OA18448A - Use of certain herbicide combinations in tuberous root crop plants - Google Patents

Abstract

The present invention primarily relates to the use of herbicide combinations comprising at least three specific herbicides or of a composition comprising such herbicide combinations for controlling harmful plants in tuberous root crop plants, preferably in cassava. The present invention also relates to the use of said specific herbicide combinations or of a composition comprising said specific herbicide combinations as plant growth regulators for tuberous root crop plants, preferably as plant growth regulators for cassava. Furthermore, the present invention relates to a corresponding method of controlling harmful plants in tuberous root crop plants and to a corresponding method of regulating plant growth of tuberous root crop plants.

Description

Use of certain herbicide combinations In tuberous root cror> niant»

The present invention prîmarily relates to the use of herbicide combinations comprising at least three spécifie herbicides or of a composition comprising such herbicide combinations for controlling harmful plants in tuberous root crop plants, preferably in cassava. The present invention also relates to the use ofsaid spécifie 5 herbicide combinations or ofa composition comprising said spécifie herbicide combinations as plant growth regulators for tuberous root crop plants, preferably as plant growth regulators for cassava. Furthermore, the present invention relates to a corresponding method ofcontrolling harmful plants in tuberous root crop plants and to a corresponding method of regulating plant growth of tuberous root crop plants

Cassava (Manlhot esculenta Crantz) is a major source of carbohydrate for several hundred million people, 10 mainly in Africa and to some extent in Asia and Latin America. In Africa, yields of cassava are generally comparatively low, which to a large extent is due to effects of weed compétition or to uncontrolled or unsuflïciently controlled weed growth. Hœ-weeding still is a common practice among cassava farmers.

The Proceedings ofthe 1 Ith 1SRTC-AB, Kinshasa, Démocratie Republic Congo, 4-8 October 2010, pages 269-275 report on the évaluation of commercially available herbicides for weed control in cassava. The 15 treatments there comprised pre-emergent herbicides employing such as chloroacetanilide, prometryn or Smetolachlor.

In the Crop recommendation #17 of the Mînistry of Agriculture of Barbados the following herbicides for weed control în cassava are mentioned: paraquat (optionally mixed with diquat), glyphosate, sulfosate, pendimethalin, metolachlor, fluazifop-butyl, sethoxydim or propaquizafop.

CNI02428919A teaches a postemergence cassava field herbicide with mesotrion as an active component

CN 103392724A suggests the use ofatemaiy herbicide composition as cassava field herbicide with the active components of halosulfuron, oxyfluorfen and an amide herbicide selected from the group of butachlor, propisochlor and metolachlor.

GB 1,028,976 discloses a process for the treatment of plants with storage organs, for example cassava, sweet 25 potato or yam, which comprises spraying the plants with a substituted benzoîc acid herbicide in a spécifie time fram before harvest. There, herbicides like (optionally further substituted) di-, tri- or tetrachlorobenzoic acids are preferred.

African Crop Science Journal 1994,519-530 reports on weeds and their control in cassava. There, mainly the following herbicides were tested; metobromuron, fluometuron, prometryn (optionally în combination with 30 ametryne), terbutryn, paraquat and diuron.

Planta Daninha, 2010,28(4), 807-816 describes the application ofdifterent herbiedes on weeds in cassava. Inter alia the effects of herbicides like diuron, metribuzin, îsoxaflutole, atrazine, ametryn, and several

-2combinations comprising said herbicides are reported therein on two cassava varieties grown in the state of Paranâ, Brazil.

In their application, herbicidal crop protection agents (herbicides) known to date for controlling harmful plants or unwanted végétation in tuberous root crop plants hâve some disadvantages, be it (a) that they hâve 5 no or else insufficient herbicidal activity against spécifie harmful plants, (b) that the spectrum of harmful plants which can be controlled with the herbicides is not broad enough, and/or (c) that the selectivity of herbicides in and the compatibility with tuberous root crop plants is too low, thereby causing unwanted damage and/or unwanted reduced harvest yields of the tuberous root crops.

Overall, the herbicidal activity (above aspects (a) and (b)) and/or the selectivity/compatibility (aboveaspect 10 (c)) of the herbicides used so far in tuberous root crop plants still allow improvement.

For the reasons mentioned above, there still is a need for alternative, highly active herbicides or herbicidal compositions for the sélective application for controlling harmful plants or unwanted végétation in tuberous root crop plants.

Surprisingly, it has now been found that certain herbicide combinations or compositions comprising said 15 herbicide combinations exhibit the desired herbicidal activity and are able to selectively control harmful plants or unwanted végétation in tuberous root crop plants.

The présent invention primarily relates to the use of a combination of herbicides (herbicide combination) or of a composition comprising a combination of herbicides (herbicide combination)

- for controlling harmful plants in tuberous root crop plants, and/or

- as plant growth regulators in tuberous root crop plants, wherein said combination of herbicides comprises or consists of (i) flufenacet, (ii) flurtamone and (iii) diflufenican.

The présent invention further releates to the use of a composition as defined herein in the context of the 25 présent invention which additionally comprises one or more further components selected from the group consisting of formulation auxiliaries, additives customary in crop protection, and further agrochemically active compounds (i.e. agrochemically active compounds different from components (i), (ii) and (iii) as defined above, i.e. agrochemically active compounds other than (i) flufenacet, (fl) flurtamone and (iii) diflufenican).

However, when a combination of herbicides used in the context of the présent invention consists of herbicides (i) flufenacet, (H) flurtamone and (iii) diflufenican, this means that in such a case thecombination

-3of herbicides used in the context of the présent invention or the composition comprising said combination of herbicides used in the context of the présent invention does not contain any further (i.e. no additional) herbicidal active ingrédient, and preferably does not contain any further agrochemically active compound.

In this context, the term “further herbicidal active ingrédient” and “further agrochemically active compound” 5 refers to the herbicides and agrochemically active compounds (pesticides), respectively, listed in The Pesticide Manual, 16th édition, The British Crop Protection Council and the Royal Soc. ofChemistry,2012 other than flufenacet, flurtamone and dïflufenican.

The herbicide combinations and the compositions comprising said herbicide combinations used in accordance with the présent invention not only exhibit an excellent herbicidal activity in controlling harmful plants or 10 unwanted végétation in tuberous root crop plants, but also show compatibility with tuberous root crop plants,

i.e. said herbicides do not cause significant damage and/or unwanted reduced harvest yields ofthe tuberous root crops.

The herbicide combinations used in accordance with the présent invention and the compositions comprising said herbicide combinations used in accordance with the présent invention allow excellent (total) weed 15 control at an agronomically acceptable level of damage ofthe tuberous root crop plants. Further, the type of damage observed with the herbicide combinations and the compositions comprising said herbicide combinations used in accordance with the présent invention is less harmful and/or less severe, and the tuberous root crop plants aflected largely or fully recover from said type of damage.

Further, the herbicide combinations used in accordance with the présent invention and the compositions 20 comprising said herbicide combinations used in accordance with the présent invention can be used as plant growth regulators for tuberous root crop plants, preferably as plant growth regulators for cassava, thereby increasing harvest yields tuberous root crop plants (in particular the weight of the tuberous root) and/or increasing the plant growth of the tuberous root crop plants (in particular the growth of the leaves of the tuberous root crop plants), in each case in comparison to tuberous root crop plants not treated with herbicides 25 (untreated control).

The présent invention preferably relates to the use of a combination of herbicides or of a composition comprising a combination of herbicides as defined in the context of the présent invention, wherein the tuberous root crop plants are selected from the group consisting of sweet potato (ipomoea batatas), cassava (Manihot esculentà), and yam (plant species in the genus Dioscorea). more preferably wherein the tuberous 30 root crop plant is cassava (Manihot esculentà).

The herbicides used in the context ofthe présent invention are known per se, and described inter alia in The Pesticide Manual, 16thédition, The British Crop Protection Council and the Royal Soc. of Chemistry, 2012 and the literature cited therein. The herbicides used in the context ofthe présent invention are described in more detail hereinbelow.

-4The herbicide combinations used in the context of the présent invention and also certain compositions comprising the herbicide combinations used în the context of the présent invention as such are known. The herbicide combinations used în the context ofthe présent invention and also certain compositions comprising the herbicide combinations used in the context of the présent invention are commercially available.

Tuberous roots (also called root tubers) are perennating organs. thickened roots that store nutrients over periods when the plant cannot actively grow, thus permitting survival from one year to the next.

Tubers should not be confused with tuberous roots. Tubers are modified shoots, whereas tuberous roots are modified roots.

A tuberous root is a modified latéral root, enlarged to function as a storage organ. The enlarged area of the 10 root-tuber, or storage root, can be produced at the end or middle ofa root or involve the entire root. It is thus different in origin but similar in function and appearance to a stem tuber. Examples of plants with notable tuberous roots include the sweet potato, cassava, yam and dahlia.

