-PLANTED CROPS

This application claims the benefit of U.S. Provisional Application No. 60/632,119, filed December 1 , 2004.

FIELD OF THE INVENTION

The present invention relates to the field of protecting the underground germplasm of trans-planted crops against unwanted soil pests.

BACKGROUND OF THE INVENTION

Soil pests attack underground germplasm of trans-planted crops such as seeds, roots, rootstocks, tubers, bulbs and underground stem parts. Soil pests' attack of the underground germplasm can result in decreased plant vitality, selective plant death, quality loss and reduced yields. In order to have a quick, strong, healthy emergence and growth of the crops, the underground germplasm should be protected from soil pests. Chemical seed treatment, granular insecticides or combinations of both are generally used to achieve control of soil pests.

Use of seed treatment products (for example imidacloprid or fipronil) has been suspended in France for several crops (corn, sweet corn, sunflowers) due to suspicion of bee toxicity. New soil pests in Europe like Diabrotica vergifera are not well controlled with seed treatment solutions at normal (registered) rates. Additionally, the activity of the current seed treatment products in heavy soil pest conditions is ineffective, resulting in double applications of both seed-treatment and granular insecticides.

Granular insectides known for use in control of soil pests are amongst others carbofuran, carbosulfan, ethoprofos and terbufos. Granular insecticides must be applied to the area where the soil pests are located. There are considerable shortcomings in using the aforementioned granular insecticides for controlling soil pests. For example, these granules are applied at high rates of active ingredient per hectare, they have unfavorable worker safety ratings (they are classified T/T+ in toxicity in Europe), they have avian toxicity and in some instances, they fail to perform due do enhanced microbiological degradation. Clearly, current chemical methods of treatment against soil pests, by seed treatment and granular insecticides, are lacking in performance for the control of soil pests with the insecticides presently being used.

A different class and application technique of insecticides than those set forth above is needed to protect underground germplasm of plants from attack by soil pests.

SUMMARY OF THE INVENTION hi accordance with the present invention, it has been found that the use of a pyrethroid when distributed in the soil near the underground germplasm of transplanted crops (seeds, roots, rootstocks, tubers, bulbs and underground stem parts) during or just before planting can protect the underground germplasm of these transplanted crops effectively against soil pests. Also, as pyrethroids show certain volatility, a repellant layer remains active around the zone where the pyrethroid was applied. This repellant layer forms an effective barrier to pest entry from deeper soil layers to the underground plant germplasm zone. By comparison, the insecticides (seed treatment and granular varieties) previously used for controlling soil insects do not show a repellant layer around the underground germplasm. Specifically, the present invention is a method for protecting an underground germplasm part of a trans-planted crop against attack of a soil pest, said method comprising applying an effective amount of a pyrethroid or its agriculturally-acceptable salts, esters, acids or metabolites to a locus where said germplasm part is planted or growing. Other aspects of the present invention will become apparent from the description below.

DETAILED DESCRIPTION OF THE INVENTION

One aspect of the present invention relates to a method for protecting an underground germplasm part of a trans-planted crop against attack of a soil pest, said method comprising applying an effective amount of a pyrethroid or its agriculturally-acceptable salts, esters, acids or metabolites to a locus where said germplasm part is planted or growing.

The trans-planted crop is preferably selected from the group consisting of corn, sunflower, potato, tomato and sugarbeat. More preferably, the trans-planted crop is selected from the group consisting of corn, sunflower and potato. The pyrethroid is preferably selected from the group consisting of bifenthrin, beta- cyfluthrin and zeta-cypermethrin. More preferably, the pyrethroid is bifenthrin. The soil pest is preferably selected from the group consisting of wireworms and Diabrotica vergifera. The application of an effective amount of a pyrethroid can be a T-band application.

An embodiment of the invention is when the trans-planted crop is corn or sunflower, the soil pest is wireworm and the effective amount of a pyrethroid is from 40 to 80 grams active ingredient per hectare. Preferably, the trans-planted crop is corn or sunflower, the soil pest is wireworm and the effective amount of a pyrethroid is from 40 to 60 grams active ingredient per hectare.

