Minimizing abrasion losses from film-coated corn seeds

Authors: ACCINELLI, CESARE - University Of Bologna; Abbas, Hamed; BRUNO, VERONICA - University Of Bologna; KHAMBHATI, VIVEK - Mississippi State University; Little, Nathan; EBELHAR, WAYNE - Mississippi State University; SHIER, THOMAS - University Of Minnesota

Submitted to: Journal of Crop Improvement
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/3/2020
Publication Date: 12/21/2020
Citation: Accinelli, C., Abbas, H.K., Bruno, V., Khambhati, V.K., Little, N., Ebelhar, W.M., Shier, T.W. 2020. Minimizing abrasion losses from film-coated corn seeds. Journal of Crop Improvement. https://doi.org/10.1080/15427528.2020.1861156.
DOI: https://doi.org/10.1080/15427528.2020.1861156

Interpretive Summary: Some important agricultural pests attack crop plants at the seed germination stage causing increased costs for additional seed, which is used at higher than optimal levels to compensate for the associated losses. To protect germinating seeds and seedlings, there is increased use of seed coatings or treatments that control pests and help establish vigorous and healthy seedlings. With Seed coating treatments that incorporate chemical pesticides can help seed germination or prevent early infection of the seedling by fungi and other diseases, are commonly applied directly to seeds as part of a film-coating formulation. However, many coatings lack durability and can be easily damaged during the transportation, storage, and planting processes, resulting deceased effectiveness and environmental damage to other species such as bees and other pollinators. Strengthening the integrity of the seed coatings prevents or reduces these problems. In this project, several new coating agent formulations were evaluated for resistance to abrasive removal before seed germination. Furthermore, the seed coating process was improved by first removing the outer wax coating of the seed and then applying the protective coating. This modification reduced coating fragment loss from seeds by over 95%. Ultimately, these findings should help to protect the environment, improve plant growth, and provide better products for farmers and industry professionals.

Technical Abstract: Film-coating is a widely used technology to apply plant protection agents, beneficial microorganisms, and other substances to agronomically-important seeds. During handling and planting operations, fragments of the seed coat can become detached by mechanical abrasion and are released into the environment. Modest reductions in abrasion losses have been achieved by selecting polymers and formulations with improved adherence to seed surfaces. The objective of this study was to investigate a novel approach for reducing abrasion risk with film-coated corn seeds and to evaluate an improved image-based protocol for rapid and effective evaluation of seed abrasion. This study demonstrated that the risk of abrasion losses from film-coated corn seeds was minimized by removing the outer wax layer of the seed pericarp prior to applying coat formulations. Removal of the outer wax layer did not affect seed germination or seedling growth, but it did improve adhesion strength of the coat to the seed surface and effectively reduced abrasion losses. Coating surface dewaxed seeds with three different treatment formulations, including a commercial seed-coating polymer, a starch-based bioplastic and a soy protein isolate-based preparation reduced fragment release by 97.6, 94.8, and 98.9%, respectively, with respect to non-surface dewaxed seeds. Seed coatings placed in soil for six days deteriorated 2.5, and 72.1% for commercial and bioplastic formulations, respectively, whereas the soy protein isolate coating formulation deteriorated almost completely under the same conditions. Thus, removing the outer wax layer before film-coating seeds and using novel seed coat formulations resulted in a better environmental profile for coated seeds.