FIELD OF INVENTION

This invention relates to methods and compositions relating to agricultural coatings and, in particular, to seeds coated with guar or guar derivatives, and methods for use, as well as improved dust suppression effects from using such compositions.

BACKGROUND OF THE INVENTION

Seeds are sometimes commercially treated to promote good seedling establishment. Protection of seeds and young seedlings from pests in and around the soil during the early stages of plant growth is one concern. Another concern is the protection of seeds and seedlings from drought or damage from lack of available water.

U.S. Pat. No. 4,543,370 appears to describe seed coatings containing a cellulosic film-forming polymer, a pigment, a plasticizer, silica and a surfactant. U.S. Pat. Nos. 4,513,019 and 4,576,646 describe a process for coating seeds with a cellulosic film-forming composition, at least one alpha-cellulose, and a suitable plasticizer.

SUMMARY OF INVENTION

Described herein are dry or semi-dry seed coating compositions that promote seedling establishment through water retention or water absorption. Also described herein are dry seed coating compositions that promote seedling establishment as one or more layers of the seed coating composition act as a wetting agent, which wets the adjacent/surrounding area of soil around the seed. Further, described herein are dry coating compositions that promote the retention of active ingredients or agricultural compounds in the soil, such that the agricultural compounds are available or more readily available to plants, vegetation, grasses, trees, and the like. Further, described herein are coating compositions that promote the ability to maintain or sustain active ingredients or agricultural compounds in the soil, such that the active ingredients are available or more readily available to plants, vegetation, grasses, trees, and the like.

Currently, one drawback when applying active ingredients or agricultural compounds, such as pesticides, herbicides, and the like, to soil is that these agricultural compounds active ingredients or are lost with water runoff or drainage, and thus not available for grass and plants and the like. The phrases “dry seed coating compositions” and “dry coating composition” are defined herein as excluding hydrogels but not excluding seeds which comprise normal moisture which is necessary to maintain viability.

In one aspect, described herein are coated seed compositions comprising:

at least one seed; and

at least one layer coating all or part of the seed, the layer comprising:

a crosslinked biopolymer; and

optionally, a second binder comprising guar, derivatized guar, starch, derivatized starch, or a combination of any of the foregoing.

In one embodiment, a crosslinked biopolymer has an average particle size of less than about 400 nm, or in another embodiment has an average particle size of less than about 600 nm, or in another embodiment has an average particle size of less than about 800 nm. In a further embodiment, the crosslinked biopolymer has an average particle size of less than 1000 nm, or 900 nm, or 800 nm, or 700 nm, or 600 nm, or 500 nm, or 300 nm, or 200 nm. In another embodiment, the crosslinked biopolymer has an average particle size of less than 200 nm, or 175 nm, or 150 nm, or 125 nm, or 100 nm, or 75 nm, or 50 nm, or 25 nm. In one embodiment, the crosslinked biopolymer is a concentrated and stable dispersion of a crosslinked biopolymer.

In one embodiment, the layer comprises at least both the crosslinked biopolymer and the second binder. In one embodiment, the crosslinked biopolymer is amylose or amylopectin.

In a further embodiment, the composition of the present invention is characterized by a dust value, as measured using a Heubach dustmeter device, which is lower by at least 30% as compared to an analogous composition that does not contain the crosslinked biopolymer. The Heubach dustmeter can be set with values such as rotation speed (from 1 rpm to 100 rpm), rotation time (1 sec to 500 seconds), airflow rate (from 1 L/min to 500 L/min). In one embodiment, the Heubach dustmeter is set with the following parameters: rotation speed 30 rpm, rotation time 120 seconds and airflow rate 20 L/min.

In another embodiment, the composition is characterized by a dust value, as measured using a Heubach dustmeter device, which is lower by at least 40%, or which is lower by at least 50%, or which is lower by at least 60%, or which is lower by at least 70%, or which is lower by at least 80%, or which is lower by at least 90%, as compared to an analogous composition that does not contain the crosslinked biopolymer or, in other embodiments, the at least one layer.

In one embodiment, the Heubach dustmeter is set with the following parameters: rotation speed: 10-50 rpm, rotation time: 40-200 seconds and airflow rate 5-40 L/min. In one embodiment, the Heubach dustmeter is set with the following parameters: rotation speed: 20-40 rpm, rotation time: 90-150 seconds and airflow rate 10-30 L/min.

