A bioplastic-based seed coating improves seedling growth and reduces production of coated seed dust. Journal of Crop Improvement

Authors: ACCINELLI, CESARE - University Of Bologna; Abbas, Hamed; SHIER, W. THOMAS - University Of Minnesota

Submitted to: Seed Science Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/5/2018
Publication Date: 1/15/2018
Citation: Accinelli, C., Abbas, H.K., Shier, W. 2018. A bioplastic-based seed coating improves seedling growth and reduces production of coated seed dust. Journal of Crop Improvement. Seed Science Research. Pages 1-13. https://doi:10.1080/15427528.2018.1425792.
DOI: https://doi.org/10.1080/15427528.2018.1425792

Interpretive Summary: Nowadays seeds of many important crops are routinely film-coated with polymeric materials impregnated with synthetic fungicides and insecticides, as well as with spores of biological control and growth-promoting microbial species. The present study investigates the effectiveness of seed coatings formulated with gelatinized corn starch-based bioplastic applied to corn and canola seeds. The bioplastic coating caused no significant reduction of percent germination or seedling growth, even when impregnated with the pesticides imidacloprid, a neonicotinoid insecticide, and pyraclostrobin, a fungicide. Incorporation of spores of the plant growth-promoting bacterium Bacillus subtilis QST 713 into the bioplastic matrix resulted in significantly greater elongation of stems and roots of corn and canola seedlings. Bioplastic-based corn and canola seed coatings exhibited significantly less dust release under abrasive conditions than coatings with a commercial seed coating matrix, when measured by a novel optical approach developed for these studies.

Technical Abstract: Although recently introduced, film-coating of agronomic seeds is now widely accepted in modern agriculture as an effective technology for protecting germinating seeds and seedlings. These experiments explored the possibility of using a bioplastic-based formulation to film-coat corn (maize) and canola seeds, alone and in combination with synthetic pesticides and plant growth-promoting bacteria. The thin bioplastic coat did not affect percent germination or seedling growth. However, incorporating spores of the plant growth-promoting bacterium Bacillus subtilis QST 713 into the bioplastic matrix resulted in a greater elongation of corn and canola seedlings. Specifically, stems and roots of seedlings that germinated from corn seeds coated with bioplastic containing spores were 18.0% and 21.4% longer, respectively, than stems and roots from uncoated control seeds. In canola seeds, these values were 19.9% and 20.9% longer for stem and roots, respectively. Incorporating a neonicotinoid insecticide, imidacloprid, and a fungicide, pyraclostrobin, into bioplastic coatings along with B. subtilis spores gave results comparable to spores and bioplastic alone. Coated seeds were also evaluated for their potential to generate dust after abrasion testing, using a novel image-based method made possible because seed coatings are usually artificially colored. Abraded seed coat fragments are consequently easily detectable with conventional optical instruments. Corn and canola seeds coated with bioplastic released up to 86.1% and 97.6% less dust during abrasive handling than seeds coated with a commercial seed coating matrix measured by the optical approach described here.