Cassava (Manihot esculenta Crantz), also called manioc, yuca, balinghoy or kamoteng kahoy (în the Philippines), tabolchu (în Northeast India), mogo (in Africa), mandioca, tapioca-root, kappa (predominantly 15 in India) and manioc root, a woody shrub of the Euphorbîaceae (spurge) family native to South America, is extensively cultivated as an annual crop in tropical and subtropical régions for its edible starchy tuberous root, a major source of carbohydrates. Cassava, when dried to a powdety (or pearly) extract, is called tapioca; its fermented, flaky version is named garri.

Cassava is the third largest source of food carbohydrates in the tropics, after rice and maize. Cassava is a 20 major staple food în the developing world, providing a basic diet for over half a billion people. It îs one ofthe most drought-tolerant crops, capable of growing on marginal soils. Nigeria is the world's largest producer of cassava, while Thailand is the largest exporting country of dried cassava.

Cassava grows poorly in weedy fields and consequently produces fewer and smaller storage roots.

Yam is the common name for some plant species in the genus Dioscorea (family Dioscoreaceae) that form 25 edible tubers. These are perennial herbaceous vines cultîvated for the consumption of their starchy tubers in

Africa, Asia, Latin America, the Caribbean and Oceania, There are many cultivars of yam. Although some varietîes ofsweet potato (Ipomoea batatas) are also calledyam in parts of the United States and Canada, it is not part of the family Dioscoreaceae.

Yams are monocotyledons, related to Iilies and grasses. Native to Africa and Asia, yam tubers vary in size 30 from that of a small potato to over 60 kilograms. There are over 600 varietîes of yams and 95 percent of these crops are grown in Africa.

According to the présent invention the expression composition includes compositions comprising a herbicide combination as defined herein, and can be used in various acceptable or agronomically typical forms and formulations, for example in a single ready-mix form.

The herbicides (i), (ii) and (in) used in the herbicide combinations used in the context ofthe présent invention 5 and the compositions comprising the herbicide combinations used in the context ofthe présent invention may be a combined spray mixture composed from separate formulations ofthe single active compounds, such as a tank-mix, or said composition can be a combined use ofthe single active ingrédients when applied in a sequentia! manner, i.e. one after the other within a reasonably short period, such as a few hours (and preferably less than 24 hours).

The herbicides (i), (ii) and (iii) used in the herbicide combinations used inthe context ofthe présent invention include ail stereoisomers and their mixtures, in particular also racémie mixtures and - if enantiomers are possible - the respective bïoîogicaîîy active enantiomer.

If, in the context of this description, the short form of the common name of an active compound is used, thîs includes in each case ail customary dérivatives, such as the esters and salts, and isomers, in particular optical 15 isomers, in particu ! ar the commercî ally available form or forms. I f the common name dénotés an ester or sait, this in each case also comprises ail other customary dérivatives, such as other esters and salts, the free acids and neutral compounds, and isomers, in particular optical isomers, in particular the commercially available form or forms. The given chemical compound names dénoté at least one ofthe compounds embraced by the common name, frequently a preferred compound. In the caseof sulfonamîdes such as sulfonylureas, salts also 20 include the salts formed by exchanging a hydrogen atom on the sulfonamide group by a cation.

The salts of compounds used în the context of the présent invention may be used in the form ofthe respective alkali métal salts, alkaline earth salts or ammonium salts, preferably in the form of the respective alkali métal salts, more preferably in the form of the respective sodium or potassium salts, most preferably in the form of the respective sodium salts.

Flufenacet (ÎUPAC-Name: 4'-fluoro-jV-IsopropyI-2-[5-(trifIuoromethyl)-l ,3,4-thiadiazol-2-yloxy]acetanillde, CAS Reg. No. 142459-58-3) is described for example in EP 0 348 737 Al and US 4,968,342 A.

Flurtamone (IUPAC-Name: (2ÆS)-5-methylamino-2-phenyl-4-(a,a,a-trifluoro-m-tolyl)furan-3(2Z/)-one, CAS Reg. No. 96525-23-4) is described for example in US 4,568,376 A.

Diflufenican (IUPAC-Name: 2’,4'-difluoro-2-(a,a,a-trifluoro-m-tolyIoxy)nicotinaniIide, CAS Reg. No. 30 83164-33-4) is described for example in EP 0 053 011 Al and US 4,618,366 A.

-6WO 94/02014 A2 and US 5,759,955 A relate to herbicide combinations of certain heterocyclic aryioxyacetamides and a further herbicide. Therein, inter alia the combination of flufenacet and diflufenican are described.

WO 2007/112834 A2 relates to herbicidal compositions as dispersion comprising diflufenican and flurtamone. Therein, inter alia aqueous dispersion comprising diflufenican, flurtamone and flufenacet are disclosed.

In accordance with the présent invention, the herbicide combinations as defîned herein or the composition comprising a herbicide combination as defîned herein comprise a herbicidally effective amount of said herbicide combination and may comprise further components, for example agrochemically active compounds 10 ofa different type and/or formulation auxiliaires and/or additives customary in crop protection, or they may be employed together with these.

In accordance with the présent invention, the herbicide combinations as defîned herein or the composition comprising a herbicide combination as defîned herein may be applied as a split application over time. Another possibility is the application of the individual herbicides (i), (ii) and (iii) as defîned herein or the 15 herbicide combinations in a plural ity o f portions (sequenti al app! ication), for example after pre-emergence applications, followed by post-emergence applications orafter early post-emergence applications, followed by applications at medium or late post-emergence.

Preferred is the simultaneous or nearly simultaneous application ofthe herbicides (i), (ii) and (iii) as defîned herein. In the latter context, a nearly simultaneous application of the herbicides (i), (ii) and (iii) as defîned 20 herein means that the herbicide (i) flufenacet, the herbicide (ii) flurtamone and the herbicide (iii) diflufenican are ail applied within 24 hours, preferably within 12 hours, more preferably within 6 hours, even more preferably within 3 hours.

In a particularly preferred embodiment, the herbicides (i), (ii) and (iii) as defîned herein are used together, I.e. at the same time. Thus, in a particularly preferred embodiment a composition comprising the herbicides (i), 25 (ii) and (iii) as defîned herein is used.

In a preferred embodiment, the herbicides (i), (ii) and (iii) used in accordance with the présent invention or a composition comprising the herbicides (i), (ii) and (iii) used in accordance with the présent invention are only used once per season. It was found that one application per season of the herbicides (i), (ii) and (iii) used in accordance with the présent invention or ofa composition comprising the herbicides (i), (ii) and (iii) used in 30 accordance with the présent invention is sufficient to achieve the effects described in the context of the présent invention, in particular regarding herbicidal activity (above aspects (a) and (b)) and/or the selectivity/ compatibility (above aspect (c)).

In a preferred embodiment, the herbicides (i), (ii) and (iii) used în accordance with the présent invention or a composition comprising the herbicides (i), (ii) and (iii) used in accordance with the présent invention is applied once, twice or three times per Gregorian calendar year, i.e. in one application, in two applications or in three applications per year according to the Gregorian calendar.

In a preferred embodiment, the herbicides (i), (il) and (iii) used in accordance with the présent invention or a composition comprising the herbicides (i), (ii) and (iii) used in accordance with the présent invention is applied one time per Gregorian calendar year, i.e. in one application per year according to the Gregorian calendar.

In a preferred embodiment, the herbicides (i), (ii) and (iii) used in accordance with the présent invention or a 10 composition comprising the herbicides (i), (ii) and (ΐΐΐ) used in accordance with the présent invention is applied one time in about 12 months, i.e. in one application în about 12 months.

The effects observed when using the herbicides (î), (ii) and (iii) as defined herein or a composition comprising the herbicides (i), (ii) and (iii) as defined herein allow a more potent herbicidal action, the control of hitherto uncontrolable species (activity gaps), an extended application period and/or a reduced number of 15 required individual applications and - as a resuit for the user - more advantageous weed control Systems both from an economical and ecologïcal point of view.

As already mentioned above, the herbicides (i), (H) and (iii) as defined herein or a composition comprising the herbicides (i), (ii) and (iii) as defined herein may be used in pre-emergence applications and/or in postemergence applications.

Preferaby, the herbicides (i), (ii) and (üï) as defined herein or a composition comprising the herbicides (i), (ii) and (iii) as defined herein are used in pre-emergence applications.

In the herbicide combinations used in accordance with the présent invention and or in the composition comprising a herbicide combination used În accordance with the présent invention the ratio by weight ofthe total amount of the herbicides (i) flufenacet, (ii) flurtamone and (iii) diflufenican preferably is in the 25 following ranges:

(i) flufenacet to (ii) flurtamone is in the range of from 10 :1 to 1 :5, and/or (i) flufenacet to (iii) diflufenican is in the range of from 10 : 1 to 1 :3, and/or (ii) flurtamone to (iii) diflufenican is in the range of from 6 : 1 to 1 : 3,

-8în each case based on the total amount of (i) flufenacet, (ii) flurtamone, (iii) diflufenican in said combination of herbicides.