Another embodiment of the invention is when the trans-planted crop is corn, the soil pest is Diabrotica vergifera and the effective amount of a pyrethroid is from 50 to 100 grams active ingredient per hectare. Preferably, the trans-planted crop is corn, the soil pest is Diabrotica vergifera and the effective amount of a pyrethroid is from 80 to 100 grams active ingredient per hectare.

Yet another embodiment of the invention is when the trans-planted crop is potato, the soil pest is wireworm and the effective amount of a pyrethroid is from 50 to 100 grams active ingredient per hectare. Preferably, the the trans-planted crop is potato, the soil pest is wireworm and the effective amount of a pyrethroid is from 60 to 100 grams active ingredient per hectare.

Under certain conditions it is advantageous in the protection of an underground germplasm part of a trans-planted crop against the attack of a soil pest to combine an effective amount of a pyrethroid with soil activity of the present invention with a second insecticide. Of particular advantage is the combination of one or more other insecticides that are known to have insecticidal activity on unwanted soil and/or foliar pests of various crops or are known for other uses, such as carbofuran, carbosulfan or cadusafos. A preferable combination of a pyrethroid with soil activity and insecticides known for activity on unwanted soil pests of various crops would be bifenthrin and one or more of carbofuran, carbosulfan or cadusafos.

As used in this specification and unless otherwise indicated the terms "pyrethroid", "pyrethroid with soil activity", "soil-pyrethroid", "repellant pyrethroid", or "soil insect repellant" as these terms relate to the insecticides of the present invention as set forth herein are one and the same. The term "protecting" refers to the avoidance of, or minimizing the amount of attack of an underground germplasm part of a trans-planted crop by a soil pest to a point where it no longer poses a threat to plant vitality, selective plant death, quality loss and/or reduced yields. The term "germplasm" refers to the seeds, roots, rootstocks, tubers, bulbs and underground stem parts of a trans-planted crop or plant. The term "transplanted crop" refers to field crops, row crops, vegetable crops and other agricultural crops.

One skilled in the art will, or course, recognize that the formulation and mode of application of a toxicant may affect the activity of the material in a given application. Thus, for use in protecting underground germplasm of various crops against the attack of soil pests, the pyrethroid with soil activity finding utility in the present invention may be formulated as granules of relatively large particle size, as water-soluble or water-dispersible granules, as dusts, as wettable powders, as emulsifiable concentrates, as flowables, as micro-emulsions, as microencapsulated formulations, as capsule suspensions, as solutions, or as any of several other known types of formulations, depending on the desired mode of application. It is to be understood that the amounts specified in this specification are intended to be approximate only, as if the word "about" were placed in front of the amounts specified.

These insecticidal compositions may be' applied either as water-diluted sprays, or dusts, or granules to the areas in which protection of underground germplasm is desired. These formulations may contain as little as 0.1%, 0.2% or 0.5% to as much as 95% or more by weight of active ingredient. Dusts are free flowing admixtures of the active ingredient with finely divided solids such as talc, natural clays, kieselguhr, flours such as walnut shell and cottonseed flours, and other organic and inorganic solids which act as dispersants and carriers for the toxicant; these finely divided solids have an average particle size of less than about 50 microns. A typical dust formulation useful herein is one containing 1.0 part or less of the insecticidal compound and 99.0 parts of talc.

Wettable powders are in the form of finely divided particles, which disperse readily in water or other dispersant. The wettable powder is ultimately applied either as a dry dust or as an emulsion in water or other liquid. Typical carriers for wettable powders include Fuller's earth, kaolin clays, silicas, and other highly absorbent, readily wet inorganic diluents. Wettable powders normally are prepared to contain about 5 - 80% of active ingredient, depending on the absorbency of the carrier, and usually also contain a small amount of a wetting, dispersing or emulsifying agent to facilitate dispersion. For example, a useful wettable powder formulation contains 80.0 parts of the insecticidal compound, 17.9 parts of Palmetto clay, and 1.0 part of sodium lignosulfonate and 0.3 part of sulfonated aliphatic polyester as wetting agents.

