BEE-FRIENDLY DUST-FREE SEED COATING FOR POLLINATOR HEALTH

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: SMALL BUSINESS GRANT
• Reporting Frequency: Annual
• Accession No.: 1012690
• Grant No.: 2017-33610-26740
• Cumulative Award Amt.: $99,993.00
• Proposal No.: 2017-00351
• Project Start Date: Jun 15, 2017
• Project End Date: Aug 14, 2018
• Grant Year: 2017
• Program Code: [8.13]- Plant Production and Protection-Engineering

Recipient Organization
NANO TERRA, INC.
737 CONCORD AVENUE
CAMBRIDGE,MA 02138

Performing Department
(N/A)

Non Technical Summary
Pollinators, typically honey bees, are critical for marketable yields of around 90 crops, including apples, blueberries, cucumbers and almonds. Honey bees, however, have been under considerable pressure from Colony Collapse Disorder (CCD), leading to unprecedented and unsustainable colony losses. Pesticide exposure, especially neonicotinoids in seed coating, is one key stressor causing the general declining health of honey bees based on research in the US and Europe. This proposal will address the USDA's presidential priority area to reduce pesticide exposure to bees by using dust-free seed coatings. The proposed coating will adhere well to the seed surface forming a smooth and abrasion-resistant film. In addition, a surface-active additive will be incorporated to provide a lubricious surface. The proposed seed coating will significantly reduce the risk of pesticide exposure to bees in the following ways: 1) The dust-free seed coating will not release pesticides to the air, protecting honey bees and other pollinators from unintended pesticide exposure; 2) The proposed seed coating is self-lubricating, eliminating the need for lubricant powders (e.g. talcum powder, graphite, or fluency agent) during planting, further reducing off-target drift of applied pesticides that are toxic to bees; and 3) The new coating technology may reduce the total amount of pesticides in the coating by >10% due to improved targeting efficiency.

Animal Health Component

80%

Research Effort Categories

Basic

20%

Applied

80%

Developmental

0%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
314	3010	2000	80%
314	3010	2020	20%

Knowledge Area
314 - Toxic Chemicals, Poisonous Plants, Naturally Occurring Toxins, and Other Hazards Affecting Animals;

Subject Of Investigation
3010 - Honey bees;

Field Of Science
2020 - Engineering; 2000 - Chemistry;

Keywords

colony collapse disorder

dust-free

honey bee

pollinator

seed coating

neonicotinoid

Goals / Objectives
The goal of the proposed Phase I effort is to develop a novel seed-coating formulation that is non-dusting and self-lubricating, removing a key pathway for harm to pollinators in the area. This objective will be achieved by optimizing our existing coating formulations and creating aqueous formulations that will outperform current products using dust-free and self-lubricating film-forming polymers. We will conduct planting and bee toxicity studies in Phase II.The Technical Objective defining the criteria for success in Phase I is as follows:Demonstrate >90% reduction of dust formation than the best seed treatmentproducts on the market as measured using a Heubach Dust MeterDemonstrate comparable plantability to current lubricant-containing treated seeds without using lubricant powderDemonstrate uniform coverage of the seed coating and the ability to incorporate colors as is standard practiceSpecific research questions to be answered by this work:Does the new coating formulation generate dust in a Heubach testing?Do the coated seeds have desired ability to flow in a lab test?Does the dust-free seed coating perform similarly to the current seed coating products with regard to: a) loading level of neonicotinoids in the seed, and b) coverage and homogeneity of the coating?Does the new coating adversely affect seed germination?

