METHOD FOR GROWING PLANTS

Abstract

The present invention relates to a method for growing plants, wherein said method comprises supplying plant defence inducers (PDI) in particular for the purpose of protecting plants against pests without negatively affecting their growth and development.

Description

FIELD OF THE INVENTION

The present invention relates to a method for growing plants, wherein said method comprises supplying plant defence inducers (PDI) in particular for the purpose of protecting plants against pests without negatively affecting their growth and development.

BACKGROUND OF THE INVENTION

Raising agricultural yields on existing farmlands has become essential for both feeding the continuously growing world population and for protecting natural habitats. In this perspective, controlling crop diseases, pests, and weeds has proven to be an important lever for action. For this purpose, the industry mainly relies on the use of synthetic pesticides as plant protection products (PPP). However, the use of such products is under debate, as their environmental impact is being questioned. Reported adverse effects of conventional pesticides in agriculture impact human and animal health, the environment, beneficial organisms, pollinators, decomposers, and natural enemies. Accordingly, the development of sustainable PPP to manage pests and weeds has become essential.

One promising technology to protect plants against pests and weeds in a sustainable way is the use of plant defence inducers (PDI). Commercial PDI such as acibenzolar are commercially available to growers, while others are actively studied by the research community. These include bet-aminobutyric acid (BABA), jasmonic acid (JA) and salicylic acid (SA). The main drawback hindering the commercial development of these compounds is their negative impact on the growth and development of plants, likely due to the fitness cost incurred by resistance induction. For BABA, this effect was demonstrated by Silué D. and co-workers (Induction of resistance to downy mildew (Peronospora parasitica) in cauliflower by DL-beta-amino-n-butanoic acid (BABA). Plant Pathology (2002), 51, 97-102), who reported a 14.7% reduction in growth of cauliflower seedlings treaded with 20 mM BABA, whereas higher concentrations caused even stronger phytotoxic side effects in most seedlings.

Until now, most efforts to cope with these drawbacks and allow safe use of PDI at a commercial scale have focussed on reducing the rates of application of these products, limiting the field uses, combining PDI with conventional pesticides or screening for synergistic effects with safening compounds.

Luna E. et al. (Optimizing chemically induced resistance in tomato against Botrytis cinerea. Plant Disease (2016), 100, 704-710) describe the effect of PDI on growth repression on Tomato plants at different rates. The authors describe the use of relatively low concentrations of PDI as means to reduce the negative impact on plant growth. However, root growth repression was observed when treating seedlings with as low as 0.5 mM BABA and 0.25 mM JA.

Controlling damages caused by the phytotoxic side effects of PDI is very complex due to the multiplicity of the causes of damage brought about by the PDI.

In view of the above, there is thus a strong need for methods for growing plants for the purpose of protecting the plants against pests without negatively affecting their growth and development, namely methods for reducing or avoiding the phytotoxic side effects of plant defence inducers.

SUMMARY OF THE INVENTION

The inventors have now surprisingly found that it is possible to provide an improved method fulfilling the above-mentioned needs.

Thus, there is now provided a method for growing plants, wherein said method comprises at least the steps of

• • (i) supplying at least one plant defence inducer [inducer (P), herein after] or a salt thereof to at least part of a plant, or a seed, wherein said inducer (P) has phytotoxic side effects and has a general formula (I_P):

• • • wherein
      • each of X is independently selected from O, S, or NR₄, wherein R₄, equal to or different from each other and at each occurrence, is independently selected from hydrogen, C_1-36 alkyl, C_2-36 alkenyl, or OR₅, and wherein each of R₅, equal to or different from each other and at each occurrence, is C_1-4 alkyl;
      • each of R is independently selected from hydrogen, C_1-36 alkyl, or C_2-36 alkenyl, and wherein said C_1-36 alkyl, or C_2-36 alkenyl are optionally substituted with one or more substituents selected from halo, C_1-4 alkyl, or CF₃;
      • each of R₁ is C_1-6 alkyl;
      • each of R₂ is independently selected from hydrogen, or C_1-6 alkyl; and
      • each of R₃ is independently selected from hydrogen, C_1-10 alkyl, C_2-10 alkenyl, COR₇, or C(O)OR₇, and wherein each of R₇, equal to or different from each other and at each occurrence, is independently selected from C_1-4 alkyl, C_2-4 alkenyl, or C_2-4 alkynyl, and wherein said C_1-4 alkyl, C_2-4 alkenyl, or C_2-4 alkynyl are optionally substituted with one or more substituents independently selected from halo, or CF₃;
      • and
  • (ii) reducing or avoiding said phytotoxic side effects by supplying additionally to the at least part of the plant or the seed at least one compound [compound (A), herein after] selected from
    • a) salts, chelates, oxides or hydroxides of iron(II) or iron(III); or
    • b) vitamin C or derivatives thereof, vitamin E or derivatives thereof or carotenoids; or
    • c) flavonoids [flavonoid (F), herein after] having a general formula (II) or salts thereof:

• • • wherein the dash bond represents an optional double bound and wherein
    • each of Y is independently selected from O, or OH;
    • each of Z is independently selected from hydrogen, or OR₇, and
    • wherein each of R₇, equal to or different from each other and at each occurrence, is independently selected from hydrogen, or C_1-4 alkyl;
    • each of R₈, R₉, and R₁₀, equal to or different from each other and at each occurrence, is independently selected from hydrogen, or C_1-4 alkyl; and
    • each of j is an integer in the range from 1, 2, 3, 4, or 5.

The present invention further provides the use of the compound (A), as defined above, for reducing or avoiding the phytotoxic side effects of at least one inducer (P), as defined above, which is supplied to at least part of a plant or a seed.

DETAILED DESCRIPTION OF THE INVENTION

Within the context of the present invention, the term “comprising” should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It needs to be interpreted as specifying the presence of the stated features, integers, steps, or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a composition comprising components A and B” should not be limited to compositions consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the composition are A and B. Accordingly, the terms “comprising” and “including” encompass the more restrictive terms “consisting essentially of” and “consisting of”.

As used herein, the terms “optional” or “optionally” means that a subsequently described event or circumstance can or cannot occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

The inventors have surprisingly found that by additionally supplying a compound [compound (A), herein after], as defined above, to plants to which at least one plant defence inducer of Formula (I_P) [inducer (P), herein after] or a salt thereof, as defined above, is also supplied, the phytotoxic side effects of said inducer (P) or salt thereof could be reduced or avoided.

It is understood that, within the context of the method according to the present invention, the inducer (P) is supplied to at least part of a plant or a seed which grows or will be grown. As a general rule, such growth occurs on a substrate, such as soil (for example in a pot, in borders or in the field) or artificial media. The terms “grows”, “grown” and “growing” as used herein include all physiological processes leading to an increase in cell size and/or cell number as well as those leading to cellular differentiation.

Within the context of the present invention, the expression “at least one plant defence inducer of Formula (I_P) [inducer (P), herein after] or a salt thereof” is intended to denote one or more than one inducer (P). Mixtures of inducers (P) of Formula (I_P) can also be used for the purpose of the invention.

In the rest of the text, the expression “at least one inducer (P)” is understood, for the purposes of the present invention, both in the plural and the singular, that is to say the method for growing plants of the present invention may comprise supplying one or more than one inducer (P).

As used herein the term “alkyl”, “alkenyl” and “alkynyl” have the broadest meaning generally understood in the art and may include a moiety which is linear or branched, or a combination thereof.

The term “alkyl”—alone or in combination means a straight or branched alkane-derived radical, for example, C_F-G alkyl defines a straight or branched alkyl radical having from F to G carbon atoms, e.g. C_1-4 alkyl defines a straight or branched alkyl radical having from 1 to 4 carbon atoms such as for example methyl, ethyl, 1-propyl, 2-propyl (isopropyl), 1-butyl, 2-butyl, 2-methyl-2-propyl (tert-butyl), 2-methyl-1-propyl (isobutyl).

The term “alkenyl”, alone or in combination, means a straight or branched hydrocarbon containing at least one carbon to carbon double bond, for example C_H-I alkenyl defines a straight or branched alkenyl radical having from H to I carbon atoms, e.g. C_2-4 alkenyl defines a straight or branched alkenyl radical having from 2 to 4 carbon atoms. Examples of C_2-4 alkenyl groups include ethynyl, propenyl, isopropenyl, butenyl, and the like.

The term “alkynyl” alone or in combination means a straight, or branched hydrocarbon containing at least one carbon to carbon triple bond, for example CJ-K alkynyl defines a straight or branched alkynyl radical having from J to K carbon atoms, e.g. C_2-4 alkynyl defines a straight or branched alkynyl radical having from 2 to 4 carbon atoms. Examples of C_2-4 alkynyl groups include ethynyl, propynyl, butynyl and the like.

According to the method of the present invention, the inducer (P) is according to general Formula (I_P)

wherein

• • each of X is independently selected from O, S, or NR₄, wherein each of R₄, equal to or different from each other and at each occurrence, is independently selected from hydrogen, C_1-36 alkyl, C_2-36 alkenyl, or OR₅, and wherein each of R₅, equal to or different from each other and at each occurrence, is C_1-4 alkyl;
  • each of R is independently selected from hydrogen, C_1-36 alkyl, or C_2-36 alkenyl, and wherein said C_1-36 alkyl, or C_2-36 alkenyl are optionally substituted with one or more substituents selected from halo, C_1-4 alkyl, or CF₃;
  • each of R₁ is C_1-6 alkyl;
  • each of R₂ is independently selected from hydrogen, or C_1-6 alkyl; and
  • each of R₃ is independently selected from hydrogen, C_1-10 alkyl, C_2-10 alkenyl, CORE, or C(O)OR₆, and wherein each of R₆, equal to or different from each other and at each occurrence, is independently selected from C_1-4 alkyl, C_2-4 alkenyl, or C_2-4 alkynyl, and wherein said C_1-4 alkyl, C_2-4 alkenyl, or C_2-4 alkynyl are optionally substituted with one or more substituents independently selected from halo, or CF₃.

In a preferred embodiment of the method according to the present invention, each of X is independently selected from O, or NR₄, wherein each of R₄, equal to or different from each other and at each occurrence, is independently selected from hydrogen, C_1-24 alkyl, C_2-24 alkenyl, or OR₅, and wherein each of R₅, equal to or different from each other and at each occurrence, is C_1-4 alkyl, or each of X is independently selected from O, or NR₄, wherein each of R₄, equal to or different from each other and at each occurrence, is independently selected from hydrogen, C_1-12 alkyl, C_2-12 alkenyl, or OR₅, and wherein each of R₅, equal to or different from each other and at each occurrence, is methyl, or each of X is independently selected from O, or NR₄, wherein each of R₄, equal to or different from each other and at each occurrence, is independently selected from hydrogen, C_1-4 alkyl, or C_2-4 alkenyl, or each of X is independently selected from O, or NR₄, wherein each of R₄, equal to or different from each other and at each occurrence, is independently selected from hydrogen, methyl, ethyl, propyl, or isopropyl, or R₄ is hydrogen. Desirably, each of X is O.

In a preferred embodiment of the method according to the present invention, each of R is independently selected from hydrogen, C_1-24 alkyl, or C_2-24 alkenyl, and wherein said C_1-24 alkyl, or C_2-24 alkenyl are optionally substituted with one or more substituents selected from halo, C_1-4 alkyl, or CF₃, or each of R is independently selected from hydrogen, C_1-18 alkyl, or C_2-18 alkenyl, and wherein said C_1-18 alkyl, or C_2-18 alkenyl are optionally substituted with one or more substituents selected from methyl, ethyl, propyl, or isopropyl, or each of R is independently selected from hydrogen, C_1-12 alkyl, or C_2-12 alkenyl, and wherein said C_1-12 alkyl, or C_2-12 alkenyl are optionally substituted with one or more substituents selected from methyl, or ethyl, or each of R is independently selected from hydrogen, C_1-6 alkyl, or C_2-6 alkenyl, and wherein said C_1-6 alkyl, or C_2-6 alkenyl are optionally substituted with one or more substituents selected from methyl, or ethyl, or each of R is independently selected from hydrogen, C_1-4 alkyl, or C_2-4 alkenyl, or each of R is independently selected from hydrogen, methyl, ethyl, propyl, isopropyl. Desirably, each of R is independently selected from hydrogen, or methyl, more desirably, each of R is hydrogen.

