From the Field-Agronomy Notes

— Written By jbhenry2

Tobacco Research Update:

Development of an Online Nutrient Disorder Diagnostic Key for Tobacco

Over the next few weeks, we will be providing updates about our current research project of developing a web-based nutrient disorder identification key. The project is supported by the North Carolina Tobacco Foundation.

This web-based diagnostic key will be freely available online and accessible via a computer or mobile device. The site will be automatically optimized for use on both tablets and smart phones. NC State University Extension Specialists and Researchers have already created a Strawberry Diagnostic Key with a similar design to this new tobacco diagnostic key (https://diagnosis.ces.ncsu.edu/strawberry/). This initial year will focus on recording symptoms and capturing high quality images and videos of nutrient disorders of tobacco.

While there is a wealth of identification information available online, there is no single source that is complete and offers a set of photographs illustrating the progression of nutritional disorder symptoms. Historical photos of tobacco nutrient deficiencies have been created in the past, but there is a lack of accessibility to that information. This project will induce nutrient disorders in tobacco, create photographs and videos which document the progression of symptoms, and create a website and other resources that can be used to identify disorders. This project focuses on both flue cured and burley tobacco.

We began work on the project on July 1st (Fig. 1). We will utilize an automated irrigation system that was custom built for inducing nutrient disorders. The system was built with PVC pipes, automatic time clocks, and includes individual production lines for inducing a single nutrient disorder (-N, -P, -K, etc) (Fig. 2). A customized blend of fertilizer salts is mixed for each line. We induce a deficiency by withholding a single nutrient, while adjusting the fertilizer blend so that the remaining nutrients are still provided. The plants are grown in silica sand to avoid any nutrient contaminations from the soil (Fig. 3). This system has been successfully used for over 10 years to induce nutrient disorders and capture images of these symptoms on over 40 floriculture, vegetable, fruit and tree (teak) species.

We would like to express our appreciation to the North Carolina Tobacco Foundation for supporting this project. We will be providing updates as the various symptoms progress over the course of the nutrient disorder induction phase of the experiment.

Figure 1. Installation of the tobacco seedlings into the automated nutrient disorder irrigation system, with Josh Henry, M.S. Research Assistant in Horticultural Science (left) and Paul Cockson, B.S. Research Assistant in Agroecology (right). ©2016 Forensic Floriculture

Figure 1. Installation of the tobacco seedlings into the automated nutrient disorder irrigation system, with Josh Henry, M.S. Research Assistant in Horticultural Science (left) and Paul Cockson, B.S. Research Assistant in Agroecology (right).
©2016 Forensic Floriculture

Figure 2. View of a newly transplanted burley tobacco plant in the nutrient disorder irrigation system. Note the yellow drip emitters used to deliver the nutrient solution. ©2016 Forensic Floriculture

Figure 2. View of a newly transplanted burley tobacco plant in the nutrient disorder irrigation system. Note the yellow drip emitters used to deliver the nutrient solution.
©2016 Forensic Floriculture

Figure 3. Close up view of adding the silica sand around the tobacco seedling. Note the use of silica sand to avoid nutrient contamination. ©2016 Forensic Floriculture

Figure 3. Close up view of adding the silica sand around the tobacco seedling. Note the use of silica sand to avoid nutrient contamination.
©2016 Forensic Floriculture

Key Contact: Dr. Matthew Vann, Department of Crop and Soil Science, mcvann@ncsu.edu

Contributing Authors: Josh Henry, Paul Cockson, Matthew Vann, and Brian Whipker.

Funding Source: North Carolina Tobacco Foundation

Project Team: Josh Henry (NC State M.S. student in Horticultural Science), Paul Cockson (NC State B.S. student in Agroecology), Ingram McCall (Research Technician in Horticultural Science), Rhonda Conlon (Extension IT at NC State), Matthew Vann (Tobacco Extension Specialist, Dept. of Crop and Soil Science), and Brian Whipker (Professor of Floriculture and Plant Nutrition in Horticultural Science).