Other useful formulations for insecticidal applications are emulsifiable concentrates (ECs) which are homogeneous liquid compositions dispersible in water or other dispersant, and may consist entirely of the insecticidal compound and a liquid or solid emulsifying agent, or may also contain a liquid carrier, such as xylene, heavy aromatic naphthas, isphorone, or other non-volatile organic solvents. For insecticidal application these concentrates are dispersed in water or other liquid carrier and normally applied as a spray to the area to be treated. The percentage by weight of the essential active ingredient may vary according to the manner in which the composition is to be applied, but in general comprises 0.5 to 95% of active ingredient by weight of the insecticidal composition.

Flowable formulations are similar to ECs except that the active ingredient is suspended in a liquid carrier, generally water. Flowables, like ECs, may include a small amount of a surfactant, and will typically contain active ingredients in the range of 0.5 to 95%, frequently from 5 to 50%, by weight of the composition. For application, flowables may be diluted in water or other liquid vehicle, and are normally applied as a spray to the area to be treated. Typical wetting, dispersing or emulsifying agents used in certain formulations include, but are not limited to, the alkyl and alkylaryl sulfonates and sulfates and their sodium salts; alkylaryl polyether alcohols; sulfated higher alcohols; polyethylene oxides; sulfonated animal and vegetable oils; sulfonated petroleum oils; fatty acid esters of polyhydric alcohols and the ethylene oxide addition products of such esters; and the addition product of long chain mercaptans and ethylene oxide. Many other types of useful surface - active agents are available in commerce. Surface-active agents, when used, normally comprise 1 to 15% by weight of the composition. Still other useful formulations for insecticidal applications include simple solutions of the active ingredient in a solvent in which it is completely soluble at the desired concentration, such as acetone, alkylated naphthalenes, xylene, or other organic solvents. Granular formulations, wherein the toxicant is carried on relative coarse particles, are of particular utility for aerial distribution or for penetration of a cover canopy. Pressurized sprays, typically aerosols wherein the active ingredient is dispersed in finely divided form as a result of vaporization of a low-boiling dispersant solvent carrier may also be used. Water-soluble or water-dispersible granules are free flowing, non-dusty, and readily water-soluble or water-miscible. In use by the farmer on the field, the granular formulations, emulsifiable concentrates, flowable concentrates, solutions, etc., may be diluted with water to give a concentration of active ingredient in the range of say 0.1 % or 0.2% to 1.5% or 2%.

The following examples further illustrate the present invention, but, of course, should not be construed as in any way limiting its scope. The examples are organized to present protocols for the evaluation of certain pyrethroids with soil activity when placed in the soil near the underground germplasm of plants, and set forth certain biological data indicating the efficacy of such compounds. Unless otherwise indicated, the "IOWA Root index" is a scale from 0 to 6 wherein a higher number indicates more damage. A "T-band application" is a spraying procedure comprising i) opening the furrow, ii) dropping the seed in the furrow, iii) spraying the product as a 10 to 15 cm band over and in the furrow, and over the seed, iv) closing the furrow using a press wheel or similar equipment.

Example 1

Efficacy Test of bifenthrin applied in the soil near the underground germplasm of

Corn

Two trials were conducted by spraying 40-50 grams AI/Hectare and 80 grams AI/Hectare of bifenthrin formulated as an 80 Flow (equivalent to 0.5-0.625 and 1.0 L/Ha of MULTISTAR S/TALSTAR 80 FLOW containing 80 g/1 bifenthrin) in a T-band application near the underground germplasm of corn at planting. The corn was evaluated periodically after application on the attack by wireworms. Percent (%) control or efficacy was determined as a percentage of corn plants damaged at 40-70 days after treatment (DAT) as compared to an untreated reference. Four replicates were conducted.

The results, shown as an average of the four replicates, are compared with results observed in the same trials with carbofuran (Curater 5G) applied at 12 kg/Ha (600 gAI/Ha). The results and comparison are in Tablel below.