In a preferred embodiment of the method according to the present invention, each of R₁ is C_1-5 alkyl, or each of R₁ is independently selected from methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, or isobutyl, or each of R₁ is independently selected from methyl, ethyl, propyl, or isopropyl. Desirably, each of R₁ is independently selected from methyl, or ethyl, more desirably, each of R₁ is methyl.

In a preferred embodiment of the method according to the present invention, each of R₂ is independently selected from hydrogen, or C_1-5 alkyl, or each of R₂ is independently selected from hydrogen, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, or isobutyl, or each of R₂ is independently selected from hydrogen, methyl, or ethyl. Desirably, each of R₂ is independently selected from hydrogen, or methyl, more desirably, each of R₂ is hydrogen.

In a preferred embodiment of the method according to the present invention, each of R₃ is independently selected from hydrogen, C_1-8 alkyl, C_2-8 alkenyl, COR₆, or C(O)OR₆, and wherein each of R₆, equal to or different from each other and at each occurrence, is independently selected from C_1-4 alkyl, or C_2-4 alkenyl, and wherein said C_1-4 alkyl, or C_2-4 alkenyl, are optionally substituted with one or more substituents independently selected from halo, or CF₃, or each of R₃ is independently selected from hydrogen, C_1-6 alkyl, C_2-6 alkenyl, COR₆, or C(O)OR₆, and wherein each of R₆, equal to or different from each other and at each occurrence, is independently selected from methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, or isobutyl, or each of R₃ is independently selected from hydrogen, C_1-4 alkyl, or COR₇, and wherein each of R₆, equal to or different from each other and at each occurrence, is independently selected from methyl, ethyl, propyl, isopropyl, or each of R₃ is independently selected from hydrogen, methyl, ethyl, propyl, or isopropyl. Desirably, each of R₃ is independently selected from hydrogen, or methyl, more desirably, each of R₃ is hydrogen.

According to a preferred embodiment of the method of the present invention, the at least one inducer (P) is according to general Formula (I_Pa)

wherein R₁, R₂, R₃ and X have the same meaning as defined above.

According to a preferred embodiment of the present invention, the at least one inducer (P) according to general Formula (I_P) is a compound chosen among those of Formula (I_P1) [inducer (P₁), herein after], Formula (I_P2) [inducer (P₂), herein after], and Formula (I_P3) [inducer (P₃), herein after]:

wherein

• • each of R′ is independently selected from hydrogen, C_1-12 alkyl, or C_2-12 alkenyl, and wherein said C_1-12 alkyl, or C_2-12 alkenyl are optionally substituted with one or more substituents selected from methyl, or ethyl;
  • each of R″ is independently selected from hydrogen, C_1-12 alkyl, or C_2-12 alkenyl, and wherein said C_1-12 alkyl, or C_2-12 alkenyl are optionally substituted with one or more substituents selected from methyl, or ethyl;
  • each of R′″ is independently selected from hydrogen, C_1-12 alkyl, or C_2-12 alkenyl, and wherein said C_1-12 alkyl, or C_2-12 alkenyl are optionally substituted with one or more substituents selected from methyl, or ethyl;
  • each of R₃′ is independently selected from hydrogen, C_1-4 alkyl, C_2-4 alkenyl, or OR₄′, and wherein each of R₄′, equal to or different from each other and at each occurrence, is methyl;
  • each of R₁′ is independently selected from methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, or isobutyl; and
  • each of R₂′ is independently selected from hydrogen, C_1-4 alkyl, C_2-4 alkenyl, COR₅′, or C(O)OR₅′, and wherein each of R₅′, is independently selected from C_1-4 alkyl, or C_2-4 alkenyl, and wherein said C_1-4 alkyl, or C_2-4 alkenyl are optionally substituted with one or more substituents independently selected from halo.

In a preferred embodiment of the method according to the present invention, each of R′ is independently selected from hydrogen, C_1-6 alkyl, or C_2-6 alkenyl, and wherein said C_1-6 alkyl, or C_2-6 alkenyl are optionally substituted with one or more substituents selected from methyl, or ethyl, or each of R′ is independently selected from hydrogen, C_1-4 alkyl, or C_2-4 alkenyl, or each of R′ is independently selected from hydrogen, methyl, ethyl, propyl, or isopropyl. Desirably, each of R′ is independently selected from hydrogen, or methyl, more desirably, each of R′ is hydrogen.

In a preferred embodiment of the method according to the present invention, each of R″ is independently selected from hydrogen, C_1-6 alkyl, or C_2-6 alkenyl, and wherein said C_1-6 alkyl, or C_2-6 alkenyl are optionally substituted with one or more substituents selected from methyl, or ethyl, or each of R″ is independently selected from hydrogen, C_1-4 alkyl, or C_2-4 alkenyl, or each of R″ is independently selected from hydrogen, methyl, ethyl, propyl, or isopropyl. Desirably, each of R″ is independently selected from hydrogen, or methyl, more desirably, each of R″ is hydrogen.

In a preferred embodiment of the method according to the present invention, each of R′″ is independently selected from hydrogen, C_1-6 alkyl, or C_2-6 alkenyl, and wherein said C_1-6 alkyl, or C_2-6 alkenyl are optionally substituted with one or more substituents selected from methyl, or ethyl, or each of R′″ is independently selected from hydrogen, C_1-4 alkyl, or C_2-4 alkenyl, or each of R′″ is independently selected from hydrogen, methyl, ethyl, propyl, or isopropyl. Desirably, each of R′″ is independently selected from hydrogen, or methyl, more desirably, each of R′″ is hydrogen.

In a preferred embodiment of the method according to the present invention, each of R₃′ is independently selected from hydrogen, methyl, ethyl, propyl, or isopropyl, or each of R₃′ is independently selected from hydrogen, methyl, or ethyl. Desirably, each of R₃′ is independently selected from hydrogen, or methyl, more desirably, each of R₃′ is hydrogen.

In a preferred embodiment of the method according to the present invention, each of R₁′ is independently selected from methyl, ethyl, propyl, or isopropyl, or each of R₁′ is independently selected from methyl, or ethyl. Desirably, each of R₁′ is methyl.

In a preferred embodiment of the method according to the present invention, each of R₂′ is independently selected from hydrogen, methyl, ethyl, propyl, isopropyl, or COR₅′, and wherein each of R₅′, is independently selected from hydrogen, methyl, ethyl, propyl, or isopropyl, or each of R₂′ is independently selected from hydrogen, methyl, or ethyl, or each of R₂′ is independently selected from hydrogen, or methyl. Desirably, each of R₂′ is hydrogen.

According to a preferred embodiment of the present invention, the at least one inducer (P) according to general Formula (I_Pa) is a compound chosen among those of Formula (I_P1a) [inducer (P_1a), herein after], Formula (I_P2a) [inducer (P_2a), herein after], and Formula (I_P3a) [inducer (P_3a), herein after]:

wherein R₁′ and R₂′ have the same meaning as defined above.

According to a more preferred embodiment of the present invention, the at least one inducer (P) according to general Formula (I_P) is the inducer (P₁) according to Formula (I_P1) herein below:

wherein

• • each of R′ is independently selected from hydrogen, C_1-12 alkyl, or C_2-12 alkenyl, and wherein said C_1-12 alkyl, or C_2-12 alkenyl are optionally substituted with one or more substituents selected from methyl, or ethyl, or each of R′ is independently selected from hydrogen, C_1-6 alkyl, or C_2-6 alkenyl, and wherein said C_1-6 alkyl, or C_2-6 alkenyl are optionally substituted with one or more substituents selected from methyl, or ethyl, or each of R′ is independently selected from hydrogen, C_1-4 alkyl, or C_2-4 alkenyl, or each of R′ is independently selected from hydrogen, methyl, ethyl, propyl, or isopropyl, or, desirably, each of R′ is independently selected from hydrogen, or methyl, or, more desirably, each of R′ is hydrogen;
  • each of R₁′ is independently selected from methyl, or ethyl, or, desirably, each of R₁′ is methyl; and
  • each of R₂′ is independently selected from hydrogen, methyl, or ethyl, or each of R₂′ is independently selected from hydrogen, or methyl, or, desirably, each of R₂′ is hydrogen.

Preferred inducers (P) according to general Formula (I_Pa), for use in the method according to the present invention, is the inducer (P_1a) according to Formula (I_P1a) herein below:

wherein R₁′ and R₂′ have the same meaning as defined above for Formula (I_P1), Formula (I_P2), and Formula (I_P3), respectively.

A preferred inducer (P) according to Formula (I_P1a) is the one according to Formula (I_P1a-a1) herein below:

It is further understood that the salt of the inducer (P) according to general Formula (I_P), for use in the method according to the present invention, as detailed above, can advantageously be chosen among those salts which are known to those skilled in the art of plant defence inducers. For example and without any limitation, exemplary salts may include alkali metal salts such as sodium or potassium salts, alkaline earth metal salts such as calcium or magnesium salts, hydrohalide salts such as hydrochloride or hydrobromide salts, phosphate salts, sulphate salts, organic salts such as formate or acetate or trifluoroacetate or p-toluenesulphonate or diethylammonium or dicyclohexylammonium salts, and the like.

Preferred salts of the inducer (P) according to general Formula (I_P), for use in the method according to the present invention, as detailed above, are phosphate salts.

The inducer (P) of Formula (I_P) as specified herein, at least when R₁ and R₂ are different from each other, or a compound of any of the subgroups of inducers of Formula (I_P1), Formula (I_P2), Formula (I_P3), Formula (I_P1a), Formula (I_P2a), and/or Formula (I_P3a) as specified herein, has at least one center of chirality and may exist as stereochemically isomeric forms. The term “stereochemically isomeric forms” as used herein defines all the possible compounds made up of the same atoms bonded by the same sequence of bonds but having different three-dimensional structures. The bond C-R₁ in the inducer (P) of Formula (I_P), as detailed above, and the bond C-R₁′ in the inducers of Formula (I_P1), Formula (I_P2), Formula (I_P3), Formula (I_P1a), Formula (I_P2a), and/or Formula (I_P3a) may adopt both an (R)- and (S)-configuration.

Unless otherwise mentioned or indicated, the chemical designation of the inducer (P) of Formula (I_P) as specified herein, or a compound of any of the subgroups of inducers of Formula (I_P1), Formula (I_P2), Formula (I_P3), Formula (I_P1a), Formula (I_P2a), and/or Formula (I_P3a) as specified herein, encompasses the mixture of all possible stereochemically isomeric forms, which said compound may possess. Said mixture may contain all diastereomers and/or enantiomers of the basic molecular structure of said compound. All stereochemically isomeric forms of the compounds of the present invention both in pure form or mixed with each other are intended to be embraced within the scope of the present invention.

Pure stereoisomeric forms of the inducer (P) of Formula (I_P) as specified herein, or a compound of any of the subgroups of inducers of Formula (I_P1), Formula (I_P2), Formula (I_P3), Formula (I_P1a), Formula (I_P2a), and/or Formula (I_P3a) as specified herein, and intermediates as mentioned herein are defined as isomers substantially free of other enantiomeric or diastereomeric forms of the same basic molecular structure of said compounds or intermediates. In particular, the term “stereoisomerically pure” concerns compounds or intermediates having a stereoisomeric excess of at least 80% (i.e. minimum 90% of one isomer and maximum 10% of the other possible isomers) up to a stereoisomeric excess of 100% (i.e. 100% of one isomer and none of the other), more in particular, compounds or intermediates having a stereoisomeric excess of 90% up to 100%, even more in particular having a stereoisomeric excess of 94% up to 100% and most in particular having a stereoisomeric excess of 97% up to 100%. The terms “enantiomerically pure” and “diastereomerically pure” should be understood in a similar way, but then having regard to the enantiomeric excess, and the diastereomeric excess, respectively, of the mixture in question.

