|Shrefler, James - OSU, LANE,OK|
Submitted to: Proceedings of Southern Weed Science Society
Publication Type: Abstract Only
Publication Acceptance Date: January 28, 2006
Publication Date: March 15, 2006
Citation: Webber III, C.L., Shrefler, J.W. 2006. Organic weed control in squash [abstract]. Proceedings of Southern Weed Science Society. 59:146. Technical Abstract: Corn gluten meal (CGM) has been identified as an organic herbicide for weed control in turf and established vegetable plants, direct contact with vegetable seeds can decrease crop seedling development and plant survival by inhibiting root and shoot development. Therefore, the use of CGM as a preemergence or preplant-incorporated organic herbicide is not recommended for use with direct-seeded vegetable production. The development of equipment to apply CGM in banded configurations has created an opportunity to investigate whether banded CGM applications will provide significant crop safety for direct-seeded vegetables. The objective of this research was to determine the impact of banded corn gluten meal applications on squash plant survival and yields. This factorial field study was conducted during the summer of 2005 on 32-inch (81-cm) wide raised beds at Lane, OK with two application configurations (banded and solid), two CGM formulations (powdered and granulated), two incorporation treatments (incorporated and non-incorporated), and three application rates [5, 10, and 15 lb/100 ft**2 (250, 500, and 750 g/m**2)]. The two CGM formulations at three application rates were uniformly applied in both banded and solid patterns on August 19. The banded application created a 3-inch (7.6-cm) wide CGM-free planting zone in the middle of the raised bed. The CGM applications were then either incorporated into the top 1 to 2 inches (2.5 to 5.0 cm) of the soil surface with a rolling cultivator or left undisturbed on the soil surface. 'Lemondrop' summer squash (Cucurbita pepo L.) was then direct-seeded into the center of the raised beds. When averaged across the other factors, there was no significant difference between powdered and granulated CGM formulations or incorporating and non-incorporating the CGM for either squash plant survival or yields. CGM application rates did make a significant difference for both crop squash survival and yields when averaged across all other factors. As the CGM application rates increased the plant survival and yields decreased. When averaged across all other factors, the banded application resulted in significantly greater crop safety (90% plant survival) and yields (180 cartons/a) than the broadcast (solid) applications (45% plant survival and 127 cartons/a). The banded application of CGM increase yields beyond the level of the weed-free treatment by 11%, while the weedy-check treatment reduced squash yields by 25% compared to the weed-free treatment. The increase in squash yields may be the result of the 9 to 10% nitrogen content of CGM. The plants in the field also looked larger and greener. The research demonstrated the potential usefulness of CGM in direct-seeded squash production, if used in banded application configuration. Additional research should further investigate the interaction of CGM application rates and the width of the CGM-free zone on crop safety for various vegetables.