Research on a Post-Frame Burley Tobacco Curing Structure for Wire-Frame Racks

Abstract

The purpose of this research is to develop a post-frame structure to utilize wire-frame racks in the curing of burley tobacco in non-traditional growing areas. The Piedmont and Coastal Plain regions of North Carolina have little existing burley curing infrastructure. The current trend for mechanically harvested burley tobacco utilizes the cut-notch method. Wire-frame racks are used by many growers as part of an in-field curing structure for cut-notch harvested plants. Incorporating wire-frame racks into a post-frame structure provides greater protection from adverse weather than a typical in-field wire-frame rack curing structure. All of the in-field advantages and mechanisms of wire-frame racks are retained with this design. A two-tier test building was designed and constructed to handle modified wire-frame racks. Individual rack weight data were collected during the curing season to observe the effect of plant weight loss on structural load duration. Individual rack weight change was recorded for the entire curing process. The most significant changes in weight and color occurred during the first twenty-eight days. The tobacco underwent three different color stages during the curing process: green, yellow and brown. When examining these stages on an individual basis, weight loss rates doubled between curing stages. The overall data set followed a simple decay differential equation. The rate at which the plant lost weight can be attributed directly to water loss and the plant’s rate of water loss was directly proportional to the amount of water remaining.