Title of Invention

"METHODS AND COMPOSITIONS TO DEFOLIATE CROP PLANTS AND MINIMIZE PLANT REGROWTH FOLLOWING DEFOLIATION"

Abstract Concurrent or sequential application of an auxin transport inhibitor and a defoliating agent synergistically improve defoliation of crop plants and minimize crop plant regrowth. Pre¬ferably, the auxin transport inhibitor is a semicarbazone compound. The defoliating agent may be an ethylene response or ethylene-type response agent such as a phosphonic acid deriva¬tive. Most preferably, the semicarbazone compound is diflufenzo-pyr and the phosphonic acid derivative is ethephon (i.e., ethe-phon (2-chloroethyl) phosphonic acid).
Full Text

Methods and compositions to defoliate crop plants and minimize plant regrowth following defoliation
Description
The present invention relates to the defoliation of crop plants. In preferred forms, the present invention is embodied in composi¬tions and processes whereby crop plants (e.g., cotton) may be de¬foliated prior to harvest and/or to compositions which effec¬tively prevent regrowth of defoliated crop plants.
Cotton is the most widely used textile fiber and is grown around the world. The cotton plant (Gossypium hirsutum) is a perennial plant of tropical origins that is cultivated in an annual manner in temperate regions.
The cotton plant continually produces fruit (bolls) starting at the seven to nine leaf stage through the end of the season. Gen¬erally, the bolls produced in the early part of the growing sea¬son obtain a larger size by harvest than the bolls produced in the last part of the growing season. The bolls produced in the first part of the season will open several days or weeks before the bolls produced in the last part of the season. However, once open, the cotton bolls begin to lose fiber quality due to the continued exposure to weather. For this reason, it benefits the cotton grower to begin harvesting before the plants are com¬pletely mature.
When cotton plants are mechanically harvested while green leaves remain on the plant, a green stain will often be visibly present on the cotton fiber during the harvesting process. This green stain reduces the value of the fiber at market. For this reason, a defoliation agent is often applied to the cotton plants before they are mechanically harvested. Although defoliation of cotton plants has been practiced in the past, there is still a need for improvement.
Broadly, the present invention relates to'the discovery that the concurrent or sequential application of a plant growth regulator (preferably, an auxin transport inhibitor) and a defoliation agent (preferably, an ethylene response or ethylene-type response inducing agent) synergistically improve defoliation of crop plants and/or will minimize (if not prevent entirely) plant re¬growth following defoliation. Preferably, the auxin transport in¬hibitor is a semicarbazone compound and the ethylene response or ethylene-type response agent is a phosphonic acid derivative.

Most preferably, the semicarbazone compound is diflufenzopyr and the phosphonic acid derivative is ethephon (i.e., ethephon {2-chloroethyl) phosphonic acid).
Other aspects and advantages of the present invention will become more clear after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.
The preferred auxin transport inhibitors that may be employed in the practice of the present invention include substituted semi-carbazones and related compounds, such as thiosemicarcarbazones and isothiosemicarbzones and salts thereof, as described more fully in U.S. Patent Nos. 5,098,462 and 5,098,466 (the entire content of each U.S. patent being expressly incorporated hereinto by reference). These compounds may be synthesized by reacting a carbonyl compound and a semicarbazide or thiosemicarbazide to¬gether at room temperature in the presence of an alcohol solvent, such as methanol or ethanol and with or without an acid catalyst to give the semicarbazones that may be employed in the practice of the present invention. The most preferred■semicarbazone employed in the practice of this invention is diflufenzopyr.
The preferred ethylene response or ethylene-type response induc¬ing agent is a compound of the following formula:

