Mixtures and methods for the induction of resistance in plants

Abstract

Mixtures are described comprising two or more compounds selected from at least two of the following groups: i) salicylic acid and/or its functional analogous products (ESA), ii) promoting compounds (PRO) and iii) modulating compounds (MOD), and their use for stimulating the natural defence systems of plants and for inducing resistance in plants. The use is also described, of two or more compounds selected from at least two of the following groups: one or more compounds belonging to the ESA group and/or one or more compounds belonging to the PRO group and/or one or more compounds belonging to the MOD group, individually adopted by means of application programs which envisage alternating application, to stimulate the natural defence systems of plants and inducing resistance in plants.

1 . A blend comprising two or more compounds selected from at least two of the following groups: 
 i) salicylic acid and/or its functional analogous products (ESA), ii) promoting compounds (PRO) and    iii) modulating compounds (MOD)    
   
   
       2 . The blend according to  claim 1 , characterized in that the ESA compounds of group I) are selected from salicylic acid, a compound deriving from salicylic acid and/or a mimetic compound of salicylic acid.  
   
   
       3 . The blend according to  claim 1 , characterized in that the ESA compounds of group I) are selected from: a salicylic compound having formula (I):  
     
       
         
         
             
             
         
       
     
     wherein: 
 R 1  represents a hydrogen atom or a C 1 -C 6  alkyl group, or a metal cation;  
 R 2  represents a hydrogen atom or an acyl group COR′, or a metal cation;  
 R 1  and R 2  can jointly coordinate the same metal cation;  
 R′ represents a hydrogen atom or a C 1 -C 6  alkyl group, or a benzyl group optionally substituted;  
 R 3 , the same or different when n is 2, represents a halogen atom, optionally selected from fluorine, chlorine, bromine and iodine, or a C 1 -C 6  alkyl group, a C 1 -C 6  alkoxyl group, a C 1 -C 6  thioalkyl group, a C 1 -C 6  thioalkoxyl group, a C 2 -C 7  carboalkoxyl group, a cyano group, a phenyl group optionally substituted, a hydroxyl group, a nitro group; n is a number between 0 and 2; X and Y, the same or different, have the meaning of oxygen or sulphur or NH; or a mimetic compound of salicylic acid having formula (IIa) or (IIb):  
                     
 wherein R 1 , X and Y have the meanings defined above.  
 
   
   
       4 . The blend according to  claim 3 , characterized in that compounds (I), (IIa) and (IIb), when salified with metallic cations are present in any acid/metal molar ratio, depending on the valence of the metal itself.  
   
   
       5 . The blend according to  claim 4 , characterized in that the acid/metal molar ratio is equal to 1:1 or 1:2 for a bivalent metal.  
   
   
       6 . The blend according to  claim 1 , characterized in that the PRO promoter compounds of group ii) are selected from the sub-groups a-f: 
 a: salts or oxides of metals such as sodium, lithium, potassium, magnesium, calcium, copper, zinc, iron, manganese, as sulphates, nitrates, phosphates, phosphonates or phosphites, carbonates or organic chelates, such as, for example, titanium dioxide, titanium citrate, titanium malate, zinc oxide, zinc sulphate, zinc nitrate, iron sulphate, iron nitrate, calcium sulphate,iron oxides, magnesium sulphate, copper sulphate, zinc carbonate, calcium phosphate, silica, silicic acid, iron polycarboxylates;    b: dyes and pigments, such as, for example, Prussian blue, Bengal pink, phthalocyanines, metal porphyrins, natural or synthesis optical bluing products, such as, for example, esculetin, esculin, umbellipheron, stilbene derivatives;    c: saccharides and derivatives, such as, for example, glucosamine, chitin, chitosane, glucanes, such as, for example, lamarine or glucopyranes optionally substituted with fatty acids or galactomannans, such as, for example, guar;    d: nitroso-donor compounds, such as, for example, sodium nitroferrocyanide;    e: organic acids and derivatives such as esters and amides,—for example, aspartame and saccharin; and amino acids, such as, for example, benzoic acid, cinnamic acid, propionic acid, 1-amino-1-cyclopropanecarboxylic acid, β-aminobutyric acid (BABA), free dextrorotatory amino acids of the protein type, or incorporated in oligopeptides, or blends of said dextro- or levo-rotatory free amino acids or incorporated in oligopeptides;    f: proteins inducing immune vegetable responses such as arpine.    
   
