Compositions of volatile organic compounds and methods of use thereof

Abstract

The present invention provides compositions and methods for treating, inhibiting or preventing the developing of a plant pathogenic disease. The compositions comprise volatile organic compounds effective to inhibit the growth of, or kill pathogenic microbes, including Ganoderma boninense . Invention compositions are especially useful in preventing and treating basal stem rot in the oil palm, and can be applied in the vicinity of the plant or used to sterilize the plant growth medium prior to or concurrent with plant growth therein.

What is claimed is: 
     
         1 . A method for treating, inhibiting or reducing the incidence of the development of a plant pathogenic disease, wherein said method comprises applying a composition in the vicinity of a host plant, said composition comprising:
 three or more compounds, wherein the first of said three or more compounds is isobutyric anhydride; and   the second of said three or more compounds is selected from the group consisting of one or more of isobutyric acid, methyl isobutyrate, ethyl isobutyrate, propyl isobutyrate, isobutyric acid-allyl ester, and naphthalene, and   the third of said three or more compounds is selected from the group consisting of one or more of: caryophyllene and a plant essential oil.   
     
     
         2 . A method according to  claim 1 , wherein the second of said three or more compounds is isobutyric acid. 
     
     
         3 . A method according to  claim 2 , wherein the third of said three or more compounds is caryophyllene. 
     
     
         4 . A method according to  claim 2 , wherein the composition comprises 20-70% isobutyric anhydride and 20-70% isobutyric acid. 
     
     
         5 . A method according to  claim 1 , wherein the composition comprises 1-10% naphthalene, or 1-10% caryophyllene, or 1-10% of a plant essential oil. 
     
     
         6 . A method according to  claim 4 , wherein the composition further comprises 1-10% caryophyllene. 
     
     
         7 . A method according to  claim 1 , wherein the composition further comprises an agriculturally effective amount of a pesticidal compound or composition selected from the group consisting of an acaricide, a bactericide, a fungicide, an insecticide, a microbicide, a nematicide, and a food preservative. 
     
     
         8 . A method according to  claim 1 , wherein the composition is in the form of a powder, a granule, a pellet, a gel, an aqueous suspension, a solution, or an emulsion. 
     
     
         9 . A method according to  claim 1 , wherein the composition further comprises an agriculturally acceptable carrier. 
     
     
         10 . A method according to  claim 9 , wherein the carrier is a seed. 
     
     
         11 . A method according to  claim 1  wherein the host plant is a crop plant. 
     
     
         12 . A method according to  claim 1 , wherein the host plant is an oil palm plant. 
     
     
         13 . A method according to  claim 1 , wherein the second of said two or more compounds is selected from the group consisting of isobutyric acid, methyl isobutyrate, ethyl isobutyrate, propyl isobutyrate, and isobutyric acid-allyl ester. 
     
     
         14 . A method according to  claim 1 , wherein said plant essential oil is selected from the group consisting of the plant essential oils listed in Table 3. 
     
     
         15 . A method according to  claim 4 , wherein the composition comprises 42-53% isobutyric anhydride and 42-53% isobutyric acid. 
     
     
         16 . A method according to  claim 15 , wherein the composition further comprises 3-7% caryophyllene. 
     
     
         17 . A method according to  claim 1  wherein the plant essential oil is isocaryophyllene or α-humulene. 
     
     
         18 . A method according to  claim 1  wherein the composition is applied or coated on a seed. 
     
     
         19 . A method according to  claim 1 , wherein the pathogen is selected from the group consisting of  Aspergillus fumigatus, Botrytis cinerea, Cerpospora betae, Curvularia  sp.,  Ganoderma boninense, Geotrichum candidum, Mycosphaerella fijiensis, Phytophthora palmivora, Phytophthora ramorum, Pythium ultimum, Rhizoctonia solani, Rhizopus  sp.,  Schizophyllum  sp.,  Sclerotinia.sclerotiorum, Verticillium dahliae , and  Xanthomona axonopodis.    
     
     
         20 . A method according to  claim 1 , wherein the composition is applied in the vicinity of or onto the roots, stems, trunk, seed, or leaves of the host plant. 
     
     
         21 . A method according to  claim 1 , wherein the composition is injected into the roots, stems, trunk, seed, or leaves of the host plant. 
     
     
         22 . A method for treating, inhibiting, or reducing the incidence of a plant pathogenic disease, said method comprising exposing or contacting the growth medium of a host plant to or with the composition of  claim 1  prior to or concurrent with plant growth in said growth medium. 
     
     
         23 . A method for screening microbial strains, said method comprising:
 (i) exposing or contacting candidate microbial strains with a composition according to  claim 1 ,   (ii) selecting microbial strains resistant to the composition, and   (iii) characterizing the selected microbial strain,   wherein said method identifies a microbial strain useful for treating, inhibiting or reducing the incidence of a plant pathogenic disease.   
     
     
         24 . An isolated microbial strain obtained by the method according to  claim 23 .