wherein:
Ri is haloethyl, and R2 and R3 are selected from (1) a chlorine atom and a hydroxy group, (2) the group -OR4 and the group -O-CH2R4 wherein each R4 is one member of the group of unsubsti-tuted aryl, substituted aryl and a heterocyclic group, (3) the group -OR4 and the group -O-CH2R4 wherein each R4 is a different member of the group of hydrogen, unsubstituted alkyl, substituted alkyl, unsubstituted cycloalkyl, substituted cycloalkyl, unsub¬stituted aryl, substituted aryl, a heterocyclic group, alkene and alkyne, provided that when one R4 'is selected from unsubstituted alkyl, substituted alkyl, alkene and alkyne, the other R4 is se¬lected from unsubstituted aryl, substituted aryl and a hetero¬cyclic group, (4) together R2 and R3 represent the group:


where R5 and Re are each connected to the phosphorous atom by a separate single bond, and where one of R5 and Rg is -0- and the other is selected from the group of -0-, -OCH2, -CO-0- and -CONH, and R7 repii'esents a cyclic group selected from benzene, substi¬tuted benzene, a heterocyclic ring and a substituted heterocyclic ring, (5) one of R2 and R3 is -ORs and the other is:

wherein each RQ is the same or different and is selected from hy¬drogen, unsubstituted alkyl, substituted alkyl, unsubstituted aryl, substituted aryl and a heterocyclic group, and wherein Ri is as defined above.
Suitable ethylene response and ethylene-type response inducing agents within the definition above are described in U.S. Patent Nos. 3,879,188, 4,240,819, 4,352,869, 4,374,661, 4,401,454 and 5,123,951, the entire content of each such patent being incorpo¬rated expressly hereinto by reference. The most preferred ethyl¬ene inducing agent is 2-chloroethyl-phosphonic acid colloquially known as ethephon as well as its immediate derivatives.
Specific phosphonic acid derivative compounds usable in the prac¬tice of the present invention include the bis(acid chloride) or 2-chloroethylphosphonic acid, the pyrocatechol cyclic ester of 2-chloroethylphosphonic acid, the 4-chloropyrocatechol cyclic es¬ter of 2-chloroethylphosphonic acid, the mixed ethyl and 2-hydro-xyphenyl diester of 2-chloroethyl-phosphonic acid, the mixed bu¬tyl and 2-hydroxyphenyl diester of 2-chloroethyl-phosphonic acid, the 2-chloroethyl monoester of 2-chloroethylphosphnic acid, 2-bromoethylphosphonic acid, the bis(phenyl)ester of 2-chloroe¬thylphosphonic acid,' the tetrachloropyrocatechol cyclic ester of 2-chloroethylphosphonic acid, 2-iodoethylphosphoic acid, the sal-igen cyclic ester of 2-chloroethylphosphonic acid, salicyclic acid cyclic ester of 2-chloroethylphosphonic acid, the ethyl-nionoester 'of 2-bromoethylphosphonic acid, the butyl monoester of 2-iodoethylphosphonic acid, the 3-hydroxyphenyl monoester of