More preferably, in the herbicide combinations used in accordance with the présent invention and or in the composition comprising a herbicide combination used in accordance with the présent invention the ratio by 5 weight of the total amount of the herbicides (i) flufenacet, (ii) flurtamone and (iii) diflufenican is in the following ranges:

(i) flufenacet to (ii) flurtamone îs in the range of from 8 :1 to I : 3, and/or (i) flufenacet to (iii) diflufenican is in the range of from 6 : 1 to I : 2, and/or (ii) flurtamone to (iii) diflufenican is in the range of from 4:1 to 1:2, in each case based on the total amount of (i) flufenacet, (ii) flurtamone, (iii) diflufenican in said combination of herbicides.

Even more preferably, in the herbicide combinations used in accordance with the présent invention and or in the composition comprising a herbicide combination used in accordance with the présent invention the ratio by weight of the total amount of the herbicides (i) flufenacet, (ii) flurtamone and (iii) diflufenican is in the following ranges:

(i) flufenacet to (ii) flurtamone is in the range of from 6 :1 to 2 :3, and/or (i) flufenacet to (iii) diflufenican is in the range of from 5 :1 to 2 :3, and/or (ii) flurtamone to (iii) diflufenican is in the range of from 4 :1 to 2 : 3, in each case based on the total amount of (î) flufenacet, (ii) flurtamone, (iii) diflufenican in said combination of herbicides.

Even more preferably, in the herbicide combinations used in accordance with the présent invention and or in the composition comprising a herbicide combination used in accordance with the présent invention the ratio by weight of the total amount of the herbicides (i) flufenacet, (ii) flurtamone and (iii) diflufenican is in the following ranges:

-9(i) flufcnacct to (ii) flurtamone is in the range of from 3:1 to 2 :3, and/or (î) flufenacet to (ni) dîflufenican is in the range of from 4 :1 to 2 :3, and/or · (îî) flurtamone to (iii) dîflufenican is in the range of from 3 :1 to 2 :3, in each case based on the total amount of (i) flufenacet, (ii) flurtamone, (iii) dîflufenican in said combination of herbicides.

Particularly preferably, in the herbicide combinations used in accordance with the présent invention and or in the composition comprising a herbicide combination used in accordance with the présent invention the ratio 10 by weight of the total amount of the herbicides (i) flufenacet, (ii) flurtamone and (iii) dîflufenican is în the following ranges:

(i) flufenacet to (ii) flurtamone is in the range of from 8 :1 to I : 3, and (i) flufenacet to (iii) dîflufenican is in the range of from 6 ; I to 1 :2, in each case based on thetotal amount of (i) flufenacet, (li) flurtamone, (iii) dîflufenican in said combination 15 of herbicides.

Particularly preferably, in the herbicide combinations used in accordance with the présent invention and or in the composition comprising a herbicide combination used in accordance with the présent invention the ratio by weight of the total amount of the herbicides (i) flufenacet, (ii) flurtamone and (iii) dîflufenican is in the following ranges:

(i) flufenacet to (ii) flurtamone is in the range of from 6 :1 to 2 :3, and (i) flufenacet to (iii) dîflufenican is in the range of from 5 :1 to 2 :3, în each case based on the total amount of(i) flufenacet, (ii) flurtamone, (iii) dîflufenican in said combination of herbicides.

Particularly preferably, in the herbicide combinations used in accordance with the présent invention and or in 25 the composition comprising a herbicide combination used in accordance with the prèsent invention the ratio by weight of the total amount of the herbicides (i) flufenacet, (ii) flurtamone and (iii) dîflufenican is in the following ranges:

(i) flufenacet to (ii) flurtamone is in the range of from 3:1 to 2 : 3, and

(i) flufenacet to (ni) diflufenîcan is in the range of from 4 : l to 2 :3, in each case based on the total amount of (i) flufenacet, (ii) flurtamone, (iii) diflufenîcan în said combination of herbicides.

Most preferably, in the herbicide combinations used în accordance with the présent invention and or în the 5 composition comprising a herbicide combination used in accordance with the présent invention the ratio by weight of the total amount of the herbicides (i) flufenacet, (ii) flurtamone and (iii) diflufenîcan is în the following ranges:

(i) flufenacet to (ii) flurtamone is in the range of from 3:1 to 2 :3, and (i) flufenacet to (iii) diflufenîcan is in the range of from 4 :1 to 2 :3, and (ii) flurtamone to (iii) diflufenîcan is in the range of from 3 :1 to 2: 3, în each case based on the total amount of (i) flufenacet, (ii) flurtamone, (iii) diflufenîcan in said combination of herbicides.

The preferred application rates [indicated as g aJJha, i.e. grams of active ingrédient per hectare] of the herbicides used in the context ofthe présent invention as defined herein are as follows:

In ail ofthe above-mentioned embodiments, preferably the total amount of(i) flufenacet, (ii) flurtamone, (iii) diflufenîcan does not exceed 2000 g a.îJha, preferably is equal to or less than 1500 g a.iJha.

In ail ofthe above-mentioned embodiments, preferably the total amount of(i) flufenacet, (ii) flurtamone, (iii) diflufenîcan is in the range of from 70 to 1440 g a.i Jha, more preferably is in the range of from 100 to 1120 g a.i Jha, and particularly preferably is in the range of from 150 to 840 g a.i Jha.

Flufenacet is preferably applied at a rate în the range of 30 to 600 g a.îJha, more preferably at a rate in the range of45 to 480 g a.iJha, particularly preferably at a rate în the range of 60 to 360 g aJJha.

Flurtamone is preferably applied at a rate in the range of 30 to 480 g aJJha, more preferably at a rate in the range of 45 to 320 g a.iJha, particularly preferably at a rate in the range of 60 to 240 g a.iJha.

Diflufenîcan is preferably applied at a rate in the range of 10 to 360 g a.i Jha, more preferably at a rate in the 25 range of 20 to 320 g a.iJha., particularly preferably at a rate in the range of 30 to 240 g aâJha.

The herbicides (i) flufenacet, (ii) flurtamone and (iii) diflufenîcan as defined herein more preferably are applied in the more preferred rates as defined above (as defined after the term “more preferably”), and particularly preferably are applied in the particularly preferred rates as defined above (as defined after the term “particularly preferably”).

-11Furthermore, the herbicides (i), (ii) and (iii) as defined herein can be used together with other agrochemically active compounds, for example from the group of the safeners, fongicides, insecticides, other herbicides and other plant growth regulators, or with formulation auxiliaries and additîves customary in crop protection. Additives are, for example, fertilizers and colorants. Préférence is in each case given to the ratios by weight mentioned above for flufenacet, flurtamone and diflufenican, and the application rates or the application rate ranges mentioned above for flufenacet, flurtamone and diflufenican.

The most important and most noxious weed species in cassava fields în Colombia reported are (African Crop Science Journal 1994, 519-530): Pteridium aquilinum L. Kuhn, Imperata cylindrica L. Beauv., Melinis ninutiflora Beauv., Sida acuta B urm F., Cyperus rotundus L., Commelina diffusa Burm F. sub-species diffuse 10 J.K. Morton, Agératum conyzoides L. and Portulaca oleraceae L., Cyperus rotundus L (purple nutsedge),

Rottboellia exaltata (Lour) Clayton (Raoul grass), Sorghum halepense L. Pers (Johnson grass)and Ipomoea sp. (moming glory).

In Nigeria, broad-leaved species were the most frequent weeds in ail areas, averaging 71-78% of ail the species recorded. Only 17-19% of the weed species présent were grasses and 4-7% were sedges. Five weed 15 species, namely, Agératum conyzoides L., Alternenthera sessilis L. R. Br. ex Roth, Mimosa invisa Mart, Digitaria horizontalis Willd, and Panicum maximum Jacq occurred in the entire area surveyed.

In south western Nigeria it was observed that annual weeds, especially broad-leaved weeds, were the most common în cassava, and the prévalent species were Euphorbia hlrta L. and Talinum triangulate Willd.

African Crop Science Journal 1994, Vol. 2. No.4, pp. 519-530 summarizes the ten most common weed 20 species in cassava fields în Umuahia, southem Nigeria:

Agératum conyzoide, Calopogonium mucunoides, Alternenthera sessilis, Boreiria ocymoides, Commelina erecta, Chromolacna odorata. Mimosa invisa, Commelina benghalansis, Tridax procumbens, Brachiaria delfexa, Platostoma qfricanum, Digitaria adscendens, Synedrella nodiflora, Panicum maximum, Cyperus rotundus, Cyperus esculentus.

Further relevant weed species occurring in cassava fields in Nigeria are (grasses, sedges and broadleaf weeds): Imperata cylindrica, Cynodon dactylon, Pennisetum polystachion, Afariscus altemifolius, Euphorbia heterophylla, Talinum triangulare.

