ARS | Publication request: Corn gluten meal application equipment evaluations for organic weed control

Submitted to: Proceedings of Southern Weed Science Society
Publication Type: Abstract
Publication Acceptance Date: January 31, 2007
Publication Date: May 1, 2007
Citation: Shrefler, J.W., Webber III, C.L. 2007. Corn gluten meal application equipment evaluations for organic weed control [abstract]. Proceedings of Southern Weed Science Society. 60:141.

Technical Abstract: Corn gluten meal (CGM) produces an inhibitory effect and reduces root formation in several weed species. One limitation to further use of CGM in vegetable production is the difficulty in achieving a uniform application to the soil surface and detrimental impact of CGM on direct-seeded vegetables. The development of equipment to mechanically apply CGM would avoid the difficulty involved with manual application of CGM. Suitable equipment would also enable evaluation of the potential benefits of banded applications for weed control efficacy and crop safety of direct-seeded vegetables. The objective of this research was to develop and test equipment that would permit either solid (broadcast) or banded application of corn gluten meal to a field. An applicator was assembled using various machinery components for the purpose of uniformly applying corn gluten meal to the soil surface in either a solid (broadcast) or banded pattern. The equipment was evaluated using two CGM formulations (powdered and granulated), three application rates (5, 10, and 15 lb/100 ft**2), and two application configurations (solid and banded). Tractor speed was varied to achieve the desired application rates within formulation and application configurations. Differences between CGM formulations affected the flow rate within each application configuration and between application configurations. The granulated formulation flowed at a faster rate than the powdered formulation, and the banded configuration flowed faster than the solid application. It was determined that the CGM powder used with the solid application configuration was inconsistent and unreliable and not feasible for use with the same equipment without further modification. Field evaluations determined that the equipment setup with the CGM granulated formulation resulted in the most reliable and precise delivery of the three application rates (5, 10, and 15 lb/100 ft**2) for both application configurations compared to the powdered CGM formulation applied in the banded configuration. These evaluations demonstrated the feasibility of using equipment, rather than manual applications, to apply corn gluten meal to raised beds for organic weed control purposes. The successful mechanical application of CGM in the banded configuration will enable the use of CGM for direct-seeded vegetable productions. A number of equipment alterations will increase the efficiency and potential usefulness of mechanical applications of CGM. Future equipment developments and evaluations should focus on increasing the application rate to decrease the time to apply corn gluten meal to a field.