2-chloroethylphosphonic acid (which exists in polymeric form), the bis{2-oxo-prrolidinylmethyl) ester of 2-chloroethylphosphonic acid, the o-hydroxyphenyl monoester of 2-chloroethylphosphonic acid, the mixed isopropyl and 2-hydroxyphenyl diester of 2-chlo¬roethylphosphonic acid, 2-fluoroethylphosphonic acid, the mixed octyl and 2-hydroxyphenyl diester of 2-chloroethylphosphonic acid, the mixed hexadecyl and 2-hydroxyphenyl diester of 2-chlo¬roethylphosphonic acid, the mixed tridecyl and 2-hydroxyphenyl diester of.2-chloroethylphosphonic acid, the anhydride of 2-chlo¬roethylphosphonic acid, 2-chloroethylphosphonic acid, the mixed butyl and 2-hydroxyphenyl diester of 2-chloroethylphosphonic acid, and the 2-bromoethyl monoester of 2-bromoethylphosphonic acid.
Other useful phosphonic acid derivative compounds within the above formula include salicyclic acid cyclic ester of phosphona-midic acid, the mixed phenyl and 2-hydroxyphenyl diester of 2-chloroethylphosphonic acid, 2-chloroethyldichlorophosphine, the bis (pentachlorophenyl) ester of 2-chloroethylphosphonic acid; 2-chloropropylphosphonic acid, 2-phenylthioethylphosphonic acid, the 2,3-pyridinedio cyclic ester of 2-chloroethylphosphonic acid, 2-chloroethylthiophosphonic acid, (2-bromo, 2-fluoro and 2-iodo) and 2-chloroethyl-2,3-dibromo-4-hydroxy-2-butenyl ester polymer. Salts of the phosphonic derivatives of this invention may be used. Examples of such salts include the sodium, aluminum, zinc, potassium and lithium salts.
Other preferred defoliation agent that may be employed are protox inhibitors like cinidon-ethyl, or S,S,S-tributylphosphortri-thioate (commercially available from Bayer Corporation as Def®5) or phenylureas like thidiazuron (commercially available form Agro Evo as Dropp® 50WP).
The semicarbazone is applied to the locus of growing crop plants at rates ranging between 0.005 to about 0.09, and more preferably between about 0.01 to 0.05, pounds of active ingredient per acre (lb. ai/A). The ethylene response or ethylene -type response in¬ducting agent, on the other hand, is most preferably applied to the locus of the plant in an amount between about 0.25 to about 2.5 lb. ai/A, more preferably in an amount between about 0.5 to about 2.0 lb ai/A. The active ingredients may be applied concur-rentl-y to the plant (e.g. as part of a tank mixture of ingredi¬ents) , or may be applied sequentially. If applied sequentially, it is most preferred that the semicarbazone compound be applied to the locus of the growing plant first, followed within at least about 3 to about 21 days of the semicarbazone compound applica¬tion, by the application of the ethylene response or ethylene-

type response inducing agent. When applied sequentially, then the respective amounts of active ingredient applied should be within the ranges noted above.
i The active ingredients may be applied either collectively or se¬quentially in the form of dusts, granules, solutions, emulsions, wettable powders, flowables and suspensions. Application of a compound as an active ingredient is made according to conven¬tional procedure to the locus of the plant in need of the same using the appropriate amount" of the compound per acre as will be described below. According to the present invention the applica¬tion of the compound to the "locus" of the plant includes ap¬plication to the plant or parts of the plant or the soil in which the plant is growing.
The active ingredients be applied to above ground portions of the plants. The application of liquid and particulate solid compounds and/or compositions to above ground portions of plants may be carried out by conventional methods, for example, boom and hand application, including sprayers or dusters. The compounds and/ or compositions may be applied aerially as a spray, if desired. The active ingredients employed in the practice of the present inven¬tion are most preferably used in the form of aqueous solutions. The solutions may be applied in a conventional manner, for exam¬ple, by spraying, atomizing or watering the locus of the plant.
The active ingredients may also be applied in conjunction with other ingredients or adjuvants commonly employed in the art. Ex¬amples of such ingredients include drift control agents, defoam-) ing agents, preservatives, surfactants, fertilizers, phytotoxi-cants, herbicides, pesticides, insecticides, fungicides, wetting agents, adherents, nematocides, bactericides, trace elements, synergists, antidotes, mixtures thereof and other such adjuvants well known in the plant growth regulating art.
The present invention will be further illustrated by way of the following non-limiting examples.
EXAMPLES
In the Examples which follow, PREP™ Brand ethephon (ETP) for cot¬ton and tobacco commercially' available from Rhone-Poulenc Ag com¬pany was employed which contained as active ingredient ethephon (2-chloroethyl)phosphonic acid in an amount of 55.4%.