A relevant parasitic weed species occurring in cassava fields (for example in Nigeria) is Cuscuta austraiis.

The combination of herbicides as defined herein or the composition comprising a combination of herbicides 30 as defined herein hâve an outstanding herbicidal activity against a broad spectrum ofeconomically important harmful monocotyledonous and dicotyledonous harmful plants in tuberous root crop plants, particularly in cassava.

In the context ofthe présent invention “controlling dénotés a signîficant réduction ofthe growth ofthe harmful piant(s) in comparison to the untreated harmful plants. Preferably, the growth ofthe harmful plant(s) îs essentially diminished (60-79%), more preferably the growth ofthe harmful plant(s) is largeiy or fully suppressed (80-100%), and in particular the growth ofthe harmful plant(s) is almost fully or fully suppresscd (90-100%).

Preferably, the présent invention relates to the use ofthe combination of herbicides as defined herein or the composition comprising a combination of herbicides as defined herein, wherein one, several or ail harmful plants are selected from the group of weed species consisting of Agératum spp., Calopogonium spp., Altemanthera spp., Boreiria spp., Commelina spp., Chromolaena spp., Mimosa spp., Tridax spp., Brachiaria 10 spp., Platostoma spp., Digitaria spp., Synedrella spp., Panicum spp., Cyperus spp., Imperata spp., Cynodon spp., Pennisetum spp., Mariscus spp., Euphorbîa spp., Talinum spp., Pteridium spp., Melinis spp., Sida spp., Portulaca spp., Rottboeliia spp., Sorghum spp., Ipomea spp., Dactyloctenium spp., Spigelia spp., Boerhaavia spp., Aspilia spp., Aneilima spp., Hyparrhenia spp., Andropogon spp., Paspalum spp., Rhynchelytrum spp., Eleusine spp., Setaria spp., Triumfetta spp., Stachytarpheta spp., Desmodium spp., Gomphrena spp., 15 Tephrosia spp., Acanthospermum spp., Hyptis spp., Cenchrus spp., Urena spp., Vemonia spp., Cleome spp., Crotalaria spp., Kyllinga spp., Corchonis spp., Ipomoea spp., Mitracarpus spp., Meianthera spp., Centrosema spp., Emilia spp, Croton spp, Phyllanthus spp. Passiflore spp, Axonopus spp, Oldenlandia spp, Schwenckia spp, Acalypha spp, Solenostemon spp, Celosia spp, Indigofera spp, Heterotis spp, Acmella spp, Leucaena spp, Boerhavia spp, Spermacoce spp, Oplismenus spp, and Fimbristylis spp..

In a preferred aspect, the présent invention relates to the use of the combination of herbicides as defined herein or the composition comprising a combination of herbicides as defined herein, wherein one, several or ail harmful plants are selected from the group of weed species consisting of Agératum spp, Calopogonium spp, Altemanthera spp, Boreiria spp, Commelina spp, Chromolaena spp. Mimosa spp, Tridax spp, Brachiaria spp, Platostoma spp, Digitaria spp, Synedrella spp, Panicum spp, Cyperus spp, Imperata spp, 25 Cynodon spp, Pennisetum spp, Mariscus spp, Euphorbîa spp, Talinum spp, Pteridium spp, Melinis spp. Sida spp, Portulaca spp, Rottboellia spp, Sorghum spp, Ipomea spp, Dactyloctenium spp, Spigelia spp, Boerhaavia spp, Aspilia spp, Aneilima spp, Hyparrhenia spp, Andropogon spp, Paspalum spp, Rhynchelytrum spp, Eleusine spp, Setaria spp, Triumfetta spp, Stachytarpheta spp, Desmodium spp, Gomphrena spp, Tephrosia spp, Acanthospermum spp, Hyptis spp, Cenchrus spp, Urena spp, Vemonia 30 spp, and Cleome spp..

Particularly, the combination of herbicides as defined herein or the composition comprising a combination of herbicides as defined herein are used to control one, several or ail harmful plants selected from the group of weed species consisting of Agératum spp, Calopogonium spp, Altemanthera spp, Boreiria spp, Commelina spp, Chromolaena spp. Mimosa spp, Tridax spp, Brachiaria spp, Platostoma spp, Digitaria spp, 35 Synedrella spp, Panicum spp, Cyperus spp, Imperata spp, Cynodon spp, Pennisetum spp, Mariscus spp,

Euphorbîa spp, Talinum spp, Pteridium spp, Melinis spp. Sida spp, Portulaca spp, RottboeUia spp.

-13Sorghum spp., Ipomea spp., Dactyloctenium spp., Spigelia spp., Boerhaavia spp., Desmodium spp.,

Gomphrena spp., Tephrosia spp., Acanthospermum spp., Hyptis spp., Cenchrus spp., Urena spp., Vemonia spp., and Cleome spp..

More particularly, the combination of herbicides as defined herein or the composition comprising a 5 combination of herbicides as defined herein are used to control one, several or ail harmful plants selected from the group of weed species consisting of Agératum spp., Calopogonium spp., Altemanthera spp., Boreiria spp., Commelina spp., Chromolaena spp., Mimosa spp., Tridax spp., Brachiaria spp., Platostoma spp., Digitaria spp., Synedrella spp., Panicum spp., Cyperus spp., Imperata spp., Cynodon spp., Pennisetum spp., Mariscus spp., Euphorbia spp., Talinum spp., Pteridium spp., Melinis spp., Sida spp., Portulaca spp., 10 Rottboellia spp., Sorghum spp., Ipomea spp., Dactyloctenium spp., Spigelia spp., and Boerhaavia spp..

Specîfîcally, examples may be mentioned of some représentatives of the monocotyledonous and dicotyledonous weed flora which can be controlled by the combinations according to the présent invention.

In a more spécifie aspect, the présent invention relates to the use ofthe combination of herbicides as defined herein or the composition comprising a combination of herbicides as defined herein, wherein one, several or 15 ail harmful plants are selected from the group consisting of Agératum conyzoides, Calopogonium mucunoides, Altemanthera sessilis, Boreiria ocymoides, Commelina erecta, Chromolaena odorata, Mimosa invisa, Commelina benghalensis, Tridaxprocumbens, Brachiaria delfexa, Platostoma africanum, Digitaria adscendens, Digitaria horizontalis, Synedrella nodiflora, Panicum maximum, Cyperus rotundus, Cyperus esculentus, Imperata cylindrica, Cynodon dactylon, Pennisetum polystachion, Pennisetum purpureum, 20 Pennisetum violaceum, Mariscus altemifolius, Euphorbia heterophylla, Euphorbia hirta, Talinum triangulare, Pteridium aquilinum, Melinis ninutiflora, Sida acuta. Sida rhombifolia, Commelina diffusa, Portulaca oleraceae, Rottboellia exaltata, Rottboellia cochinchinensis, Sorghum halepense, Ipomea triloba, Dactyloctenium aegyptium, Brachiara lata, Spigelia anthemia, Boerhaavia erecta, Aspilia africana, Aneilima beniniense, Hyparrhenia involucrate, Andropogon gayanus, Paspalum conjugatum, Paspalum 25 orbiculatum, Rhynchelytrum repens, Eleusine indica, Setaria barbota, Setaria megaphylla, Triumfetta cordifolia, Stachytarpheta cayennensis, Desmodium scorpiurus, Gomphrena celosioides, Tephrosia bracteolata, Acanthospermum hispidum, Hyptis suaveolens, Cenchrus biflorus, Urena lobata, Vemonia ambigua, Cleome viscosa, Cuscuta australis, Corchorus olitorius, Mïtracarpus villosus, Melanthera scandens, Centrosema pubescens, Emilia coccinea, Croton hirtus, Phyllanthus amarus, Corchorus 30 trilocularis, Passiflora foetida, Ipomoea involucrate, Axonopus compressus, Oldenlandia corymbosa,

Acalypha ciliata, Schwenckia americana, Solenostemon monostachyus, Celosia trigyna, Indigofera hirsute, Heterotis rotundifolia, Acmella brachyglossa, Leucaena leucocephala, Boerhavia diffusa, Spermacoce ocymoides, Oplismenus burmannii, Fimbristylis littoralis, Cyperus iris, and Kyllinga erecta.