Pure stereoisomeric forms of the compounds and intermediates of this invention may be obtained by the application procedures known in the art. For instance, enantiomers may be separated from each other by the selective crystallization of their diastereomeric salts with optically active acids or bases. Examples thereof are tartaric acid, dibenzoyltartaric acid, ditoluoyltartaric acid and camphorsulfonic acid. Alternatively, enantiomers may be separated by chromatographic techniques using chiral stationary phases. Said pure stereochemically isomeric forms may also be derived from the corresponding pure stereochemically isomeric forms of the appropriate starting materials, provided that the reaction occurs stereospecifically. Desirably, if a specific stereoisomer is desired, said compound will be synthesized by stereospecific methods of preparation. These methods will advantageously employ enantiomerically pure starting materials.

Preferred inducers (P) according to general Formula (I_P), for use in the method according to the present invention, are those of Formula (I_P1-1) [inducer (P_1-1), herein after], Formula (I_P2-2) [inducer (P_2-2), herein after], or Formula (I_P3-3) [inducer (P_3-3), herein after]:

wherein R₁′, R₂′, R₃′, R′, R″ and R′″ have the same meaning as defined above for Formula (I_P1), Formula (I_P2), and Formula (I_P3), respectively.

Preferred inducers (P) according to general Formula (I_Pa), for use in the method according to the present invention, are those of Formula (I_P1a-1) [inducer (P_1a-1), herein after], Formula (I_P2a-2) [inducer (P_2a-2) herein after], or Formula (I_P3a-3) [inducer (P_3a-3), herein after]:

wherein R₁′ and R₂′ have the same meaning as defined above for Formula (I_P1), Formula (I_P2), and Formula (I_P3), respectively.

A preferred inducer (P) according to Formula (I_P1a-1) is the one according to Formula (I_P1a-1-a1) herein below:

It is further understood that all definitions and preferences as described for the inducer (P) above equally apply for all further embodiments, as described below.

The inducer (P) can be prepared by any method known in the art for the manufacture of beta-amino carbonyl compounds.

In general, the carboxylic acid precursor of the inducer (P) can be esterified by methods known in the art. Non-limiting examples of such methods well-known in the art are Fisher-Speier esterifications, Steglich esterifications, alkylation of carboxylate salts, from alcohols and acid chlorides, from alcohols and acid anhydrides, and for example those notably described in ChemBiochem 2018, 19, 696-705 by Van der Poorten et al., Bull. Chem. Soc. Ethiop. 2012, 26, 415-420 by Tang et al., Synthetic Commun. 2001, 31, 2169-2175 by Rivero et al., Synthetic Commun. 1998, 28, 1963-1965 by Anand et al., Molecules 2008, 13, 1111-1119 by Li et al., and the like.

Non-limitative examples of processes for producing beta-amino carbonyl compounds are taught in Tetrahedron 1995, 51, 12337-12350 by Caputo et al., in Org. Synth. 2002, 79, 154 by Linder et al., and in Synth. Comm. 2005, 35, 2789-2794 by Koch et al.

As discussed above, it was already described in the prior art that supplying beta-amino carbonyl compounds, such as beta-aminobutyric acid (BABA), in small amounts comprised between 1.0×10⁻³ and 100.0 μmole/gram of fresh weight of plant or seed resulted in protection of said plant or seed against pests. However, it was further demonstrated that such compounds also display phytotoxic side effects, despite being supplied in such low amounts.

The inventors have now surprisingly found that said phytotoxic side effects could be avoided or reduced by additionally supplying to said plant or seed, a compound [compound (A), herein after], as described above, as evidenced by the examples below.

Within the context of the present invention, the expression “phytotoxic side effects” broadly refers to any symptom of damage which can be considered as unacceptable to plants, such as but not limited to morphological modifications, reduced quality or yield, chlorosis, necrosis, loss of membrane integrity, oxidative damages, wilting, bleaching, discolorations, reduced growth, inhibition or delay of seed germination, inhibition or delay of flowering, reduced yield, induction of stress-responsive genes and cell death.

It is understood that specific phytotoxic side effects might be more frequently observed for specific plants or seeds. For example, the inducer (P) may cause reduced plant height in tomatoes, cucumbers, strawberries, development of necroses in dicotyledonous crops such as grapevines and lettuces, reduction of fertility of in tomatoes and cucumbers, recoloration of the green leaf tissue such as for example reding.

Within the context of the invention, the term “pest” broadly refers to any harmful organism or disease, such as but not limited to, insects, mites, arachnids, nematodes, molluscs, rodents, bacteria, phytoplasmas, viruses, viroids, molds, fungi, and spores.

As non-limiting examples of plants which can be protected by inducing resistance against pests without negatively affecting their growth and development according to the present invention, mention can be made of cereals (such as durum and other wheat, rye, barley, triticale, oats, rice, or maize (fodder maize and sugar maize/sweet and field corn)), beet (such as sugar beet or fodder beet), fruits (such as pomes, stone fruits or soft fruits, e.g. apples, pears, plums, peaches, nectarines, almonds, cherries, papayas, strawberries, raspberries, blackberries or gooseberries), leguminous plants (such as beans, lentils, peas, alfalfa or soybeans), oil plants (such as rapeseed (oilseed rape), turnip rape, mustard, olives, sunflowers, coconut, cocoa beans, castor oil plants, oil palms, ground nuts or soybeans), cucurbits (such as squashes, pumpkins, cucumber or melons), fiber plants (such as cotton, flax, hemp or jute), citrus fruit (such as oranges, lemons, grapefruits or mandarins), vegetables (such as eggplant, spinach, lettuce, chicory, cabbage, asparagus, cabbages, carrots, onions, garlic, leeks, tomatoes, potatoes, cucurbits or sweet peppers), herbs (such as parsley, mint, basil, sage, rosemary, thyme, rosemary or sage), lauraceous plants (such as avocados, cinnamon or camphor), energy and raw material plants (such as corn, soybean, rapeseed, sugar cane or oil palm; tobacco), nuts (such as walnuts), pistachios, coffee, tea, bananas, vines (such as table grapes and grape juice grape vines), hop, sweet leaf (also called Stevia), natural rubber plants or ornamental and forestry plants (such as flowers (e.g. carnation, petunias, Geranium/pelargoniums, pansies and Impatiens), shrubs, broad-leaved trees (such as poplar) or evergreens (such as conifers)), Eucalyptus, turf, lawn, grass such as grass for animal feed or ornamental uses.

In a preferred embodiment, plants which can be protected by inducing resistance against pests without negatively affecting their growth and development according to the present invention are selected from potatoes, sugar beets, tobacco, wheat, rye, barley, oats, rice, corn, cotton, soybeans, rapeseed, legumes, sunflowers, coffee or sugar cane, fruits, herbs, vines, ornamentals, or vegetables, such as cucumbers, tomatoes, beans or squashes. Desirably, plants which can be protected by inducing resistance against pests without negatively affecting their growth and development according to the present invention are selected from strawberry, tomato, potato, lettuce, grapes, soybean, and cucurbits.

Within the context of the present invention, the term “plant” is to be understood as including wild type plants and plants which have been modified by either conventional breeding, or mutagenesis or genetic engineering, or by a combination thereof.

In the rest of the text, the terms “plant” and “seed” are understood, for the purposes of the present invention, both in the plural and the singular form.

Within the context of the present invention, the expression “fresh weight of plant or seed” is intended to denote the weight recorded immediately after harvest of said plant or seed.

It is understood that, within the context of the method according to the present invention, the expression “at least one plant part” also includes the whole plant.

It is also understood that, within the context of the present invention, the term “seed” embraces seeds and plant propagules of all kinds. Non-limiting examples include but are not limited to true seeds, seed pieces, suckers, corms, bulbs, fruit, tubers, grains, cuttings, cut shoots and the like.

It is further understood that the at “least part of a plant or a seed” to which the inducer (P) and additionally the compound (A) are supplied refers to at least plant parts or seeds of the plants which are to be protected by inducing resistance against pests without negatively affecting their growth and development according to the present invention.

As to the amount of inducer (P) which is supplied to the at least one plant part or seed, it understood that said amount will be determined according to general practice, in order to obtain the desired effect of inducing plant protection against pests. It is understood that said amount of inducer (P) which is supplied to the at least one plant part or seed will depend on the development stage of the plant or seed to which it is supplied.

As a general rule, the inducer (P), as detailed above, is supplied to a seed in an amount of at least 1.0×10⁻³ μmol/gram, or at least 5.0×10⁻³ μmol/gram or at least 1.0×10⁻² μmole/gram, or at least 5.0×10⁻² μmole/gram, desirably at least 1.0×10⁻¹ μmole/gram of fresh weight of said seed.

It is further understood that the upper limit of the supplied amount of the inducer (P), as detailed above, is not critical. Desirably, the inducer (P) is supplied to the at least one seed in an amount of less than 20 μmole/gram, or less than 10 μmole/gram, or less than 5 μmole/gram, more desirably less than 2 μmole/gram of fresh weight of seed.

In a preferred embodiment of the method of the present invention, the amount of inducer (P) supplied to the at least one seed, relative to the fresh weight of said seed, ranges from 1.0×10⁻³ μmol/gram to 20 μmol/gram, or from 5.0×10⁻³ μmol/gram to 10 μmol/gram, or from 1.0×10⁻² μmol/gram to 5 μmol/gram, or from 1.0×10⁻¹ μmol/gram to 2 μmol/gram.

As a general rule, the inducer (P), as detailed above, is supplied to a plant or plant part in an amount of at least 5.0×10⁻³ μmol/gram, or at least 1.0×10⁻² μmol/gram or at least 5.0×10⁻² μmole/gram, or at least 1.0×10⁻¹ μmole/gram, desirably at least 1.0 μmole/gram of fresh weight of said plant or plant part.

It is further understood that the upper limit of the supplied amount of the inducer (P), as detailed above, is not critical. Desirably, the inducer (P) is supplied to the at least one plant or plant part in an amount of less than 100 μmole/gram, or less than 50 μmole/gram, or less than 20 μmole/gram, more desirably less than 10 μmole/gram of fresh weight of plant or plant part.

In a preferred embodiment of the method of the present invention, the amount of inducer (P) supplied to the at least one plant or plant part, relative to the fresh weight of said seed, ranges from 5.0×10⁻³ μmol/gram to 100 μmol/gram, or from 1.0×10⁻² μmol/gram to 50 μmol/gram, or from 5.0×10⁻² μmol/gram to 20 μmol/gram, or from 1.0 μmol/gram to 10 μmol/gram.

Generally, when an inducer (P), as detailed above, is supplied to at least a plant or a seed in an amount sufficient to obtain the desired effect of inducing plant protection against pests, said inducer (P) will also cause phytotoxic side effects.

The inventors have now surprisingly found that said phytotoxic side effects could be avoided or reduced by additionally supplying to said plant or seed, at least one compound [compound (A), herein after], as described above, as evidenced by the examples below.

Within the context of the present invention, the expression “at least one compound [compound (A), herein after]” is intended to denote one or more than one compound (A). Mixtures of compounds (A) can also be used for the purpose of the invention. By way of example, vitamins C or derivatives thereof, vitamin E or derivatives thereof or carotenoids; can be combined with salts, chelates, oxides or hydroxides of iron (II) or iron (III), and the like.