In one embodiment, the seed is selected from the group consisting of rice, corn, wheat, barley, oats, soybean, sunflower, alfalfa,sorghum, rapeseed, sugar beet, tomato, bean, carrot, tobacco and flower seeds. In another embodiment, the composition further comprises at least one active ingredient. The active ingredient can be any one or more of: herbicides, plant growth regulators, crop dessicants, fungicides, bacteriocides, bacteriostats, insecticides, insect repellants, adjuvants, surfactants, fertilizers and any mixtures thereof.

In one embodiment, the derivatized guar comprises carboxymethyl guar, hydroxyethyl guar, hydroxypropyl guar, carboxymethylhydroxypropyl guar, cationic guar, cationic hydroxypropyl guar, hydrophobically modified guar, hydrophobically modified carboxymethyl guar, hydrophobically modified hydroxyethyl guar, hydrophobically modified hydroxypropyl guar, cationic hydrophobically modified hydroxypropyl guar, hydrophobically modified carboxymethylhydroxypropyl guar, hydrophobically modified cationic guar, or any combination thereof.

In one embodiment, the seed has a shelf-life at room temperature in ambient conditions in an unsealed container without added salts or adjuvants of at least two months. The composition can also further comprise at least one filler. The filler can comprise: wood flours, clays, activated carbon, carbohydrates, sugars, dextrins, maltodextrins, diatomaceous earth, cereal flours, wheat flour, oat flour, barley flour, calcium carbonate, calcium bentonite, kaolin, china clay, talc, perlite, mica, vermiculite, silicas, quartz powder, montmorillonite and/or mixtures thereof.

In an additional aspect, described herein are methods for preparing a coated seed composition having dust suppression benefits comprising the step of contacting at least a portion of at least one seed with at least one layer comprising:a crosslinked biopolymer; andoptionally, a second binder comprising guar, derivatized guar, starch, derivatized starch, or a combination of any of the foregoing,

wherein the coated seed composition is characterized by a dust value, as measured using a Heubach dustmeter device, which is lower by at least 30% as compared to an analogous composition that does not contain the crosslinked biopolymer.

In one embodiment, the second binder comprises a hydroxypropyl guar, a cationic hydroxypropyl guar, or a combination thereof. In one embodiment, the second binder comprises trimethyamino (2-hydroxyl)propyl cationic guar. In other embodiments, the second binder is a cationic compound selected from the following: homopolymers and copolymers of cationic styrenic monomers, homopolymers and copolymers of cationic allylic monomers, homopolymers and copolymers of (meth)acrylamido cationic monomers, homopolymers and copolymers of (meth)acrylate cationic monomers, polyvinylamine, cationic polyacrylamide, cationic polyvinyl alcohol, Polyquaternium-2; polyureylene ammonium salt, cationic starch, cationic cellulose, cationic hydroxyl-ethyl cellulose, cationic xanthan gum, cationic carageenan gum, cationic karaya gum, cationic arabic gum, cationic Lara gum, cationic canafen gum, cationiccassiagum, cationic konjac gum, cationic daincha, cationic fenugreek gum, cationic locust bean gum, cationic psyllium seed gum, cationic konjak, cationic mesquite gum, cationic ivory nut mannan gum, cationic alginate, cationicagar, cationic ulvane, cationic tragacanth gum, cationic ghatti gum, cationic tamarind gum, cationic xyloglucan, cationic inulin, cationic proteins, cationic pectin and cationic hemicellulose.

The present invention relates to the development of novel bio-based binding material for seed treatment applications in agricultural industry. The binding material is made from renewable bio-sources. Thus, such material can be easily mixed into seed treatment formulations and used in seed treatment process. This binding material reduces the loss of seed treatment formulation ingredients from dust-off. The present invention provides a binding material from bio-source and shows good performance in dust-off reduction, seed safety, and processability (i.e., ease of processing).

Thus, the present invention and its use of bio-based binding material are important to seed treatment industry due to its effects of: (1) Preventing the loss of active ingredients (AIs) in the seed coating after treatment, (2) Reducing the potential negative sequence from unintended deposit of hazardous active ingredients, and (3) Facilitating the seed treatment process