In a more preferred aspect, the présent invention relates to the use ofthe combination ofherbicides as defined 35 herein or the composition comprising a combination ofherbicides as defined herein, wherein one, several or

all harmful plants are selected from the group consisting of Agératum conyzoides, Calopogonium mucunoides, Altemantherasessilis, Boreiria ocymoides, Commelina erecta, Chromolaena odorata, Mimosa invisa, Commelina benghalensis, Tridaxprocumbens, Brachiaria delfexa, Platostoma africanum, Digitaria adscendens, Digitaria horizontalis, Synedrella nodiflora, Panicum maximum, Cyperus rotundus, Cyperus 5 esculentus, Imperata cylindrica, Cynodon dactylon, Pennisetum polystachion, Pennisetum purpureum, Pennisetum violaceum, Mariscus altemifolius, Euphorbia heterophylla, Euphorbia hirta, Talinum triangulare, Pteridium aquilinum, Alelinis ninutiflora, Sida acuta. Sida rhombifolia, Commelina diffusa, Portulaca oleraceae, Rottboellia exaltata, Rottboellia cochinchinensis, Sorghum halepense, Ipomea triloba,

Dactyloctenium aegyptium, Brachiara lata, Spigelia anthemia, Boerhaavia erecta, Aspilia africana, 10 Aneilima beniniense, Hyparrhenia involucrate, Andropogon gayanus, Paspalum conjugatum, Paspalum orbiculatum, Rhynchelytrum repens, Eleusine indica, Setaria barbata, Setarla megaphylia, Triumfetta cordifolia, Stachytarpheta cayennensis, Desmodium scorpiurus, Gomphrena celosioides, Tephrosia bracteolata, Acanthospermum hispidum, Hyptis suaveolens, Cenchrus biflorus, Urena lobata, Vemonia ambigua, Cleome viscosa, and Cuscuta australis.

Particularly, the combination of herbicides as defined herein or the composition comprising a combination of herbicides as defined herein are used to control one, several or al! harmful plants selected from the group consisting ofAgératum conyzoides, Calopogonium mucunoides, Altemantherasessilis, Boreiriaocymoides, Commelina erecta, Chromolaena odorata, Mimosa invisa, Commelina benghalensis, Tridaxprocumbens, Brachiaria delfexa, Platostoma africanum, Digitaria adscendens, Digitaria horizontalis, Synedrella 20 nodiflora, Panicum maximum, Cyperus rotundus, Cyperus esculentus, Imperata cylindrica, Cynodon dactylon, Pennisetum polystachion, Mariscus altemifolius, Euphorbia heterophylla, Euphorbia hirta, Talinum triangulare, Pteridium aquilinum, Melin is ninutiflora, Sida acuta, Commelina diffusa, Portulaca oleraceae, Rottboellia exaltata, Sorghum halepense, Ipomea triloba, Dactyloctenium aegyptium, Brachiara lata, Spigelia anthemia, Boerhaavia erecta, Desmodium scorpiurus, Gomphrena celosioides, Tephrosia 25 bracteolata, Acanthospermum hispidum, Hyptis suaveolens, Cenchrus biflorus, Urena lobata, Vemonia ambigua, Cleome viscosa, and Cuscuta australis.

More particularly, the combination of herbicides as defined herein or the composition comprising a combination of herbicides as defined herein are used to control one, several or ail harmful plants selected from the group consisting of Agératum conyzoides, Calopogonium mucunoides, Altemanthera sessllis, 30 Boreiria ocymoides, Commelina erecta. Chromolaena odorata, Mimosa invisa, Commelina benghalensis, Tridax procumbens, Brachiaria delfexa, Platostoma africanum, Digitaria adscendens, Digitaria horizontalis, Synedrella nodiflora, Panicum maximum, Cyperus rotundus, Cyperus esculentus, Imperata cylindrica, Cynodon dactylon, Pennisetum polystachion, Mariscus altemifolius, Euphorbia heterophylla, Euphorbia hirta, Talinum triangulare, Pteridium aquilinum, Melinis ninutiflora, Sida acuta, Commelina diffusa, 3 5 Portulaca oleraceae, Rottboellia exaltata, Sorghum halepense, Ipomea triloba, Dactyloctenium aegyptium, Brachiara lata, Spigelia anthemia, Boerhaavia erecta and Cuscuta australis.

-15If a herbicide combination used according to the présent invention or if a composition comprising a herbicide combination used in the context ofthe présent invention is applied to the soil surface before germination, then the weed seedlings are either prevented completely from emerging, or the weeds grow until they hâve reached the cotylédon stage but then their growth stops, and, eventually, after three to four weeks hâve elapsed, they die completely.

I fa herbicide combination used according to the présent invention or if a composition comprising a herbicide combination used in the context of the présent invention is applied post-emergence to the green parts ofthe plants, growth likewise stops drastically a very short time after the treatment and the weed plants remain at the growth stage of the point of time of application, or they die completely after a certain time, so that in this 10 manner compétition by the weeds, which is harmful to the crop plants, is eliminated at a very early point in time and in a sustained manner.

The use of a herbicide combination used according to the présent invention and the use of a composition comprising a herbicide combination used in the context of the présent invention is characterized by a rapidly commencing and long-lasting herbicidal action.

In particular when the herbicide combinations as defined in the context of the présent invention and the compositions comprising a herbicide combination as defined in the context of the présent invention are employed application rates may be reduced, a broader spectrum of broad-leaved weeds and grass weeds maybe control led, the herbicidal action may take place more rapidly, the duration of action may be longer, the harmful plants may be controlled better while using only one, or few, applications, and the application period 20 which is possible to be extended.

The abovementîoned properties and advantages are of benefit for weed control practice to keep agricultural crops free from undesired competing plants and thus to safeguard and/or increase the yields from the qualitative and quantitative point of view. These novel combinations markedly exceed the technical state of the art with a view to the properties described.

* 25 While the herbicide combinations according to the présent invention hâve an outstanding herbicidal activity against monocotyledonous and dicotyledonous weeds, the crop plants are damaged only to a minor extent, if at ail.

Moreover, some ofthe compositions according to the présent invention hâve outstanding growth-regulatory properties on the crop plants. They engage in the plants’ metabolism in a regulatory manner and can thus be 30 employed for provoking directed effects on plant constituents and to facilitate harvesting such as for example by triggering desiccation and stunted growth. Moreover, they are also suitable for the general control and inhibition of undesired végétative growth without simultaneously destroying the plants. An inhibition of végétative growth is very important in a large number of monocotyledonous and dicotyledonous crops since yield fosses as a resuit oflodging can thus be reduced, or prevented completely.

-16Owing to their hcrbicidal and plant-growth-rcgulatory properties, the compositions according to the présent invention can be employed for controlling harmful plants in genetically modified crop plants or crop plants obtained by mutation/selection. These crop plants are distinguished as a nile by particular, advantageous properties, such as résistances to herbicîdal compositions or résistances to plant diseases or causative agents of plant diseases such as particular insects or microorganisms such as fungi, bacteria or viruses. Other particular properties relate, for example, to the harvested material with regard to quantity, quality, storability, composition and spécifie constituents. Thus, for example, transgenic plants are known whose starch content is increased or whose starch quality is altered, or those where the harvested material has a different fatty acid composition.

The tuberous root crop pl ants can also hâve been genetically modi fled or been obtained by mutation sélection.

For example, WO 97/44473 Al relates to transforming and producing cassava plant (protoplasts). WO 92/05259 Al descibes transgenic plants having modified carbohydrate content, inter alia cassava plants.

The présent invention also relates to a method of controlling undesired végétation (e.g. harmful plants) in tuberous root crop plants, which comprises applying a herbicide combination and compositions as defined in 15 the context of the présent invention or applying a composition comprising a herbicide combination as defined in the context of the présent invention, for example by the pre-emergence method, by the post-emergence method or by the pre-emergence and the post-emergence method, to the plants, for example harmful plants, parts of these plants, plant seeds or the area where the plants grow, for example the area under cultivation.

Thus, in a further aspect, the présent invention relates to a method for

- controlling undesired plant growth, and/or

- controlling harmful plants In tuberous root crop plants, and/or

- rcgulating plant growth in tuberous root crop plants, comprising the step of applying a combination of herbicides or a composition comprising a combination of herbicides as defined hereinabove onto the tuberous root crop plants, parts of tuberous root crop plants, seeds of tuberous root crop plants, the area where the tuberous root crop plants grow or the area where the tuberous root crop plants are intended to grow.

Preferably, in a method according to the présent invention as defined above, the tuberous root crop plants are 30 selected from the group consisting of sweet potato (Ipomoea batatas), cassava.(Manihot esculenta), and yam

-17(plant species in the genus Dioscorea), more preferably the tuberous root crop plant is cassava (Manihot esculenta).

In another aspect, the présent invention relates to a method according to the présent invention as defined above, wherein one, several, or ail harmful plants as mentioned above are controlled.

In another aspect, the présent invention relates to a method according to the présent invention as defined abov, wherein the tuberous root crop plants hâve been genetically modified, preferably said tuberous root crop plants art transgenic plants or obtained by mutatïon/selection.

As already mentioned above, the herbicide combinations as defined in the context ofthe présent invention can not only be used as mixed formulations, if appropriate together with further agrochemically active 10 compounds, additives and/or customary formulation auxiliaries, which are then applied in the customary manner as a dilution with water, but also as so-called tank mixes byjointly dîluting theseparately formulated, or partially separately formulated, components with water.