Project Methods
Effort 1. Develop a coating formulation and coating processIn this effort, Nano Terra will develop various formulations requiring either dual-coat or single-coat applications, including active ingredients and surface-active additives. The layer(s) should have a sufficient amount of active ingredients (e.g., neonicotinoids) for effective treatment of the plant. The product should adhere well to the seed surface. For multi-layer coatings, the layers should also adhere well to each other without destroying the structure or formulation of any layer. The outer surface should be extremely smooth and durable with good lubricity. Nano Terra will design the layer(s) to be applied in the same coater. We will use a 5 lb pan coater for dust, lubricity, and germinations tests, and then scale-up the coating process in our pilot scale drum coater to check compatibility with commercial scale seed coaters.Effort 1.1. Formulate coating optimal dust reductionIn this effort, Nano Terra will focus on coating formulations composed of co-polymers. We will evaluate at least three type of polymers and incorporatepesticides separately into the formulation. The concentration range of the neonicotinoids will be 0.05 mg to 0.2 mg/seed, which is similar to the loading level of commercial seed coatings.Both corn seeds and soybean seeds will be coated and evaluated. In the development process, we will test and optimize the adhesion strength of the coating. In addition, we will test the release kinetics of the coated seeds in wet soil and ensure that the coating does not significantly retard germination. The release profile of the active molecule should be similar to the commercial coating. The target thickness for the dust reduction solution will be in the range of 25-80 microns.Effort 1.2. Improve functionality for lubricityIn this effort, Nano Terra will focus on the development of an increased lubricity coating while keeping the optimal dusting level. We will concentrate on adding functional groups and additional polymers to the co-polymer formulations developed for dust reduction. We have obtained very promising initial results using this approach. Ratios of the base polymer, surface active additives, and emulsifiers will be evaluated and optimized.The key performance parameters for coating system are mechanical stability, abrasion resistance, and surface lubricity.Pigment and dyes will be added to the formulations for commercial readiness.The target thickness for the overall solution will be in the range of 25-80 microns. The various formulations will be tested as described in Effort 2.Effort 2. Test new coating formulationIn this effort, Nano Terra will test coating formulations developed in Effort 1. Key tasks will include dust formation under abrasive conditions, surface lubricity, and plantability. To ensure that our coatings do not negatively affect the treated seeds, we also will conduct germination tests for selected coating formulations. At the end of this task, we will have selected coating formulations that have significant reduction in dust formation (tested in Effort 2.1 below) and can be planted without the use of lubricant powder. In addition, the selected seed coatings should have a similar loading level of neonicotinoid(s) and a similar release profile to commercially available coated seeds.Effort 2.1. Quantification of dust formationIn this task, Nano Terra will quantify and compare dust particles using the standard method with a Heubach dustmeter. As described in the standard procedure, we will use 100 g of coated seeds to obtain quantitative results. Both humidity and temperature will carefully controlled and recorded for every experiment. During abrasion process, both fine powders and large pieces of coating may be formed. We will determine the amount of each type of particles. The Heubach dust value will be recorded in gram of dust/100 kg of treated seeds.Effort 2.2. Evaluate lubricity and plantabilityIn this effort, Nano Terra will conduct two tests to evaluate surface lubricity and plantability: 1) flow rate of coated seeds, and 2) Bench seed dispenser test. We will use the seed flow meter test for a quick screening of coating formulations. We will compare our coated seeds with commercially available seeds both withand withoutlubricant powder. The most promising coating formulations will be scaled-up for the bench-level plantability test. The plantability test will be carried out as described in the literature. In this test, the nominal spacing (distance between seeds) is defined as 0.2 m. We will record distances between seeds greater than 1.5 times and smaller than 0.5 times of normal spacing. The benchmark for success in lubricity and plantability will be a formulationsimilar to commercially available seed coatings.Effort 2.3. Seed germination testIn this test, to demonstrate that there is no harm to the germination of the seeds, Nano Terra will evaluate the germination performance of coated seeds using a standard lab test. Pyrex® casserole dishes are used as containers; two paper towels will be used as base substrate materials on which 60 mL of water is applied to ensure complete dampness. Seeds will be placed on the substrate. The seed germination count at 45 hours and 72 hours will be recorded. The germination performance of coated, uncoated, and commercially available coated seeds will be compared.Effort 2.4. Candidate selectionIn this effort, Nano Terra will analyze the test data and select promising coating formulations for further development and testing in phase II.Effort 3. Develop Phase II test plan and write final reportIn this effort, Nano Terra will complete a final report of the phase I effort.Dissemination of the results of the project will occur through papers and/orpatents if appropriate.In addition, we will define a detailed development and testing plan for Phase II. We will identify suppliers for raw materials, testing facilities for field trials and testing facilities for pollinator health.

