Micronutrient-enhanced polymeric seed coatings
Improved, micronutrient-supplemented polymeric seed coatings are provided which include at least one polyanionic polymer in combination with respective amounts of Zn, Mn, and Cu micronutrients. Preferably, the coatings comprise polyanionic polymers having a backbone comprising dicarboxylic repeat units with Zn, Mn, and Cu bound to the backbone. The most preferred polymers contain maleic and itaconic repeat units, optionally with sulfonate repeat units. The invention also provides a method of treating seeds using the coatings, and coated seed products.
1. A water soluble coating composition for seeds, comprising a polymer have a backbone containing maleic, itaconic, and two sulfonate repeats units and having micronutrients selected from the group consisting of Fe, Mg, alkaline earth metals, and mixtures thereof, wherein said polymer is in a partial salt form, wherein said polymer has at least 80 mole percent of repeat units including at least one anionic group, where the total amount of all of the repeat units in the polymer is taken as 100 mole percent, and wherein said coating composition has a polymer content of from about 35% to about 55% by weight based on the total weight of the coating composition.
2. The coating composition of claim 1 , said micronutrients being chemically bound to said polymer backbone.
3. The coating composition of claim 1 , wherein the alkaline earth metal is Ca.
4. The coating composition of claim 1 , said coating composition being an aqueous mixture containing said polymer.
5. The coating composition of claim 4 , said mixture having a pH of about 3-8.
6. The coating composition of claim 5 , said mixture having a pH of about 4-6.5.
7. The composition of claim 1 , wherein said two sulfonate repeat units are allylsulfonic repeat units and methallylsulfonic repeat units.
8. The composition of claim 1 , said polymer having about 1-20 mole percent methallylsulfonic repeat units and about 0.1-10 mole percent allylsulfonic repeat units, where the total amount of all of the repeat units in the polymer is taken as 100 mole percent.
9. The composition of claim 1 , wherein the partial salt form further comprises boron.
10. A method of treating seeds comprising the step of coating seeds with the coating composition of claim 1 .
11. The method of claim 10 , said seeds selected from the group consisting of wheat and corn.
12. The method of claim 10 , said coating composition being applied by spraying onto said seeds, or by dipping the seeds in the coating composition.
13. A seed product comprising a seed having on the surface thereof the coating composition of claim 1 .
14. The seed product of claim 13 , wherein said seed is selected from the group consisting of wheat and corn.
15. The coating composition of claim 1 , wherein the polymer comprises about 2-40 mole percent of sulfonated repeat units, where the total amount of all of the repeat units in the polymer is taken as 100 mole percent.
16. The coating composition of claim 1 , wherein the anionic polymer comprises maleic acid 35-50 mole percent, itaconic 20-55 mole percent, methallylsulfonic acid 1-15 mole percent, and allyl sulfonic acid 1-20 mole percent, where the total amount of all of the repeat units in the polymer is taken as 100 mole percent.
17. The method of claim 10 , wherein the polymer comprises about 2-40 mole percent sulfonated repeat units, where the total amount of all of the repeat units in the polymer is taken as 100 mole percent.
18. The method of claim 10 , wherein the anionic polymer comprises maleic acid 35-50 mole percent, itaconic 20-55 mole percent, methallylsulfonic acid 1-15 mole percent, and allyl sulfonic acid 1-20 mole percent, where the total amount of all of the repeat units in the polymer is taken as 100 mole percent.