According to the method of the present invention, the compound (A) is selected from

• • a) salts, chelates, oxides or hydroxides of iron(II) or iron(III); or
  • b) vitamin C or derivatives thereof, vitamin E or derivatives thereof or carotenoids; or
  • c) flavonoids [flavonoid (F), herein after] having a general formula (II) or salts thereof,

wherein the dash bond represents an optional double bound and wherein

• • each of Y is independently selected from O, or OH;
  • each of Z is independently selected from hydrogen or OR₇, and wherein each of R₇, equal to or different from each other and at each occurrence, is independently selected from hydrogen, or C_1-4 alkyl;
  • each of R₈, R₉, and R₁₀, equal to or different from each other and at each occurrence, is independently selected from hydrogen, or C_1-4 alkyl; and
  • each of j is an integer in the range from 1, 2, 3, 4, or 5.

Non-limiting examples of salts of iron(II) (i.e. ferrous iron) or iron(III) (i.e. ferric iron) notably include acetates, ascorbates, bromides, carbonates, carboxylates, citrates, chlorides, chromates, formates, gluconates, iodides, lactates, nitrates, oxalates, phosphates, salicylates, succinates, malonates, sulphates, sulphides, tartrates and combinations thereof Preferred salts of iron(II) (i.e. ferrous iron) or iron(III) (i.e. ferric iron) may include sulphates, citrates, gluconates and ascorbates.

Non-limiting examples of chelating agents which can be used to obtain iron(II) and iron(III) chelates according to the present invention include ethylenediamine tetraacetic acid (EDTA), diethylenetriamine pentaacetic acid (DTPA), N-(2-hydroxyethyl)ethylenediamine triacetic acid (HEDTA), cyclohexane-1,2-diamine tetraacetic acid (CDTA), ethylenediamine-N,N′-bis(o-hydroxyphenylacetic) acid (EDDHA), ethylenediamine-N-(o-hydroxyphenylacetic)-N′-(p-hydroxyphenylacetic) acid (o,p-EDDHA), ethylenediamine-N,N′-bis(2-hydroxy-4-methylphenylacetic) acid (EDDHMA), ethylenediamine-N,N′-bis(5-carboxy-2-hydroxyphenylacetic) acid (EDDCHA), ethylenediamine-N,N′-bis (2-hydroxy-5-sulfophenylacetic) acid (EDDHSA), N,N′-bis (2-hydroxyphenyl)ethylendiamine-N,N′-diacetic acid (HBED), and ethylenediamine-N,N′-disuccinic acid (EDDS) and combinations thereof.

In one embodiment of the method according to the present invention, the compound (A) is selected from Fe₂SO₄, ferric citrate, ferrous gluconate, and ferrous ascorbate.

Non-limiting examples of vitamin C and derivatives thereof according to the present invention include (L)-ascorbic acid, ascorbyl palmitate, tetrahexyldecyl ascorbate, and salts thereof.

Non-limiting examples of vitamin E and derivatives thereof according to the invention include alpha-tocopherol, beta-tocopherol, gamma-tocopherol, delta-tocopherol, tocopheryl acetate, alpha-tocotrienol, beta-tocotrienol, gamma-tocotrienol, delta-tocotrienol in all their stereoisomeric forms. Desirable forms include (RRR)-alpha-tocopherol.

Non-limiting examples of carotenoids according to the invention include xanthophylls (such as lutein, zeaxanthin, neoxanthin, violaxanthin, flavoxanthin, alpha- and beta-crytoxanthin, rhodopsin, diadinoxanthin, citroxanthin, astaxanthin, canthaxantin, capsanthin, capsorubin, echinenone, fucoxanthin), carotenes (such as alpha-carotene, beta-carotene and lycopene), apocarotenoids (such as bixin, citranaxanthin, crocetin, crocin). Desirable forms include those having anti-oxidant properties, such as lycopene and beta-carotene.

In a preferred embodiment of the method according to the present invention, each of Z in the flavonoid (F) having a general formula (II) is independently selected from hydrogen or OR₇, and wherein each of R₇, equal to or different from each other and at each occurrence, is independently selected from hydrogen, methyl, ethyl, propyl, or isopropyl, or each of R₇, equal to or different from each other and at each occurrence, is independently selected from hydrogen, methyl, or ethyl, or each of R₇, equal to or different from each other and at each occurrence, is independently selected from hydrogen or methyl. Desirably, each of Z is independently selected from hydrogen or OR₇, and wherein each of R₇, equal to or different from each other and at each occurrence, is hydrogen.

In a preferred embodiment of the method according to the present invention, each of R₈ in the flavonoid (F) having a general formula (II) is independently selected from hydrogen, methyl, ethyl, propyl, or isopropyl, or each of R₈ is independently selected from hydrogen, methyl, or ethyl, or each of R₈ is independently selected from hydrogen, or methyl. Desirably, each of R₈ is hydrogen.

In a preferred embodiment of the method according to the present invention, each of R₉ in the flavonoid (F) having a general formula (II) is independently selected from hydrogen, methyl, ethyl, propyl, or isopropyl, or each of R₉ is independently selected from hydrogen, methyl, or ethyl, or each of R₉ is independently selected from hydrogen, or methyl. Desirably, each of R₉ is hydrogen.

In a preferred embodiment of the method according to the present invention, each of R₁₀ in the flavonoid (F) having a general formula (II) is independently selected from hydrogen, methyl, ethyl, propyl, or isopropyl, or each of R₁₀ is independently selected from hydrogen, methyl, or ethyl, or each of R₁₀ is independently selected from hydrogen, or methyl. Desirably, each of R₁₀ is hydrogen.

In a preferred embodiment of the method according to the present invention, each of j in the flavonoid (F) having a general formula (II) is an integer in the range from 1, 2, 3, or 4, or each of j is an integer in the range from 1, 2, or 3. Desirably, each of j is an integer in the range from 1, or 2.

According to one embodiment of the method according to the present invention, the flavonoid (F) according to general Formula (II) is a compound chosen among those of Formulae (II_A) [flavonoid (F) of class (I), herein after]:

wherein Z, R₈, R₉, R₁₀ have the same meaning as defined above and wherein:

• • each of R₁₁ is independently selected from hydrogen, or C_1-4 alkyl; and
  • each of m is an integer in the range from 0, 1, 2, 3, or 4.

In a preferred embodiment of the method according to the present invention, each of R₁₁ is independently selected from hydrogen, methyl, ethyl, propyl, or isopropyl, or each of R₁₁ is independently selected from hydrogen, methyl, or ethyl, or each of R₁₁ is independently selected from hydrogen, or methyl. Desirably, each of R₁₁ is hydrogen.

In a preferred embodiment of the method according to the present invention, each of m is an integer in the range from 0, 1, 2, 3, or 4, or each of m is an integer in the range from 0, 1, 2, or 3, or each of m is an integer in the range from 0, 1, or 2. Desirably, each of m is an integer in the range from 0, or 1.

Preferred compounds of class (I) are selected from those of Formulae (II_A1) to (II_A3) herein below:

wherein Z, R₈, R₉, R₁₀, R₁₁ have the same meaning as defined above.

Most preferred compounds of class (I) are selected from those of Formulae (II_A1-a) to (II_A1-b) and from those of Formulae (II_A2-a) to (II_A2-b) herein below:

According to another embodiment of the method according to the present invention, the flavonoid (F) according to general Formula (II) is a compound chosen among those of Formulae (II_B) [flavonoid (F) of class (II), herein after]:

wherein R₈, R₉, R₁₀, R₁₁ have the same meaning as defined above and wherein:

• • each of Z′ is independently selected from hydrogen, or OR₁₂, and wherein each of R₁₂, equal to or different from each other and at each occurrence, is independently selected from hydrogen, or C_1-4 alkyl; and
  • each of n is an integer in the range from 0, 1, 2, 3, or 4.

In a preferred embodiment of the method according to the present invention, each of Z′ is independently selected from hydrogen or OR₁₂, and wherein each of R₁₂, equal to or different from each other and at each occurrence, is independently selected from hydrogen, methyl, ethyl, propyl, or isopropyl, or each of R₁₂, equal to or different from each other and at each occurrence, is independently selected from hydrogen, methyl, or ethyl, or each of R₁₂, equal to or different from each other and at each occurrence, is independently selected from hydrogen, or methyl. Desirably, each of Z′ is hydrogen.

In a preferred embodiment of the method according to the present invention, each of n is an integer in the range from 0, 1, 2, 3, or 4, or each of n is an integer in the range from 0, 1, 2, or 3, or each of n is an integer in the range from 0, 1, or 2, or each of n is an integer in the range from 0, or 1. Desirably, each of n is an integer equal to 0.

Preferred compounds of class (II) are selected from those of Formulae (II_B1) herein below:

wherein R₈, R₉, R₁₀, R₁₁ have the same meaning as defined above.

More preferred compound of class (II) is the one of Formula (II_B1-a1) herein below:

The flavonoid (F) according to Formula (II_B) as specified herein, or a compound of the subgroup of flavonoids of Formula (II_B1) has at least one center of chirality and may exist as stereochemically isomeric forms. The term “stereochemically isomeric forms” as used herein defines all the possible compounds made up of the same atoms bonded by the same sequence of bonds but having different three-dimensional structures. The wavy bonds in the flavonoid (F) according to Formula (II_B) or a compound of the subgroup of flavonoids of Formula (II_B1) indicate that the configuration is undefined and that both an (R)- or (S)-configuration may be adopted.

Furthermore, more preferred compounds of class (II) are selected from those of Formulae (II_B1-1) herein below:

wherein R₈, R₉, R₁₀ have the same meaning as defined above.

Most preferred compound of class (II) is the (2S)-stereoisomer according to Formula (II_B1-1-a1) herein below:

According to yet another embodiment of the method according to the present invention, the flavonoid (F) according to general Formula (II) is a compound chosen among those of Formulae (II_C) [flavonoid (F) of class (III), herein after]:

wherein R₈, R₉, R₁₀, R₁₁, m have the same meaning as defined above and wherein:

• • each of Z″ is independently selected from hydrogen, or OR₁₃, and wherein each of R₁₃, equal to or different from each other and at each occurrence, is independently selected from hydrogen, or C_1-4 alkyl; and
  • each of Z′″ is independently selected from hydrogen, or OR₁₄, and wherein each of R₁₄, equal to or different from each other and at each occurrence, is independently selected from hydrogen, or C_1-4 alkyl;

In a preferred embodiment of the method according to the present invention, each of Z″ is independently selected from hydrogen, or OR₁₃, and wherein each of R₁₃, equal to or different from each other and at each occurrence, is independently selected from hydrogen, methyl, ethyl, propyl, or isopropyl, or each of R₁₃, equal to or different from each other and at each occurrence, is independently selected from hydrogen, methyl, or ethyl, or each of R₁₃, equal to or different from each other and at each occurrence, is independently selected from hydrogen, or methyl. Desirably, each of Z″ is OR₁₃, and wherein each of R₁₃, equal to or different from each other and at each occurrence, is hydrogen.

In a preferred embodiment of the method according to the present invention, each of Z′″ is independently selected from hydrogen, or OR₁₄, and wherein each of R₁₄, equal to or different from each other and at each occurrence, is independently selected from hydrogen, methyl, ethyl, propyl, or isopropyl, or each of R₁₄, equal to or different from each other and at each occurrence, is independently selected from hydrogen, methyl, or ethyl, or each of R₁₄, equal to or different from each other and at each occurrence, is independently selected from hydrogen, or methyl. Desirably, each of Z′″ is OR₁₄, and wherein each of R₁₄, equal to or different from each other and at each occurrence, is hydrogen.

Preferred compounds of class (III) are selected from those of Formulae (II_C1) to (II_C3) herein below:

wherein Z″, Z″, R₈, R₉, R₁₀, R₁₁ have the same meaning as defined above.

More preferred compounds of class (III) are selected from those of Formulae (II_C4) to (II_C6) herein below:

wherein R₈, R₉, R₁₀, R₁₁ have the same meaning as defined above.