The herbicide combinations as defined in the context of the présent invention and the compositions comprising a herbicide combination as defined in the context of the présent invention can be formulated in 15 various ways, dependîng on the prevail ing bîological and/or chemical-physical parameters. The following are examples of general possibilîties for formulations: wettable powders (WP), water-soluble concentrâtes, emulsifiable concentrâtes (EC), aqueous solutions (SL), émulsions (EW) such as oil-in-water and water-in-oil émulsions, sprayable solutions or émulsions, suspension concentrâtes (SC), oil dispersions (OD), oil- or water-based dispersions, suspoemulsions, dusts (DP), seed-dressing materials, granules for soil application or 20 for broadeasting, or water-dispersible granules (WG), ULV formulations, microcapsules or waxes.

Preferably, the herbicide combinations used in accordance wi th the présent invention and or the composition comprising a herbicide combination used in accordance with the présent invention are used in the context of the présent invention in the form ofaqueous dispersions, preferably aqueous dispersions as disclosed in WO 2007/112834 A2, wherein more preferably addîtionally the ratio by weight of the total amount of the 25 herbicides (i) flufenacet, (ii) flurtamone and (iii) dîflufenican preferably is in the ranges defined above in the context ofthe preferred, more preferred or particularly preferred or most preferred embodiments.

The individual formulation types are known in principle and are described for example, in: WinnackerKüchler, Chemische Technologie, Volume 7, C. Hauser Verlag Munich, 4* Edition, 1986; van Valkenburg, Pesticide Formulations, Marcel Dekker N.Y., 1973; K. Martens, Spray Drying Handbook, 3 rd Ed. 1979, 30 G. Goodwin Ltd. London.

The formulation auxiliaries required, such as ïnert materials, surfactants, solvents and other additives are also known and are described, for example, in Watkins, Handbook of Insecticide Dust Diluents and Carriers, 2nd Ed., Darland Books, Caldwell N.J.; H.v. Olphen, Introduction to Clay Colloid Chemistry; 2nd Ed., J.

Wiley & Sons, N.Y. Marsdcn, Solvents Guide, 2nd Ed., Interscience, N.Y. 1950; McCutcheon's,

Détergents and Emulsi fiers Annual, MC Publ. Corp., Ridgewood N J.; S isley and Wood, Encycloped ia of Surface Active Agents, Chem. Publ. Co. Inc,, N.Y. 1964; SchOnfeldt, GrenzflSchenaktive Âthylenoxidaddukte [Surface-active ethylene oxide adducts], Wiss. Verlagsgesellschaft, Stuttgart 1976, 5 Winnacker-Küchler, Chemische Technologie, Volume 7, C. Hauser Verlag Munich, 4* Edition 1986.

Based on these formulations, combinations with other agrochemically active substances, such as other herbicides not belonging to constituents (i), (ii) and (iii) as defined in the context ofthe present invention, fongicides or insecticides, and with safeners, fertilizers and/or growth regulators, may also be prepared, for example in the form of a readymix or a tank mix.

Wettable powders (sprayable powders) are products which are uniformly dispersible in water and which, besides the active compound, also comprise Ionie or nonionic surfactants (wetters, dispersants), for example polyoxethylated alkylphenols, polyethoxylated fatty alcohols or fatty amines, alkanesulfonates or alkylbenzenesulfonates, sodium lignosulfonate, sodium 2,2’-dinaphthylmethane-6,6^,-disulfonate, sodium dibutylnaphthalenesulfonate or else sodium oleoylmethyltauride, in addition to a diluent or inert material.

Emulsi fiable concentrâtes are prepared by dissolving the active compound in an organic solvent, for example butanol, cyclohexanone, dïmethylformamide, xylene or else higher-boiling aromatics or hydrocarbons with addition of one or more ionic or nonionic surfactants (emulsifiers). Examples of emulsifiers which may be used are: calcium saits of alkylarylsulfonic acids, such as calcium dodecylbenzene sulfonate, or nonionic emulsifiers such as fatty acid polyglycol esters, aikylaryl polyglycol ethers, fatty alcohol polyglycol ethers, 20 propylene oxide/ethylene oxide condensâtes, alkyl polyethers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters or polyoxethylene sorbitol esters.

Dusts are obtained by grinding the active compound with finely divided solid materials, for example talc, natural clays such as kaolin, bentonite and pyrophyliite, or diatomaceous earth.

Suspension concentrâtes (SC) can be water- or oil-based. They can be prepared, for example, by wet grinding 25 by means ofcommercially available bead mi iis and, if appropriate, addition of forther surfactants as they hâve already been mentioned for example above in the case of the other formulation types.

Emulsions, for example oïl-in-water émulsions (EW), can be prepared for example by means of stirrers, coiloid mills and/or static mixers using aqueous organic solvents and, if appropriate, forther surfactants as hâve already been mentioned for example above in the case of the other formulation types.

0 Granules can be prepared either by spraying the active compound onto adsorptive, granulated inert material or by applying active compound concentrâtes to the surface of carriers such as sand, kaolinîtes or granulated inert material with the aid of binders, for example polyvînyl alcohol, sodium polyacryiate or else minerai oiis. Suitable active compounds may also be granulated in the manner conventionalîy used for the production of

fertilïzer granules, if desired in a mixture with fertilizers. As a rule, water-dïspersîble granules are prepared by customary processes such as spray drying, fluidized-bed granulation, disk granulation, mixing with highspeed mixers and extrusion without solid inert material. Regarding the production of disk granules, fluidizedbed granules, extrader granules and spray granules, see, for example, the methods in Spray-Drying

Handbook 3rd ed. 1979, G. Goodwin Ltd., London; J.E. Browning, Agglomération, Chemical and

Engineering 1967, page 147 et seq; Pertys Chemical Engineer’s Handbook, 5th Ed., McGraw-Hill, New

York 1973, pp. 8-57.

As regards further details on the formulation of crop protection products, see, for example, G.C. Klingmam,

Weed Control as a Science, John Wiley and Sons, Inc., New York, 1961, pages 81 -96 and J.D. Freyer, S.A.

Evans, Weed Control Handbook, 5th Ed., Blackwell Scientific Publications, Oxford, 1968,pages 101-103.

As a raie, the agrochemical formulations comprise 1 to 95% by weight, of active compounds, the following concentrations being customary, depending on the type of formulation:

The active compound concentration in wettable powders is, for example, approximately 10 to 95% by weight, the remainder to 100% by weight being composed of customary formulation constituents. In the case of 15 emulsifiable concentrâtes, the active compound concentration may amount to, for example, 5 to 80% by weighL Formulations in the form of dusts comprise, in most cases, 5 to 20% by weight of active compound, sprayable solutions approximately 0.2 to 25% by weight of active compound. In the case of granules such as dispersible granules, the active compound content dépends partly on whether the active compound is présent in liquid or solid form and on which granulation auxiliaries and fillers are being used. As a raie, the content 20 amounts to between 10 and 90% by weight in the case of the water-dïspersible granules.

In addition, the abovementioned active compound formulations may comprise, if appropriate, the conventional adhesives, wetters, dispersants, emulsifiers, preservatîves, antifreeze agents, solvents, fillers, colorants, carriers, antifoams, évaporation inhibitors, pH regulators or viscosity regulators.

The herbicidal action ofthe herbicide combinations according to the présent invention can be improved, for 25 example, by surfactants, preferably by wetters from the group ofthe fatty alcohol polyglycol ethers. The fatty alcohol polyglycol ethers préférable contain 10-18 carbon atoms in the fatty alcohol radical and 2-20 ethylene oxide units in the polyglycol ether moiety. The fatty alcohol polyglycol ethers can be nonionic or ionic, for example in the form of fatty alcohol polyglycol ethers sulfates, which can be used, for example, as alkali métal salts (e.g. sodium salts or potassium salts) or ammonium salts, but also as alkaline earth métal 30 salts such as magnésium salts, such as sodium Ci^Cu-fatty alcohol diglycol ether sulfate (Genapol® LRO,

Clariant); see, for example, EP-A-0476555, EP-A-0048436, EP-A-0336151 or US-A-4,400,196 and also Proc. EWRS Symp. Factors Affecting Herbicidal Activity and Selectivity, 227 - 232 (1988). Nonionic fatty alcohol polyglycol ethers are, for example, (Cio-Cu)-, preferably (Cio-Ci<)-fatty alkohol polyglycol ethers containîng 2 - 20, preferably 3-15, ethylene oxide units (e.g. isotridecyl alcohol polyglycol ether), for

example from the Genapol* sériés, such as Genapol* X-030, Genapol* X-060, Genapol* X-080 or Genapol* X-150 (ail from Clariant GmbH).

