50th TWC, Tob. Work. Conf., 2022, abstr. 42

Assessment of a maleic hydrazide spray system attached to a mechanical harvester

North Carolina State University, Raleigh, NC, USA

Maleic hydrazide (MH) is a systemic plant growth regulator used to control “sucker” growth in flue-cured tobacco. Conventional application methods involve applying MH over the top of the plant to ensure proper coverage and effectiveness. But this application method may also contribute to elevated residue levels, potentially damaging the marketability of US cured leaf. The goal of this project is to reduce MH residues found in cured leaf by developing a precision spray system capable of stalk applying the MH during mechanical harvesting of lower-stalk tobacco, while maintaining adequate sucker control. To monitor MH residue levels within the plant, green and cured leaf samples were collected from the on-farm test location. While it has been determined that adequate sucker control can be achieved through stalk application of MH, the elevated residues in the cured leaf samples indicate that more work is needed to determine the proper application rates. (Reprinted with permission)