Most preferred compounds of class (III) are selected from those of Formulae (II_C4-a1) to (II_C5-a1) herein below:

The flavonoid (F) according to Formula (II_C) as specified herein, or a compound of any of the subgroups of flavonoids of Formula (II_C1), Formula (II_C2), Formula (II_C3), Formula (II_C4), Formula (II_C5), and/or Formula (II_C6) has at least one center of chirality and may exist as stereochemically isomeric forms. The term “stereochemically isomeric forms” as used herein defines all the possible compounds made up of the same atoms bonded by the same sequence of bonds but having different three-dimensional structures. The wavy bonds in the flavonoid (F) according to Formula (II_C), or a compound of any of the subgroups of flavonoids of Formula (II_C1), Formula (II_C2), Formula (II_C3), Formula (II_C4), Formula (II_C5), and/or Formula (II_C6) indicate that the configuration is undefined and that both an (R)- or (S)-configuration may be adopted.

Furthermore, preferred compounds of class (III) are selected from those of Formulae (II_C1-1) to (II_C3-3) herein below:

wherein Z″, Z″, R₈, R₉, R₁₀, R₁₁ have the same meaning as defined above.

More preferred compounds of class (III) are selected from those of Formulae (II_C4-4) to (II_C6-6) herein below:

wherein R₈, R₉, R₁₀, R₁₁ have the same meaning as defined above.

Most preferred compounds of class (III) are selected from those (2R,3S,4S)-stereoisomers according from Formulae (II_C4-4-a1) to (II_C5-5-a1) herein below:

It is understood that the amount of compound (A) which is supplied to the at least one plant part or seed additionally to the inducer (P), will depend on the nature of said compound (A).

As a general rule, if the compound (A), is a salt, chelate, oxide or hydroxide of iron(II) or iron(III), it is supplied to a plant or a plant part or a seed in an amount of at least 1.0×10⁻⁶ μmol/gram, or at least 5.0×10⁻⁶ μmol/gram or at least 1.0×10⁻⁵ μmole/gram, or at least 5.0×10⁻⁵ μmole/gram, desirably at least 1.0×10⁻⁴ μmole/gram of fresh weight of said seed.

It is further understood that the upper limit of the supplied amount of the salt, chelate, oxide or hydroxide of iron(II) or iron(III), as detailed above, is not critical. Desirably, the salt, chelate, oxide or hydroxide of iron(II), or a salt, chelate, oxide or hydroxide of iron(III) is supplied to the at least one seed in an amount of less than 5.0×10⁻¹ μmole/gram, or less than 1.0×10⁻¹ μmole/gram, or less than 5.0×10⁻² μmole/gram, more desirably less than 1.0×10⁻² μmole/gram of fresh weight of seed.

In a preferred embodiment of the method of the present invention, the amount of salt, chelate, oxide or hydroxide of iron(II) or iron(III) supplied to the at least one seed, relative to the fresh weight of said seed, ranges from 5.0×10⁻⁶ μmol/gram to 5.0×10⁻¹ μmol/gram, or from 1.0×10⁻⁵ μmol/gram to 1.0×10⁻¹ μmol/gram, or from 5.0×10⁻⁵ μmol/gram to 5.0×10⁻² μmol/gram, or from 1.0×10⁻⁴ μmol/gram to 1.0×10⁻² μmol/gram.

As a general rule, if the compound (A), is vitamin C or a derivative thereof, or vitamin E or derivatives thereof or a carotenoid it is supplied to a plant or a plant part or a seed in an amount of at least 1.0×10⁻⁶ μmol/gram, or at least 5.0×10⁻⁶ μmol/gram or at least 1.0×10⁻⁵ μmole/gram, or at least 5.0×10⁻⁵ μmole/gram, desirably at least 1.0×10⁻⁴ μmole/gram of fresh weight of said seed.

It is further understood that the upper limit of the supplied amount of the vitamin C or a derivative thereof, or vitamin E or derivatives thereof or carotenoid, as detailed above, is not critical. Desirably, the vitamin C or a derivative thereof, or vitamin E or derivatives thereof or carotenoid is supplied to the at least one seed in an amount of less than 5.0×10⁻¹ μmole/gram, or less than 1.0×10⁻¹ μmole/gram, or less than 5.0×10⁻² μmole/gram, more desirably less than 1.0×10⁻² μmole/gram of fresh weight of seed.

In a preferred embodiment of the method of the present invention, the vitamin C or a derivative thereof, or vitamin E or derivatives thereof or carotenoid supplied to the at least one seed, relative to the fresh weight of said seed, ranges from 5.0×10⁻⁶ μmol/gram to 5.0×10⁻¹ μmol/gram, or from 1.0×10⁻⁵ μmol/gram to 1.0×10⁻¹ μmol/gram, or from 5.0×10⁻⁵ μmol/gram to 5.0×10⁻² μmol/gram, or from 1.0×10⁻⁴ μmol/gram to 1.0×10⁻² μmol/gram.

As a general rule, if the compound (A), is a flavonoid (F) having a general formula (II) it is supplied to a plant or a plant part or a seed in an amount of at least 1.0×10⁻⁷ μmol/gram, or at least 5.0×10⁻⁷ μmol/gram or at least 1.0×10⁻⁶ μmole/gram, or at least 5.0×10⁻⁶ μmole/gram, desirably at least 1.0×10⁻⁵ μmole/gram of fresh weight of said seed.

It is further understood that the upper limit of the supplied amount of the flavonoid (F) having a general formula (II), as detailed above, is not critical. Desirably, the flavonoid (F) having a general formula (II) is supplied to the at least one seed in an amount of less than 5.0×10⁻² μmole/gram, or less than 1.0×10⁻² μmole/gram, or less than 5.0×10⁻³ μmole/gram, more desirably less than 1.0×10⁻³ μmole/gram of fresh weight of seed.

In a preferred embodiment of the method of the present invention, the flavonoid (F) having a general formula (II) supplied to the at least one seed, relative to the fresh weight of said seed, ranges from 5.0×10⁻⁷ μmol/gram to 5.0×10⁻² μmol/gram, or from 1.0×10⁻⁶ μmol/gram to 1.0×10⁻² μmol/gram, or from 5.0×10⁻⁶ μmol/gram to 5.0×10⁻³ μmol/gram, or from 1.0×10⁻⁵ μmol/gram to 1.0×10⁻³ μmol/gram.

It is understood that, within the context of the present invention, the inducer (P) and the compound (A) can be supplied either concomitantly or sequentially.

According to certain embodiments of the method according to the present invention the inducer (P) and/or the compound (A), as described above, are supplied directly to the at least one plant part or seed, meaning that the inducer (P) and/or the compound (A) is applied directly to a seed, a whole plant or a plant part, typically the foliage, stem or roots.

According to further embodiments of the method according to the present invention, the inducer (P) and/or the compound (A), as described above, is supplied indirectly to the at least one plant part or seed, meaning that the inducer (P) and/or the compound (A) is applied to the locus in which the at least one plant or seed is growing or may grow. Non-limiting examples of such locus include the habitats, soils, areas, materials or environments in which plants or seeds are able to grow.

The inducer (P) and/or the compound (A), as detailed above, can either be supplied in a solid form or in liquid form.

In one embodiment of the present invention, the compound (A) and/or the inducer (P) is supplied in a solid form. Non-limiting examples of suitable solid forms notably include: powders, dusts, tablets, pellets, or granular forms such as granules, microcrumbs, and regular crumbs or mixtures thereof. Desired solid forms include granular forms.

The term “granules”, as used herein, is intended to refer to particles of any shape and any density with a size of at least 2.5 mm, or at least 2.9 mm, or at least 3.2 mm, desirably of at least 3.5 mm.

It is further understood that the upper limit of the size of the granules is not restricted but advantageously equal to or less than 9.0 mm, or equal to or less than 8.0 mm, or equal to or less than 7.5 mm, desirably equal to or less than 7.0 mm.

Advantageously, the size of the granules ranges from 2.5 mm to 9.0 mm, or from 2.9 mm to 8.0 mm, or from 3.2 mm to 7.5 mm, or from 3.5 mm to 7.0 mm.

The term “microcrumbs”, as used herein, is intended to refer to particles of any shape and any density with a size of at least 0.1 mm, or at least 0.3 mm, or at least 0.5 mm, desirably at least 0.7 mm.

It is further understood that the upper limit for the size of the microcrumbs advantageously equal to or less than 3.0 mm, or equal to or less than 2.7 mm, or equal to or less than 2.5 mm, or equal to or less than 2.3 mm, desirably equal to or less than 2.1 mm.

Advantageously, the size of the microcrumbs ranges from 0.1 mm to 3.0 mm, or from 0.3 mm to 2.7 mm, or from 0.5 mm to 2.5 mm, or from 0.7 mm to 2.1 mm.

The term “regular crumbs”, as used herein, is intended to refer to particles of any shape and any density with a size of at least 1.0 mm, or at least 1.5 mm, or at least 1.9 mm, desirably, at least 2.1 mm.

It is further understood that the upper limit if the size of the regular crumbs is advantageously equal to or less than 5.0 mm, or equal to or less than 4.5 mm, or equal to or less than 4.1 mm, or equal to or less than 3.8 mm, desirably equal to or less than 3.5 mm.

Advantageously, the size of the regular crumbs ranges from 1.0 mm to 5.0 mm, or from 1.5 mm to 4.5 mm, or from 1.9 mm to 4.1 mm, or from 2.1 mm to 3.8 mm.

Generally, particle size such as the size of granules, microcrumbs and regular crumbs as defined above, may be measured by known methods in the art, in particular by sieving with screens as notably described in ISO 8397:1988, the whole content of which is herein incorporated by reference.

It is understood that the particle size expressed in mm refers to the median (or geometric mean) of the particles sizes corresponding to P(X<x)=50 wt. %, wherein X is the particles size expressed in mm, P us the percentage by weight of particles smaller than the sieve screen size x expressed in mm, relative to the total weight of the sieved sample.

According to one alternative embodiment of the method according to the present invention, the compound (A) and the inducer (P) are supplied concomitantly in one solid entity, desirably a granule.

According to a further alternative embodiment of the method according to the present invention, the compound (A) and the inducer (P) are supplied sequentially in the solid state, desirably in the form of granules of compound (A) and granules of inducer (P). As a general rule, when the compound (A) and the inducer (P) are supplied sequentially in the solid state it is desirable that the compound (A) is supplied before the inducer (P) is supplied.

According to a preferred embodiment of the method according to the present invention, the compound (A) and/or the inducer (P) is supplied in a liquid form. Non-limiting examples of suitable liquid forms notably include: solutions, dispersions such as emulsions and suspensions and foams.

According to a more preferred embodiment of the method according to the present invention, the compound (A) and the inducer (P) are supplied concomitantly in a liquid form.

Desirably, when the compound (A) and the inducer (P) according to the present invention are supplied concomitantly in a liquid form, both the compound (A) and the inducer (P) are comprised in a concentrated composition [concentrated composition (C_C), herein after].

According to a particular embodiment of the method according to the present invention, the amount of the at least one inducer (P), as detailed above, is equal to or at least 1.0×10¹ millimoles per litre of the concentrated composition (C_C) [mM, herein after], or equal to or at least 5.0×10¹ mM, or equal to or at least 1.0×10² mM, or equal to or at least 5.0×10² mM or equal to or at least 1.0×10³ mM.

It is further understood that the lower limit of the amount of the at least one inducer (P), as detailed above, is equal to or less than 1.0×10⁵ mM, or equal to or less than 5.0×10⁴ mM, or equal to or less than 1.0×10⁴ mM, or equal to or less than 5.0×10³ mM, per litre of the concentrated composition (C_C).

In a preferred embodiment of the method of the present invention, the amount of the at least one compound inducer (P), as detailed above, ranges from 1.0×10¹ mM to 1.0×10⁵ mM, or from 5.0×10¹ mM to 5.0×10⁴ mM, or from 1.0×10² mM to 1.0×10⁴ mM, or from 1.0×10³ mM to 5.0×10³ mM, per litre of concentrated composition (C_C).