The présent invention furthermore embraces the combination of herbicides (i), (ii) and (iii) as defined above with the wetting agents mentioned above from the group of the fatty alcohol polyglycolethers which 5 preferably contain 10-18 carbon atoms in the fatty alcohol radical and 2-20 ethylcne oxide units în the polyglycol ether moiety and which can be présent in nonionic or ionic form (for example as fatty alcohol polyglycol ether sulfates). Préférence is given to Cu/Cu-fatty alcohol diglycol ether sulfate sodium (Genapol* LRO, Clariant); and isotridecy! alcohol polyglycol ether with 3-15 ethylcne oxide units, for example from the Genapol® X sériés, such as Genapol* X-030, Genapol® X-060, Genapol* X-080 or Genapol* X-150 (ail 10 from Clariant GmbH). It is furthermore known that fatty alcohol polyglycol ethers such as nonionic or ionic fatty alcohol polyglycol ethers (for example fatty alcohol polyglycol ether sulfates) are also suitable for use as pénétrants and activity enhancers for a number of other herbicides, inter alia also for herbicides from the group ofthe îmidazolinones (see, for examplc, EP-A-0502014).

Moreover, it is known that fatty alcohol polyglycol ethers such as nonionic or ionic fatty alcohol polyglycol 15 ethers ( for exam pie fatty al cohol polyglycol ether sul fates) are al so suitabl e as pénétrants and synergists for a number of other herbicides, inter alia also herbicides from the group of the îmidazolinones; (see, for example, EP-A-0502014).

The herbicidal effect of the herbicide combinations according to the présent invention can also be increased using vegetable oils. The term vegetable oils is to be understood as meanîng oils from oil-plant species, such 20 as soya oil, rapeseed oil, com oil, sunflower oil, cottonseed oil, linsecd oil, coconut oil, palm oil, safllower oil or castor oil, in particular rapeseed oil, and their transestérification products, for example alkyl esters, such as rapeseed oil methyl ester or rapeseed oil ethyl ester.

The vegetable oils are preferably esters of C10-C21-, preferably Cu-Cio-fatty acids. The Cio-Cîi-fatty acid esters are, for example, esters of unsaturated or saturated C10-C22-fatty acids, in particular those with an even 25 number of carbon atoms, for example erucic acid, lauric acid, palmitic acid and, in particular, Cii-fatty acids such as stearic acid, oleic acid, linoleic acid or lïnolenic acid.

Preferred Ci-Cïo-alkyl-Cio-Cu-fatty acid esters are the methyl, ethyl, propyl, butyl, 2-ethylhexyl and dodecyl esters. Preferred glycol- and glycerol-Cio-C^-fatty acid esters are the uni form or mixed glycol esters and glycerol esters of C10-C22-fatty acids, in particular those fatty acids which hâve an even number of carbon 30 atoms, for example erucic acid, lauric acid, palmitic acid and, in particular, Cu-fatty acids such as stearic acid, oleic acid, linolîc acid or lïnolenic acid.

The vegetable oils can be présent in the herbicidal compositions according to the présent invention for example in the form ofcommercially available oîl-containing formulation additives, în particularthose based on rapeseed oil such as Hasten* (Victorien Chemical Company, Australia, hereinbelow termed Hasten, main

-21constituent: rapeseed oil ethyl ester), Actirob*B (Novance, France, hereinbelow termed ActirobB, main constituent: rapeseed oil methyl ester), Rako-Binol* (Bayer AG, Germany, termed Rako-Binol hereinbelow, main constituent: rapeseed oil). Rend* (Stefes, Germany, termed Renol hereinbelow, vegetable oïl constituent: rapeseed oil methyl ester), or Stefes Mero® (Stefes, Germany, hereinbelow termed Mero, main constituent: rapeseed oîl methyl ester).

In a further embodiment, the présent invention embraces the combination of a herbicide combination as defined in the context ofthe présent invention with the vegetable oils mentîoned above. Thus, in a further embodiment, the présent invention embraces the use of compositions comprising a herbicide combination as defined in the context of the présent invention comprising the vegetable oils mentîoned above, such as 10 rapeseed oïl, preferably in the form of commercially available oil-containing formulation additives, in particular those based on rapeseed oil such as Hasten* (Victorian Chemical Company, Australia, hereinbelow termed Hasten, main constituent; rapeseed oil ethyl ester), Actirob’B (Novance, France, hereinbelow termed ActirobB, main constituent: rapeseed oil methyl ester), Rako-Binol* (Bayer AG, Germany, termed RakoBinol hereinbelow, main constituent: rapeseed oil), Renol® (Stefes, Germany, termed Renol hereinbelow, 15 vegetable oil constituent: rapeseed oil methyl ester), or Stefes Mero® (Stefes, Germany, hereinbelow termed Mero, main constituent: rapeseed oil methyl ester).

For use, the formulations, which are présent in commercially available form, are optionally diluted in the customary manner, for example using water in the case of wettable powders, emulsifiable concentrâtes, dispersions and watcr-dispersible granules. Préparations in the form of dusts, soil granules, granules for 20 broadeasting and sprayable solutions are usually not diluted further with other înert substances prior to use.

The active compounds can be applied to the plants, parts ofthe plants, seeds ofthe plants or the area under cultivation (soil of a field), preferably to the green plants and parts of the plants and, if appropriate, additionally to the soil ofthe field.

A composition comprising a herbicide combination used in the context of the présent invention has the 25 advantage of being easier to apply, and the quantifies ofthe components are advantageously already presented in the correct ratio to each other, Moreover, the adjuvants in the formulation can be matched optïmally to each other.

Examnles

1. Products used

The following commercially available herbicides and herbicide combinations were tested (ail products available from Bayer CropScience):

-22ProductPl contained 120 g/L of(i) flufenacet, 120 g/L of (ii) flurtamone and 120 g/Lof (iii) diflufenîcan, and was a suspension concentrate (SC formulation)

Product P2 contained 240 g/L of (i) flufenacet, 120 g/L of (ii) flurtamone and 60 g/Lof (iii) diflufenîcan, and was a suspension concentrate (SC formulation)

ProductP3contained240g/Lof(i)flufenacet, 120g/Lof(H)flurtamoneand90g/Lof(iii)diflufenîcan,and was a suspension concentrate (SC formulation)

2, Bioîogicaî Trials

Trials were conducted on cassava plants on a Research Farm in Abia State, Nigeria.

Table 1 shows the respective total weed control ratings for the different products tested ïn pre-emergence 8 10 weeks after treatment. In each case the total weed control takes into account the control of broad-leaved species, grasses and sedges. Total weed control was assessed based on the total weed dry matter in the respective plot in comparison to the total weed dry matter of a corresponding untreated control plot

Inter alia controlling of the following weeds was assessed: Acalypha ciliate, Celosia trigyna, Corchorus trilocularïs, Indigofera hirsute, Oldenlandia corymbosa, Euphorbia heterophylla, Phyllanthus amarus, 15 Mitracarpus villosus, Spigelia anthemia, Tridax procumbens, Talinum trianguiare, Triumfetta cordifolia,

Acmella brachyglossa, Passiflora foetida, Spermacoce ocymoides, Leucaena leucocephala, Centrosema pubescens, Brachiaria deflexa, Panicum maximum, Emilia coccinea, Croton hirtus, Jpomoea involucrate, Chromolaena odorata, Calopogonium mucunoides, Mimosa invisa, Aspilia africana, Cyperus rotundus, Mariscus altemifolius, Solenostemon monostachyus, Heterotis rotundifolia, Oplismenus burmannii, Setaria 20 barbota, and Paspalum scrobiculatum.

Table 2 shows the plant growth reguiating effects of the respective products P2 and P3 (herbicide compositions used in accordance with the présent invention) on cassava crop plants after harvest relative to hoe-weeded cassava crop plants (as reference). The plant growth reguiating effects were measured as the respective fresh root cassava yields, in each case as perecentage in comparison to the fresh root cassava yield 25 of hoe-weeded cassava crop plants as reference (defined as 100%).

Table 1: Ratings of total weed control in plots treated pre-emergence with the respective product 8 weeks after treatment

Product	Amount of Product applied	Total Weed Control in %
Pl	1.5 L/ha	80
P2	1,0 L/ha	83

P2	1.5 L/ha	94
P3	1.0 L/ha	83
P3	1.5 L/ha	88

The damages observed in each casse were chlorosis and bleaching to an agronomically acceptable extent, the treated cassava plants recovered after 2 to 3 weeks after treatment with the respective product PI to P3.

Table 2: Plant growth regulating efTects of producst P2 and P3, respectively, on tuberous root crop plants 5 indicated as fresh root yield

Product or treatment	Amount of Product appiied	Yieid of fresh root yield in comparison to hoe-weeding
P2	1.5 L/ha	159%
P3	1.0 L/ha	120%
P3	1.5 L/ha	155%
Hoe-weeding (Reference)		100%

Claims (11)

1. Use of a combination of herbicides orof a composition comprising a combination of herbicides

- for controlling harmful plants în tuberous root crop plants, and/or

- as plant growth regulators in tuberous root crop plants, wherein

- said combination of herbicides comprises or consists of (i) flufenacet, (ii) flurtamone and (iii) diflufenican; and

- the tuberous root crop plants are cassava (Manihot esculenla).