   
       7 . The blend according to  claim 1 , characterized in that the MOD modulating compounds of group iii) can be selected from: glutathione (GSH), or a compound capable of favouring accumulation in vegetable tissues, 4-hydroxyproline and its derivatives, allantoine, L-glutamic acid and its derivatives, tert-butylhydroquinone, ′betaine, cystine, cysteine, or its derivative having formula (III):  
     
       
         
         
             
             
         
       
     
     (III) wherein: 
 R 1  has the meanings defined above,  
 R 4  and R 5 , the same or different, can have the meaning of a hydrogen atom, a C 1 -C 6  alkyl group, a methyl carboxylic group, a C 2 -C 7  methyl carboalkoxylic group, an optionally substituted phenyl group,  
 R 4  and R 5 , jointly, can have the meaning of the alkylidene group —(CH 2 )m—,  
 m has the value of 1 or 2,  
 R5 represents a hydrogen atom, or an acyl COR′ group.  
 
   
   
       8 . The blend according to  claim 7 , characterized in that the compounds having general formula (I), (IIa), (IIb) and (III) are also present in hydrate form by the coordination of any number of water molecules or are salified by organic bases, such as piperidine, piperazine, morpholine and natural amino acids.  
   
   
       9 . The blend according to  claim 1 , characterized in that each compound, selected from those defined as ESA, PRO, MOD, is present in a quantity ranging from 0.5 g to 5 kg per hectare.  
   
   
       10 . The blend according to  claim 1 , characterized in that each compound, selected from those defined as PRO, is in micronized form.  
   
   
       11 . The blend according to  claim 10 , characterized in that the particles of the micronized form have a particle size lower than 1 micron.  
   
   
       12 . The blend according to  claim 10 , characterized in that the PRO compounds are selected among compounds of sub-group a), preferably among titanium dioxide, zinc oxide, silicic acid.  
   
   
       13 . The blend according to  claim 1  to , comprising other active principles compatible with the ESA, PRO and MOD compounds such as other fungicides, phytoregulators, antibiotics, herbicides, insecticides, fertilizers.  
   
   
       14 . The blend according to  claim 13 , characterized in that the concentration of active principle ranges from 1 to 90%.  
   
   
       15 . The use of a mixture comprising two or more compounds selected from at least two of the following groups: i) salicylic acid and/or its functional analogous products (ESA), 
 ii) promoting compounds (PRO) and    iii) modulating compounds (MOD),    wherein ESA, PRO and MOD have the meanings according to  claim 2 , for stimulating the natural defence systems of plants and inducing resistance in plants.    
   
   
       16 . The use of two or more compounds selected from at least two of the following groups: one or more compounds belonging to the ESA group and/or one or more compounds belonging to the PRO group and/or one or more compounds belonging to the MOD group, wherein ESA, PRO and MOD have the meanings according  claim 2 , applied singly by means of applicative programs which envisage their alternating application, for stimulating the natural defence systems in plants and inducing resistance in plants.  
   
   
       17 . The use according to  claim 15 , for controlling phytopathogen fungi in agricultural crops of both a curative and preventive nature.  
   
   
       18 . A method for stimulating the natural defence systems of plants and inducing resistance in plants, which envisages the application of one or more ESA compounds and/or in a mixture with one or more PRO compounds and/or in a mixture with one or more MOD compounds, wherein ESA, PRO and MOD have the meanings according to  claim 2 , either mixed with each other or individually by means of applicative programs which comprise their alternating application.  
   
   
       19 . The method according to  claim 18  for controlling phytopathogen fungi in agricultural crops of both a curative and preventive nature.  
   
   
       20 . The method according to  claim 18 , wherein the application of the blend is effected on all parts of the plant, for example on the leaves, stems, branches and roots, or on the seeds themselves before sowing, or on the ground in which the plant grows.  
   
   
       21 . The method according to  claim 18 , characterized in that the quantity of each compound, selected from those defined as ESA, PRO, MOD, to be applied, is present in a quantity ranging from 0.5 g to 5 kg per hectare.