Within the context of the invention, the expression “wherein said at least one inducer (P) is present in an amount equal to at least 1.0×10¹ millimoles per litre of the concentrated composition (C_C) [mM, herein after]” refers either to the amount of inducer (P), as detailed above when the concentrated composition (C_C) contains only one inducer (P), or to the sum of the amounts of inducers (P) when the concentrated composition (C_C) contains more than one inducer (P). This implies that when more than one inducer (P) is present, then it is the sum of the amounts of each of said inducer (P) that is present in an amount equal to or at least 1.0×10¹ millimoles per litre of concentrated composition (C_C).

According to a further embodiment of the method according to the present invention, the amount of the at least one compound (A) per litre of the concentrated composition (C_C) will depend on the nature of said compound (A).

As a general rule, if the compound (A), is a salt, chelate, oxide or hydroxide of iron(II) or iron(III), as detailed above, the amount of the at least one compound (A) will be equal to or at least 1.0 millimoles per litre of the concentrated composition (C_C) [mM, herein after], or equal to or at least 5.0 mM, or equal to or at least 10.0 mM, or equal to or at least 20.0 mM or equal to or at least 50.0 mM.

It is further understood that the lower limit of the amount of the at least one salt, chelate, oxide or hydroxide of iron(II) or iron(III), as detailed above, is equal to or less than 500.0 mM, or equal to or less than 300.0 mM, or equal to or less than 200.0 mM, or equal to or less than 150.0 mM, per litre of the concentrated composition (C_C).

In a preferred embodiment of the method of the present invention, the amount of the at least one salt, chelate, oxide or hydroxide of iron(II) or iron(III), as detailed above, ranges from 1.0 mM to 500.0 mM, or from 10.0 mM to 300.0 mM, or from 20.0 mM to 200.0 mM, or from 50.0 mM to 150.0 mM, per litre of concentrated composition (C_C).

As a general rule, if the compound (A), is vitamin C or derivatives thereof, vitamin E or derivatives thereof or a carotenoid, as detailed above, the amount of the at least one compound (A) will be equal to or at least 10.0 millimoles per litre of the concentrated composition (C_C) [mM, herein after], or equal to or at least 20.0 mM, or equal to or at least 50.0 mM, or equal to or at least 100.0 mM or equal to or at least 150.0 mM.

It is further understood that the lower limit of the amount of the at least one vitamin C or derivatives thereof, vitamin E or derivatives thereof or carotenoid, as detailed above, is equal to or less than 700.0 mM, or equal to or less than 500.0, or equal to or less than 300.0 mM, or equal to or less than 250.0 mM, per litre of the concentrated composition (C_C).

In a preferred embodiment of the method of the present invention, the amount of the at least one vitamin C or derivatives thereof, vitamin E or derivatives thereof or carotenoid, as detailed above, ranges from 10.0 mM to 700.0 mM, or from 50.0 mM to 500.0 mM, or from 100.0 mM to 300.0 mM, or from 150.0 mM to 250.0 mM, per litre of concentrated composition (C_C).

As a general rule, if the compound (A), is a flavonoid (F) having a general formula (II), as detailed above, the amount of the at least one compound (A) will be equal to or at least 1.0 millimoles per litre of the concentrated composition (C_C) [mM, herein after], or equal to or at least 2.0 mM, or equal to or at least 5.0 mM, or equal to or at least 10.0 mM or equal to or at least 15.0 mM.

It is further understood that the lower limit of the amount of the at least one flavonoid (F) having a general formula (II), as detailed above, is equal to or less than 150.0 mM, or equal to or less than 100.0 mM, or equal to or less than 75.0 mM, or equal to or less than 50.0 mM, per litre of the concentrated composition (C_C).

In a preferred embodiment of the method of the present invention, the amount of the at least one flavonoid (F) having a general formula (II), as detailed above, ranges from 1.0 mM to 150.0 mM, or from 5.0 mM to 100.0 mM, or from 10.0 mM to 75.0 mM, or from 15.0 mM to 50.0 mM, per litre of concentrated composition (C_C).

According to an alternative embodiment of the method according to the present invention, the compound (A) and the inducer (P) are supplied sequentially in a liquid form. In such case, the compound (A) and the inducer (P) can be comprised in two separate concentrated compositions. It is understood that in such case, the amounts of the inducer (P) and the compound (A) per litre of their respective concentrated compositions are the same as set forth above for the concentrated composition (C_C). As a general rule, when the compound (A) and the inducer (P) are supplied sequentially in a liquid form it is desirable that the compound (A) is supplied within 24 hours of supply of the inducer (P).

Generally, all aspects of the present invention discussed herein in the context of the concentrated composition (C_C) comprising both the inducer (P) and the compound (A) according to the invention apply mutatis mutandis to the respective concentrated compositions comprising either the inducer (P) or the compound (A), as defined above.

In general, the concentrated composition (C_C) will be diluted in a solvent, thereby obtaining a diluted composition [diluted composition (C_D), herein after]. Desirably, the solvent used for diluting the concentrated composition (C_C) is water.

Either of the concentrated composition (C_C) or the diluted composition (C_D) can be supplied to the at least part of a plant or seed according to the present invention.

As to the dilution factor of the concentrated composition (C_C) which is to be applied in order to obtain the diluted composition (C_D) according to the method of the present invention, it is understood that the skilled person in the art will practise said dilution in order to comply with the suitable amount of compound (A), which is supplied per gram of fresh weight of plant or seed, as detailed above.

Within the context of the present invention, the dilution factor refers to the ratio of the volume of the initial solution (i.e. the concentrated composition (C_C)) to the volume of the final solution (i.e. the diluted composition (C_D)).

Generally, the lower limit of the dilution factor of the concentrated composition (C_C) applied in order to obtain the diluted composition (C_D) will be determined, amongst others by the phytotoxicity of said composition (C_C) towards the plant or seed to which it is supplied.

The upper limit of the dilution factor of the concentrated composition (C_C) applied in order to obtain the diluted composition (C_D) will be adapted to avoid washing out of said composition (C_C) or diluted composition (C_D) when it is supplied.

An optimal dilution factor will also have the advantage of allowing efficient application of the composition (i.e. reduced phytotoxicity and complete coverage of the plant, plant part, seed) while at the same time reducing the volumes supplied per area in order to optimise the refilling time of the dispensing device, resulting in more efficient use of equipment, fuel and operator time.

According to some embodiments of the present invention, the dilution factor of the concentrated composition (C_C) applied in order to obtain the diluted composition (C_D) will be equal to at least 1:20 or equal to or at least 1:100, or equal to or at least 1:1000, or equal to or at least 1:5000.

By means of example, if the concentration of compound (A) is 100 millimoles per litre of concentrated composition (C_C) then in order to supply 1.0 μmol/gram fresh weight plant to a plant having a fresh weight of 10.0 grams, the skilled in the art may supply 100 μL of concentrated composition (C_C) to said plant. However, in order to ease application, the skilled in the art will generally dilute the concentrated composition (C_C) in order to supply the equivalent amount of compound (A) to said plant in a larger volume. For the purpose of achieving a concentration of compound (A) in the diluted composition (C_D) of 1 mM, concentrated composition (C_C) will be diluted 100 times, the dilution factor will be 1:100, and 10 mL of diluted composition (C_D) will be supplied to the plant.

Among the suitable manners for supplying the concentrated composition (C_C) or diluted composition (C_D), mention can notably be made of spraying (such as aerial spraying or ground spraying, atomizing, vaporizing, drenching, watering, squirting, sprinkling, pouring, fumigating, injecting, painting, seed treating, coating, immersing, soaking and the like by using conventional equipment such as a handpump, a backpack sprayer, a boom sprayer, and the like. Desirably, the concentrated composition (C_C) or diluted composition (C_D) are supplied by spraying or by drenching.

According to certain embodiments of the method according to the present invention, either of the concentrated composition (C_C) or the diluted composition (C_D), as detailed above, may further comprises at least one surfactant.

Within the contest of the present invention, the expression “at least one surfactant” is intended to denote one or more than one surfactant. Mixtures of surfactants can also be used for the purpose of the invention. In the remainder of the text, the term “surfactant” is understood, for the purposes of the invention both in the plural and the singular form.

When present in the concentrated composition (C_C), the surfactant can desirably be used to stabilize the composition (C) so that the mixture maintains one single liquid phase. Additionally, when present in the diluted composition (C_D), the surfactant can improve the penetration of compound (A) in the part of plant or seed to which it is supplied, thereby reducing the onset of action as well as the application rate of compound (A).

Within the context of the present invention, the term “surfactant” is intended to refer to cationic, anionic, amphoteric or non-ionic surfactants.

Non-limiting examples of cationic surfactants include cetrimonium bromide, cetylpyridinium chloride, benzalkonium chloride, benzethonium chloride, dimethyldioctadecylammonium chloride and dioctadecylmethylammonium bromide.

Non-limiting examples of anionic surfactants include ammonium lauryl sulfate, sodium lauryl sulfate, sodium dodecyl sulfate, sodium laureth sulfate, sodium myreth sulfate, dioctyl sodium sulfosuccinate, perfluorooctanesulfonate, perfluorobutanesulfonate, alkyl-aryl ether phosphates and alkyl ether phosphates.

Non-limiting examples of amphoteric surfactants include alkyl betaine, alkyl dimethyl betaine, alkylamido betaine, alkyl amide betaine, alkylamidopropyl betaine, alkyl dimethylammonium betaine, alkyl amidopropyl betaine, alkyl sulfobetaine; alkyl, alkylampho glycinate, alkylamphocarboxy glycinate, alkyl or alkyl substituted imidazoline monocarboxylate, alkyl or alkyl substituted imidazoline dicarboxylate, sodium salts of alkyl monocarboxylates, sodium salts of alkyl monocarboxylates, alkyl beta amino acids, alkyl amidopropyl hydroxysultaine, alkyl ether hydroxysultaine, alkyl amidopropyl dimethyl ammonia acetate, alkyl ampho monoacetate, alkyl ampho diacetate, alkyl dipropionate, alkyl ampho dipropionate, alkyl amino dipropionate, alkyl amphopropionate, alkyl beta amino propionic acid, alkyl dipropionate, alkyl beta iminodipropionate, branched or n-alkyl dimethylamidopropionate, alkyl carboxylated propionate, alkyl imidazoline, methyl alkyl imidazoline, fluorinated alkyl amphoteric mixtures.

Non-limiting examples of non-ionic surfactants notably include polyethoxylated fatty acids; vegetable oils; fatty alcohols; alcohol alkoxylates; alkoxylated alkyl alcohols; polyoxyethylene alkyl alcohols; polyol esters of fatty acids; polyoxyethylene esters of fatty acids; fatty acid amides; polyoxyethylene fatty acid amides; polyalkylene oxide block copolymers; ethoxylated alkyl mercaptans and the like.

Preferred non-ionic surfactants may be chosen among octaethylene glycol monododecyl ether, pentaethylene glycol monododecyl ether, nonoxynols, polyoxyethylene octyl phenyl ether, polyethoxylated tallow amine, cocoamide monoethanolamine, cocoamide dietholamine, poloxamers, glycerol monostearate, glycerol monolaurate, sorbitan monolaurate, sorbitan monosetearate, sorbitan tristearate, polyethylene glycol (20) sorbitan monolaurate, (i.e. PEG(20)sorbitan monolaurate or Tween 20), polyethylene glycol (20) sorbitan monostearate, polyoxyethylene (20) sorbitan monooleate, polyoxyethylene (20) sorbitan monopalmitate, decyl glucoside, lauryl glucoside, octyl glucoside, lauryldimethylamine oxide, Brij™, glycerol, glyceryl polyethylene glycol ricinoleate (PEG); wherein the number of ethylene oxide units varies from 2 to 200, polyglyceryl ester, polyglyceryl monooleate, decaglyceryl monocaprylate, propylene glycol dicaprilate, triglycerol monostearate, ethoxylated castor oil or mixtures thereof.

