Effect of Tray Type and Tray Covering on Wicking Speed, Germination, and Spiral Rooting of Tobacco

Poor tray wicking and spiral rooting continue to be recurring concerns in tobacco float systems. Poor wicking of trays can usually be attributed to old media or media that was improperly stored for extended periods of time. Tray design may also influence speed of wicking. The clay-based pelleting materials used to coat tobacco seeds are thought to cause damage to the emerging root radical under certain conditions, leading to an increased incidence of spiral root. Practices that change the microenvironment at the top of the cell area surrounding the seed may reduce spiral rooting by altering the breakdown of the pellet. Several transplant growers in Tennessee routinely cover trays with a thin fabric such as Reemay® or Continental® fabric as they are floated and remove the fabric 14 to 21 days later in an effort to reduce spiral rooting