Example 1
ETP and diflufenzopyr (DFP) were applied to greenhouse grown red kidney bean plants and cotton plants alone and as a mixture in combination with one another. The percent defoliation of the treated plants was determined three and fourteen days after treatment (DAT), with the percent regrowth also being determined fourteen days after treatment for the kidney bean plants, and both fourte'en and twenty-eight days after treatment for the cot¬ton plants. The results for the kidney bean plants are shown in Table lA below, while the results for the cotton plants are shown in Table IB below:

The data in Tables lA and IB demonstrate that either ethephon or diflufenzopyr provide poor defoliation of 51% or less in green¬house tests on kidney bean and cotton plants. Ethephon used alone tended to reduce plant height and drop a few leaves. Diflufenzo¬pyr produced epinasty (twisting of new growth and/or cupping of leaves) at rates of 0.01 and 0.05 lb ai/A and reduced growth. The epinasty produced by diflufenzopyr was severe on kidney beans. The data demonstrate, however, that ethephon and diflufenzopyr at

rates of 0.01 and 0.05 lbs ai/A provide defoliation greater than either product used alone in greenhouse tests. Regrowth from the combination of ethephon and high rates of diflufenzopyr was less than the regrowth that occurred from ethephon when used alone, i EXAMPLE 2
Example 1 was repeated in a field study in Mississippi. The per¬cent defoliation of the plants was examined and appears in Table I 2 below.

The data above show an improvement in defoliation with the com¬bination of ethephon and diflufenzopyr at rates of 0.005 to 0.020 lbs ai/A as compared to either product alone, especially at seven days after treatment.
Example 3
Greenhouse grown red kidney bean plants were treated with either a tank mixed, or sequential applications of DFP and ETP. In this example, DFP was applied at a rate of 0.005 lb. ai/A.
For the sequential application, DFP was applied at intervals 3, 14 and 21 days prior to the application of ETP. ETP was applied in an amount of 0.1 lb ai/A and 0.4 lb ai/A. The results appear in Table 3 below.



The data above show that pretreatment of kidney beans with DFP seven days before the application of ETP increased the defolia¬tion activity of the later compound.
i Example 5
Field grown potato plants were treated with mixtures of DFP and ETP in the amounts set forth below in Table 5. The percent of de¬foliation of the potato plants was examined 4 and 18 days after treatment, with the data appearing in Table 5 below.

Example 2 was repeated using field grown cotton plants in Louisi¬ana (LA), Georgia (GA) and North Carolina (NC) using between 0.03 to 0.09 lbs ai/A of DFP with and without ETP. The percent re-growth of the plants was examined at selected days after treat¬ment (DAT) at each facility, with the data appearing in Table 6 below.


Example 8
Greenhouse studies on kidney beans were conducted using combina¬tions of DFP and other defoliation or desiccation agents as fol¬lows :
cinidon-ethyl (See, U.S. Patent Nos. 4,933,001 and 5,123,955, the entire content of each being expressly incorporated hereinto by reference).

DEF® 6: a.i. S, S,S-tributyl phosphorotrithioate defolitant com¬mercially available from Bayer Corporation
DROPP® 50WP: thidiazuron cotton defoliant commercially available from AgroEvo.
In these greenhouse studies, leaves were clipped off the kidney beans at seven (7) days after treatment (DAT) on four of the six replications to encourage uniform regrowth. The data appear in Tables 8A-8C below, wherein the percent regrowth was determined as a percent of the untreated check plants.


As can be seen from the above aaca, cne use or urf oy icseif re¬duced regrowth as compared to the untreated check. The use of BASF 123W and DEF® 6 tended to promote regrowth. Combining cini-don ethyl or DEF® 6 with DFP at 0.004 lbs ai/A significantly re¬duced regrowth. The use of DROPP 50WP slightly suppressed re¬growth. Combining DROPP® 50WP with DFP at 0.004 lbs ai/A signifi¬cantly reduced regrowth as compared to the use of DROPP® 50WP alone.
While the invention has been described in connection with what is presently considered to be the most practical and preferred em¬bodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is in¬tended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.