As to the amount of the surfactant it is understood that the skilled person in the art will practise said surfactant in a suitable amount according to the standard and general practice known by said skilled person in the art.

According to a particular embodiment of the present invention, the amount of the surfactant, as detailed above, relative to the total weight of the concentrated composition (C_C) is generally equal to at least 5.0×10⁻³ wt. %, or equal to or at least 1.0×10⁻² wt. %, or equal to or at least 5.0×10⁻² wt. %, or equal to or at least 1.0×10⁻¹ wt. %. It is further understood that, when present, the amount of the surfactant, as detailed above, relative to the total volume of the concentrated composition (C_C) is generally equal to or less than 80.0 wt. %, or equal to or less than 70.0 wt. %, or equal to or less than 60.0 wt. %, or equal to or less than 50.0 wt. %.

In a preferred embodiment of the method of the present invention, the amount of the surfactant, as detailed above, relative to the total volume of concentrated composition (C_C) ranges from 5.0×10⁻³ to 80 wt. %, or from 1.0×10⁻² wt. % to 70 wt. %, or from 5.0×10⁻² to 60 wt. %, or from 1.0×10⁻¹ to 50 wt. %.

According to a particular embodiment of the present invention, the amount of the surfactant, as detailed above, relative to the total weight of the diluted composition (C_D) is generally equal to at least 5.0×10⁻⁵ wt. %, or equal to or at least 1.0×10⁻⁴ wt. %, or equal to or at least 5.0×10⁻⁴ wt. %, or equal to or at least 1.0×10⁻³ wt. %. It is further understood that, when present, the amount of the surfactant, as detailed above, relative to the total volume of the diluted composition (C_D) is generally equal to or less than 20.0 wt. %, or equal to or less than 10.0 wt. %, or equal to or less than 5.0 wt. %, or equal to or less than 2.5 wt. %.

In a preferred embodiment of the method of the present invention, the amount of the surfactant, as detailed above, relative to the total volume of diluted composition (C_D) ranges from 5.0×10⁻⁵ to 20.0 wt. %, or from 1.0×10⁻⁴ wt. % to 10.0 wt. %, or from 5.0×10⁻⁴ to 5.0 wt. %, or from 1.0×10⁻³ to 2.5 wt. %.

According to certain embodiments of the present invention, either of the concentrated composition (C_C) or the diluted composition (C_D), as detailed above, further comprises at least one other additional ingredient [ingredient (I_C), herein after] to enhance the appearance, storage, transport, handling and/or performance of the composition (C).

Within the context of the present invention, the expression “at least ingredient of other additional ingredients [ingredient (I_C), herein after]” is intended to denote one or more than one ingredient (I_C). Mixtures of ingredients (I_C) can also be used for the purpose of the invention. In the remainder of the text, the expression “ingredient (I_C) is understood, for the purposes of the present invention, both in the plural and the singular form.

Said ingredients (I_C) are known to those skilled in the art of agricultural and pest control compositions. Non-limiting examples of ingredients (I_C) notably include: suspending agents and similar ingredients to enhance the shelf life of the product, colorants, fragrances, solvents, thinning agents and thickening agents, any material that facilitate the application of the composition (C) such as spreading or sticking agents, antifreezes, evaporation inhibitors, anti-caking agents, defoamers and any other materials customarily employed in formulating pest control compositions.

As to the amount of the additional ingredients (I_C), it is understood that the skilled person in the art will practise said additional ingredients (I_C) in a suitable amount according to standard and general practice known by said skilled person in the art.

According to some embodiments of the present invention, the weight ratio of the at least one compound (A) to the additional ingredient (I_C) is equal to at least 1:10, preferably equal to at least 1:5, more preferably equal to at least 1:2.

In a preferred embodiment of the method according to the present invention, either of the concentrated composition (C_C) or the diluted composition (C_D), comprises the at least one inducer (P), as detailed above, at least one compound (A), as detailed above, water, optionally at least one surfactant, as detailed above, and optionally at least one additional ingredient (I_C).

According to a preferred embodiment of the present invention, the concentrated composition (C_C) comprises water and the at least one inducer (P), as detailed above, the at least one compound (A), as detailed above, the at least one surfactant, as detailed above, and optionally at least one additional ingredient (I_C), as detailed above, and comprises:

• • 1.0×10¹-1.0×10⁵ mM of at least one inducer (P) of general Formula (I_P1a-1-a1), as defined above;
  • 1.0-700.0 mM of at least one compound (A), as defined above;
  • 1.0×10⁻¹-50.0 wt. % of at least one non-ionic surfactant, as detailed above;
  • optionally at least one additional ingredient (I_C)wherein the amount of inducer (P) and of compound (A) is relative to the total volume of the concentrated composition (C_C), whereas the amount of surfactant is relative to the total weight of the concentrated composition (C_C).

According to a preferred embodiment of the present invention, the concentrated composition (C_C) comprises water and the at least one inducer (P), as detailed above, the at least one compound (A), as detailed above, the at least one surfactant, as detailed above, and optionally at least one additional ingredient (I_C), as detailed above, and comprises:

• • 1.0×10¹-1.0×10⁵ mM of at least one inducer (P) of general Formula (I_P1a-1-a1), as defined above;
  • 1.0-500.0 mM of at least one salt, chelate, oxide or hydroxide of iron(II) or iron(III);
  • 1.0×10⁻¹-50.0 wt. % of at least one non-ionic surfactant, as detailed above;
  • optionally at least one additional ingredient (I_A)wherein the amount of inducer (P) and of compound (A) is relative to the total volume of the concentrated composition (C_C), whereas the amount of surfactant is relative to the total weight of the concentrated composition (C_C).

According to a more preferred embodiment of the present invention, the concentrated composition (C_C) comprises water and the at least one inducer (P), as detailed above, the at least one compound (A), as detailed above, the at least one surfactant, as detailed above, and optionally at least one additional ingredient (I_C), as detailed above, and comprises:

• • 1.0×10³-5.0×10³ mM of at least one inducer (P) of general Formula (I_P1a-1-a1), as defined above;
  • 50.0-150.0 mM of Fe(SO)₄;
  • 1.0×10⁻¹-50.0 wt. % of at least one non-ionic surfactant, as detailed above;
  • optionally at least one additional ingredient (I_A)wherein the amount of inducer (P) and of compound (A) is relative to the total volume of the concentrated composition (C_C), whereas the amount of surfactant is relative to the total weight of the concentrated composition (C_C).

According to a preferred embodiment of the present invention, the concentrated composition (C_C) comprises water and the at least one inducer (P), as detailed above, the at least one compound (A), as detailed above, the at least one surfactant, as detailed above, and optionally at least one additional ingredient (I_C), as detailed above, and comprises:

• • 1.0×10¹-1.0×10⁵ mM of at least one inducer (P) of general Formula (I_P1a-1-a1), as defined above;
  • 10.0-700.0 mM of at vitamin C or derivatives thereof, vitamin E or derivatives thereof, or carotenoids;
  • 1.0×10⁻¹-50.0 wt. % of at least one non-ionic surfactant, as detailed above;
  • optionally at least one additional ingredient (I_A)wherein the amount of inducer (P) and of compound (A) is relative to the total volume of the concentrated composition (C_C), whereas the amount of surfactant is relative to the total weight of the concentrated composition (C_C).

According to a more preferred embodiment of the present invention, the concentrated composition (C_C) comprises water and the at least one inducer (P), as detailed above, the at least one compound (A), as detailed above, the at least one surfactant, as detailed above, and optionally at least one additional ingredient (I_C), as detailed above, and comprises:

• • 1.0×10³-5.0×10³ mM of at least one inducer (P) of general Formula (I_P1a-1-a1), as defined above;
  • 150.0-250.0 mM of ascorbic acid;
  • 1.0×10⁻¹-50.0 wt. % of at least one non-ionic surfactant, as detailed above;
  • optionally at least one additional ingredient (I_A)wherein the amount of inducer (P) and of compound (A) is relative to the total volume of the concentrated composition (C_C), whereas the amount of surfactant is relative to the total weight of the concentrated composition (C_C).

According to yet another preferred embodiment of the present invention, the concentrated composition (C_C) comprises water and the at least one inducer (P), as detailed above, the at least one compound (A), as detailed above, the at least one surfactant, as detailed above, and optionally at least one additional ingredient (I_C), as detailed above, and comprises:

• • 1.0×10¹-1.0×10⁵ mM of at least one inducer (P) of general Formula (I_P1a-1-a1), as defined above;
  • 1.0-150.0 mM of at least one flavonoid (F) of class (I) or class (II), as described above;
  • 1.0×10⁻¹-50.0 wt. % of at least one non-ionic surfactant, as detailed above;
  • optionally at least one additional ingredient (I_A)wherein the amount of inducer (P) and of compound (A) is relative to the total volume of the concentrated composition (C_C), whereas the amount of surfactant is relative to the total weight of the concentrated composition (C_C).

According to a more preferred embodiment of the present invention, the concentrated composition (C_C) comprises water and the at least one inducer (P), as detailed above, the at least one compound (A), as detailed above, the at least one surfactant, as detailed above, and optionally at least one additional ingredient (I_C), as detailed above, and comprises:

• • 1.0×10³-5.0×10³ mM of at least one inducer (P) of general Formula (I_P1a-1-a1), as defined above;
  • 15.0-50.0 mM of a flavonoid (F) of Formula (II_A2-a) or a flavonoid (F) of Formula (II_B1-1-a1), as described above;
  • 1.0×10⁻¹-50.0 wt. % of at least one non-ionic surfactant, as detailed above;
  • optionally at least one additional ingredient (I_A)wherein the amount of inducer (P) and of compound (A) is relative to the total volume of the concentrated composition (C_C), whereas the amount of surfactant is relative to the total weight of the concentrated composition (C_C).

The concentrated composition (C_C) can be prepared by a variety of methods known in the art.

In one embodiment of the present invention, the method for manufacturing the concentrated composition (C_C), as detailed above, comprises intimate admixing of the at least one inducer (P), the at least one compound (A), water, optionally a surfactant, as defined above, and optionally the at least one additional ingredient (I_C), as defined above.

It is understood that the skilled person in the art will carry out said intimate admixing according to general practice such as notably using optimal time, speeds, weights, volumes, and batch quantities.

In a further embodiment of the present invention, additional nutrients and/or plant protection products can also be added to either of the concentrated composition (C_C) or the diluted composition (C_D), as detailed above, thereby producing a formulation for growing plants [formulation (F), herein after)]. Another aspect of the present invention, is said formulation (F) which is suitable for growing plants, and comprises:

• • a) either of the concentrated composition (C_C) or the diluted composition (C_D), as detailed above,
  • and either of or both of
  • b) one or more plant nutrients in a collective amount of at least 50 dry weight percent (dry wt. %), based on the dry weight of the formulation; and
  • c) one or more plant protection product comprising other plant defence inducers, herbicides, pesticides, insecticides, miticides, acaricides, nematicides, fungicides, bactericides, rodenticides, growth-regulating agents or the like.

The concentrated composition (C_C) and the diluted composition (C_D) in the formulation includes any of the embodiments of the concentrated composition (C_C) and the diluted composition (C_D) described above.

The plant nutrients may comprise primary nutrients, secondary nutrients and/or micronutrients. Examples of suitable primary nutrients include sources of potassium, phosphorus, nitrogen. Examples of suitable secondary nutrients include sources of calcium, magnesium, and sulphur. Examples of suitable micronutrients include sources of boron, cobalt, iron, manganese, molybdenum, zinc, chlorine, and copper.

It is a further object of the present invention to provide the use of at least one compound (A), as defined above, for reducing or avoiding the phytotoxic side effects of at least one inducer (P), as defined above, which is supplied to at least part of a plant or a seed.

