Compositions comprising pesticide precursors and methods of making and use
Disclosed is a two-part pesticide formulation and methods of making and using. The pesticide formulation comprises a first part comprising a glucosinolate concentrate, and a second part comprising a plant material comprising myrosinase. The parts may be stored and transported in inactive form, and are activated upon application to a substrate requiring pesticide treatment.
1. A two-part fungicide precursor system comprising
(a) a first contained part comprising a sinigrin-containing glucosinolate concentrate obtained from a Brassica plant material comprising less than 0.5% of glucosinolate breakdown products, and
(b) a second separately contained part comprising a Sinapis alba plant material comprising an active myrosinase complex in a concentration sufficient to release an effective amount of allyl isothiocyanate upon mixing of the first and second part in the presence of water,
and
wherein the amount of sinigrin in the first part, the amount and activity of the myrosinase complex in the second part, and the relative amounts of the first and second parts are such that, upon mixing of the two parts in the presence of water, a fungicide formulation is obtained in which the myrosinase activity is less than 0.5 of myrosinase enzyme activity units/mg of sinigrin naturally present in Brassica plant material, and more than 12.5 μmol of sinigrin is hydrolyzed per minute per unit of active myrosinase complex.
2. The two-part fungicide precursor system according to claim 1 wherein upon mixing of the two parts a formulation is obtained in which the myrosinase activity is less than 0.10 myrosinase enzyme activity units/mg of sinigrin, and more than 12.5 μmol of sinigrin is hydrolyzed per minute per unit of active myrosinase complex.
3. A two-part fungicide precursor system according to claim 1 , wherein the first part is a dry sinigrin containing glucosinolate concentrate and the second part is a dry Sinapis alba plant material.
4. The two-part fungicide precursor system according to claim 3 wherein the dry Sinapis alba plant material is a Sinapis alba seed meal.
5. A two-part fungicide precursor system according to claim 1 , wherein the first part is a sinigrin-containing dry glucosinolate concentrate and the second part is a dry Sinapis alba plant material, wherein the relative humidity of each of the sinigrin-containing glucosinolate concentrate and the dry Sinapis alba plant material is about 15% or less.
6. The two-part fungicide precursor system according to claim 1 , wherein at least one of the two parts is prepared in liquid form and the two parts are separate until application to a substrate in need of treatment by the fungicide formulation.
7. A two-part fungicide precursor system according to claim 1 , wherein the myrosinase activity is less than 0.47 myrosinase enzyme activity units/mg of sinigrin.
8. A method of preparing a two-part fungicide precursor system comprising preparing
(a) a first contained part comprising a sinigrin-containing glucosinolate concentrate obtained from a Brassica plant material comprising less than 0.5% of glucosinolate breakdown products, and
(b) a second separately contained part comprising a Sinapis alba plant material comprising an active myrosinase complex in a concentration sufficient to release an effective amount of allyl isothiocyanate upon mixing of the first and second component in the presence of water,
wherein the amount of sinigrin in the first part, the amount and activity of the myrosinase complex in the second part, and the relative amounts of the first and second parts are such that, upon mixing of the two parts in the presence of water, a fungicide formulation is obtained in which the myrosinase activity is less than 0.5 myrosinase enzyme activity units/mg of sinigrin naturally present in Brassica plant material, and more than 12.5 μmol of sinigrin is hydrolyzed per minute per unit of active myrosinase complex.
9. The method according to claim 8 wherein the Sinapis alba plant material comprising an active myrosinase complex is a Sinapis alba seed meal.
10. The method according to claim 8 wherein the first part is a dry sinigrin-containing glucosinolate and the second part is a dry Sinapis alba plant material.
11. The method according to claim 8 wherein the first part is a dry sinigrin-containing glucosinolate and the second part is a dry Sinapis alba plant material and wherein the relative humidity of each of the dry sinigrin-containing glucosinolate concentrate and the Sinapis alba plant material comprising an active myrosinase complex is less than about 15%.
12. A method of preparing a two-part fungicide precursor system according to claim 8 , wherein the myrosinase activity is less than 0.47 myrosinase enzyme activity units/mg of sinigrin.
13. A method for controlling fungal pests comprising:
(a) providing a two-part fungicide precursor system, said system comprising:
(i) a first contained part comprising an aqueous sinigrin-containing glucosinolate concentrate obtained from a Brassica plant material less than 0.5% of glucosinolate breakdown products comprising in excess of 10% (v/v) water; and (ii) a second separately contained part comprising a Sinapis alba plant material comprising an active myrosinase complex in a concentration sufficient to release an effective amount of allyl isothiocyanate upon the addition of water to the mixture;
(b) mixing the first part and second part of the system to obtain a mixture wherein the amount of sinigrin in the first part, the amount and activity of the myrosinase complex in the second part, and the relative amounts of the first and second parts are such that, upon mixing of the two parts, a mixture is obtained in which the myrosinase activity is less than one half of the myrosinase activity per unit mass of sinigrin naturally present in the Brassica plant material;
(c) adding water to the mixture to obtain a fungicide formulation; and
(d) applying the fungicide formulation to a substrate in need of fungicide treatment, wherein upon mixing of the two parts in step (c) the fungicide formulation is obtained wherein the myrosinase activity is less than 0.5 myrosinase enzyme activity units/mg of sinigrin naturally present in the Brassica plant material, and wherein more than 12.5 μmol of sinigrin is hydrolyzed per minute per unit of active myrosinase complex.
14. A method for controlling fungal pests according to claim 13 , wherein upon adding water in step (c) the myrosinase activity is less than 0.1 myrosinase enzyme activity units/mg of sinigrin, and wherein more than 12.5 μmol of sinigrin is hydrolyzed per minute per unit of active myrosinase complex.
15. A method for controlling fungal pests according to claim 13 , wherein the myrosinase activity is less than 0.47 myrosinase enzyme activity units/mg of sinigrin.