Progress 06/15/17 to 08/14/18

Outputs
Target Audience:The outcome of the project is aimed at seed companies and at farmers. The effectiveness of the seed coating formulations developed in this grant are very comparable to new products that have been released by large agriculture companies. For this reason, Nano Terra has not reached out to those who provided letters of support. We do not see a feasible path forward for commercialization due to the influence, competition, and existing infrastructure of the large agriculture companies with competing products. We will not be pursuing additional Phase II funding. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Impact StatementSeed companies and farmers have vested interest to reduce dust generated in processing and planting seeds (reduce negative health effects onpollinators & farmers),increaseplanting efficiency (savetime & money), and extend seedshelf-life (eliminate waste). The goal was to develop a seed coating to bringpositive impacts in each area. Materials were screenedand one selected tocompareto existing technologies to reduce dust and increase flowability. In select instances, the formulation could reduce dustcompared to traditional procedures and materials. Given declines in pollinator populations from neonicotinoid dissemination via dust generation atplanting, polymer-based coatings to reduce dust should slow pollinator decline resulting in reduced costs to maintain bee populations and allow pollinators to continue theessential role in the agricultural supply chain. Demonstrate >90% reduction of dust formation than best seed treatmentproducts on the market as measured using a Heubach Dust Meter Activities Coating development-dust reduction Development focused on identifying a polymer emulsion in water to provide a shell to guard against impact during planting while supplying good adhesion to a soybean. Polymer classes included styrene-butadiene co-polymers, acrylic co-polymers, and styrene-acrylic co-polymers. One formulation was chosen to compare with multiple state-of-the-art formulations. Formulations were applied to soybeans vialab-scale drum coater; dust generation was measured with Heubach style dust collection. Quantify-dust We quantified dusting with standard method forHeubach dustmeter. Here, 100±1gseeds used for testing. Number of seeds wasbased on Thousand Seed Weight. The dustmeter turns at 30rpm, has airflowof 20 lpm, and rotationduration was 120sec. Testing was at room temperature and relative humidity30-50%. Whatman GF 92 filter was used. Dust value was recorded in grams dust/100kg seed. Data Dust generation data was collected for commercialpolymers and NT formulated polymers applied to soybeans with Thiamethoxam and Imidacloprid neonicotinoids (N1 and N2). Formulations required 4-10 dust collections for sample analysis, totaling ~50 samples. Data was collected for 12 coatings to look at performance of NT polymer with 2 neonicotinoid formulations in combo with state-of-the-art dust reduction and flow enhancement additives. Summary Testresults demonstrated polymeric formulation P1had lowest dusting of all samples. In N1 formulation, the P1 system did not demonstrate statistically significant difference compared to control sample. One other commercial polymer P3 provided results not statistically different than controlhowever variance in this system is very high. Incomparison, average and standard deviation for N1 with P1 and P3 was 14.0+/-0.9 and 28.1+/-18.7mg respectively. Results showed dust of system N1 was maintainedand not increased like a majority of commercial products. In N2 formulation, the P1 system reduced dustcompared to base polymeric system. Of commercialpolymersP2 reduced dust compared to control. The ability of P1 polymer to reduceor not increase dust in the N1 and N2 system demonstratesability of this material to perform well compared to commercial options across neonicotinoid varieties. P1 system provides the best (lowest) dusting performance for all polymer and neonicotinoid formulations tested in theprogram. Outcomes The key outcome for this experimentset was a polymeric system that provides the lowest dustacross multiple neonicotinoid formulations. This suggests the polymer may provide dust reduction across a range of formulations. Demonstrate comparable plantability to current lubricant-containing treated seeds without using lubricant powder Activities Coating development-lubricity and plantability NT planned to further develop the reduced dust coating to increaselubricity, but some polymers showedpromise in also increasing lubricity. The NT polymer selectedshowed improvement in both dust reduction and increased flowability. Quantify-lubricity and plantability We evaluated surface lubricity by measuring time a sample flows through a stainless funnel. The seed mass was recorded prior to testing. Seed was transferred to the funnel. An automated system opened a blast gate and started a timer. A load cell monitored seed mass that passed through the funnel. Once initial seedmass was matched, the timer stopped. Plantability was notmeasured within the course of Phase I of this award as planned due to time and budget required to complete dust and flow testing, however we expect apositiveimpact on plantability. It is related to flowability ofseeds;we anticipate plantability will be maintained compared to currently used seeds, with no negative effects on plantability or how seeds transportwithinplanting equipment. Data Flowdata was collected for commercial polymers and NT formulated polymers applied to soybeans with Thiamethoxam and Imidacloprid neonicotinoids. Formulations required 4-10 flowruns to establishdata for sample analysis. Data collected wastime required for a set mass of seedto travel through a 40mm diameter opening. Time is related to the ability of seeds to pass by each other and through the opening, and to acceleration due to gravity and inversely to friction forces on seeds' surface. The data shows reduction in flow time for a set mass of seedfor coatings detailed above. Summary Data shows flowability for all samples is equal or improved from control sample. Data shows the flowability increased (time to flow decreased) from 0.22/s for the control to 0.28/s for the Base formulation. For several other samples, the increase in flowability is not statistically significant compared to control sample, but they all have an average increase in flowability. While plantability of coated seedwas not directly investigated,plantability is mainly determined by ability of seed to travel through planting systems without jamming or mis-planting, both of which are controlled by surface friction of seed. Outcomes The outcome of this objective areseveral polymeric systems that reduceor maintain lubricity and plantability of seed. This finding suggests a polymeric coating will be sufficiently lubricious to enable good plantability of the seeds. Demonstrate uniform coverage of seed coating and ability to incorporate colors Activities Soybeans were coated in a lab-scale drum coater mimicingcoverage of large-scale commercial equipment. The rate the coating was appliedand duration spent in the drum coater were initially established and held consistent. A red dye was utilized for all formulations. Other colors of this dye are readily available such that integration in the NT polymer could be ensured. Dyes are FDA approved for application on food products. Data Drum speed and liquid injection rate were varied on the seed coating equipment. Drum speed varied from 1-10and application rate from <<1-2sec/mL. Controls were used to establish speeds and rates and kept constant for all formulations. Tackiness of the seeds was evaluated qualitatively to determine ideal coating parameters. Dye concentration was adjusted so color was easily distinguishable after coating and coverage was visually uniform. Coverage wasdetermined by microscopy on sectioned samples. Summary Results demonstrated uniform coating achieved withstandard drum coating and compatible with high throughput systems in commercial settings. The process yielded a robustuniform coating. Dye concentration could be varied to ensure coating was visibleand uniform. Thickness was measured by bisecting the seedand using digital microscopic measurement. The process was challenging since the natural seed coating is ~0.1 mm thick while NTcoating is ~50x thinner. Visual inspection was sufficient to determine uniformity. Outcomes The key outcome is a uniform coating with industry standard dye applied to seeds using a scalable manufacturing process.