2. Use according to claim 1, wherein a composition is employed which additionally comprises one or more further components selected from the group consisting of formulation auxiliaries, additives customary in crop protection, and further agrochemically active compounds.

3. Use according to claim 1 or 2, wherein the ratio by weight in the combination of herbicides of (i) flufenacet to (ii) flurtamone is in the range of from 10 : 1 to 1 : 5, and/or (i) flufenacet to (iii) diflufenican is in the range of from 10 : 1 to 1 : 3, and/or (ii) flurtamone to (iii) diflufenican is in the range of from 6 : 1 to 1 : 3, în each case based on the total amount of (i) flufenacet, (ii) flurtamone, (iii) diflufenican in said combination of herbicides.

4. Use according to any one of claims l to 3, wherein the ratio by weight in the combination of herbicides of (i) flufenacet to (ii) flurtamone is în the range of from 8 :1 to 1 : 3, and/or (i) flufenacet to (iii) dîflufenican is in the range of from 6 :1 to 1 : 2, and/or (ii) flurtamone to (iii) dîflufenican is in the range of from 4 : 1 to 1 :2, în each case based on the total amount of (i) flufenacet, (ii) flurtamone, (iii) diflufcnican in said combination of herbicides.

5. Use according to any one of claims 1 to 4, wherein one, several or ail harmful plants are selected from the group of weed species consisting of Agératum spp., Calopogonium spp., Altemanthera spp., Bore i ri a spp., Commelina spp., Chromolaena spp., Mimosa spp., Tridax spp., Brachiaria spp., Platostoma spp., Digitaria spp., Synedrella spp., Panicum spp., Cyperus spp., Imperata spp., Cynodon spp., Pennisetum spp., Mariscus spp., Euphorbia spp., Talinum spp., Pteridium spp., Melin is spp., Sida spp., Portulaca spp., Rottboellia spp., Sorghum spp., lpomea spp., Dactyloctenium spp., Spigelia spp., Boerhaavia spp., Aspilia spp., Aneilima spp., Hyparrhenîa spp., Andropogon spp., Paspalum spp., Rhynchelytrum spp., Eleusine spp., Setaria spp., Triumfetta spp., Stachytarpheta spp., Desmodium spp., Gomphrena spp., Tephrosia spp., Acanthospermum spp., Hyptis spp., Cenchrus spp., Urena spp., Vemonia spp., Cleome spp., Crotalarîa spp., Kyllinga spp., Corchorus spp., Ipomoea spp., Mitracarpus spp., Melanthera spp., Centrosema spp., Emilia spp., Croton spp., Phyllanthus spp., Passiflora spp., Axonopus spp., Oldenlandia spp., Schwenckia spp., Acalypha spp., Solenostemon spp., Celosïa spp., Indigofera spp., Heterotis spp., Acmella spp., Leucaena spp., Boerhavia spp., Spermacoce spp., Oplismenus spp., and Fimbristylis spp..

6. Use according to any one of claims 1 to 5, wherein one, several or ail harmful plants are selected from the group of weed species consistingof Agératum spp., Calopogonium spp., Altemanthera spp., Boreîria spp., Commelina spp., Chromolaena spp., Mimosa spp., Tridax spp., Brachiaria spp., Platostoma spp., Digitaria spp., Synedrella spp., Panicum spp., Cyperus spp., Imperata spp., Cynodon spp., Pennisetum spp., Mariscus spp., Euphorbia spp., Talinum spp., Pteridium spp., Mclinisspp., Sida spp., Portulaca spp., Rottboellia spp., Sorghum spp., lpomea spp., Dactyloctenium spp., Spigelia spp., Boerhaavia spp., Aspilia spp., Aneilima spp., Hyparrhenîa spp., Andropogon spp., Paspalum spp., Rhynchelytrum spp., Eleusine spp., Setaria spp., Triumfetta spp.,

-26Stachytarpheta spp., Desmodium spp., Gomphrena spp., Tephrosia spp., Acanthospcrmum spp.,

Hyptis spp., Cenchrus spp., Urena spp., Vemonia spp., and Cleome spp..

7. Use according to any one of claims ! to 6, wherein one, several or ail harmful plants are selected from the group consisting of Agératum conyzoides, Calopogonium mucunoides, Âltemanthera sessilis, Boreiria ocymoides, Commelina erecta, Chromolaena odorata. Mimosa invisa, Commelina benghalensis, Tridaxprocumbens, Brachiaria delfexa, Platostoma africanum, Digitaria adscendens, Digitaria horizontalis, Synedrella nodiflora, Panicum maximum, Cyperus rotundus, Cyperus esculentus, Impcrata cylindrica, Cynodon dactylon, Pennisetum polystachion, Pennisetum purpureum, Pennisetum violaceum, Mariscus altemifolius, Euphorbia heterophylla, Euphorbia hirta, Talinum triangulare, Pteridium aquilinum, Melinis ninutiflora, Sida acuta, Sida rhombifolia, Commelina diffusa, Portulaca oleraceae, Rottboellia exaltata, Rottboellia cochinchinensis, Sorghum halepense, Ipomca iriloba, Dactyloctenium aegyptium, Brachiara lata, Spigelia anthemia, Boerhaavia erecta, Aspilia africana, Aneilima beniniense, Hyparrhenia Involucrate, Andropogon gayanus, Paspalum conjugatum, Paspalum orbiculatum. Rhynchelytrum repens, Eleusine indica, Setaria barbata, Setaria megaphylla, Triumfetta cordifolia, Stachytarpheta cayennensis, Desmodium scorpiurus, Gomphrena celosioides, Tephrosia bracteolata, Acanthospcrmum hispidum, Hyptis suaveolens, Cenchrus biflorus, Urena lobata, Vemonia ambîgua, Cleome viscosa, Cuscuta australis, Corchorus olitorius, Mitracarpus villosus, Melanthera scandens, Centrosema pubcscens, Emilia coccinea, Croton hirtus, Phyllanthus amarus, Corchorus trilocularis, Passiflora foetida, Ipomoea involucrate, Axonopus compressas, Oldenlandia corymbosa, Acalypha ciliata, Schwenckia americana, Solenostemon monostachyus, Celosia trigyna, Indigofera hirsute, Heterotis rotundifolia, Acmella brachyglossa, Leucaena leucocephala, Boerhavia diffusa, Spermacoce ocymoides, Oplismenus burmannii, Fimbristylis littoralis, Cyperus iris, and Kyllinga erecta.

8. Use according to any one of claims 1 to 7, wherein one, several or al! harmful plants are selected from the group consisting of Agératum conyzoides, Calopogonium mucunoides, Altemanthera sessilis, Boreiria ocymoides, Commelina erecta, Chromolaena odorata, Mimosa invisa, Commelina benghalensis, Tridax procumbens, Brachiaria delfexa, Platostoma africanum, Digitaria adscendens, Digitaria horizontalis, Synedrella nodiflora, Panicum maximum, Cyperus rotundus, Cyperus esculentus, Imperata cylindrica, Cynodon dactylon, Pennisetum polystachion, Pennisetum purpureum, Pennisetum violaceum, Mariscus altemifolius, Euphorbia heterophylla, Euphorbia hirta, Talinum triangulare, Pteridium aquilinum, Melinis ninutiflora, Sida acuta, Sida rhombifolia, Commelina diffusa, Portulaca oleraceae, Rottboellia exaltata, Rottboellia cochinchinensis, Sorghum halepense, Ipomea triloba, Dactyloctenium aegyptium, Brachiara lata, Spigelia anthemia, Boerhaavia erecta, Aspilia africana, Aneilima beniniense, Hyparrhenia involucrate, Andropogon gayanus, Paspalum conjugatum, Paspalum orbiculatum, Rhynchelytrum repens, Eleusine indica, Setaria barbota, Setaria megaphylla, Triumfetta cordifolia, Stachytarpheta cayennensis, Desmodium scorpiurus, Gomphrena celosioides, Tephrosia bracteolata, Acanthospermum hispidum, Hyptis suaveolens, Cenchrus biflorus, Urena lobata, Vernonia ambigua, Cleome viscosa, and Cuscuta australis.

9. Method for

- controlling undesired plant growth, and/or

- controlling harmful plants in tuberous root crop plants, and/or

- régulâting plant growth in tuberous root crop plants, comprising the step of applying a combination of herbicides or a composition comprising a combination of herbicides as defined in any one of claims 1 to 4 onto the tuberous root crop plants, parts of tuberous root crop plants, seeds of tuberous root crop plants, the area where the tuberous root crop plants grow or the area where the tuberous root crop plants are intended to grow, wherein the tuberous root crop plants are cassava (Manihot esculenta).

10. The method according to claim 9, wherein one, several, or ail harmful plants as defined in any one of claims 5 to 8 are controlled.

11. The method according to claim 9 or claim 10, wherein the tuberous root crop plants hâve been genetically modified, preferably said tuberous root crop plants are transgenîc plants or obtained by mutât ion/selection.