We claim:
1. A method of defoliating crop plants and minimizing regrowth following defoliation comprising applying to the locus of a growing crop plant in need of defoliation a defoliating ef¬fective amount of an auxin transport inhibitor and a defo¬liating agent, wherein the auxin transport inhibitor is a semicarbazone, and the defoliating agent is an ethylene re¬sponse or ethylene-type response inducing agent.
2. The method of claim 1, wherein the ethylene response or eth¬ylene-type response inducing agent is a phosphonic acid de¬rivative .
3. The method of claim 2, wherein the semicarbazone is diflufen-zopyr and the phosphonic acid derivative is ethephon.
4. The method of claim 3, wherein the diflufenzopyr and ethephon are applied concurrently to the locus of the plant.
5. The method of claim 4, wherein the diflufenzopyr and ethephon are applied to the locus of the plant in the form of a mix¬ture .
6. The method of claim 3, wherein the diflufenzopyr is first ap¬plied to the locus of the plant followed by the application of the ethephon.
7. The method of claim 6, wherein the ethephon is applied to the locus of the plant within about three days or more following application of the diflufenzopyr to the locus of the plant.
8. The method of claim 7, wherein the ethephon is applied to the locus of the plant within about three to about 21 days fol¬lowing application of the diflufenzopyr to the locus of the plant.
9. The method as in any one of claims 3-8, wherein the diflufen-zopyr is applied to the locus of the plant in an amount be¬tween about 0.005 to about 0.09 lb. ai/A, and wherein the ethephon is applied to the locus of the plant in an amount between about 0.2 5 to about 2.5 lb. ai/A.
10. The method of claim 9, wherein the diflufenzopyr is applied to the locus of the plant in an amount between about 0.01 to about 0.05 lb. ai/A, and wherein the ethephon is applied to

the locus of the plant in an amount between about 0.5 to about 2.0 lb. ai/A.
11. The method of claim 1, wherein the plant is selected from the group consisting of cotton, red kidney bean and potato plants.
12. The method of claim 1, wherin the defoliating agent is a pro-tox inhibitor, S,S,S,-tributylphosphorotrithioate or a pheny-lurea.
13. A plant composition for defoliating crop plants and minimiz¬ing plant regrowth, which composition comprises a plant defo¬liating regrowth minimizing effective amount of a auxin transport inhibitor and a defoliating agent, wherein the a\ixin transport inhibitor is a semicarbazone, and the defo¬liating agent is an ethylene response or ethylene-type re¬sponse inducing agent.
14. The composition of claim 13, wherein the auxin transport in¬hibitor is a semicarbazone, and the ethylene response or eth-ylene-type response inducing agent is a phosphonic acid de¬rivative .
15. The composition of claim 14, wherein the semicarbazone is di-flufenzopyr and the phosphonic acid derivative is ethephon.
16. The composition of any one of claims 13-15 wherein the semi¬carbazone is present in an amount between about 0.005 to about 0.09 lb. ai/A, and wherein the ethylene response or ethylene-type response inducing agent is present in an amount between about 0.25 to about 2.5 lb. ai/A.
17. The composition of any one of claims 13-15, wherein the di-flufenzopyr is present in an amount between about 0.005 to about 0.09 lb. ai/A, and wherein the ethephon is present in an amount between about 0.25 to about 2.5 lb. ai/A.
18. The composition of claim 17, wherein the diflufenzopyr is present an amount between about 0.01 to about 0.05 lb. ai/A, and wherein the ethephon is present in an amount between about 0.5 to about 2.0 lb. ai/A.
19. A plant composition for defoliating crop plants and minimiz¬ing plant growth, which composition comprises a plant growth minimizing effective amount of a axixin transport inhibitor and a defoliating agent, wherein the axixin transport

inhibitor is a semicarbazone and the defoliating agent is a protox inhibitor, S,S,S-tributylphosphorotrithioate or a phe-nylurea.

20. A method of defoliating crop plants substantially as herein described
and exemplified.
21. A plant composition for defoliating crop plants substantially as herein
described and exemplified.