Publications

Progress 06/15/17 to 06/14/18

Outputs
Target Audience:The outcome of the project is aimed at seed companies and at farmers. Brief updates were provided to Brandt Consolidated during this reporting period through informal meetings and discussions. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals?During the next two months, we will continue work to further develop the seed coating formulations aiming to show reduced dust generation with added lubricity and efficient plantability. We will also be evaluating the effect our additives have on the germination of the coated seeds. After dust, flowability, plantability, andgerminationis complete, we will begin drafting a Phase II plan.

Impacts
What was accomplished under these goals? In this reporting period, Nano Terra (NT) has worked to develop and test seed coating formulations that reduce dust-off at the time of planting, increase flowability without added lubricant powders, and show no negative impact on germination of the soybeans to which the coating formulation was applied. We have developed formulations containing neonicotinoids with a variety of polymers, applied these formulations to soybeans, and measured the dust generated by the coated soybeans employing parameters specified for the industry-standard Heubach test. In addition, the flowability of the coated soybeans was compared to uncoated soybeans. Next steps include evaluating the effect on germination of the coated seeds and continuing to explore additional formulations for more neonicotinoid containing additives. Laboratory work and testing: Development of the coating formulation focused on identifying a polymer emulsion in water that, upon drying, would provide a tough shell to guard against impact during planting while supplying good adhesion to the surface of a soybean. The polymers were sourced in emulsion form and incorporated with a neonicotinoid containing insecticide prior to being applied via a lab-scale drum coater. When the NT formulations were applied in the lab-scale drum coater, there was a slight increase in tackiness of the seeds which can be attributed to the added wet mass applied. In addition to the polymer emulsion being added to the total formulation, other solvents were required to allow the polymer to dry in a manner that would result in a smooth finish. EPA approved dyes/pigments were also used for visualizing the coating on the seed. While NT plans to further develop the reduced dust coating to increase its lubricity, some of the dust-reducing polymers have shown promise in also increasing the lubricity. Additional polymers and surface functional groups will be investigated as additives to NT formulations. Nano Terra has developed in-house testing capabilities to investigate dust-off levels and flowability values of coated seed. The dust tester design was based on a traditional Heubach dust test machine. It was updated to more accurately reflect the Heubach design and to provide more exact and reproducible results.

Publications