ARS | Publication request: Precision placement of corn gluten meal for weed control in organic vegetable production

Submitted to: International Conference on Precision Agriculture Abstracts & Proceedings
Publication Type: Abstract
Publication Acceptance Date: January 28, 2008
Publication Date: July 24, 2008
Citation: Webber III, C.L., Taylor, M.J., Shrefler, J.W. 2008. Precision placement of corn gluten meal for weed control in organic vegetable production [abstract]. International Conference on Precision Agriculture. Paper No. 187. p. 165.

Technical Abstract: Producers of organic vegetables continue to rank weeds as one of their most troublesome, time consuming, and costly production problems. As a result of the limited number of organically approved weed control herbicides, the precision placement of these materials increases their potential usefulness throughout organic production systems. Corn gluten meal (CGM), a by-product of the wet-milling process for corn, is phytotoxic. As a non-selective preemergence or preplant-incorporated herbicide, CGM inhibits root development; decreases shoot length, and reduces plant survival. The development of a mechanized application system for the precise placement of CGM will increase its use in organic vegetable production, especially in direct-seeded vegetables. The research objective was to develop a mechanized method to uniformly apply CGM to the soil surface in either a solid (broadcast) or banded pattern. An applicator was constructed using various machinery components (fertilizer box, rotating agitator blades, 12-volt motor, and fan shaped, gravity-fed, row banding applicators). The equipment was evaluated for the application of two CGM formulations (powdered and granulated), three application rates (250, 500, and 750 g/m**2), and two application configurations (solid and banded). Field evaluations were conducted on 81-cm wide raised beds at Lane, OK. Differences between CGM formulations affected flow rate within, and between, application configurations. The granulated formulation flowed at a faster rate, without clumping, compared to the powdered formulation, while the CGM in the banded configuration flowed faster than the solid application. The delivery of CGM powder with the solid application configuration was inconsistent and unreliable, and therefore this material is considered impracticable when used in this configuration without further modifications to the equipment. The feasibility of using equipment, rather than manual applications, to apply CGM to raised beds for organic weed control purposes were demonstrated. Further equipment alterations will increase the efficiency and potential usefulness of this equipment.