Method of controlling the release of agricultural active ingredients from treated plant seeds
A method of controlling the release rate of an agricultural active ingredient from a seed that has been treated with that active includes providing a seed that has been treated with the active ingredient, applying to the treated seed a film that includes an emulsion of a polymer in a liquid in which both the agricultural active ingredient and the polymer have low levels of solubility, and then curing the film to form a water insoluble polymer coating on the surface of the treated seed. Seeds that have been treated by this method are also provided.
1. A method of controlling the release rate of an agricultural active ingredient from a seed treated with the active ingredient, the method comprising the steps of:
providing a seed that has been treated with an agricultural active ingredient;
applying to the treated seed, at a temperature of about 34° F. (about 1° C.), an aqueous emulsion of a polymer latex, wherein the polymer latex has a solubility in water at 25° C. of less than 5% by weight, a glass transition temperature of about 15° C. to about 40° C. and wherein the active ingredient has a solubility in water at 20° C. of less than 10 g/L; and
curing the polymer latex emulsion to form a water insoluble, non-migrating polymer coating on the surface of the treated seed, wherein the polymer coating that is formed from the polymer latex emulsion has a glass transition temperature within the range of from about 15° C. to about 40° C., thereby providing a coating which retards the release rate of the agricultural active ingredient from the seed.
2. The method according to claim 1 , wherein the ratio of the weight of the coating to the weight of the treated seed is from about 1:1 to about 1:1,000.
3. The method according to claim 1 , wherein the ratio of the weight of the coating to the weight of the treated seed is from about 1:10 to about 1:600.
4. The method according to claim 1 , wherein the ratio of the weight of the film to the weight of the treated seed is from about 1:20 to about 1:400.
5. The method according to claim 1 , wherein the agricultural active ingredient is a pesticide.
6. The method according to claim 5 , wherein the pesticide is selected from the group consisting of herbicides, insecticides, acaracides, fungicides, nematocides, and bactericides.
7. The method according to claim 1 , wherein the seed is the seed of a plant selected from the group consisting of corn, peanut, canola/rapeseed, soybean, curcubits, cotton, rice, sorghum, sugar beet, wheat, barley, rye, sunflower, tomato, sugarcane, tobacco, oats, vegetables, and leaf crops.
8. The method of claim 1 , wherein the polymer latex has a glass transition temperature of 15° C.
9. The method of claim 1 , wherein the polymer latex has a glass transition temperature of 25° C.