Table 1 Bifenthrin 8 SC Protection of Underground Corn Germplasm against

Wireworm

Treatment Rate of Appln. Damaged Plants @ 40-70 (grams AI/ DAT Hectare) (%)

Bifenthrin 8 SC 40-50 12

Bifenthrin 8 SC 80 8

Carbofuran 5G 600 13

Untreated 0 32

Example 2

Efficacy Test of bifenthrin applied in the soil near the underground germplasm of Sunflower

Two trials were conducted by spraying 40-50 grams AI/Hectare and 80 grams AI/Hectare of bifenthrin formulated as an 80 Flow (equivalent to 0.5-0.625 and 1.0 L/Ha of MULTISTAR S/TALSTAR 80 FLOW containing 80 g/1 bifenthrin) in a T-band application near the underground germplasm of sunflower at planting. The sunflower was evaluated periodically after application (29-42 DAT). Percent (%) control or efficacy was determined as a percentage un-attacked sunflower plants compared to an untreated reference. Four replicates were conducted. The results, shown as an average of the four replicates, are compared with results observed in the same trials with carbofuran (Curater 5G) applied at 12 kg/Ha (600 gAI/Ha). The results and comparison are in Table 2 below. Table 2

Bifenthrin 8 SC Protection of Underground Sunflower Germplasm against

Wireworm

Treatment Rate of Appln. Plants Unattacked @ (grams AI/ 29-42 DAT Hectare) (%)

Bifenthrin 8 SC 40-50

Bifenthrin 8 SC 80 88

Carbofuran 5G 600 83

Untreated 0 60

Example 3

Corn

Three trials were conducted by spraying different rates of bifenthrin (0.32, 0.64 and 0.96 grams AI/100 meters of row) formulated from an 80 Flow (equivalent to MULTISTAR S/TALSTAR 80 FLOW containing 80 g/1 bifenthrin) in a T-band application near the underground germplasm of corn at planting. The corn was evaluated periodically after application for attack by Diabrotica vergifera larvae. Control or efficacy was determined as IOWA Root index (0-6) of the corn periodically after treatment compared to an untreated reference. Three replicates were conducted. The results, shown as an average of the three replicates, are in Table 3 below.

Table 3

Bifenthrin 8 SC Protection of Underground Corn Germplasm against Diabrotica vergifera Larvae

Treatment Rate of Appln. Root Damage (grams AI/ 100 m (IOWA scale 0-6) row)

Bifenthrin 8 SC 0.32 2.8

Bifenthrin 8 SC 0.64 2.5

Bifenthrin 8 SC 0.96 2.6

Untreated 0 4.1 Four more trials were conducted with bifenthrin. Two trials with bifenthrin applied as a granule formulated as a 0.2% granule at different rates (0.48 and 0.8 gAI/100 M of row) in-furrow by a granulator. Two trials with spraying different rates of bifenthrin (0.48 and 0.8 grams AI/100 meters of row) formulated from an 80 Flow (equivalent to MULTISTAR S/TALSTAR 80 FLOW containing 80 g/1 bifenthrin) in a T-band application near the underground germplasm of corn at planting. The corn was evaluated periodically after application for attack by Diabrotica vergifera larvae. Control or efficacy was determined as IOWA Root index (0-6) of the corn periodically after treatment compared to an untreated reference. Three replicates were conducted. The results, shown as an average of the three replicates are compared with results observed with carbofuran (Furadan 10G) applied at 6 gAI/100 M row. The results and comparison are in Table 4 below.

Table 4

Bifenthrin 8 SC and Bifenthrin 0.2G Protection of Underground Corn Germplasm against Diabrotica vergifera Larvae

Treatment Rate of Appln. Root Damage @

(grams AI/ 62-90 DAT

100 m row) (IOWA scale 0-6)