Generally, all aspects of the present invention discussed herein in the context of a method for growing plants according to the invention apply mutatis mutandis to the use of at least one compound (A), as defined above, for reducing or avoiding the phytotoxic side effects of at least one inducer (P), as defined above, which is supplied to at least part of a plant or a seed.

EXAMPLES

The invention will now be described in more details with examples, whose purpose is merely illustrative and not intended to limit the scope of the invention.

Preparation of the Compositions

The characteristics of the water-based compositions of comparative example 1 (CEx 1) and examples 2-9 (Ex 2-9) are shown in Table 1.

	TABLE 1
	Ingredients
	(concentration (mM) relative to the total
	volume of the composition)
	Inducer	Flavonoid	Flavonoid
	(P) of	(F) of	(F) of
	formula	Formula	Formula		Ascorbic
	(IP1a−1-a1)	(IIB1−1-a1)	(IIA2-a)	FeSO4	acid
CEx 1	2.50	—	—	—	—
Ex 2	2.50	—	—	0.40	—
Ex 3	2.50	—	—	—	0.40
Ex 4	2.50	—	—	0.20	—
Ex 5	2.50	—	—	—	0.20
Ex 6	2.50	0.05	—	—	—
Ex 7	2.50	0.10	—	—	—
Ex 8	2.50	—	0.05	—	—
Ex 9	2.50	—	0.10	—	—
Ex 10	2.50	—	—	0.20	0.40
All ingredients were mixed until a homogenous mixture was obtained. All compositions contained 0.02 wt. % Tween 20 (Corda International PLC) as surfactant.

Example 1

The water-based compositions of Comparative Example 1, and Examples 2 and 3, as listed in Table 1 were applied to two-weeks old tomato seedlings of the commercial variety Moneymaker transplanted seven days earlier in pots containing 85-90 grams of soil. Each composition was applied by spraying uniformly over each plant resulting in the application of 6.5 mL of each composition per plant. In addition, control plants were sprayed with a composition consisting of water and 0.02 wt. % Tween 20. Each treatment was replicated 5 times.

No difference in shoot height was observed between the different treatments before application of the compositions.

After treatment, the plants were grown in a growth chamber for ten days, after which an assessment of the height of the shoots was carried out.

The results of this assessment are listed in Table 2.

TABLE 2
          Average shoot height 10 days after
Treatment application (cm)
Control   19.4
CEx 1     15.4
Ex 2      18.5
Ex 3      17.6

The water-based composition of Comparative Example 1 resulted in a strong reduction of the shoot height of the tomato seedlings as compared to the control-treated seedlings.

Plants treated with the water-based compositions of Examples 2-3 showed a significant increase in shoot height as compared to those plants treated with the water-based composition of Comparative Example 1.

Example 2

The water-based compositions of Comparative Example 1, and Examples 2-9, as listed in Table 1 were applied to two-weeks old tomato seedlings of the commercial variety Moneymaker transplanted seven days earlier in pots containing 85-90 grams of soil. Each composition was applied by spraying uniformly over each plant resulting in the application of 6.5 mL of each composition per plant. In addition, control plants were sprayed with a composition consisting of water and 0.02 wt. % Tween 20. Each treatment was replicated 5 times.

No difference in root weight was observed between the different treatments before application of the compositions.

After ten days of growth in a growth chamber, an assessment of the root fresh weight of the plants was carried out.

The results of this assessment are listed in Table 3.

TABLE 3
          Average root fresh weight 10 days after
Treatment application (grams)
Control   0.3796
CEx 1     0.1776
Ex 2      0.3214
Ex 3      0.2904
Ex 4      0.3396
Ex 5      0.2658
Ex 6      0.2893
Ex 7      0.2524
Ex 8      0.2418
Ex 9      0.2048

The water-based composition of Comparative Example 1 resulted in a strong reduction of the root fresh weight of the tomato seedlings as compared to the control-treated seedlings.

Plants treated with the water-based compositions of Examples 2-9 showed a significant increase in root fresh weight as compared to those plants treated with the water-based composition of Comparative Example 1.

Example 3

The water-based compositions of Comparative Example 1, and Examples 4 and 10, as listed in Table 1 were applied to two-weeks old tomato seedlings of the commercial variety Moneymaker transplanted seven days earlier in pots containing 85-90 grams of soil. Each composition was applied by spraying uniformly over each plant resulting in the application of 6.5 mL of each composition per plant. In addition, control plants were sprayed with a composition consisting of water and 0.02 wt. % Tween 20. Each treatment was replicated 5 times.

Twenty-four hours after the treatments, each tomato seedling was inoculated with 250 J2 larvae of Meloidogyne javanica.

Twenty-eight days after inoculation of the larvae, an assessment of the shoot height, root weight, number of galls and egg mass on the rooting system was carried out.

The results of this assessment are listed in Table 4.

TABLE 4
	Average	Average root	Mean	Mean number of
	shoot	fresh weight	number of	egg mass/root
Treatment	height (cm)	(grams)	galls/plant	system
Control	48.4	22.3	94.4	81.5
CEx 1	39.3	16.3	51.9	26.8
Ex 4	53.1	21.3	61.6	40.8
Ex 10	50.1	27.8	33.9	12.3

Plants treated by spraying with the water-based composition of Comparative Example 1 and Examples 4 and 10 showed a reduction of the number of galls and egg mass on the rooting system as compared to the control plants. However, the water-based composition of Comparative Example 1 resulted in a strong reduction of both the shoot height and the root fresh weight of the tomato seedlings as compared to the control-treated seedlings, which was not observed for the seedlings treated with the water-based composition of Examples 4 and 10.

In addition to the fact that plants treated with the composition of Examples 4 and 10 did not show a reduction in plant growth, the results in Table 4 show that the compositions of Example 4 and 10, as used in the method of the present invention, are still active for inducing plant defense against the nematode M. javanica in an manner equivalent to the composition of Comparative Example 1, which is a potent plant defense inducer shown to induce phytotoxicity and reduction of plant growth.

Example 4

The water-based compositions of Comparative Example 1, and Examples 4 and 10, as listed in Table 1 were applied to two-weeks old tomato seedlings of the commercial variety Moneymaker transplanted seven days earlier in pots containing 85-90 grams of soil. Each composition was applied by drenching uniformly over each plant resulting in the application of 6.5 mL of each composition per plant. In addition, control plants were sprayed with a composition consisting of water and 0.02 wt. % Tween 20. Each treatment was replicated 5 times.

Twenty-four hours after the treatments, each tomato seedling was inoculated with 250 J2 larvae of Meloidogyne javanica.

Twenty-eight days after inoculation of the larvae, an assessment of the shoot height, root weight, number of galls and egg mass on the rooting system was carried out.

The results of this assessment are listed in Table 5.

TABLE 5
	Average	Average root	Mean	Mean number of
	shoot	fresh weight	number of	egg mass/root
Treatment	height (cm)	(grams)	galls/plant	system
Control	48.4	22.3	94.4	81.5
CEx 1	43.4	15.9	52.3	30.9
Ex 4	50.4	29.3	78.5	58.1
Ex 10	53.1	19.0	64.3	53.8

Plants treated by drenching with the water-based composition of Comparative Example 1 and Examples 4 and 10 showed a reduction of the number of galls and egg mass on the rooting system as compared to the control plants. However, the water-based composition of Comparative Example 1 resulted in a strong reduction of both the shoot height and the root fresh weight of the tomato seedlings as compared to the control-treated seedlings, which was not observed for the seedlings treated with the water-based composition of Examples 4 and 10.

In addition to the fact that plants treated with the composition of Examples 4 and 10 did not show a reduction in plant growth, the results in Table 4 show that the compositions of Example 4 and 10, as used in the method of the present invention, are still active for inducing plant defense against the nematode M. javanica in an manner equivalent to the composition of Comparative Example 1, which is a potent plant defense inducer shown to induce phytotoxicity and reduction of plant growth.

Claims

1. A method for growing plants, wherein said method comprises at least the steps of (i) supplying at least one plant defence inducer [inducer (P), herein after] or a salt thereof to at least part of a plant, or a seed, wherein said inducer P has phytotoxic side effects and has a general formula (IP):

2. The method according to claim 1, wherein the at least one inducer (P) or a salt thereof is selected from those of Formulae (IP1a) [inducer (P1a), herein after], or (IP2a) [inducer (P2a), herein after], or (IP3a) [inducer (P3a), herein after] herein below:

3. The method according to claim 1, wherein the at least one inducer (P) or a salt thereof corresponds to the following formula (IP1a-a1):

4. The method according to claim 1, wherein the amount of the at least one inducer (P) supplied to at least part of a plant or a seed is comprised between 1.0×10−3 and 100 μmol/gram of fresh weight of said at least part of a plant or seed.

5. The method according to claim 1, wherein the at least one compound (A) is a salt, chelate, oxide or hydroxide of iron(II) or iron(III) selected from Fe2SO4, ferric citrate, ferrous gluconate, and ferrous ascorbate.

6. The method according to claim 1, wherein the at least one compound (A) is vitamin C or derivatives thereof, vitamin E or derivatives thereof, or carotenoids, and is selected from (L)-ascorbic acid, ascorbyl palmitate, tetrahexyldecyl ascorbate, and salts thereof, (RRR)-alpha-tocopherol, lycopene and beta-carotene.

7. The method according to claim 1, wherein the at least one compound (A) is a flavonoid (F) selected from those of Formulae (IIA1) to (IIA3), or (IIB1), or (IIC1) to (IIC3) herein below:

8. The method according to claim 1, wherein the at least one compound (A) is a flavonoid (F) selected from those of Formulae (IIA1-a) to (IIA1-b), or (IIA2-a) to (IIA2-b), or (IIB1-a1), or (IIC4-a1) to (IIC5-a1) herein below:

9. The method according to claim 1, wherein the at least one compound (A) is a flavonoid (F) selected from those of Formulae (IIB1-1-a1), or (IIA2-a) herein below:

10. The method according to claim 1, wherein the at least one compound (A) and the at least one inducer (P) are comprised in in a concentrated composition [concentrated composition (CC), herein after] and wherein the amount of the at least one inducer (P), per liter of concentrated composition (CC), ranges from 1.0×101 mM to 1.0×105 mM, or from 5.0×101 mM to 5.0×104 mM, or from 1.0×102 mM to 1.0×104 mM, or from 1.0×103 mM to 5.0×103 mM.

11. The method according to claim 10, wherein the concentrated composition (CC) further comprises a surfactant.

12. The method according to claim 10, wherein the concentrated composition (CC) further comprises at least one additional ingredient [ingredient (IC), herein below] selected from the group consisting of suspending agents, colorants, fragrances, solvents, thinning agents and thickening agents, spreading or sticking agents; antifreezes, evaporation inhibitors, anti-caking agents and defoamers.

13. The method according to claim 10, wherein the concentrated composition (CC) comprises water and comprises: a. 1.0×101−1.0×105 mM of at least one inducer (P) or a salt thereof corresponding to the following formula (IP1a):

14. The method according to claim 10, wherein the concentrated composition (CC) comprises water and comprises: a. 1.0×102−1.0×104 mM of at least one inducer (P) or a salt thereof corresponding to the following formula (IP1a):

15. The method according to claim 10, wherein said method further comprises the step of diluting the concentrated composition (CC) in a solvent, thereby obtaining a diluted composition [diluted composition (CD), herein after], such that the dilution factor of the concentrated composition (CC) applied in order to obtain the diluted composition (CD) is equal to at least 1:20, or equal to at least 1:100, or equal to at least 1:1000, or to at least 1:5000.

16. A formulation for growing plants [Formulation (F), herein after] comprising: a. the concentrated composition (CC) according to any one of claims 10 to 14, and either of or both ofb. one or more plant nutrients in a collective amount of at least 50 dry weight percent (dry wt. %), based on the dry weight of the formulation; andc. one or more plant protection product comprising other plant defence inducers, herbicides, pesticides, insecticides, miticides, acaricides, nematicides, fungicides, bacterides, rodenticides, growth-regulating agents and the like.