Documents:

in-pct-2002-0902-che abstract.pdf

in-pct-2002-0902-che claims.pdf

in-pct-2002-0902-che correspondence-others.pdf

in-pct-2002-0902-che correspondence-po.pdf

in-pct-2002-0902-che description (complete).pdf

in-pct-2002-0902-che form-1.pdf

in-pct-2002-0902-che form-19.pdf

in-pct-2002-0902-che form-26.pdf

in-pct-2002-0902-che form-3.pdf

in-pct-2002-0902-che form-5.pdf

in-pct-2002-0902-che pct.pdf

IN-PCT-2002-902-CHE AMENDED PAGES OF SPECIFICATION 29-12-2011.pdf

IN-PCT-2002-902-CHE CORRESPONDENCE OTHERS 22-08-2012.pdf

IN-PCT-2002-902-CHE FORM-13 29-12-2011.pdf

IN-PCT-2002-902-CHE POWER OF ATTORNEY 29-12-2011.pdf

IN-PCT-2002-902-CHE AMENDED CLAIMS 27-10-2011.pdf

IN-PCT-2002-902-CHE AMENDED PAGES OF SPECIFICATION 27-10-2011.pdf

IN-PCT-2002-902-CHE CORRESPONDENCE OTHERS 12-04-2011.pdf

IN-PCT-2002-902-CHE CORRESPONDENCE OTHERS 14-10-2013.pdf

IN-PCT-2002-902-CHE CORRESPONDENCE OTHERS. 08-04-2013.pdf

IN-PCT-2002-902-CHE FORM-3 08-04-2013.pdf

IN-PCT-2002-902-CHE FORM-3 14-10-2013.pdf

IN-PCT-2002-902-CHE OTHER PATENT DOCUMENT 29-12-2011.pdf

IN-PCT-2002-902-CHE AMENDED CLAIMS 19-04-2013.pdf

IN-PCT-2002-902-CHE CORRESPONDENCE OTHERS 29-12-2011.pdf

IN-PCT-2002-902-CHE CORRESPONDENCE OTHERS 18-11-2011.pdf

IN-PCT-2002-902-CHE EXAMINATION REPORT REPLY RECEIVED 27-10-2011.pdf

IN-PCT-2002-902-CHE FORM-1 29-12-2011.pdf

IN-PCT-2002-902-CHE FORM-3 18-11-2011.pdf

IN-PCT-2002-902-CHE FORM-3 27-10-2011.pdf

IN-PCT-2002-902-CHE OTHER PATENT DOCUMENT 18-11-2011.pdf

IN-PCT-2002-902-CHE OTHER PATENT DOCUMENT 27-10-2011.pdf

IN-PCT-2002-902-CHE OTHERS 19-04-2013.pdf

IN-PCT-2002-902-CHE POWER OF ATTORNEY 27-10-2011.pdf

IN-PCT-2002-902-CHE CORRESPONDENCE OTHERS 19-04-2013.pdf

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Patent Number 258044
Indian Patent Application Number IN/PCT/2002/902/CHE
PG Journal Number 48/2013
Publication Date 29-Nov-2013
Grant Date 28-Nov-2013
Date of Filing 14-Jun-2002
Name of Patentee BASF CORPORATION
Applicant Address 100 CAMPUS DRIVE FLORHAM PARK,NJ 07932
Inventors:
# Inventor's Name Inventor's Address
1 EVANS,JOHN R 6400 BRANDYWINE, RALEIGH, NC 27607,
2 EVANS, RICHARD, R., 144 BAYOU ROAD, GREENVILLE, MS 38701
3 HARRELL, ANITA ,L., 204 HUNTER STREET, APEX, NC 27502,
4 STEWART, WALLACE, W., 123 MEADOWVIEW DRIVE, BRANDON, MS 39047,
5 KING, DAVID, L., 1689 DOLORES DRIVE, BRANDON, MS39047,
PCT International Classification Number A01N61/00
PCT International Application Number PCT/EP00/12202
PCT International Filing date 2000-12-05
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 09/461,383 1999-12-15 U.S.A.