Bifenthrin 8 SC 0.48 2.2

Bifenthrin 8 SC 0.8 2.2

Bifenthrin 0.2 G 0.48 2.2

Bifenthrin 0.2 G 0.8 2.2

Carbofuran 1OG 6 2.45

Untreated 0 2.85

Example 4

Potato

Two trials were conducted by spraying 50 grams AI/Hectare and 100 grams AI/Hectare of bifenthrin formulated as an 80 Flow (equivalent to 0.625 and 1.25 L/Ha of MULTISTAR S or TALSTAR 8SC containing 80 g/1 bifenthrin) in a soil application around the underground germplasm of potato in pots containing one potato and 7 wireworms per pot. The potato and soil were evaluated 52 days after application. Control or efficacy was determined as the number of surviving wireworms in the respective pots and the number of holes in the tuber of the potato as compared to an untreated reference. Four replicates were conducted. The results, shown as an average of the four replicates, are compared with results observed in the same trials with ethoprofos (Mocap 20GS) applied at 20 kg/Ha. Soil treatment with 0.625 and 1.25 L/ha of bifenthrin 8 SC resulted in an excellent control of wireworms damage up to seven weeks after treatment. The results and comparison are in Table 5 and Table 6 below.

Table 5 Bifenthrin 8 SC Protection of Underground Potato Germplasm against Wireworm

Treatment Rate of Appln. Number of Living

(grams AI/ Wireworms per Pot @

Hectare) 52 DAT

Bifenthrin 8 SC 50 3.8

Bifenthrin 8 SC 100 4.5

Ethoprofos 20GS 2,000 1.5

Untreated 0 4.5

Table 6

Bifenthrin 8 SC Protection of Underground Potato Germplasm against

Wireworm

Treatment Rate of Appln. Number of Holes per

(grams AI/ Potato Tuber @ 52

Hectare) DAT

Bifenthrin 8 SC 50 0

Bifenthrin 8 SC 100 0.3

Ethoprofos 20GS 2,000 0

Untreated 0 12

While this invention has been described with an emphasis upon preferred embodiments, it will be understood by those of ordinary skill in the art that variations of the preferred embodiments may be used and that it is intended that the invention may be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications encompassed within the spirit and scope of the invention as defined by the following claims.

Claims

What is claimed is:

Claim 1. A method for protecting an underground germplasm part of a transplanted crop against attack of a soil pest, said method comprising applying an effective amount of a pyrethroid or its agriculturally-acceptable salts, esters, acids or metabolites to a locus where said germplasm part is planted or growing.

Claim 2. The method of claim 1, wherein the trans-planted crop is selected from the group consisting of corn, sunflower, potato, tomato and sugarbeat.

Claim 3. The method of claim 2, wherein the trans-planted crop is selected from the group consisting of corn, sunflower and potato.

Claim 4. The method of claim 1, wherein the pyrethroid is selected from the group consisting of bifenthrin, beta-cyfluthrin and zeta-cypermethrin.

Claim 5. The method of claim 4, wherein the pyrethroid is bifenthrin.

Claim 6. The method of claim 1 , wherein the pyrethroid is applied by a T-band application.

Claim 7. The method of claim 1, wherein the soil pest is selected from the group consisting of wireworms and Diabrotica vergifera.

Claim 8. The method of claim 1, wherein the trans-planted crop is corn or sunflower, the soil pest is wireworm and the effective amount of the pyrethroid is from 40 to 80 grams of active ingredient per hectare.

Claim 9. The method of claim 8, wherein the effective amount of the pyrethroid is from 40 to 60 grams of active ingredient per hectare.

Claim 10. The method of claim 1, wherein the trans-planted crop is corn, the soil pest is Diabrotica vergifera and the effective amount of the pyrethroid is from 50 to 100 grams of active ingredient per hectare.

Claim 11. The method of claim 10, wherein the effective amount of the pyrethroid is from 80 to 100 grams of active ingredient per hectare.

Claim 12. The method of claim 1, wherein the trans-planted crop is potato, the soil pest is wireworm and the effective amount of the pyrethroid is from 50 to 100 grams of active ingredient per hectare.

Claim 13. The method of claim 12, wherein the effective amount of the pyrethroid is from 60 to 100 grams of active ingredient per hectare.

Claim 14. The method of claim 1, wherein the pyrethroid is combined with another insecticide.

Claim 15. The method of claim 14, wherein the other insecticide is selected from the group consisting of carbofuran, carbosulfan and cadusafos.

Claim 16. The method of claim 14, wherein the pyrethroid is bifenthrin.